Entries |
Document | Title | Date |
20080205490 | Method and apparatus for managing finger resources in a communication system - In a communication system, a method and an accompanying apparatus determine a number of available fingers ( | 08-28-2008 |
20080205491 | Method and Apparatus for Reducing the Interferences Between a Wideband Device and a Narrowband Interferer - A method includes a main interference reduction mode for reducing the interference generated by a wideband device toward a narrowband device. The main interference reduction mode is performed within the wideband device and includes at least one of detecting an emission from and a reception performed by the narrowband device. A group of at least one sub-carrier having frequencies interfering with frequencies used by the narrowband device is determined from the detection step. The bits of the punctured stream that correspond to the information carried by the interfering sub-carriers of the group are determined and processed so that the processed bits are mapped into a reference symbol having an amplitude within a threshold of zero. | 08-28-2008 |
20080212655 | SIMPLE AND ROBUST DIGITAL CODE TRACKING LOOP FOR WIRELESS COMMUNICATION SYSTEMS - A simple and robust CTL is used for time tracking of multipath components of a spread spectrum signal transmitted over a wireless multipath fading channel. A digital code-tracking loop includes the implementations of despreading early and late data samples by use of a pseudonoise sequence, an error signal output generated by the despreading, and adjustment for a plurality of on-time, early and late samples, a data rate of a control signal provided as a fractional proportion of a data rate of error signals. | 09-04-2008 |
20080219328 | Receiver Apparatus, Receiving Method, Program, and Recording Medium - A receiver apparatus includes a plurality of signal receiving means; a plurality of channel signal outputting means for sampling signals received by the plurality of signal receiving means at sampling rates switched within a predetermined range or between multiple values and outputting channel signals; control means for controlling the sampling rates in the plurality of channel signal outputting means; response estimating means for estimating responses on the basis of the channel signals output from the plurality of channel signal outputting means; evaluating means for evaluating reception characteristics on the basis of the responses estimated by the response estimating means; and determining means for determining the sampling rates in the plurality of channel signal outputting means on the basis of the reception characteristics at the multiple sampling rates evaluated by the evaluating means. | 09-11-2008 |
20080232438 | 2D Rake Receiver For Use in Wireless Communication Systems - A 2D Rake receiver is proposed, comprising: a control module, for generating, according to a reference signal and the radio signals received by a plurality of antenna elements, the multipath information about the radio signals; a weight factor calculating unit, for calculating the corresponding weight factors of the received radio signals corresponding to different antenna elements according to the multipath information; a plurality of 1 D Rake receivers, each of which is for receiving radio signals from the corresponding antenna element and weighting the radio signals received by the Rake receiver with the corresponding weight factor; a combining unit, for combing the weighted radio signals outputted from the plurality of 1 D Rake receivers, to output a combined signal. | 09-25-2008 |
20080232439 | Adaptive equalizer for communication channels - Adaptive equalizers for a communication channel and corresponding methods of equalizing are described. The adaptive equalizer includes: a fixed pre-filter configured to be coupled to a received signal and provide a pre-filter signal; an adaptive filter coupled to and configured to compensate the pre-filter signal for changes in phase and amplitude; and an interference remover coupled to the adaptive filter and configured to reduce interference in the received signal. | 09-25-2008 |
20080232440 | CHIP BLANKING AND PROCESSING IN SCDMA TO MITIGATE IMPULSE AND BURST NOISE AND/OR DISTORTION - A system for mitigating impairment in a communication system includes a delay block, a signal level block, a moving average window block, an impulse noise detection block, and a combiner. The delay block receives and delays each chip of a plurality of chips in a spreading interval. The signal level block determines a signal level of each chip of the plurality of chips in the spreading interval. The moving average window block determines a composite signal level for a chip window corresponding to the chip. The impulse noise detection block receives the signal level, receives the composite signal level, and produces an erasure indication for each chip of the plurality of chips of the corresponding chip window. The combiner erases chips of the plurality of chips of the spreading interval based upon the erasure indication. | 09-25-2008 |
20080240207 | MULTI-USER DETECTION USING EQUALIZATION AND SUCCESSIVE INTERFERENCE CANCELLATION - A plurality of signals are received in a shared spectrum. Samples of the received user signals are produced as a received vector. The received vector is segmented into a plurality of segments. For each segment, successively determining symbols for each user or group of signals (the group of signals having similar received power) by determining symbols for one user/group and removing a contribution of that one user/group from the received vector. The determined symbols corresponding to each segment are assembled into a data vector. | 10-02-2008 |
20080260005 | Time-Tracking for Clustered Demodulation Elements in a Spread Spectrum System - An apparatus, such as a subscriber unit or a base station within a spread spectrum communication system, provides advanced control over the time-tracking of demodulation elements when unresolvable multipath situations arise. The apparatus provides merge protection that prevents clustered demodulation elements from contracting beyond a minimum time span. In addition, the apparatus provides a master/slave feature for synchronizing the time-tracking of the demodulation elements when clustered around a multipath signal. | 10-23-2008 |
20080260006 | IMPROVED FREQUENCY OFFSET ESTIMATOR - Determining a frequency offset of a received signal utilizing two or more multipath components of the received signal is provided herein. By way of example, the received signal can be correlated with a synchronization sequence in a time domain or a frequency domain, resulting in separation of the two or more multipath components of the received signal. Analysis of at least one of the multipath components can provide a frequency offset of the received signal. Furthermore, by analyzing the multipath components, estimation of the frequency offset can be improved as compared with single-signal analysis techniques. | 10-23-2008 |
20080267261 | Efficient Computation of a Waveform Correlation Matrix - A method and apparatus for reducing the complexity of waveform correlation computations used by a multicode receiver is described herein. One exemplary multicode receiver includes a despreading unit, channel estimator, and waveform correlation calculator. The despreading unit despreads a received multicode signal to generate despread symbols. The channel estimator estimates channel coefficients associated with the despread symbols. The waveform correlation calculator determines waveform correlations between the transmitted symbols in successive processing windows that span two or more symbol periods and that overlap in time. To reduce the computational complexity associated with computing waveform correlations, the calculator may reuse channel coefficients and/or net channel correlations for multiple symbol periods and/or processing windows. The calculator may also reduce complexity by reusing one or more waveform correlations from a previous processing window as waveform correlations for one or more subsequent processing windows and/or by exploiting the Hermitian symmetry of the waveform correlation matrix. | 10-30-2008 |
20080267262 | Efficient Computaton of Soft Scaling Factors for Linear Multi-User Detector - A symbol detector converts initial symbol estimates of received symbols to soft estimates for decoding. The symbol detector computes spreading waveform correlations between a spreading waveform for a symbol of interest and spreading waveforms for one or more interfering symbols. Interference rejection terms are computed by scaling the spreading waveform correlations by corresponding signal powers and compensating for noise. A soft scaling factor for the symbol of interest is computed from the interference rejection terms. The soft scaling factors are then applied to the initial symbol estimates to generate the soft estimates. | 10-30-2008 |
20080267263 | Shared Filter Design for Pilot Symbol Averaging in Rake Fingers in WCDMA Systems - A rake receiver having a shared moving average filter that is operable in a multiplexed manner to receive and filter outputs from a plurality of pilot signal correlators. | 10-30-2008 |
20080285631 | SPREAD SPECTRUM COMMUNICATION METHOD AND SYSTEM USING DIVERSITY CORRELATION AND MULTI-USER DETECTION - A communication system transmits and receives a plurality of spread-spectrum signals having differences in at least one diversity parameter. The signals are highly correlated when their diversity parameters are similar, and the signals are uncorrelated when at least one diversity parameter is different Any combination of a transmitter, a receiver, and a communication channel may diversity-encode the signals to effect differences in their diversity parameters. A receiver diversity-decoder compensates for differences in a diversity-parameter of at least one received signal to make the signal highly correlated with at least one other received signal. A correlator combines at least two of the received signals to recover an embedded information signal. The communication system enables the use of true-noise signals for spreading information signals, provides simplified receiver designs, and enables antenna arrays to spatially process spread-spectrum signals. | 11-20-2008 |
20080291980 | CANCELLATION OF INTERFERENCE IN A COMMUNICATION SYSTEM WITH APPLICATION TO S-CDMA - Cancellation of interference in a communication system with application to S-CDMA. A relatively straight-forward implemented and computationally efficient approach of selecting a predetermined number of unused codes is used to perform weighted linear combination selectively with each of the input spread signals in a multiple access communication system. If desired, the predetermined number of unused codes is always the same in each implementation. Alternatively, the predetermined number of unused codes is selected from within a reordered code matrix using knowledge that is shared between the two ends of a communication system, such as between the CMs and a CMTS. While the context of an S-CDMA communication system having CMs and a CMTS is used, the solution is generally applicable to any communication system that seeks to cancel narrowband interference. Several embodiments are also described that show the generic applicability of the solution across a wide variety of systems. | 11-27-2008 |
20080291981 | Method and Apparatus for Removing Pilot Channel Amplitude Dependencies from RAKE Receiver Output - A receiver utilizes pilot channel propagation channel estimates and a signal-to-interference metric derived from the pilot channel to form combining weights for use in obtaining soft symbols from a desired channel for subsequent decoding. The soft symbols thus obtained are substantially independent of the pilot channel amplitude. | 11-27-2008 |
20080291982 | PROCESSING OF INTERFERENCE ON A RADIOFREQUENCY SIGNAL BY POWER INVERSION - The invention relates to a radiofrequency receiver, notably for satellite positioning applications, needing to operate in an environment where interference is dense, notably when it involves pulses transmitted by DME beacons. Below the useful signal suppression threshold, amplitude or power are inverted to improve the dynamic interference response time. Advantageously, the useful signal suppression threshold and the set point power or amplitude are determined by analyzing the amplitude or power probability density function in its part enriched with low amplitude/power samples. | 11-27-2008 |
20080304553 | Method and Device for Removing Narrow Band Interference in Spreading Frequency System - A method and device for eliminating narrow-band interference in spread spectrum system, wherein the method comprises the steps of: extracting N sampling points of the data to perform frequency spectrum transform each time and obtaining N points of data; getting the energy sum of individual data after M times of transform, obtaining N energy values, in which M≧1; removing partial excessive large values from N energy values and averaging the rest, then calculating the threshold value for interference determination based on the average value; obtaining the identification information of the points that have energy values exceeding the threshold value from N energy values and performing interference suppression for the data of corresponding points after frequency spectrum transform and finally outputting the data after frequency spectrum inverse transform. The device comprises a frequency spectrum transform unit, an interference elimination unit, an interference elimination control unit and a frequency spectrum inverse transform unit. The present invention could exactly distinguish interference data from non-interference data and effectively suppress narrow-band interference. | 12-11-2008 |
20080317102 | Method and Apparatus for Interference Suppression in a Wireless Communication Receiver - According to methods and apparatus taught herein, a parametric model of received signal impairment correlations includes a parametric model term that accounts for a dominant receiver but does not result in any significant increase in parametric modeling complexity. In more detail, the parametric model models the dominant interferer as a spatial interferer, which is hypothesized as a point source of interference emanating along single-path channels to each of two or more receiver antennas. The dominant interferer thus is represented in terms of its spatial correlation across receiver antennas. The dominant interferer model term may be included in an overall model fitting process, or it may be fitted separately. Regardless, the spatial modeling approach taught herein may be used for WCDMA and other systems, and may be embodied in essentially any type of linear equalizer receiver structure. | 12-25-2008 |
20090003415 | RAKE RECEIVER AND DE-SPREADING METHOD THEREOF - The invention relates to a rake receiver and a method for de-spreading thereof. A plurality of noise branches is adopted for producing a plurality of noise components in the rake receiver. Next, a noise combining unit adjusts each noise component according to a plurality of noise weights, so as to combine the noise components to obtain an interference-plus-noise estimation value. The rake receiver eliminates the noises in the main signal generated by the signal branches through using the interference-plus-noise estimation value. Therefore, the performance of a receiving terminal can be enhanced. | 01-01-2009 |
20090003416 | Apparatus and method for canceling interference in wireless communication system - An apparatus and a method for canceling interference using a space-frequency block coding in a multi-antenna system. The method includes confirming a code for coding to minimize a Pairwise Error Probability (PEP) of a transmit signal of which the PEP is maximized according to a time variation; and coding the transmit signal with the code and transmitting the coded signal via at least two antennas. Accordingly, the interference cancellation can be accomplished while lowering the complexity of the receiver without degrading the spectral efficiency. | 01-01-2009 |
20090010313 | Receiver and Reception Processing Method - A receiver including: a delay profile generating unit to generate a delay profile from a received signal; combining unit operable to combine multiple received signals with different timings; a determining unit to determine whether or not the propagation environment of the received signals is multi-path, based on the delay profile; and a control unit operable to exclude any signal with timing whose power is equal to or lower than a predetermined threshold in the delay profile from the combining, upon the determination not being multi-path. | 01-08-2009 |
20090022210 | NOISE CANCELLATION METHOD, RECEIVER CIRCUIT, AND ELECTRONIC INSTRUMENT - A noise cancellation method includes: inputting an interference wave signal detected near a receiver section, and changing the phase and the amplitude of the input signal to generate a cancellation signal that cancels the input signal; performing correlation calculations on a signal obtained by adding the cancellation signal to a communication signal received by the receiver section and a code replica of a PRN code used for the communication signal, within a given correlation calculation target range that is included within a code phase range and a frequency range; and performing the correlation calculations within a non-signal range outside the correlation calculation target range, and controlling a phase shift amount and an amplitude change rate of the input signal based on the correlation calculation result. | 01-22-2009 |
20090028222 | INTERFERENCE CANCELLATION IN A SPREAD SPECTRUM RECEIVER - A method of cancelling interference induced by a coherent interference source in a spread spectrum receive comprises the steps of: quantifying ( | 01-29-2009 |
20090041093 | TIME-TRACKING MANAGEMENT OF DEMODULATION ELEMENTS IN A RECEIVE DIVERSITY ENABLED RAKE RECEIVER - A rake receiver comprises a plurality of receive antennas and a processing system. Each receive antenna has a plurality of demodulation elements. The processing system is configured to assign a plurality of demodulation elements from a plurality of receive antennas to a multipath group, assign the multipath group to a multipath signal, and independently adjust a time delay value of each demodulation element in the multipath group to correspond to a local time delay of the multipath signal at the corresponding receive antenna. | 02-12-2009 |
20090041094 | SIGNAL RECEIVING APPARATUS INCLUDING EQUALIZER, TERMINAL APPARATUS, SIGNAL RECEIVING METHOD, AND SIGNAL RECEIVING PROGRAM - A signal receiving apparatus which can reduce a circuit scale to reduce a cost in a mobile wireless communication system which transmits and receives a spread spectrum signal is provided. | 02-12-2009 |
20090052503 | SHIFTED CHANNEL CHARACTERISTICS FOR MITIGATING CO-CHANNEL INTERFERENCE - Methods and apparatuses for minimizing co-channel interference in communications systems are disclosed. A method in accordance with the present invention comprises shifting a characteristic of the first signal with respect to a like characteristic of the second signal to mitigate co-channel interference, and transmitting the first signal and the second signal over different channels of the communication system. | 02-26-2009 |
20090060008 | SYSTEM AND METHOD FOR BLIND SOURCE SEPARATION OF SIGNALS USING NOISE ESTIMATOR - An array has N | 03-05-2009 |
20090074037 | TRACKING APPARATUS AND METHOD IN MOBILE TERMINAL - A tracking apparatus and method in a mobile terminal are provided. The method includes extracting an on-time energy signal, an early energy signal, and a late energy signal from a received signal, estimating respective ICI components from the early energy signal and the late energy signal, measuring an early energy and a late energy by using the early energy signal and the late energy signal, and removing ICI by subtracting the estimated ICI components respective from the measured early energy and late energy. | 03-19-2009 |
20090074038 | Method for estimating hidden channel parameters of a received GNNS navigation signal - For the reduction of the multipath error of received GNSS navigation signals, a sequential Bayesian estimation is used, with a movement model underlying this estimation, which model is particularly designed for dynamic channel situations. Sequential Monte Carlo methods are used to calculate the posterior probability density functions of the signal parameters. To facilitate an efficient integration in received signal tracking loops, the invention builds on complexity reduction concepts that have previously been used in maximum likelihood (ML) estimators. | 03-19-2009 |
20090092175 | CDMA RECEIVING APPARATUS - Disclosed is a CDMA receiver including a delay profile generating unit for generating a plurality of delay profiles in time slots; path detecting units for detecting paths from the plurality of delay profiles; delay spread calculating units for calculating delay spreads based upon the detected paths; a finger-number-allocation calculating unit for calculating a number of fingers to be allocated based upon number of detected paths and delay spreads; and finger allocating units for allocating fingers to the detected paths from the number of fingers to be allocated as calculated by the finger-number-allocation calculating unit. | 04-09-2009 |
20090097534 | APPARATUS AND METHOD FOR RECEIVING MULTIPATH SIGNAL IN A WIRELESS COMMUNICATION SYSTEM - An apparatus and method for receiving a multipath signal in a wireless communication system are provided. The apparatus includes a sample buffer, a buffer index controller, a finger, and a Deskewer buffer and combiner. The sample buffer stores sample data corresponding to a defined number of chips among reception data converted into digital signals. The buffer index controller controls a position of the sample buffer to store the converted data and a position of the sample buffer to output data. The finger receives sample data from a specific position of the sample buffer and demodulates each multipath signal. The Deskewer buffer and combiner eliminates a temporal retard of each demodulated multipath signal and combines the multipath signals. | 04-16-2009 |
20090103594 | Communications module, device, and method for implementing a system acquisition function - A communications module, device and corresponding method for facilitating PN code searching. The module and device have a PN sequence generator configurable to generate a plurality of PN sequences. The module and device also include computational units configurable to correlate received signal samples of a plurality of received signal samples with a corresponding PN sequence of the plurality of PN sequences, and further configurable to provide other hardware resources. A number of computational units from the plurality of computational units are selectively configured to correlate the received signal samples with the PN sequences—the number depending upon availability of the plurality of computational units from providing the other hardware resources. According to a preferred embodiment, a plurality of configurable computational units are selectively configurable to implement the PN sequence generator. | 04-23-2009 |
20090110036 | Processing Digital Samples in a Wireless Receiver - A method of processing digital samples of a signal received at a receiver of a wireless communication system includes monitoring channel conditions and generating a channel indicator including at least one channel parameter by performing at least one of: estimating a channel mobility parameter and comparing it with a threshold; estimating a channel parameter of the energy of the channel outside a predefined temporal window, and comparing it with a threshold; estimating a channel temporal duration parameter and establishing if it meets predetermined criteria; estimating a channel-zero location parameter and establishing if it meets predetermined criteria; estimating a received-signal signal-to-disturbance power ratio, and comparing it to a threshold; estimating an estimated-channel-response signal-to-disturbance power ratio; estimating the degree of non-stationarity of the disturbance at the receiver input; and selecting one of a plurality of processing routines for processing the digital samples based on said channel indicator. Related receivers are also described. | 04-30-2009 |
20090129448 | Apparatus and Method For Generating Scrambling Codes - A wireless WCDMA (wideband code division multiple access) receiver comprises a plurality of fingers, a mask engine, a plurality of delay mask scrambling code generators and a maximal ratio combiner. Each finger process a path of a received multi-path signal having an associated delay. For each of the delays, the mask engine provides a corresponding delay mask to a delay mask scrambling code generator, which then provides a scrambling code with the appropriate offset, or delay, to the requisite finger. Output signals from the fingers are provided to the maximal ratio combiner. | 05-21-2009 |
20090141775 | MITIGATING INTERFERENCE IN A SIGNAL - A method and receiver are disclosed for mitigating or substantially canceling signal interference between signals detected at the receiver. Once a presumed interfering signal(s) is acquired, parameters are determined that allow the interferer(s) to be modeled. The phase invariance of the process eliminates the need to acquire the interferer's phase. An orthogonal projection (for projecting onto a detection subspace which is orthogonal to a subspace spanned by the interferer(s)) is applied to the composite of all signals (y) for thereby projecting y onto the detection subspace. The interference subspace is non-orthogonal to a representation of desired (but interfered) signal of the composite signals. With the receiver properly equipped to perform this projection operation, interfering signals, multipath, multipath-like, and structured jamming signals can be effectively diminished. | 06-04-2009 |
20090141776 | SYSTEMS AND METHODS FOR CONTROL OF ADVANCED RECEIVERS - A controller for advanced receivers configures a plurality of advanced receiver modules based on figures of merit computed on the input signal. The controller also selects the appropriate output signal based on figures of merit of either the input or the output signals. The controller decisions can also be made in a bursty manner, where only a subset of the decisions to be made are made at a given time, thereby limiting the processing load of the control processor. | 06-04-2009 |
20090141777 | STATION COMPRISING A RAKE RECEIVER - Stations like mobile terminals, bases stations and network nodes comprising rake receivers with fingers require relatively many calculations to be performed for despreading a symbol. By replacing despreading multipliers, integrators and dumpers in the fingers by Hadamard transformers ( | 06-04-2009 |
20090147834 | RADIO COMMUNICATION APPARATUS - An object of the invention is to stabilize the convergence operation at the automatic impedance matching time and ensure the reception quality in the convergence process in a fading environment in a radio communication apparatus which performs automatic impedance matching between an antenna and a Radio frequency section to decrease the impedance matching loss, for example, when the apparatus is brought close to a human body. A radio communication apparatus of the invention includes a Radio frequency section | 06-11-2009 |
20090154531 | Multi-Pass Parameter Estimation for G-Rake Receiver - In a parametric G-Rake receiver, a method an apparatus computes initial estimates of one or more scaling parameters and initial combining weights for the parametric G-Rake receiver; estimates the SINR of a received signal based on a mean pilot symbol estimate and the initial combining weights; computes revised estimates for one or more scaling parameters based on the estimated SINR and the initial combining weights; and computes revised combining weights based on one or more revised scaling parameter estimates. | 06-18-2009 |
20090180521 | DETECTION OF INTERFERERS USING DIVERGENCE OF SIGNAL QUALITY ESTIMATES - A method, system, and computer-readable medium for detecting an interferer in a wireless communication system are provided. The method includes receiving a signal having P tones, each of the P tones being associated with a frequency, determining a first signal quality of each of the P tones, determining a second signal quality of each of the P tones, and detecting the interferer that occupies the same frequency as one of the P tones based on the respective first signal quality and the respective second signal quality. The first signal quality and second signal quality behave differently when the interferer is present. The detecting the interferer includes determining a discrepancy in the behavior of the first signal quality and the second signal quality. | 07-16-2009 |
20090180522 | FIRST SIGNIFICANT PATH DETECTION - A scheme determines the first significant path (FSP) of a received multipath signal, from data defining the relative delay and the amplitude of the individual signal paths occurring in a series of time frames. The scheme includes filtering the data to spread the signal paths, performing a persistence test between frames to reject spurious signal paths, combining the energy of the signal paths in a frame, applying a test to determine the time at which the combined energy satisfies a criterion, and selecting the FSP dependent on that time. The combined energy may be evaluated within a sliding window, and the position of the window within the frame determined that maximizes the combined energy. Alternatively, the combined energy may be evaluated as the cumulative energy through the frame, and the position determined at which the cumulative energy reaches a threshold. | 07-16-2009 |
20090190633 | INTERFERENCE MITIGATION OF SIGNALS WITHIN THE SAME FREQUENCY SPECTRUM - Various apparatuses and methods are described herein to reduce the interference in receivers in bands were more than one signal is present. The embodiments also describe a receiver that is capable of providing interference mitigation for both WiFi and Bluetooth and wireless telephony standards in the same receiver. The receiver is capable of receiving WiFi and Bluetooth at the same time in the same ISM channel and removing the mutual interference. The embodiments also include the capability to remove other extraneous interfering signals from WiFi and Bluetooth in the ISM band to include cordless phones and energy from microwave ovens. The interfering signals are isolated and subtracted from the signals of interest. It also describes apparatuses and methods for pre-distorting signals to provide for the operation of amplifiers in the non-linear region where the PAE is greatest. | 07-30-2009 |
20090213907 | Method and Apparatus for Block-Based Signal Demodulation - Teachings presented herein combine the relative simplicity of equalization with the performance of maximum likelihood (ML) processing. These teachings are applied to the detection of symbols in a stream of symbol blocks. In one or more embodiments, block-based equalization, including feedforward filtering, suppresses inter-block interference and produces detection statistics for the symbols in each symbol block, and joint detection addresses intra-block interference by jointly detecting the most likely combination of symbols within each symbol block, based on the corresponding detection statistics. The joint detection obviates the need to address intra-block interference within the equalization filters, while, at the same time, the block-based equalization produces detection statistics for each symbol block thereby simplifying the joint detection process. Overall complexity is less than would be needed for full MLSE processing of the symbol blocks without equalization preprocessing, while performance is close to or on par with full MLSE processing. | 08-27-2009 |
20090213908 | Method and Apparatus for Symbol Detection via Reduced Complexity Sequence Estimation Processing - Teachings presented herein offer the performance advantages of sequence estimation for received signal symbol detection, while simultaneously providing potentially significant reductions in computational overhead. Initial demodulation of a received signal identifies a reduced number of candidate symbol values for all or a subset of a sequence of symbols represented in a received signal. A sequence estimation process, e.g., an MLSE process, constrains its state spaces to the reduced number of candidate symbols values, rather than considering all possible symbol values. | 08-27-2009 |
20090213909 | Code Power Estimation for MIMO Signals - Methods and apparatus for estimating code-reuse interference associated with a received multi-stream multiple-input multiple-output (MIMO) signal are disclosed. An estimate for the data-to-pilot power ratio, Γ | 08-27-2009 |
20090213910 | Code Power Estimation for MIMO Signals - Methods and apparatus for estimating code-reuse interference associated with a received multi-stream multiple-input multiple-output (MIMO) signal are disclosed. In an exemplary method, impairment covariance associated with the received multi-stream MIMO signal is measured, and first and second sets of samples for received traffic data symbols are collected, using first and second sets of RAKE combining weights corresponding to effective net channel responses for first and second streams of the multi-stream MIMO signal, respectively. A per-code energy value for at least one stream of the received multi-stream MIMO signal is computed, as a function of the measured impairment covariance, the effective net channel responses for the first and second streams, and the first and second sets of samples. Finally, code-reuse interference associated with the first stream is calculated, as a function of the per-code energy value and the effective net channel response corresponding to the first stream. | 08-27-2009 |
20090219977 | RADIO COMMUNICATION APPARATUS - A radio communication apparatus includes a mapping unit configured to map data to a burst data transmission region corresponding to radio resources; and a transmitter configured to transmit the data mapped to the burst data transmission region, where a reference signal used for canceling an interference wave is mapped to the data transmission region. | 09-03-2009 |
20090238246 | DIVERSITY RECEIVER - A receiver, includes a plurality of antennas to receive radio signals from a plurality of transmission paths, and a plurality of sets of RAKE fingers to generate first signals. Each set of RAKE fingers is coupled to a respective one of the plurality of antennas, and a weighting factor generator generates weighting factors for weighting the first signals, wherein the weighting factor for one of the first signals is generated by using first signals generated by at least two of the plurality of sets of RAKE fingers. Further, at least two of the first signals used to generate the weighting factor are received from the same transmission path. | 09-24-2009 |
20090238247 | LOW-COST AND LOW-COMPLEXITY INNER COMMUNICATION RECEIVER FOR RECEIVE DIVERSITY - A communication receiver includes first and second antenna elements for receiving first and second signals respectively representative of first and second symbols encoded with a first or second channel coefficient and first and second delay lines for delaying the first and second signals respectively. A master rake module up-samples a pilot channel sequence at chip rate to mix it with the second delayed signals to deliver correlated delayed signals and to determine first and second channel coefficient estimates from the first delayed signals and the correlated delayed signals. A slave rake module determines first and second auxiliary composite symbols from the first and second delayed signals, a scrambling code sequence and a spreading code sequence. Lastly the first and second auxiliary composite symbols combine with the first and second channel coefficient estimates to determine first and second output signals. | 09-24-2009 |
20090245330 | CDMA Receivers for the Golden Code - A Generalized Rake (G-Rake) receiver is adapted for Golden code reception in a CDMA system. Signals transmitted by two or more transmit antennas are received at two or more receiver antennas. The signal from each receiver antenna is despread, and channel estimation is performed for each transmit antenna. G-Rake combining weights are calculated based on impairment correlation across G-Rake fingers and channel coefficients corresponding to each transmit antenna. The despread values from each symbol period are combined over a plurality of symbol periods based on the combining weights. The combined values are processed using coefficients derived from the Golden number to generate a set of decision variables, and the Golden encoded symbols are jointly detected from the decision variables. In some embodiments, spherical decoding and triangularization significantly simplify the decoding problem formulation. | 10-01-2009 |
20090245331 | SIGNALING MESSAGE TRANSMISSION IN A WIRELESS COMMUNICATION NETWORK - Techniques for sending signaling messages in a wireless communication network are described. In an aspect, a signaling message (e.g., a reduce interference request) may be sent by mapping it to at least one specific subcarrier among a set of subcarriers reserved for sending the signaling message. The at least one subcarrier may be selected based on the message value. A signal may be sent on the at least one subcarrier in multiple symbol periods to convey the signaling message. In another aspect, a reduce interference request may be sent based on an orthogonal resource among orthogonal resources available for sending reduce interference requests. In one design, an orthogonal sequence may be selected based on the request and may be spread across a resource segment. In another design, the reduce interference request may be processed to obtain modulation symbols, and each modulation symbol may be spread across multiple subcarriers in one symbol period. | 10-01-2009 |
20090252201 | PILOT INTERFERENCE CANCELLATION - Techniques for generalized pilot interference cancellation in a communications receiver. In an exemplary embodiment, a residual pilot is cancelled from a post-traffic cancellation signal following initial first-pass pilot cancellation. Residual pilot cancellation is achieved by adding the first-pass cancelled pilot as earlier stored in memory back to the post-traffic cancellation signal, and pilot filtering the resulting signal to generate an improved pilot interference estimate. In an alternative exemplary embodiment, an arbitrary number of iterations may be applied to generate the pilot interference estimate by successively storing each generated pilot interference estimate in memory. | 10-08-2009 |
20090257477 | Method and Apparatus for Successive Interference Subtraction with Covariance Root Processing - Methods and apparatus for processing a composite communication signal comprising two or more received signals of interest are disclosed. An interference-suppressing receiver, which may comprise a G-Rake receiver or a linear chip equalizer, utilizes a square-root covariance matrix in processing received signals, where the square-root covariance matrix represents impairment covariance or data covariance for the composite communication signal. In an exemplary method, a receiver detects symbols, corresponding to a signal of interest, from the composite communication signal, using processing weights calculated from a square-root covariance matrix and a net channel response for the signal of interest. The method further comprises calculating a reconstructed version of the signal of interest from the detected first symbols, generating an updated communication signal by subtracting the reconstructed version of the first signal of interest from the composite communication signal, and updating the square-root covariance matrix to obtain an updated square-root covariance matrix. | 10-15-2009 |
20090257478 | SPREAD SPECTRUM RAKE RECEIVER - Even when the number of paths is increased, interfering noises can be effectively reduced by a rake receiver for use in a spread spectrum communication system. The rake receiver includes a timing detecting unit detecting a reception timing t | 10-15-2009 |
20090268786 | Mobile Communication System and Wireless Apparatus to be Used for the Same - A mobile communication system capable of improving the reception characteristic using a small circuit size and low power consumption is provided. The channel vector estimating section | 10-29-2009 |
20090268787 | Method and Apparatus for Compensating for Processing Timing Misalignment in a Communication Receiver - According to the teachings presented herein, a wireless communication apparatus compensates for timing misalignment in its received signal processing. In at least one embodiment, the apparatus estimates a set of path delays for a received signal and sets processing delays on the estimated path delays. The apparatus jointly hypothesizes combinations of fractional timing offsets for two or more paths, and computes a decision metric for each joint hypothesis that indicates the accuracy of the joint hypothesis. As non-limiting examples, the decision metric may be a signal quality metric, or a distance metric (such as between a measured net channel response and an effective net channel response reconstructed as a function of the combination of fractional timing offsets included in the joint hypothesis). The apparatus evaluates the decision metrics to identify a best estimate of timing misalignment, and correspondingly compensates coherent processing of the received signal. | 10-29-2009 |
20090274197 | METHOD AND APPARATUS FOR COMPENSATING FOR PHASE NOISE OF SYMBOLS SPREAD WITH A LONG SPREADING CODE - A method and apparatus for compensating for phase noise of symbols spread with a long spreading code are disclosed. To compensate for the phase noise, a phase error estimate is generated from despread symbols with a short spreading code. A phase correcting phasor is applied to chip rate data before despreading the data with a long spreading code. A signal-to-interference ratio (SIR) on a common pilot channel (CPICH) may be calculated by spreading the data with a parent spreading code in an orthogonal variable spreading factor (OVSF) code tree and by combining symbols. Alternatively, a magnitude of the symbols may be used in estimating the SIR. The SIR of a channel using a short spreading code and an SIR of a channel using a long spreading code are measured. The SIR of the channel with the long spreading code may be compensated in accordance with a difference between degradation of the SIRs. | 11-05-2009 |
20090279591 | FREQUENCY SPUR DETECTION AND SUPPRESSION - Techniques for identifying and suppressing frequency spurs in a signal are disclosed. In an embodiment, an incoming signal is rotated by a frequency related to a spur frequency, and an estimate of the content of the rotated signal is derived. The estimate may be subtracted from the rotated incoming signal, and the result de-rotated by the spur frequency. In an embodiment, the incoming signal may be rotated such that the spur is centered at DC. In an alternative embodiment, the estimate may be de-rotated before being subtracted from the original incoming signal. Techniques for addressing multiple spurs using serial and parallel architectures are disclosed. Further disclosed are techniques for searching for the presence of spurs in an incoming signal, and tracking spur frequencies over time. | 11-12-2009 |
20090279592 | SIGNALS, SYSTEM, METHOD AND APPARATUS - Embodiments of the present invention provide a method to produce a modulation signal comprising combining at least two modulation signals, for example, BOCs or derivatives thereof, having portions (chip or a number of chips) thereof with respective relative phases or states ({++, −} and {+−, −+}) selected such that the average of a plurality of said portions at least reduces cross spectral terms of the composite complex spectrum of said at least two modulation signals. | 11-12-2009 |
20090290617 | METHOD AND APPARATUS FOR COMPUTING SIR OF TIME VARYING SIGNALS IN A WIRELESS COMMUNICATION SYSTEM - A method and apparatus for correcting symbols of a common pilot channel (CPICH) to generate an accurate signal-to-interference ratio (SIR) estimate in a wireless communication system are disclosed. In one embodiment, a non-stationary mean of a group of the CPICH symbols is estimated, the CPICH symbols are delayed, and the CPICH symbols are corrected by dividing the delayed CPICH symbols by the estimated non-stationary mean of the group of CPICH symbols. In another embodiment, a signal power estimate is generated based on the magnitude of CPICH symbols, a noise power estimate is generated by subtracting the signal power estimate from a total power estimate based on the magnitude of the CPICH symbols, and a SIR estimate is generated for symbols that have undergone a time varying gain by dividing the signal power estimate by the noise power estimate. | 11-26-2009 |
20090296786 | METHOD AND SYSTEM FOR ADAPTIVE DUPLICATED FILTERS AND INTERFERENCE CANCELLATION - A method and device substantially cancel at least Multiple Access Interference (MAI) and Inter-Symbol Interference (ISI) while detecting a received spread spectrum signal in a multi-user communication system. For that purpose, a plurality of stages are formed, each comprising processing the received spread spectrum signal through an interference cancelling function to produce an essentially MAI- and ISI-free signal, and processing the essentially MAI- and ISI-free signal through a reconstruct received spread spectrum signal function to produce a received spread spectrum signal essentially free from MAI and ISI. The plurality of stages are cascaded to successively process the spread spectrum signal and improve cancellation of MAI and ISI from the spread spectrum signal. | 12-03-2009 |
20090296787 | WIRELESS COMMUNICATION METHOD AND SYSTEM FOR ASSIGNING MULTI-PATHS TO RAKE RECEIVER FINGERS - A wireless communication method and system for assigning multi-paths to Rake receiver fingers. A Rake finger assignment database is established in which multi-path signals are categorized into a verified group and an unverified group. Each multi-path is assigned to an individual bin in the database. Each bin includes a pilot phase data field, an antenna data field, a code data field, an averaged signal strength data field, an assigned flag data field, a verification flag data field, an update flag data field, an assigned Rake finger number data field and an assignment time counter data field. The multi-path signals in the verified group are further categorized into an assigned subgroup and an unassigned subgroup. During a measurement interval, each of a plurality of newly measured multi-path signals is compared to the multi-path signals in the database and is processed accordingly. | 12-03-2009 |
20090304049 | Structure Low Complexity for Implementing the Mpic Interference Canceller - This device is suitable for receiving from a multipath propagation channel a base-band spread-spectrum analog signal) conveying symbols. It has a structure with at least two stages each comprising a block for estimating said symbols and, with the exception of the final stage, a block for regenerating interference using the symbols estimated by the symbol estimating block of said stage. The signals are transmitted at the chip rate from one stage to the other and each of the interference regenerator blocks uses full Nyquist formatting. | 12-10-2009 |
20090316762 | SCALING USING GAIN FACTORS FOR USE IN DATA DETECTION - Data is estimated from a received vector comprising a plurality of communications. A received wireless signal is converted to a baseband signal, which is sampled to produce a received vector. Channel responses are estimated for the received communications. The noise variance is estimated. The noise variance is scaled by a scaling factor. Samples are processed using the estimated channel responses and the scaled noise variance to produce a spread data vector. The spread data vector is despread to recover the data of the received wireless signal. | 12-24-2009 |
20090323777 | Methods and Apparatus for Sharing Signal Correlation Data in a Receiver - Methods and apparatus are disclosed for suppressing both own-cell and other-cell interference in the processing of multiple signals of interest in a received composite signal. In an exemplary embodiment of the methods disclosed herein, combining weights for each of a first plurality of signals of interest in a composite information signal are computed, based on first shared signal correlation data computed from the composite information signal. A reduced-interference composite signal is calculated from the composite information signal, using, for instance, subtractive interference cancellation or interference projection techniques. Combining weights for processing each of a second plurality of signals of interest are computed as a function of second shared signal correlation data corresponding to the reduced-interference composite signal. Corresponding apparatus, including G-Rake and chip equalizer embodiments are also disclosed. | 12-31-2009 |
20090323778 | MULTIMODE RECEIVER ARCHITECTURE - A radio receiver comprising a compensator arranged to compensate for intersymbol interference in a signal received at the receiver and a configurator arranged to configure the compensator, wherein the compensator comprises a programmable filter and the configurator is capable of configuring the filter in a first mode to operate as an ISI equaliser or in a second mode to implement a RAKE finger set. | 12-31-2009 |
20090323779 | Method and Apparatus for Mitigating the Effects of Narrowband Interfering Signals in a GPS Receiver - A positioning system receiver that mitigates narrowband interference by dynamically choosing the mitigation technique that yields the best interference mitigation capability with the least signal degradation to maximize receiver performance parameters such as receiver sensitivity, multipath resolution, and low power. | 12-31-2009 |
20090323780 | Method and Apparatus for Mitigating the Effects of CW Interference Via Post Correlation Processing in a GPS Receiver - A positioning system receiver that mitigates the effect of continuous wave (CW) carrier interference with post correlation processing in a satellite positioning receiver, while not distorting the signal waveform or degrading receiver sensitivity and performing in low signal and dynamic interference environments. | 12-31-2009 |
20100020854 | Method and Apparatus for Communication Signal Processing Based on Mixed Parametric and Non-Parametric Estimation of Impairment Correlations - According to the teachings presented herein, a method and apparatus for communication signal processing advantageously use a mix of parametric and non-parametric correlation estimation in communication signal processing. Non-parametric estimation generates an “overall” correlation estimate for a received communication signal, and parametric estimation generates a “component” correlation estimate. The component correlation estimate is removed from the overall correlation estimate to form a partial correlation estimate that is used to process the received communication signal at least initially, such as in a pre-equalization stage. The overall and component correlation estimates are generated as impairment and/or data correlation estimates. | 01-28-2010 |
20100020855 | CONTROL APPARATUS FOR AND CONTROL METHOD OF EQUALIZER, AND WIRELESS TERMINAL HAVING THAT CONTROL APPARATUS - A channel estimation value of each path timing is determined, a path timing, the channel estimation value of which is to be set to zero, is determined based on a reception power of each path timing and a predetermined power threshold (P | 01-28-2010 |
20100027589 | METHOD AND APPARATUS FOR ESTIMATING NOISE VARIENCE - The invention is directed towards a method and apparatus for estimating a noise variance in a receiver of a code multiplex telecommunications system with orthogonal spreading codes, wherein respective real and imaginary parts of a sum and a difference of two estimated symbols having substantially same amplitudes are determined, and then respective minimum energy components of the determined real and imaginary parts of the sum and difference are determined. The respective minimum energy components are finally combined to obtain the noise variance. Thereby, noise variance can be estimated simply based on addition and comparison operations, which reduces complexity and processing load. | 02-04-2010 |
20100027590 | MODIFIED SIR VALUES FOR FAST POWER CONTROL - The present invention relates to a receiver comprising a fast power control unit, said fast power control unit being arranged to continuously control a quality measure of a radio channel. The receiver is characterized in that the quality measure is a modified Signal to Interference plus noise ratio (SIR) in which the influence from self interference has been removed. The invention further relates to a method for continuously controlling a quality measure of a radio channel, wherein a modified Signal to Interference plus noise ratio (SIR) is continuously determined in which the influence from self interference has been removed. | 02-04-2010 |
20100040116 | Dynamic Combining Threshold for a Rake Receiver - Described is a method that includes receiving a signal through a channel; considering at least one channel-related criterion and, in response to the considered at least one channel-related criterion, setting a value of an adaptive combining threshold for a maximum ratio combiner that receives the outputs of a plurality of fingers of a rake receiver. | 02-18-2010 |
20100054309 | NONPARAMETRIC MIMO G-RAKE RECEIVER - With a nonparametric G-Rake receiver, combining weights may be determined using a nonparametric mechanism in multiple-input, multiple-output (MIMO) scenarios. In an example embodiment, a method for a receiving device having a nonparametric G-Rake receiver entails calculating an impairment covariance matrix and determining combining weights. More specifically, the impairment covariance matrix is calculated based on a pilot channel using a nonparametric mechanism in a MIMO scenario in which a code-reuse interference term exists. The combining weights are determined for the nonparametric G-Rake receiver responsive to the impairment covariance matrix and by accounting for the code-reuse interference term. | 03-04-2010 |
20100054310 | METHOD OF ACQUIRING A RECEIVED SPREAD SPECTRUM SIGNAL - A method of acquiring a received spread spectrum signal comprises receiving a spread spectrum signal, analysing the received signal to detect interference within the received signal, and adapting the baseband processing of the received signal to reduce power consumption during periods of detected interference. This allows the GPS processing resources to be focussed on areas of signal where there is little or no interference, and this is possible without modification to the source of interference. The interference is detected from an analysis of the received signal, and in particular before the baseband digital signal processing. | 03-04-2010 |
20100054311 | WCDMA terminal baseband processing module having multi-path scanner module - A baseband processing module according to the present invention includes a multi-path scanner module. The multi-path scanner module is operable to receive timing and scrambling code information regarding an expected multi-path signal component of a WCDMA signal. Then, the multi-path scanner module is operable to identify a plurality of multi-path signal components of the WCDMA signal by descrambling, despreading and correlating a known symbol pattern of/with a baseband RX signal within a search window. The multi-path scanner module is operable to determine timing information for the plurality of multi-path signal components of the WCDMA signal found within the search window and to pass this information to a coupled rake receiver combiner module. | 03-04-2010 |
20100067564 | Time Multiplexed Non-Coherent Multipath Search Method and Apparatus - An apparatus for performing a multipath search including a plurality of time-multiplexed chip correlators, wherein each of the plurality of time-multiplexed chip correlators has a pipeline, and further wherein each of the plurality of time-multiplexed chip correlators has a accumulation time is described. A method is described for performing a multipath search including performing multipath search slot processing, determining if a current multipath searching slot is a last multipath searching slot, if the current multipath searching slot is not the last multipath searching slot, then repeating the performing step, if the current multipath searching slot is the last multipath searching slot, then initializing a multipath searching slot index, determining if an non-coherent accumulation has been completed if the accumulation has not been completed then repeating all steps and if the accumulation has been completed, then search results are sorted to locate energy peaks corresponding to multipath locations. | 03-18-2010 |
20100074307 | A P-ORDER METRIC UWB RECEIVER STRUCTURE WITH IMPROVED PERFORMANCE IN MULTIPLE ACCESS INTERFERENCE-PLUS-NOISE MULTIPATH CHANNELS - A UWB receiver dubbed the “p-order metric” receiver (p-omr) is proposed to detect the time-hopping ultra-wide bandwidth signal in multiple access interference channels. The receiver acquires a signal over a wireless channel, adaptively selects a shaping parameter, p, over time and generates a first set of partial statistics by, for each of a plurality N of observations per symbol, using the shaping parameter to modify the exponential order of the approximation of the noise plus multiple access interference probability density function, f(x), used in the receiver model. | 03-25-2010 |
20100080268 | CROSSCORRELATION INTERFERENCE MITIGATING POSITION ESTIMATION SYSTEMS AND METHODS THEREFOR - Provided is a method that includes dynamically adjusting a GPS signature code to minimize the interference (e.g., the cross-correlation interference) experienced due to one or more other GPS signals. Further provided is a method that includes adjusting the complexity of an adaptive solution to reduce the time and processing power associated with tracking a GPS signal. | 04-01-2010 |
20100091822 | ADAPTIVE KNOWN SIGNAL CANCELLER - An adaptive known signal canceller comprising of a known signal canceller filter responsive to a known signal including a known portion of a transmitted signal, the known signal canceller filter operative to generate a filtered known signal, and a subtractor unit responsive to an input signal and operative to generate an output signal, the subtractor unit configured to subtract the filtered known signal from the input signal to generate an output signal, such that the known portion of the transmitted signal is substantially removed from the input signal. The adaptive known signal canceller further comprising of a known signal canceller update unit, responsive to a desired signal and an output signal and operative to continually adjust the coefficients of the known signal canceller filter based on the difference between the output signal and the desired signal, so that the filter coefficients substantially reflect the impulse response of a channel. | 04-15-2010 |
20100098136 | Method and apparatus for performing signal correlation at multiple resolutions to mitigate multipath interference - A method and apparatus for selecting a signal processing resolution. A received signal is processed using a first resolution. When a multipath condition is detected, the signal is processed using a second resolution. | 04-22-2010 |
20100103987 | METHOD AND APPARATUS FOR TRANSFERRING SIGNALS IN A WIRELESS COMMUNICATION SYSTEM - Data is transferred in a wireless communication system, such as a wireless spread spectrum communication system. A plurality of transmitting antennas are provided. Data is encoded to produce a plurality of data streams for each of the plurality of codes. The plurality of data streams are spread with the plurality of spreading codes, and for each transmitting antenna, one of the spread data streams of each code together is combined to produce a spread data vector. Each transmitting antenna transmits its spread data vector. The transmitted spread data vectors are received by each of a plurality of receiving antennas as a received version, and the data is recovered using the received versions. | 04-29-2010 |
20100118921 | Self-Adaptive Digital RF Bandpass and Bandstop Filter Architecture - A system and method provides adaptive digital front end control of an incoming radio frequency (RF) signal to identify RF characteristics in that signal, such as interference or desired data signals and adaptively control digital filter elements to selectively tune only portions of the RF signal to produce a filtered output signal, on a per cycle basis, prior to communicating the RF signal to an underlying wireless communication device, such as a base station in cellular network, cellular phone, wireless router base station, cognitive radio, or other wireless communication device. Each digital filter element may be tuned in frequency and bandwidth of operation and collectively the elements form an adaptive filter stage with elements configurable into both bandpass and bandstop filters for cascaded operation. | 05-13-2010 |
20100128759 | Efficient Despread and Respread of Multi-rate CDMA Signals - A system and method, comprising a despread module that receives a descrambled signal and an identification of active codes, a soft-symbols memory communicably coupled to the despread module, and a respread module that receives the identification of active codes, a modulation type and gain estimate for the active codes, and soft symbol estimates for the active codes from the soft-symbols memory which is communicably coupled to the respread module, the despread module, comprising: a despread signal memory that receives the descrambled signal, a vector code despread module communicably coupled to the despread signal memory, an active code soft symbol grabber that receives the identification of active codes and is communicably coupled to the despread signal memory, wherein the despread signal memory receives properly arranged despread data from the vector code despread module, wherein if the despread data is associated with the identification of active codes, the active code soft symbol grabber transfers the despread data from the despread signal memory to the soft-symbols memory. | 05-27-2010 |
20100135365 | METHOD AND APPARATUS FOR MULTIPATH MITIGATION - An apparatus and method for short multipath mitigation. In one aspect the method comprises subtracting a first stronger path from a correlation function to obtain a first residual signal, wherein one component of the first residual signal is a weaker path; applying reconstruction on the first residual signal to obtain a first reconstructed weaker path; subtracting the first reconstructed weaker path from the correlation function to obtain a second residual signal; and applying reconstruction on the second residual signal to obtain a second stronger path. In one aspect, the apparatus includes an antenna for receiving a composite receive RF signal, a receiver front-end for converting the composite receive RF signal into a composite receive digital signal; and a processor for performing signal correlation on the composite receive digital signal to obtain a correlation function and for processing the correlation function to obtain a desired signal. In one aspect, the short multipath is identified by computing a Left Edge Height Ratio Indicator (LEHRI). | 06-03-2010 |
20100135366 | DATA EQUALISATION IN A COMMUNICATION RECEIVER WITH RECEIVE DIVERSITY - A method of performing data equalisation in a communication receiver with transmit and receive diversity includes (a) for each i-th receiver antenna and j-th transmitter antenna, calculating a channel response matrix H | 06-03-2010 |
20100142595 | METHOD OF TRANSMITTING AND RECEIVING SIGNAL IN COMMUNICATION SYSTEM - A communication system generates a continuously orthogonal spreading code for a user, a user signal is spreading-modulated by using the continuously orthogonal spreading codes, and then the spread signal is pre-rake combined and transmitted. A receiver processes the received signal by using a matched filter for one path. | 06-10-2010 |
20100150212 | RAKE RECEIVER FINGER ASSIGNMENT BASED ON SIGNAL PATH CONCENTRATION - A rake receiver finger assignor is configured to assign a rake receiver finger to a time offset between identified signal path time offsets in accordance with a concentration of identified signal paths from a transmitter to a rake receiver. In accordance with the exemplary embodiment, a number of identified signal paths having time offsets within a time window are observed to determine the concentration of signal paths identified by a path searcher. If the number of identified signal paths indicates a concentrated distribution of signal paths such as during a fat path condition, at least one rake finger is assigned between at a time offset between two identified signal paths. | 06-17-2010 |
20100166044 | PHASE BASED MEASUREMENT CORRECTIONS - A method for providing correction values for phase based measurements. Where averaging techniques are employed for exploiting redundancy in multiple measurements, by constraining the phase ambiguity in a correction value to be an integer multiple of the carrier wavelength, carrier phase based measurements can be used. | 07-01-2010 |
20100172396 | METHOD AND APPARATUS FOR SETTING RECEIVED SIGNAL PROCESSING DELAYS AS A FUNCTION OF CHANNEL DISPERSIVENESS - A method and apparatus provide for setting processing delay assignments in a CDMA receiver using a flat-channel placement or using a dispersive channel placement, in dependence on characterizing the channel as flat or dispersive. For example, a receiver maintains a logical flag reliably indicating the current channel state as flat or dispersive, and assigns or otherwise sets processing delays—e.g., for received signal demodulation—using a flat-channel placement algorithm or a dispersive-channel placement algorithm. The “flat-channel” placement algorithm generally provides better performance in flat-channel environments, and the “dispersive-channel” placement algorithm generally provides better performance in dispersive channel environments. Such processing may be regarded as “activating” a simplified processing delay placement grid that offers better performance if the channel truly is flat, with the underlying advantage of providing a reliable mechanism for detecting flat channel conditions. | 07-08-2010 |
20100172397 | METHOD AND SYSTEM FOR DIVERSITY PROCESSING - In an RF communication system, aspects for diversity processing may comprise processing a plurality of received multipath signals as clusters of signals. The received multipath signals may be diversity signals received from diversity transmit antennas at a base station. Timing information may be generated for tracking the clusters of signals. Complex phase and amplitude information may also be estimated for at least some of the multipath signals in the clusters of signals. At least a portion of the received multipath signals may be combined to form a single path processed diversity signal. A plurality of the single path processed diversity signals may be combined together, where each of the single path processed diversity signals may be derived from one of the plurality of diversity transmit antennas at the base station. The diversity signals may be transmitted via at least one of a plurality of diversity modes. | 07-08-2010 |
20100208774 | Iterative Interference Cancellation Using Mixed Feedback Weights and Stabilizing Step Sizes - A receiver is configured for canceling intra-cell and inter-cell interference in coded, multiple-access, spread-spectrum transmissions that propagate through frequency-selective communication channels. The receiver employs iterative symbol-estimate weighting, subtractive cancellation with a stabilizing step-size, and mixed-decision symbol estimates. Receiver embodiments may be implemented explicitly in software or programmed hardware, or implicitly in standard Rake-based hardware either within the Rake (i.e., at the finger level) or outside the Rake (i.e., at the user or sub channel symbol level). | 08-19-2010 |
20100215083 | Method for Allocating Rake Fingers in Multi-Carrier Systems - A multi-carrier RAKE receiver is described herein. The multi-carrier RAKE receiver distributes RAKE fingers between a plurality of received carriers based on a comparison between the signal-to-interference ratios (SIRs) determined for each carrier. In one embodiment, the RAKE fingers are distributed evenly between the carriers when a comparison between the largest and smallest SIR is less than or equal to a threshold. In another embodiment, the RAKE fingers are distributed to favor the carrier(s) with the strongest SIR(s) when the comparison between the largest and smallest SIR exceeds the threshold. By distributing the RAKE fingers to favor the carriers with the strongest SIRs, the embodiments of the present invention enable the system designers to limit the total number of available RAKE fingers without sacrificing performance. | 08-26-2010 |
20100232477 | MOBILE COMMUNICATION SYSTEM RECEIVER, PATH TRACKING METHOD, AND CONTROL PROGRAM THEREOF - [Problems] To prevent disabling of the path tracking function. | 09-16-2010 |
20100238980 | Signal Reception with Adjustable Processing Delay Placement - The placement of processing delays may be adjusted to facilitate signal reception. In an example embodiment, a composite signal having multiple signal images corresponding to multiple reception delays is received. A root-mean-square (RMS) delay spread is ascertained for the multiple reception delays that correspond to the multiple signal images of the composite signal. A set of temporal points is produced responsive to the RMS delay spread. Multiple processing delays are placed based on the set of temporal points. In different example implementations, the set of temporal points (e.g., of a grid) may be produced by adjusting a spacing between temporal points, by adjusting a total number of temporal points in the set, or by changing a center location of the set. The spacing and number of points may be adjusted responsive to the RMS delay spread. The center location may be adjusted responsive to at least one calculated delay. | 09-23-2010 |
20100238981 | INTERFERENCE CANCELLATION IN VARIABLE CODELENGTH SYSTEMS FOR MULTI-ACESS COMMUNICATION - A receiver employs low-rate processing to synthesize the effect of high-rate interference in a received multi-rate signal. Each high-rate subchannel is analyzed on its low-rate descendents to produce symbol estimates for each low-rate symbol interval. The symbol estimates are applied to low-rate descendent subchannels, which are then combined to synthesize the effects of the high-rate interference. An interference canceller processes the synthesized interference with the received signal for producing an interference-cancelled signal. Alternatively, analogous steps may be applied at high-rate to analyze, synthesize, and cancel the effects of low-rate interference in a multi-rate signal. | 09-23-2010 |
20100254436 | Method and Arrangement for Improved G-RAKE Scaling Parameter Estimation - The present invention discloses a method of improved impairment covariance matrix estimation for a received signal in a Generalized Rake receiver arrangement, providing SIO a plurality N of despread pilot symbols representative of the signal, determining S | 10-07-2010 |
20100260237 | Method and Appratus for Direct Estimation of Impairment Correlations for Received Signal Processing - According to the teachings disclosed in this document, a receiver estimates impairment correlations for a received signal using received pilot values. This direct estimation of impairment correlations based on direct pilot observations, provides for a rich capture of all impairment sources bearing on the received signal. Advantageously, however, estimation noise is reduced by generating a structured covariance matrix from the measured covariance matrix, and carrying out structured filtering within the structured covariance matrix. Structured filtering involves averaging matrix elements that correspond to the same processing delay difference as used for measured impairment correlation estimation. In one or more embodiments, averaged net channel estimates are used to obtain a rank one matrix, which is used to convert a measured covariance matrix to a structured covariance matrix, for carrying out structured filtering. | 10-14-2010 |
20100260238 | CANCELLATION OF PILOT AND TRAFFIC SIGNALS - A method for removing selected signals from a received signal prior to decoding begins by receiving communication signals from a transmitter over a CDMA air interface. The received communication signals are input to a traffic signal cancellation system for canceling unwanted traffic signals, thereby producing an output (O). The received communication signals are input to a pilot signal cancellation system for removing a global pilot signal, thereby producing an output (O | 10-14-2010 |
20100265994 | RAKE or G-RAKE Receiver Structure for Downlink Transmit Diversity Signals - In a RAKE or GRAKE receiver a combined set of weight factors are used for a first and a second symbol period. The output from the first and second symbol period is fed to a single mutual receiver. | 10-21-2010 |
20100265995 | TIME DIVIDED PILOT CHANNEL DETECTION PROCESSING IN A WCDMA TERMINAL HAVING A SHARED MEMORY - A method for operating a Radio Frequency (RF) receiver of a wireless terminal. During a first time interval, an RF front end is enabled and the RF receiver receives and processes an RF signal, e.g., a Wideband Code Division Multiple Access (WCDMA) signal, to produce a baseband signal and to store samples of the baseband signal. During a second time interval that differs from the first time interval, the RF front end is disabled and the RF receiver processes the plurality of samples of the baseband signal of the first time interval to measure signal strengths of a plurality of pilot signals present in the baseband signal of the first time interval. Finally, during a third time interval that differs from the first time interval and the second time interval, the RF front end is enabled and the RF receiver receives and processes an RF signal of the third time interval to extract data there from. Memory is shared between the first, second, and third time intervals for different uses. | 10-21-2010 |
20100278218 | METHOD AND SYSTEM FOR MULTI-USER INTERFERENCE CANCELLATION - Systems and methods for multi-user interference cancellation are provided. In one aspect of the disclosure, an apparatus is provided. The apparatus comprises a processing unit configured to process received chips into received symbols for a plurality of users and a detection unit configured to detect user symbols from the received symbols. The apparatus also comprises an interference cancellation unit configured to compute multi-user interference using the detected user symbols and to remove the computed multi-user interference from the received symbols. The apparatus further comprises a redetection unit configured to redetect user symbols from the received symbols with the computed multi-user interference removed. | 11-04-2010 |
20100278219 | METHOD AND SYSTEM FOR MULTI-USER DETECTION IN THE PRESENCE OF MULTIPLE SPREADING FACTORS - Methods and systems for multi-user detection in the presence of multiple spreading factors are provided. In one aspect of the disclosure, an apparatus is provided. The apparatus comprises an interference computation unit configured to compute a combined interference based on detected user symbols for a first spreading factor and detected user symbols for a second spreading factor, wherein the combined interference accounts for multi-user interference from user symbols for the first and second spreading factors. The apparatus further comprises an interference cancellation unit configured to remove the computed combined interference from a plurality of received symbols corresponding to the first spreading factor and a redetection unit configured to redetect the user symbols for the first spreading factor from the plurality of received symbols with the computed combined interference removed. | 11-04-2010 |
20100296552 | APPARATUS AND METHOD FOR HYBRID DIVERSITY COMBINING AND ADAPTIVE BEAM FORMING IN INDUSTRIAL CONTROL AND AUTOMATION SYSTEMS - An apparatus includes a plurality of antennas, where each antenna is configured to receive wireless signals transmitted using adaptive beam forming. The apparatus also includes a plurality of wireless radios, where each wireless radio is configured to output signals representing the wireless signals received by one of the antennas. The apparatus further includes a plurality of first diversity combiner units, where each first diversity combiner unit is configured to perform spread spectrum diversity combining using the signals output by one of the wireless radios. In addition, the apparatus includes a second diversity combiner unit configured to perform antenna diversity combining using signals output by the first diversity combiner units, where the second diversity combiner unit is configured to output recovered wireless signals. | 11-25-2010 |
20100296553 | PROCESSING DIGITAL SAMPLES IN A WIRELESS RECEIVER - A method of processing digital samples of a signal received at a receiver of a wireless communication system includes monitoring channel conditions and generating a channel indicator including at least one channel parameter by performing at least one of: estimating a channel mobility parameter and comparing it with a threshold; estimating a channel parameter of the energy of the channel outside a predefined temporal window and comparing it with a threshold; estimating a channel temporal duration parameter and establishing if it meets predetermined criteria; estimating a channel-zero location parameter and establishing if it meets predetermined criteria; estimating a received-signal signal-to-disturbance power ratio and comparing it to a threshold; estimating an estimated-channel-response signal-to-disturbance power ratio; estimating the degree of non-stationarity of the disturbance at the receiver input; and selecting one of a plurality of processing routines for processing the digital samples based on said channel indicator. Related receivers are also described. | 11-25-2010 |
20100303132 | Method and Apparatus for Allocating Processing Delays in Multi-Carrier Systems - A multi-carrier linear equalization receiver, e.g., a RAKE receiver or chip equalization receiver, is described herein. The multi-carrier receiver distributes processing delays among a plurality of received carriers based on a dispersion determined for each carrier. The receiver initially allocates a minimum number of processing delays sufficient for light dispersion to each carrier. For the dispersive carriers, the receiver allocates one or more additional processing delays. In one embodiment, the additional processing delays are allocated to the dispersive carriers based on SIR. | 12-02-2010 |
20100322292 | Method and System for Channel Estimation in a Single Channel (SC) Single-Input Multiple-Output (SIMO) System - The method and system for channel estimation in a single channel (SC) single-input multiple-output (SIMO) system described herein may provide a fast and cost effective approach to concurrently determine propagation channel estimates in a single-transmit (1-Tx) and multiple-receive (M-Rx) antennas wireless communication system. A single weight baseband generator may comprise a set generator, a channel estimator, and an algorithm generator. The set generator may generate orthogonal function sequences that may be applied to the M receive antennas and may be utilized by the channel estimator to generate channels estimates. The orthogonal function sequences may be transferred to the channel estimator after a delay. The algorithm generator may generate phase values based on the channels estimates that may be applied to the M receive antennas to improve the system's signal-to-noise performance. | 12-23-2010 |
20110002365 | INTERFERENCE CANCELLATION IN A MULTI-USER RECEIVER - The delay associated with performing interference cancellation in a multi-user receiver is reduced by enabling partial decoding. According to an embodiment, interference is canceled from a received signal having signal contributions from multiple users by partially decoding a first codeword obtained from the received signal and transmitted by a first user via a first signal. The first signal is reconstructed based on the partial decoding of the first codeword and canceled from the received signal to yield a reduced-interference signal. A second codeword obtained from the reduced-interference signal and transmitted by the first user or a second user via a second signal is at least partially decoded. In one embodiment, the first codeword is partially decoded by puncturing one or more coded bits of the first codeword and decoding the first codeword based on the one or more punctured coded bits and estimates of the remaining coded bits. | 01-06-2011 |
20110002366 | RAKE RECEIVER FOR SPREAD SPECTRUM CHAOTIC COMMUNICATIONS SYSTEMS - A receiver ( | 01-06-2011 |
20110044378 | Iterative Interference Canceler for Wireless Multiple-Access Systems with Multiple Receive Antennas - This invention teaches to the details of an interference canceling receiver for canceling intra-cell and inter-cell interference in coded, multiple-access, spread spectrum transmissions that propagate through frequency selective communication channels to a multiplicity of receive antennas. The receiver is designed or adapted through the repeated use of symbol-estimate weighting, subtractive cancellation with a stabilizing step-size, and mixed-decision symbol estimates. Receiver embodiments may be designed, adapted, and implemented explicitly in software or programmed hardware, or implicitly in standard RAKE-based hardware either within the RAKE (i.e., at the finger level) or outside the RAKE (i.e., at the user or subchannel symbol level). Embodiments may be employed in user equipment on the forward link or in a base station on the reverse link. It may be adapted to general signal processing applications where a signal is to be extracted from interference. | 02-24-2011 |
20110064122 | METHOD AND SYSTEM FOR PROCESSING SIGNALS UTILIZING A PROGRAMMABLE INTERFERENCE SUPPRESSION MODULE - Aspects of a method and system for processing signals utilizing a programmable interference suppression module are provided. In this regard, a received signal may be iteratively processed to generate an interference suppressed representation of the received signal. The iterative processing may comprise a weighting iteration; an addback weighting and un-addback iteration, and an addback iteration. The weighting iteration may comprise generating one or more first estimate signals that estimate user signals present in the received signal. The addback, weighting, and un-addback iteration may comprise generating one or more incremental estimate signals based on the one or more first estimate signals and the one or more second estimate signals. The addback iteration may comprise generating an interference suppressed representation of the received signal based on at least the one or more second estimate signals. | 03-17-2011 |
20110069742 | Method and Apparatus for Interference Suppression with Efficient Matrix Inversion in a DS-CDMA System - A receiver in a CDMA system comprises a front end processor that generates a combined signal per source. A symbol estimator processes the combined signal to produce symbol estimates. An S-Matrix Generation module refines these symbol estimates based on the sub channel symbol estimates. An interference canceller is configured for cancelling interference from at least one of the plurality of received signals for producing at least one interference-cancelled signal. | 03-24-2011 |
20110096813 | METHOD AND SYSTEM FOR INTERFERENCE SUPPRESSION BETWEEN MULTIPATH SIGNALS UTILIZING A PROGRAMMABLE INTERFACE SUPPRESSION MODULE - Aspects of a method and system for interference suppression between multipath signals utilizing a programmable interface suppression module may include one or more processors and/or circuits that are operable to program an interference suppression module based on one or more interference cancellation parameters. A plurality of weighting factor values may be determined based on the one or more interference suppression parameters and a received plurality of multipath signals. A plurality of estimated signals may be generated based on the plurality of weighting factor values. A plurality of updated estimated signals may be generated based on the plurality of estimated signals. A plurality of interference suppressed signals may be generated based on the plurality of updated estimated signals and/or a plurality of updated residual signals. | 04-28-2011 |
20110103431 | METHODS AND SYSTEMS FOR INTERFERENCE CANCELLATION IN MULTI-MODE COEXISTENCE MODEMS - Certain embodiments of the present disclosure support techniques for interference cancellation in a multi-mode wireless modem that supports coexistence of different radio technologies. | 05-05-2011 |
20110110400 | METHOD AND SYSTEM FOR COMPUTING A CELL NORMALIZATION FACTOR BY SHARING ARITHMETIC UNITS IN A RAKE RECEIVER TO REDUCE OVERALL IMPLEMENTATION AREA - A mobile device receives downlink transmissions comprising replicas of an original downlink transmitted signal over corresponding fingers of a RAKE receiver comprising arithmetic units. The RAKE receiver computes a cell normalization factor for each of active cells and neighbor cells associated with the RAKE receiver. The RAKE receiver uses the same arithmetic units comprising one adder, one multiplier, one divider and/or one square root unit to compute cell normalization factors. The received downlink transmitted signal is processed using the computed cell normalization factors. The RAKE receiver determines signal power from each of other cells, separately, to compute cell normalization factors to normalize fingers of the RAKE receiver. Interference over the normalized fingers are cancelled and used to process the received downlink transmitted signal, which are combined and Turbo decoded. Phase correction is performed over interference cancelled fingers for active cells, but need not be performed for neighbor cells. | 05-12-2011 |
20110122927 | Blind Spreading Factor Detection for WCDMA - In a blind spreading factor detecting receiver, the amplitude of a desired signal term is decoupled from the spreading factor hypothesis for that signal. Furthermore, the amplitude of the desired signal and the variance of an associated impairment term are estimated, and the estimates used to form a spreading factor hypothesis. Additionally, in one or more embodiments, a suboptimal detector does not rely on estimates of the amplitude of the desired signal or variance of the impairment term. Rather, the detector relies on scaled values that are partially despread using an initial spreading factor not greater than the smallest possible spreading factor used by the signal of interest, and combined using combining weights from a Rake or G-Rake processor, wherein the scaling factor is chosen to yield a unity ratio between the signal amplitude and noise variance after scaling. | 05-26-2011 |
20110129000 | METHOD AND APPARATUS FOR EFFICIENT AMLD MATRIX COMPUTATIONS - The computation of code-specific channel matrices for an Assisted Maximum Likelihood Detection (AMLD) receiver comprises separately computing high rate matrices that change each symbol period, and a low rate matrix that is substantially constant over a plurality of symbol periods. The high and low rate matrices are combined to generate a code-specific channel matrix for each receiver stage. The high rate matrices include scrambling and spreading code information, and the low rate matrices include information on the net channel response and combining weights. The low rate matrices are efficiently computed by a linear convolution in the frequency domain of the net channel response and combining weights (with zero padding to avoid circular convolution), then transforming the convolution to the time domain and extracting matrix elements. Where the combining weights are constant across stages, a common code-specific channel matrix may be computed and used in multiple AMLD receiver stages. | 06-02-2011 |
20110142100 | METHODS AND APPARATUSES FOR IDENTIFYING AND MITIGATING INTERFERENCE IN A WIRELESS SIGNAL - Methods and apparatuses are provided that may be implemented in various electronic devices and/or circuits to identify and mitigate to some extent various known and unknown interference signals that may appear in a received signal. | 06-16-2011 |
20110142101 | DATA TO PILOT RATIO ESTIMATION - A CDMA receiver computes an accurate estimate of the data to pilot power ratio. First, a biased estimate of the data to pilot power ratio is obtained from the data channel. A multiplicative correction factor is then computed from the pilot channel, and applied to the biased data to pilot power ratio estimate. | 06-16-2011 |
20110142102 | CHANNEL ESTIMATION DEVICE AND METHOD, DEMODULATION DEVICE AND METHOD, AND FADING FREQUENCY DECISION DEVICE AND METHOD - In this invention, a channel estimation value of data symbols of a data channel is calculated by weighting and averaging pilot symbols in a parallel time multiplexing method. Also, a channel estimation value of data symbols during each data symbol interval is calculated by dividing data symbols in a slot into a plurality of data symbol intervals, selecting pilot symbols suitable for calculation of a channel estimation value of data symbols during each data symbol interval and weighting and averaging that pilot symbols. Also, a fading frequency is detected based on an inner product value of pilot symbols. Weighting factors are changed based on the detected fading frequency. Also, a channel estimation value is calculated by weighting and averaging pilot signals using a plurality of weighting sequences. The calculated channel estimation value is used to demodulate received data. The output data with the highest quality is selected by judging reliability of these plurality of demodulated data. It is also possible to select some weighting sequences based on the result of the reliability judgment of the demodulated data for predetermined period of time. In this case, after the selection, demodulation is performed by using these selected weighting sequences only. | 06-16-2011 |
20110150046 | RECEIVER FOR REAL TIME LOCATING SYSTEM AND METHOD OF RECEIVING SIGNAL IN REAL TIME LOCATING SYSTEM - Provided are a receiver for a real time locating system (RTLS) and a method of receiving a signal in the RTLS. The receiver includes a down converter converting a radio frequency (RF) signal into a base band signal, a matched filter filtering the converted signal using an optimal receiving filter in view of a signal-to-noise ratio (SNR) such as a shaping filter used for a transmitter, an adaptive transversal filter (ATF) estimating an interference signal with an output of the matched filter, and filtering the output to remove interference of a heterogeneous signal of the same frequency band, a de-spreader multiplying an output of the matched filter and a code according to DSSS modulation used for spreading when a tag signal is modulated, and performing chip-matched filtering to obtain a value of correlation energy, and a detector detecting original transmission data using the correlation energy value. | 06-23-2011 |
20110182329 | DEVICE AND METHOD FOR DISTORTION-ROBUST DECODING - A device for decoding code symbols which are interfered with a distortion during a predetermined distortion time interval includes a reliability information generator to provide reliability information based on the code symbols and a decoder to decode the code symbols into code words. The decoder is configured to decode the code symbols based on weighted reliability information, wherein the weighted reliability information is generated from the reliability information by applying a first weight during times not coinciding with the distortion time interval, and by applying a second weight different from the first weight during times coinciding with the distortion time interval. | 07-28-2011 |
20110182330 | Serial cancellation receiver design for a coded signal processing engine - An interference cancelling receiver combines data from multiple paths after aligning to transmitter timing, and uses either an equalizer or a Rake receiver to compute symbol estimates. Interference estimates are generated from the symbol estimates, and multiple interference estimates are combined after re-aligning the interference estimates to receiver timing. At least two segments of symbol estimates are computed for each segment of interference cancelled data. | 07-28-2011 |
20110200075 | Device and Method for Selecting a Path from an Estimated Delay Profile of a Radio Signal - A device includes a delay profile estimator to estimate a delay profile of multiple paths of a radio signal, wherein the delay profile indicates signal powers of the multiple paths as a function of time delay. The device further includes a path selector to select a path from the delay profile if the path has a signal power higher than a threshold. The threshold has a first threshold value in a first section of the delay profile which is higher than a second threshold value in a second section of the delay profile. | 08-18-2011 |
20110255573 | Iterative Interference Suppression Using Mixed Feedback Weights and Stabilizing Step Sizes - A receiver is configured for canceling intra-cell and inter-cell interference in coded, multiple-access, spread-spectrum transmissions that propagate through frequency-selective communication channels. The receiver employs iterative symbol-estimate weighting, subtractive cancellation with a stabilizing step-size, and mixed-decision symbol estimate. Receiver embodiments may be implemented explicitly in software of programmed hardware, or implicitly in standard Rake-based hardware either within the Rake (i.e., at the finger level) or outside the Rake (i.e., at the user of subchannel symbol level). | 10-20-2011 |
20110274144 | METHOD AND SYSTEM FOR MANAGING, CONTROLLING, AND COMBINING SIGNALS IN A FREQUENCY SELECTIVE MULTIPATH FADING CHANNEL - A maximum signal energy level among a plurality of individual distinct path signals in a wirelessly received signal cluster is detected. An early aggregate power level associated with at least a portion of the plurality of individual distinct path signals received at time instants preceding a first moment time, and a late aggregate power level associated with at least a portion of the plurality of individual distinct path signals received at time instants subsequent to the first moment time are computed. The first moment time, which corresponds to the detected maximum signal energy level, is adjusted based on the early aggregate power level and the late aggregate power level. At least a portion of the plurality of individual distinct path signals is received at a corresponding plurality of time instants within a duration comprising a delay spread of the wirelessly received signal cluster based on the adjusted first moment time. | 11-10-2011 |
20110286498 | APPARATUS AND METHOD FOR CHANNEL ESTIMATION USING COMPRESSIVE SENSING - An apparatus and method for channel estimation comprising obtaining a response matrix G(l) using Q quantity pilots; constructing a sensing matrix W | 11-24-2011 |
20110286499 | Reduced Complexity Channel Estimation for Uplink Receiver - The present invention proposes an LTE eNodeB receiver channel estimation technique that is referred to as reduced complexity minimum mean squared error (MMSE) technique for channel estimation. From the invention's assumptions, estimations and modified calculations, the present invention generates precise channel estimates of RS using the reduced complexity MMSE matrix and previously computed LS channel estimates H | 11-24-2011 |
20110292974 | Methods for estimation and interference suppression for signal processing - A receiver in a CDMA system comprises a front end processor that generates a combined signal per source. A symbol estimator processes the combined signal to produce symbol estimates. An S-Matrix Generation module refines these symbol estimates based on the sub channel symbol estimates. An interference canceller is configured for cancelling interference from at least one of the plurality of received signals for producing at least one interference-cancelled signal. | 12-01-2011 |
20110299571 | RECEIVER COMPRISING A DEVICE FOR CORRECTING DOPPLER EFFECT - A OFDM digital communication receiver having channel estimate and correction means and inter carrier interference cancellation means based on the use of a temporal digital filter comprising a set of digital coefficients. The receiver includes Look-Up Tables LUT(n), each corresponding to a given set of digital coefficients and an entry pointer. | 12-08-2011 |
20120002706 | Process for Assigning a Finger of a Rake Receiver in Idle Mode, and Apparatus for Carrying Out thte Process - Process of a finger assignment in a rake receiver for a wireless communication device comprising the following steps:—detection ( | 01-05-2012 |
20120033715 | MULTI-USER INTERFERENCE CANCELLATION IN A SINGLE-CARRIER RADIO RECEIVER - A method, apparatus, and radio receiver system for canceling multi-user interference in a single-carrier radio communication system. A front-end receiver such as a RAKE receiver receives a radio signal formatted in a sequence of frames, and outputs a plurality of user signals. An ordering unit determines for a current frame, an order in which to decode and remove the interference contributions of the plurality of user signals. The order may be based on a list of user signals sorted in the order of descending signal-to-interference-plus-noise ratio (SINR), modified by the success or failure of attempts to decode each user signal. A frame calculator determines a coherence time, which is used to calculate the number of subsequent frames in which the user signals are decoded in the determined order. | 02-09-2012 |
20120063491 | SPREAD SPECTRUM SIGNAL RECEIVER, METHOD FOR MULTIPATH SUPER-RESOLUTION THEREOF, AND RECORDING MEDIUM THEREOF - A spread-spectrum signal receiver, a multipath signal super-resolution method thereof, and a recording medium thereof are disclosed. Using a least-squares based iterative multipath super-resolution (LIMS) algorithm, the spread-spectrum signal receiver accurately resolves multipath signals in a multipath channel environment so as to extract necessary information such that a rake receiver tracks the multipath signals more accurately. Since the LIMS technique has high resistance against noise and require less computation, it may be used to resolve the multipath signals in real time and to extract a first arrival path signal of a first arrival signal and may be easily implemented offline. | 03-15-2012 |
20120099621 | Scheduling Different Types of Receivers in a Radio Base Station - The invention relates to a method in a radio base station ( | 04-26-2012 |
20120106597 | Collaborative Data Sharing for CDMA Interference Subtraction - Implementations and techniques for collaborative data sharing for CDMA interference subtraction are generally disclosed. | 05-03-2012 |
20120201279 | Successive Interference Cancellation - Methods and systems in a wireless receiver for enabling the reception of input signals at varied power levels in the presence of co-channel interference utilizing combinations of space-time adaptive processing, interference cancellation multi-user detection, and combined techniques. In multi-user detection, code, timing, and possibly channel information of multiple users are jointly used to better detect each individual user. The novel combination of adaptive signal reconstruction techniques with interference cancellation techniques provides accurate temporal cancellation of interference with minimal interference residuals. | 08-09-2012 |
20120213252 | Systems and methods for control of receivers - A controller for advanced receivers configures a plurality of advanced receiver modules based on figures of merit computed on the input signal. The controller also selects the appropriate output signal based on figures of merit of either the input or the output signals. The controller decisions can also be made in a bursty manner, where only a subset of the decisions to be made are made at a given time, thereby limiting the processing load of the control processor. | 08-23-2012 |
20120213253 | MULTI-STANDARD COMMUNICATION - The present solution relates to a method in a communication node ( | 08-23-2012 |
20120230372 | DIGITAL IQ IMBALANCE COMPENSATION FOR DUAL-CARRIER DOUBLE CONVERSION RECEIVER - Digital IQ imbalance compensation is utilized for a dual-carrier double conversion receiver. First, the effect of IQ imbalance on OFDM-based digital baseband is analyzed, showing that, in the presence of IQ imbalance, the baseband signal of each carrier is obtained from its own branch as well as the other branch. Second, IQ imbalance parameters of interest are estimated using pilot signals and compensated using only digital baseband processing. | 09-13-2012 |
20120275491 | PROCESS FOR PROCESSING MIMO DATA STREAMS IN A 3GPP HSDPA RECEIVER, AND RECEIVER FOR DOING THE SAME - MIMO receiver for processing N data streams received by N antennas for a direct-sequence (DS) spread-spectrum wireless communication system comprising:
| 11-01-2012 |
20120275492 | METHOD AND DEVICE FOR MAINTAINING THE PERFORMANCE QUALITY OF A COMMUNICATION SYSTEM IN THE PRESENCE OF NARROW BAND INTERFERENCE - A system that incorporates teachings of the subject disclosure may include, for example, a method for analyzing a wide frequency band with respect to signal power levels in specified narrow frequency bands, detecting narrow band signal power levels received in the specified narrow frequency bands, determining an average composite wideband power level from the narrow band signal power levels, determining an adaptive threshold from the average composite wideband power level, detecting narrow band interference according to the adaptive threshold, and configuring a filter to substantially suppress the detected narrow band interference. Other embodiments are disclosed. | 11-01-2012 |
20120281733 | COMMUNICATION DEVICE, NOISE REMOVING METHOD, AND PROGRAM - A communication device according to an embodiment of the present invention includes a communication antenna that receives a transmission signal where a spectrum spread signal subjected to a spectrum spread is modulated; an intermediate frequency converting unit that converts the transmission signal received by the communication antenna into an intermediate frequency signal having a predetermined frequency; an analog to digital converting unit that discretizes the intermediate frequency signal and outputs a discretization signal; a noise removing unit that detects a noise other than a normal thermal noise included in the discretization signal and removes the detected noise from the discretization signal; and a demodulating unit that demodulates the spectrum spread signal, based on the discretization signal that is output from the noise removing unit. | 11-08-2012 |
20120307872 | METHOD AND SYSTEM FOR INTERFERENCE SUPPRESSION IN WCDMA SYSTEMS - Aspects of a method and system for interference suppression in WCDMA systems may include one or more circuits that are operable to receive a plurality of multipath signals via one or more receiving antennas. A plurality of weighting factor values may be computed based on the received multipath signals. Estimated signals may be based on the weighting factor values. Residual signals may be generated based on received signals and the estimated signals. Addback signals may be generated based on the estimated signals and the residual signals. Updated estimated signals may be generated based on the addback signals and the weighting factor values. Incremental signals may be generated based on the updated estimated signals and addback signals. Updated residual signals may be generated based on the incremental signals and previous residual signals. The interference suppressed signals may be generated based on the updated residual signals and updated estimated signals. | 12-06-2012 |
20120320952 | RECEIVER FOR PRODUCING PHASE CORRECTED SIGNALS - A method for receiving at least one of a plurality of channels in a communication signal includes receiving a spread spectrum communication signal, demodulating the spread spectrum communication signal using a rake receiver and a pseudo-noise pilot signal for a selected channel, despreading the demodulated signal of a selected channel, performing a QPSK hard decision in association with a complex conjugate of the despread signal to produce a correction signal, and mixing the correction signal to a rake receiver output to remove relative phase error without an absolute phase reference, to produce a corrected signal. | 12-20-2012 |
20120327976 | Method and Apparatus for Implementing Hybrid Rake/Equalizer Receiver for Spread Spectrum Systems - A UE of a spread spectrum wireless telecommunications system includes a network interface unit which receives multiple path energies of a wireless signal. The UE includes a rake receiver in communication with the network interface unit. The UE includes an equalizer in communication with the network interface unit, either the rake receiver or the equalizer processes the signal based on a predetermined criteria. A method of maintaining performance of a user equipment (UE) in a spread spectrum wireless telecommunications system includes the steps of receiving multiple path energies of a wireless signal at a network interface unit of the UE. There is the step of processing the signal with either a rake receiver of the UE in communication with the network interface unit or an equalizer of the UE in communication with the network interface unit based on a predetermined criteria. | 12-27-2012 |
20130003785 | Method and System for Interference Suppression Using Information From Non-Listened Base Stations - Aspects of a method and system for interference suppression using information from non-listened base stations are provided. A wireless communication device may be operable to receive a raw signal comprising one or more desired signals from one or more serving base transceiver stations (BTSs) and comprising one or more undesired signals from one or more non-listened BTSs. The wireless communication device may be operable to generate first estimate signals that estimate the one or more undesired signals as transmitted by the one or more non-listened BTSs, generate an interference suppressed version of the raw signal based on the first estimate signals, and recover the one or more desired signals from the interference suppressed version of the raw signal. The non-listened BTSs may comprise one or more BTSs that are not serving the wireless communication device and are not involved in a hand off of the wireless communication device. | 01-03-2013 |
20130034127 | Systems and Methods of Dynamic Spur Mitigation for Wireless Receivers - Example embodiments of the systems and methods of dynamic spur mitigation for wireless receivers disclosed herein comprise one or more of a detection module for detecting the presence of a spur and a determination of its frequency, a complex notch filter chain, and a frequency locked loop which ensures that the input spur is notch filtered even if it drifts after detection. When a spur is detected, the frequency of the tone is determined. The spur is then filtered, for example using a phase rotator and a DC separator. The phase rotation is removed in a subsequent stage. The non-DC component from the DC separator is used to track the spur to compensate for any shifting or drifting in the spur. | 02-07-2013 |
20130039390 | METHOD FOR GENERATING PROPAGATION CHARACTERISTICS OF A MULTIPATH ENVIRONMENT - A method, using a positioning module and a wireless telecommunication network comprises first and second base stations and first and second mobile terminals, said first terminal comprising a rake receiver, the method comprising:
| 02-14-2013 |
20130039391 | INDOOR POSITIONING WITH RAKE RECEIVERS - A method and a system for storing a constant path loss exponent corresponding to free space; transmitting a signal; receiving the signal via a rake receiver of a user device; identifying a maximum received signal strength based on a signal strength associated with the signal relative to fingers of the rake receiver; storing a current maximum received signal strength value; determining whether the current maximum received signal strength value is a first maximum received signal strength value; calculating a current indoor position of the user device based on the constant path loss exponent and the current maximum received signal strength value when a determination is that the current maximum received signal strength value is the first maximum received signal strength value; and outputting the current indoor position. | 02-14-2013 |
20130044790 | CORRELATION COPROCESSOR - Apparatus and method for providing correlation in a CDMA receiver. A Generic Correlation Coprocessor comprises one or more correlation blocks. Each correlation block comprises a correlation input buffer coupled to one or more correlators. The correlators are coupled to an interpolator input buffer and to a correlator output buffer. One or more interpolators are coupled to the interpolation input buffer and to the correlation output buffer. The correlators correlate the received signal with PN codes to produce a correlated signal. The correlated signal is stored in the correlator output buffer and/or the interpolation input buffer, and provided from the interpolation input buffer to the one or more interpolators. The one or more interpolators interpolate the correlated signal to produce an interpolated signal. The interpolated signal is stored in the correlator output buffer. Signals are provided from the correlator output buffer to other receiver processing systems. | 02-21-2013 |
20130051434 | SYSTEM AND METHOD FOR MITIGATING SEVERE MULTIPATH INTERFERENCE FOR GEOLOCATION & NAVIGATION - A system and method for mitigating multipath interference of signals in environments to determine the line of sight signal propagation. | 02-28-2013 |
20130070812 | DETECTION AND AVOIDANCE APPARATUS AND METHOD FOR USE IN UWB RECEIVER - A DAA (Detection And Avoidance) apparatus for use in a UWB receiver includes a frequency offset unit for adding a preset frequency offset to a UWB signal including a victim signal and an FFT unit for performing a fast-Fourier-transformation on the UWB signal with the frequency offset added thereto. The DAA apparatus further includes a DAA unit for detecting a victim signal from the fast-Fourier-transformed UWB signal and, when reception power of the victim signal is higher than a predetermined reference power level, changing a communication channel for the UWB signal to avoid interference. | 03-21-2013 |
20130077657 | FINGER PLACEMENT IN MULTI-STAGE INTERFERENCE CANCELLATION - In a receive node of a wireless network, an iterative multi-user multi-stage interference cancellation receiver is used. After each stage of interference cancellation, interference characteristics change. An adaptive finger placement strategy is used in which after each stage of interference cancellation, finger delays and combining weights of the receiver are adapted to reflect the changed interference characteristics. | 03-28-2013 |
20130083827 | Apparatus and method for selection of a set of cells for interference cancellation in a wireless communication system - Apparatus and methods are disclosed for generating and managing a set of sectors, the signals received from which are utilized to generate an interference estimate for use by an interference cancellation circuit. The set of sectors generally includes a subset of the combined set of sectors in the Active Set and the Candidate Set for an access terminal. A finger of a receiver at an access terminal can be assigned to each sector in the set of sectors for interference cancellation to improve receiver operations. Other aspects, embodiments, and features are also claimed and described. | 04-04-2013 |
20130128929 | Rake Receiver Circuit and Method for Operating a Rake Receiver Circuit - A method of operating a Rake receiver circuit includes determining a first property of a first signal received over a dedicated channel and over a first transmission path. The method further includes determining a delay profile of a second signal and determining, on the basis of the delay profile and the first property, if the first transmission path is to be assigned to a Rake finger of the Rake receiver circuit. | 05-23-2013 |
20130148699 | NON-REDUNDANT EQUALIZATION - Communication signal processing entails generating an overall signal correlation estimate that reflects overall impairment present in a received signal before despreading. Processing further includes parametrically constructing one or more component-specific correction terms as a function of one or more component signal correlation estimates, each estimate reflecting a particular component of the overall impairment. Combining weights are derived, as a function of this overall estimate and the correction term(s), so that they exclude the contribution of the impairment component(s) to the overall impairment. These weights are used to combine signal samples in an equalization process. As the combining weights exclude the contribution of the impairment component(s) to the overall impairment, the equalization process utilizing the weights exclusively suppresses impairment that is not attributable to the component(s). This advantageously avoids redundant suppression of the impairment component(s), since processing further includes despreading the received signal in a despreading process that suppresses the component(s). | 06-13-2013 |
20130177044 | Method and System for Achieving Space and Time Diversity Gain - Certain aspects of a method and system for achieving space and time diversity gain are disclosed. Aspects of one method may include modifying a generalization code of at least one pilot channel, to measure signal strengths for each of a plurality of received multipath signals. A portion of the plurality of received multipath signals may be combined based on the measured signal strengths. The signal strengths of the plurality of received multipath signals may be measured on a primary pilot channel by assigning its generalization code to zero. The signal strengths of the plurality of received multipath signals on a secondary pilot channel may measured by assigning its generalization code to a non-zero value. | 07-11-2013 |
20130223483 | NARROWBAND INTERFERENCE REJECTION FOR ULTRA-WIDEBAND SYSTEMS - A technique for reducing interference between a direct-sequence ultra-wideband communications system and a narrowband communications system uses interference-rejecting spreading codes to reduce signal power in a frequency band associated with the narrowband communications system. A method of operating an ultra-wideband communications system includes applying an interference-rejecting spreading code to a signal for transmission. The interference-rejecting spreading code is configured to reduce power in a particular frequency band of a transmit or receive power spectral density associated with the ultra-wideband signal without substantially reducing power outside that particular frequency band of the transmit or receive power spectral density associated with the ultra-wideband signal. | 08-29-2013 |
20130235909 | Method for Operating an Ignition Device for an Internal Combustion Engine and Ignition Device for an Internal Combustion Engine for Carrying Out the Method - A method and arrangement are disclosed for acquiring a spread spectrum signal produced by means of transmitter-end spreading of a bit sequence using a spread code signal, which provide for the reception of the spread spectrum signal; provision of a receiver-end spread code signal which corresponds to the transmitter-end spread code signal; performance of polyphase correlations for respective different code phases which give rise to polyphase correlation results which are each associated with different code phases; filtration using at least two of the code phases; determination of an extreme value in the filtered polyphase correlation results, and determination of the code phase which is associated with the extreme value. | 09-12-2013 |
20130272343 | METHOD AND APPARATUS FOR CHANNEL ESTIMATION - Methods and apparatuses for channel estimation are disclosed. The method includes: converting −1's in a local Barker code to 0's; receiving a first preamble symbol output from a first Barker correlator and a second preamble symbol output from a second Barker correlator with a symbol determination module, the first preamble symbol being adjacent to the second preamble symbol; multiplying a result output from the symbol determination module with a correlation result output from the cyclic Barker correlator by using a multiplication module so as to obtain a channel estimation response; and receiving channel estimation responses with a time-domain channel data storage unit, and averaging them to obtain a noise-reduced channel estimation response. The channel estimation method and apparatus of the present invention can be achieved based on few hardware resources and low computation complexity. | 10-17-2013 |
20130279547 | Blind Detection of Modulation Configuration for Interfering Signals - Techniques are disclosed for determining which channelization codes are used for an interfering HS-PDSCH transmission without knowing whether a neighboring UE targeted by that transmission has had its 64QAM capability activated by higher layer signaling. The average amplitude is measured for each of several possible groups of channelization codes for each of one or more nearby UEs that might be the targets of interfering HS-PDSCH messages. Testing whether the amplitude is approximately the same across the codes in a possible combination of channelization codes yields a metric value that indicates whether that particular combination of codes is likely to be transmitted to a given UE. A second metric that detects the most likely modulation for possible groups of channelization codes is also calculated. The metrics are combined to determine which combination of channelization codes and modulation scheme is most likely being used for addressing the neighboring UE. | 10-24-2013 |
20130287066 | Compensating for Receiver Frequency Error in Noise Estimation Processing - A receiver circuit provides improved noise estimation processing by at least partially removing receiver frequency error bias. An initial noise estimate is compensated using an error term based on the observed receiver frequency error, and the resulting compensated noise estimate can be used to improve other signal processing in the receiver. For example, the receiver may use compensated noise estimates to generate signal quality estimates, e.g., Signal-to-Interference (SIR) estimates, having improved accuracy. Additionally, or alternatively, the receiver may use the compensated noise estimates to generate RAKE combining weights having improved noise suppression characteristics. In an exemplary embodiment, the initial noise estimate is a noise correlation matrix generated from a received reference signal, e.g., pilot symbols, and the error term is an error matrix directly generated using the observed receiver frequency error and channel estimates taken from the reference signal. | 10-31-2013 |
20130301686 | Chip-Level Processing for Joint Demodulation in CDMA Receivers - A CDMA multi-code joint demodulation solution in which impairment suppression and channel matching operations are performed prior to despreading. Embodiments include a linear front end that performs chip-level suppression of signal components that are not included in a subsequent joint demodulation process. The pre-processing stage also carries out metric preparation and provides a vector decision statistic that is processed by a joint demodulation stage to extract per-code soft values for the symbols of interest in the received signal. Both code-specific and code-averaged versions of the linear processing are disclosed, as are several front-end configurations with equivalent performance, but different complexity trade-offs. These new approaches use a block formulation, requiring a set of input chip samples as an input, and perform all operations as matrix-vector multiplications, which is an approach amenable to efficient DSP or hardware implementation. | 11-14-2013 |
20130301687 | Symbol-Level Code-Specific Joint Detection for CDMA Receivers - Techniques are disclosed for processing a received spread spectrum signal containing multiple signals of interest and one or more interfering signals with known spreading codes. An example method begins with the generation of a despread signal vector for each signal of interest, for a given symbol time, using a corresponding group of correlators for each of the signals of interest. The method continues with the calculating of a covariance matrix for the given symbol time, the covariance matrix representing impairment correlations among the correlators from sources other than the signals of interest, as well as from inter-symbol interference in and among the signals of interest. The covariance matrix includes diagonal blocks that each represent impairment correlations among a single one of the groups of correlators; the diagonal blocks are calculated based on first terms that account in a code-specific manner for same-symbol-time interference from each of the interfering signals. | 11-14-2013 |
20130343434 | Method and System for Processing Multipath Clusters - In an RF communication system, aspects for processing multipath clusters may comprise tracking a plurality of received clusters of signals and estimating a phase and amplitude of at least a portion of each of the plurality of received clusters of signals. Each of the plurality of received clusters of signals may be specified in time and an aggregate of received signal paths in a single cluster for a single base station may be processed. At least one cluster path processor may be assigned to process the plurality of received clusters of signals from each transmitting antenna at a single base station. At least one cluster path processor may be assigned to each of a plurality of base stations that are utilized for soft handoff. | 12-26-2013 |
20140003470 | UNIFIED RECEIVER FOR MULTI-USER DETECTION | 01-02-2014 |
20140003471 | Methods for Estimation and Interference Suppression for Signal Processing | 01-02-2014 |
20140016677 | METHOD AND APPARATUS TO DYNAMICALLY SELECT UE PROCESSING CAPABILITIES BASED ON CHANNEL IMPULSE RESPONSE ESTIMATES - A method, an apparatus, and a computer program product for wireless communication are provided in connection with dynamic selection of a UE receiver. In one example, a communications device is equipped to obtain one or more channel impulse response (CIR) estimates, generate a delay spread metric value that characterizes a multipath delay spread of a channel based on the obtained one or more CIR estimates, and select a receiver option with a first power consumption value, for use by the UE, from a plurality receiver options with different optimal power consumption values, based on the generated delay spread metric value. In an aspect, a comparatively more complex receiver option may be selected when the channel is rich in multipath. In another aspect, a comparatively less complex receiver option may be selected when the channel exhibits flat fading. | 01-16-2014 |
20140016678 | COMMUNICATION DEVICE, NOISE REMOVING METHOD, AND PROGRAM - A communication device according to an embodiment of the present invention includes a communication antenna that receives a transmission signal where a spectrum spread signal subjected to a spectrum spread is modulated; an intermediate frequency converting unit that converts the transmission signal received by the communication antenna into an intermediate frequency signal having a predetermined frequency; an analog to digital converting unit that discretizes the intermediate frequency signal and outputs a discretization signal; a noise removing unit that detects a noise other than a normal thermal noise included in the discretization signal and removes the detected noise from the discretization signal; and a demodulating unit that demodulates the spectrum spread signal, based on the discretization signal that is output from the noise removing unit. | 01-16-2014 |
20140016679 | ADAPTIVE CLOCK SPREADING FOR PLATFORM RFI MITIGATION - An apparatus, system, and method, the method including receiving clock frequency parameter information for at least one clock source; receiving radio parameter information for at least one radio receiver; determining one or more spread spectrum clocking (SSC) profiles for the at least one clock source and the at least one radio receiver, each SSC profile to reduce radio frequency interference between the clock and radio receivers; and storing the SSC profiles. | 01-16-2014 |
20140016680 | MULTI-USER DETECTION USING EQUALIZATION AND SUCCESSIVE INTERFERENCE CANCELLATION - A method and apparatus for multi-user detection is disclosed. A signal is received in a shared spectrum, and samples of the received signals are produced as a received vector. The received vector is segmented into vector segments. Each segment has a portion that overlaps with another segment and the overlapping portion includes at least one chip less than twice a channel impulse response length. For each vector segment, symbols are successively determined for communications by determining symbols for a communication in the communications, ordering the communications by received power and removing a contribution of the communication from the vector segment. The determining of symbols includes equalizing an input vector corresponding to a segment of the received vector using fast Fourier transform. The determined symbols are assembled into a data vector for each communication in the communications. | 01-16-2014 |
20140029647 | SUPPRESSING INTRA-CELL INTERFERENCE - In one embodiment, intra-cell interference suppression is achieved upstream of a chip-level equalizer, thereby mitigating downstream processing resources. | 01-30-2014 |
20140029648 | SUCCESSIVE INTERFERENCE CANCELLATION METHOD AND APPARATUS AND DETECTION METHOD AND APPARATUS USING SUCCESSIVE INTERFERENCE CANCELLATION - A successive interference cancellation method includes: determining whether a current interfering user channel is a service cell channel of a service cell or a neighbor cell channel of a neighbor cell; correcting a phase rotation of a user signal of the neighbor channel when the interfering user channel is the neighbor cell channel; determining a tentative ruling for a user signal of the neighbor cell channel; restoring the phase rotation of the user signal of the neighbor cell channel; performing a signal reconstruction on the neighbor cell channel to obtain a reconstructed signal of the neighbor cell channel; removing the reconstructed signal of the neighbor cell channel from a reception signal to obtain a corrected signal, and completing successive interference cancellation on the current interfering user channel. With the above successive interference cancellation method, accuracy of successive interference cancellation as well as system detection performance is enhanced. | 01-30-2014 |
20140029649 | Advanced Multi-User Detector - A method for detecting multi-user signals including conducting a first energy burst detection detecting a first plurality of user signals as a first energy burst, attempting to decode a user signal from the first plurality of signals within the first energy burst, cancelling out a first user signal from the first energy burst if the first user signal is successfully decoded from the first energy burst, determining a second user signal to be discarded if the second user signal is not successfully decoded from the first energy burst, conducting a second energy burst detection detecting a second plurality of signals as a second burst, and iteratively cancelling out the first user signal successfully decoded from the first energy burst from the second energy burst, wherein the second energy burst detection is conducted when all user signals within the first energy burst are either cancelled out or determined to be discarded. | 01-30-2014 |
20140050252 | APPARATUS AND METHOD FOR ULTRA WIDEBAND COMMUNICATION USING DUAL BAND PASS FILTER - An apparatus and method for ultra wideband (UWB) communication, using a dual band pass filter (BPF) is disclosed. The UWB communication apparatus may include a first BPF performing a first band pass filtering with respect to a UWB signal, a second BPF that has a center frequency differing from a center frequency of the first BPF, and performs a second band pass filtering with respect to the UWB signal, a first envelope detector that detects a size of a first signal filtered in the first BPF, a second envelope detector that detects a size of a second signal filtered in the second BPF, and a demodulator that demodulates a UWB signal, using the size of the first signal and the size of the second signal. | 02-20-2014 |
20140086281 | Method and Apparatus for Optimizing Multipath Detection in a WCDMA/HSDPA Communication System - Methods and systems for processing signals in a wireless communication system are disclosed. Aspects of the method may include calculating at a receiver, a plurality of energy values corresponding to a plurality of signal paths detected within a communication channel. At least one of the plurality of detected signal paths may be selected for processing based on a pre-defined threshold and a dynamic threshold, in order to achieve a desired probability of misdetection and a desired probability of false alarm. The probability of misdetection is a probability that a real signal path is missed, and the probability of false alarm is a probability of detecting a false signal path. A slot boundary, a frame boundary, and/or a scrambling code may be determined for signals communicated via said plurality of signal paths. | 03-27-2014 |
20140098840 | Method, Apparatus and Computer Program for Controlling a Receiver - Linear symbol level equalisation is used to estimate a transmitted symbol vector x | 04-10-2014 |
20140133523 | METHOD AND SYSTEM FOR BLIND INTERFERENCE CANCELLATION IN A WIRELESS COMMUNICATION SYSTEMS - Aspects of the present invention include methods, systems, and computer-readable medium for canceling interference in wireless communication. The method includes receiving wireless CDMA communication signals using one or more antennas at least from a first entity via a first communication channel and a second entity via a second communication channel, determining a set of known characteristics associated with the first entity, the first set of characteristics comprising a first signal strength, a first synchronization information, and an first channel identification information, and determining an aggregate signal matrix based on signals received from at least the first entity and the second entity. The method further includes determining a covariance matrix associated with the aggregate signal value, determining a reference signal matrix based on the set of known characteristics, calculating an interference matrix by subtracting the reference signal matrix from the covariance matrix, and removing the interference estimation from the communication signals. | 05-15-2014 |
20140140378 | RAKE RECEIVER WITH NOISE WHITENING - Described devices and techniques provide noise whitening in a communication device. The noise whitening is performed by a noise whitening unit that receives signals on a first path associated with a first antenna and signals on a second path associated with a second antenna. The received signals may include radio signals and channel coefficient signals. The noise whitening unit may perform noise whitening of the received signals in consideration of a covariance of the interference and noise associated with the received radio signals. | 05-22-2014 |
20140146858 | PROCESSING SIGNALS IN A WIRELESS COMMUNICATIONS ENVIRONMENT - One aspect provides a method of processing a signal transmitted over a channel in a wireless communication system. In one embodiment, the method comprises receiving at a receiver the signal transmitted over the channel, estimating at intervals at least one parameter of a time varying communication environment of the system, monitoring at least one processor-related criterion of a processor at the receiver, and selecting a signal processing function from a plurality of signal processing functions implementable by the processor. The selecting of the signal processing function is based on both the at least one parameter and the at least one processor-related criterion. Each signal processing function comprises a plurality of code blocks which process the received signal. Each code block of the plurality of code blocks comprises a sequence of instructions for execution by on a processor platform of the processor. | 05-29-2014 |
20140161157 | Interference and Noise Estimation in a Multiple Input Multiple Output (MIMO) Receiver - A receiver circuit receives a signal including a first reference signal from a first antenna port that is allocated to the UE. The receiver circuit includes a descrambling and despreading unit that despreads and descrambles the signal using a spreading code of the first antenna port and a scrambling sequence assigned to the UE to generate a first antenna port signal. The descrambling and despreading unit despreads and descrambles the signal using a spreading code of a second antenna port and the scrambling sequence assigned to the UE, wherein the second antenna port is unallocated to the UE to generate a second antenna port signal. A channel estimator generates a channel estimate of the first antenna port based on the first antenna port signal. An estimation unit estimates an interference and noise covariance measure based on the first antenna port signal, the channel estimate and the second antenna port signal. | 06-12-2014 |
20140169410 | RECEPTION APPARATUS - A reception apparatus includes an intermediate frequency converter, an analog-to-digital converter, a plurality of noise removing units, and a controller. The intermediate frequency converter converts a plurality of transmission signals in different frequency bands into a plurality of intermediate frequency signals having different intermediate frequencies, the plurality of transmission signals each being obtained by demodulating a spectrum-spread spectrum spread signal. The analog-to-digital converter discretizes the plurality of intermediate frequency signals and outputs a plurality of discretization signals. The plurality of noise removing units remove a noise other than a normal thermal noise included in the plurality of discretization signals from the plurality of discretization signals. The controller detects the noise included in the plurality of discretization signals and sets assignment of the plurality of noise removing units to the plurality of discretization signals based on a detection result thereof. | 06-19-2014 |
20140169411 | Device And Method For Adaptively Suppressing In-Band Interference Signals In Radio Receivers - A circuit arrangement for adaptively suppressing interference signals includes a first local oscillator for generating a first local oscillator signal and a second local oscillator for generating a second local oscillator signal, each signal having an adjustable frequency. The circuit arrangement also includes a first mixer for converting a high-frequency signal into a corresponding intermediate frequency signal using the first local oscillator signal and a second mixer for converting the intermediate frequency signal into a corresponding baseband signal using the second local oscillator signal. The circuit arrangement also includes a notch filter with a rigidly defined blocking range. A control unit estimates the frequency of an interference signal contained in the intermediate frequency signal and to adjust the frequency of the local oscillator signals to the estimated frequency of the interference signal such that the frequency of the interference signal is converted into the blocking range of the notch filter. | 06-19-2014 |
20140177682 | METHODS AND APPARATUS FOR AMELIORATING SIGNAL RECEPTION - Methods and apparatus are disclosed for ameliorating signal reception. An example method disclosed herein includes receiving a composite satellite signal comprising a desired signal component and an interference signal component, converting the received composite satellite signal to a digital received composite signal, receiving a first group of samples from the digital received composite signal, generating an interference estimate of the interference signal component based on the first group of samples, combining the interference estimate and a second sample belonging to a second group of samples to remove, partially or entirely, the interference signal component from the composite satellite signal, the first group of samples received prior to the sample belonging to the second group of samples, wherein the removal is generally independent of the code chip rate of the desired signal component and substantially retains the undistorted chip edge characteristics of the desired signal component. | 06-26-2014 |
20140198829 | Receiver Unit and Method for Suppressing Interference in a Multipath Radio Signal - The invention relates to the field of radio signal receivers for use in wireless communication networks. In particular to a receiver unit having at least one antenna input for receiving multipath radio signals via a radio unit and at least one antenna from one or more user equipments is provided. The receiver unit comprises: a despreading unit configured to despread a multipath radio signal in the received multipath radio signals using a number of despreading fingers corresponding to a number of delay positions in the multipath radio signal which corresponds to a number of paths in the multipath radio signal, and a combining unit configured to apply at least one weight to the output of each of the number of allocated despreading fingers and combine the weighted outputs into a resulting equalized radio signal. The receiver unit is characterised in that it is configured to calculate auto-correlation values based on all multipath radio signals received at the at least one antenna input, determine at least one auto-correlation value based on the calculated auto-correlation values, determine at least one time value based on the at least one determined auto-correlation value, and allocate at least one interference suppression finger to a delay position in the multipath radio signal based on the at least one determined time value. The invention further relates to a receiver, a network node and a method for suppressing interference in a received multipath radio signal in a receiver unit. | 07-17-2014 |
20140204983 | METHOD AND SYSTEM OF RECEIVER PARAMETRIC COMPUTATION FOR MULTIPLE-INPUT MULTIPLE-OUTPUT (MIMO) TRANSMISSION - A method of calculating combining weight vectors associated with a received composite information signal comprising at least one data stream transmitted from at least a first antenna and a second antenna is disclosed. The method starts with computing a parametric estimate of an impairment covariance matrix including at least a first impairment term associated with common pilots deployed by the first antenna and the second antenna respectively. The first impairment term captures effects of interferences between the common pilots, in addition to effects of interferences caused by each common pilot singly. The impairment covariance matrix further includes a data covariance term capturing effects of the at least one data stream and an interference term caused at least partially by contribution of thermal noise of receiver branches. Then the method computes the combining weight vector using the computed impairment covariance matrix. | 07-24-2014 |
20140219321 | METHOD AND APPARATUS FOR PACKET ACQUISITION - Certain aspects of the present disclosure relate to a method for acquisition of a received spread spectrum signal transmitted over a wired or wireless medium. | 08-07-2014 |
20140219322 | INTERFERENCE SUPPRESSING OFDM SYSTEM FOR WIRELESS COMMUNICATIONS - An IS-OFDM system for point-to-point wireless communications that suppresses narrow-band interference comprises an IS-OFDM transmitter and an IS-OFDM receiver, wherein a transmitted signal comprises a plurality of subcarriers, and further wherein each subcarrier contains more than one and potentially all symbols transmitted in a given frame. The IS-OFDM transmitted signal is at a data rate that is equal to the data rate of the input data stream via the use of P/S converters. | 08-07-2014 |
20140241401 | Iterative Interference Suppressor for Wireless Multiple-Access Systems with Multiple Receive Antennas - This invention teaches to the details of an interference suppressing receiver for suppressing intra-cell and inter-cell interference in coded, multiple-access, spread spectrum transmissions that propagate through frequency selective communication channels to a multiplicity of receive antennas. The receiver is designed or adapted through the repeated use of symbol-estimate weighting, subtractive suppression with a stabilizing step-size, and mixed-decision symbol estimates. Receiver embodiments may be designed, adapted, and implemented explicitly in software or programmed hardware, or implicitly in standard RAKE-based hardware either within the RAKE (i.e., at the finger level) or outside the RAKE (i.e., at the user or subchannel symbol level). Embodiments may be employed in user equipment on the forward link or in a base station on the reverse link. It may be adapted to general signal processing applications where a signal is to be extracted from interference. | 08-28-2014 |
20140254635 | EFFICIENT FRAME TRACKING IN MOBILE RECEIVERS - A method for determining the validity of a most significant path in a wireless communication system wherein data is transmitted in frame units in a multipath environment begins by accumulating a correlated data sequence N times, each time at a frame offset apart from the previous time. A preliminary noise estimate (PNE) is calculated as an average of the accumulated data values. A preliminary noise threshold (PNT) is calculated according to the equation C | 09-11-2014 |
20140269847 | SYMBOL-LEVEL EQUALIZATION USING MULTIPLE SPREADING FACTORS - Techniques are described herein that perform symbol-level equalization using multiple spreading factors. The techniques may allow for symbol-level equalization to be performed between a serving cell and a non-serving cell(s) for WCDMA and HSDPA protocols, for example. A serving cell operates using a first spreading factor, and a non-serving cell(s) operates using a second, different spreading factor. Data communications received from the serving cell and the non-serving cell(s) may be aligned using extended channel representation(s) of the non-serving cell(s) and/or scrambling code offset(s). The aligned communications may be equalized using symbol-level equalization to obtain a joint linear minimum mean square error between the serving cell and the non-serving cell(s). | 09-18-2014 |
20140269848 | SPREAD-SPECTRUM APPARATUS FOR VOLTAGE REGULATOR - Described is an apparatus for providing spread-spectrum to a clock signal. The apparatus comprises: an oscillator to generate an output clock signal, the oscillator to receive an adjustable reference signal to adjust frequency of the output clock signal; a first circuit to provide a first signal indicative of a center frequency of the output clock signal; a second circuit to generate a switching waveform to provide spread-spectrum for the output clock signal; and a third circuit, coupled to the first and second circuits, to provide the adjustable reference signal according to the first signal and the switching waveform. | 09-18-2014 |
20140269849 | METHOD AND APPARATUS FOR COLLECTING AND PROCESSING INTERFERENCE INFORMATION - A system that incorporates the subject disclosure may perform, for example, a method for receiving interference information from each of the plurality of communication devices detecting interference information in a plurality of segments of a radio frequency spectrum, correlating the interference information of the plurality of communication devices to generate correlated information, and identifying a plurality of interferers according to the correlated information. Other embodiments are disclosed. | 09-18-2014 |
20140269850 | METHOD AND APPARATUS FOR MITIGATING SIGNAL INTERFERENCE IN A FEEDBACK SYSTEM - A system that incorporates the subject disclosure may include, for example, a process that includes adjusting a filter in electrical communication between an input terminal and a demodulator. The filter is applied to an information bearing signal, e.g., to mitigate interference, received at the input terminal, resulting in a filtered signal. An error signal is received, indicative of errors detected within information obtained by demodulation of a modulated carrier of the filtered signal. A modified filter state is determined in response to the error signal and the filter is adjusted according to the modified filter state, e.g., to improve mitigation of the interference. Other embodiments are disclosed. | 09-18-2014 |
20140314127 | INTERFERENCE CANCELLATION METHOD AND SYSTEM - Embodiments of the present invention relate to an interference cancellation method and system. The interference cancellation system of the present invention includes a centralized cancellation unit and at least two signal processing units, where at least a part of signal processing units in the at least two signal processing units are configured to detect at least a part of user signals in all user signals input into the interference cancellation system and reconstruct the detected user signals; the centralized cancellation unit is configured to perform cancellation on reconstructed signals and the user signals input into the interference cancellation system; and the at least two signal processing units are configured to detect, according to a residual signal after the cancellation, the user signals input into the interference cancellation system and output the detected signals. | 10-23-2014 |
20140341260 | Robust, Fast Unused-Code Detection - Techniques for processing a received multi-code code-division multiple-access (CDMA) signal to detect unused spreading codes are disclosed. An example method includes, for each of a plurality of observation time intervals and for each of one or more candidate spreading codes, determining a detection threshold for use in detecting whether the candidate spreading code is unused in the received multi-code CDMA signal, based on a target detection sensitivity and at least one of an estimate of received signal quality and an estimate of channel estimation quality. Estimated signal power for the candidate spreading code is compared to estimated noise and interference power corresponding to a spreading code that is known to be unused or corresponding to a spreading code that carries known symbol values, using the calculated detection threshold. Whether or not the candidate spreading code is unused is then determined, based on the comparison. | 11-20-2014 |
20140348215 | Method and Device for Determining Paths in Multipath Search - For determining paths in the scope of a multipath search, a device for use in a wireless communications system performs: obtaining a delay profile of a code division multiple access transmission signal, the delay profile being in a form of complex symbols, each complex symbols resulting from a despreading of said received signal after being delayed by a distinct delay; comparing the real part of said complex symbols forming the delay profile with a first threshold, the first threshold being determined on the basis of a noise level determined by the imaginary part of said complex symbols forming the delay profile; and determining said paths on the basis of the comparing. | 11-27-2014 |
20140355654 | Radio Receiver for Detecting an Additive White Gaussian Noise Channel - The method disclosed herein is implemented in a radio receiver to detect an AWGN channel, where the radio receiver comprises a rake receiver. The radio receiver receives signals transmitted via a propagation channel from a transmitter, and determines that the propagation channel is an AWGN channel when a filtered version of a minimum value of a metric is lower than a threshold value. The metric relates to a difference between a normalized measured power profile of the propagation channel and a normalized power template, which normalized power template is dependent on predetermined sampling timing shifts and on rake finger positions within the rake receiver. | 12-04-2014 |
20140362892 | MULTIPLE ANTENNA INTERFERENCE REJECTION IN ULTRA-WIDEBAND REAL TIME LOCATING SYSTEMS - Systems, methods, apparatuses, and computer readable media are disclosed for providing interference rejection in ultra-wideband real time locating systems. In one embodiment, an ultra-wideband (UWB) receiver is configured to: receive an interference signal from a source positioned outside a monitored region; receive a composite signal transmitted from a tagged object moving about a playing field within the monitored region, wherein the composite signal comprises a location signal and a component of the interference signal; detect whether the component of the interference signal exceeds a threshold value; and adjust, via a processor, filtering of the composite signal to attenuate the component of the interference signal based on whether the component of the interference signal exceeds the threshold value. Some embodiments provide for filtering of the composite signal using a combiner while others employ a tunable notch filter. Corresponding systems, methods, and computer-readable storage medium are also provided. | 12-11-2014 |
20140376598 | Phase Multi-Path Mitigation - A method for mitigating a multi-path-induced error in a global navigation satellite system comprises, for a respective measurement epoch, obtaining respective representations of a composite signal including a plurality of value-pairs of the composite signal. The method further comprises, with respect to the measurement epoch: obtaining a plurality of coefficients for a set of linear equations based on the plurality of value-pairs of the composite signal; iteratively obtaining solutions for the set of linear equations, thereby solving for a code tracking timing offset, a time delay of a multi-path signal of the composite signal relative to its direct-path signal, and orthogonal representations of the multi-path signal; determining a phase error between the composite signal and the direct-path signal, due to the time delay, in accordance with the orthogonal representations of the multi-path signal; and correcting for the code tracking timing offset and the phase error. | 12-25-2014 |
20150010043 | METHODS FOR MANAGING ALIGNMENT AND LATENCY IN INTERFERENCE SUPPRESSION - An interference cancelling receiver combines data from multiple paths after aligning to transmitter timing, and uses either an equalizer or a Rake receiver to compute symbol estimates. Interference estimates are generated from the symbol estimates, and multiple interference estimates are combined after re-aligning the interference estimates to receiver timing. At least two segments of symbol estimates are computed for each segment of interference cancelled data. | 01-08-2015 |
20150078420 | Amplification Circuit - An amplification circuit ( | 03-19-2015 |
20150085900 | METHOD FOR ACQUIRING A SATELLITE RADIO NAVIGATION SIGNAL AND SATELLITE RADIO NAVIGATION RECEIVER APPLYING THIS METHOD - This acquisition method is provided for acquiring a satellite signal emitted by a radio navigation satellite, the satellite signal containing a cyclic pseudo-random identification code specific to the satellite. The acquisition method includes the generation of a local code producing a replica of the identification code, and the production of a combined correlation (EDDC) of a received signal with the local code, the combined correlation corresponding to the linear combination of a first double delta correlation and of a second narrow correlation. | 03-26-2015 |
20150092821 | RECEIVE FILTERS TO MINIMIZE SIDE LOBES IN A UWB SYSTEM - Methods, systems, and devices for maximizing signal to interference plus noise ratio of a channel in a location tracking system. The methods, systems, and device may include tools and techniques for minimizing interference from adjacent samples at a receive filter, may include relaxing constraints at a transmitter. A receive filter or set of receive, or both, filters may be determined and utilized by specifying and or determining various transmitter, receiver, and channel characteristics. The receive filter and set of filters may be determined through an iterative approach involving one or more solution metrics. | 04-02-2015 |
20150139280 | ITERATIVE INTERFERENCE SUPPRESSOR FOR WIRELESS MULTIPLE-ACCESS SYSTEMS WITH MULTIPLE RECEIVE ANTENNAS - This invention teaches to the details of an interference suppressing receiver for suppressing intra-cell and inter-cell interference in coded, multiple-access, spread spectrum transmissions that propagate through frequency selective communication channels to a multiplicity of receive antennas. The receiver is designed or adapted through the repeated use of symbol-estimate weighting, subtractive suppression with a stabilizing step-size, and mixed-decision symbol estimates. Receiver embodiments may be designed, adapted, and implemented explicitly in software or programmed hardware, or implicitly in standard RAKE-based hardware either within the RAKE (i.e., at the finger level) or outside the RAKE (i.e., at the user or subchannel symbol level). Embodiments may be employed in user equipment on the forward link or in a base station on the reverse link. It may be adapted to general signal processing applications where a signal is to be extracted from interference. | 05-21-2015 |
20150303989 | SYSTEM AND METHOD FOR POSITIONING USING HYBRID SPECTRAL COMPRESSION AND CROSS CORRELATION SIGNAL PROCESSING - The present invention relates to a system and method for positioning and navigation using hybrid spectral compression and cross correlation signal processing of signals of opportunity, which may include Global Navigation Satellite System (GNSS) as well as other wideband energy emissions in GNSS obstructed environments. Examples of these signals of opportunity include but are not limited to GPS, GLONASS, cellular Code Division Multiple Access (CDMA) communications signals, and 802.11 Wi-Fi. Combining spectral compression with spread spectrum cross correlation enables extraction of code and carrier observables without the need to implement the tracking loops (e.g. Costas tracking loop) commonly used in conventional GNSS receivers. For applications where dynamics and transmission medium may make it difficult to continuously track carrier phase, the hybrid approach of the present invention has significant utility. | 10-22-2015 |
20150318883 | INTERFERENCE SUPPRESSION FOR CDMA SYSTEMS - Interference is cancelled from a baseband signal by synthesizing interference from estimated symbols in interfering subchannels. The estimated symbols are hard-coded, soft weighted, or zeroed, depending on the value of an estimated pre-processed signal-to-interference-and-noise ratio (SINR) in each subchannel in order to maximize a postprocessed SINR. The estimated pre-processed SINR is obtained from averages of estimated symbol energies and estimated noise variances, or from related statistical procedures. | 11-05-2015 |
20150341079 | INTERFERENCE SUPPRESSING OFDM SYSTEM FOR WIRELESS COMMUNICATIONS - An IS-OFDM system for point-to-point wireless communications that suppresses narrow-band interference comprises an IS-OFDM transmitter and an IS-OFDM receiver, wherein a transmitted signal comprises a plurality of subcarriers, and further wherein each subcarrier contains more than one and potentially all symbols transmitted in a given frame. The IS-OFDM transmitted signal is at a data rate that is equal to the data rate of the input data stream via the use of P/S converters. | 11-26-2015 |
20160020871 | METHODS, SYSTEMS, AND COMPUTER READABLE MEDIA FOR SIMPLIFIED COMPUTATION OF SQUARES AND SUMS OF SQUARES OF CODE CROSS-CORRELATION METRICS FOR SIGNAL PROCESSING - The subject matter described herein includes a method for simplified computation of metrics of cross-correlations of binary codes and for using the metrics for signal processing applications. The method includes computing an outer product matrix based on a first code vector. The method further includes computing an outer product matrix based on at least one second code vector. The method further includes computing a metric of cross-correlations between the first code and the at least one second code vector using the outer product matrices. The method further includes using the metric to perform a signal processing operation. | 01-21-2016 |
20160033637 | METHOD OF SECURE RF RANGING UNDER STRONG MULTIPATH REFLECTIONS - A receiver, including: a tuner receiving an input signal; a signal processor configured to process the input signal; an automatic gain control (AGC) controller configured to: initialize the receiver in a low gain state; determine the presence of a signal; and increase the receiver gain to determine if a weak signal is present prior to a strong signal. | 02-04-2016 |
20160036488 | APPARATUS AND METHOD FOR JOINTLY SELECTING THE TAP VALUES AND DELAYS OF THE FINGERS FOR A RAKE RECEIVER OF TWO CARRIERS - The present disclosure concerns receivers for use in nodes or devices that participate in wireless communications. In one exemplary embodiment, the receiver receives a first signal attributable to a first carrier and a second signal attributable to a second carrier. A first path searcher detects taps in the first signal attributable to the first carrier. A second path searcher detects taps in the second signal attributable to the second carrier. A channel tap selector selects, based on received energy values for taps detected by the first path searcher and the second path searcher, which tap values are to be used for taps of the receiver for both the first carrier and the second carrier. | 02-04-2016 |
20160043770 | ITERATIVE INTERFERENCE SUPPRESSOR FOR WIRELESS MULTIPLE-ACCESS SYSTEMS WITH MULTIPLE RECEIVE ANTENNAS - This invention teaches to the details of an interference suppressing receiver for suppressing intra-cell and inter-cell interference in coded, multiple-access, spread spectrum transmissions that propagate through frequency selective communication channels to a multiplicity of receive antennas. The receiver is designed or adapted through the repeated use of symbol-estimate weighting, subtractive suppression with a stabilizing step-size, and mixed-decision symbol estimates. Receiver embodiments may be designed, adapted, and implemented explicitly in software or programmed hardware, or implicitly in standard RAKE-based hardware either within the RAKE (i.e., at the finger level) or outside the RAKE (i.e., at the user or sub channel symbol level). Embodiments may be employed in user equipment on the forward link or in a base station on the reverse link. It may be adapted to general signal processing applications where a signal is to be extracted from interference. | 02-11-2016 |
20160065266 | RECEIVING DEVICE AND RECEIVING PROCESS METHOD - A communication processor in a receiving device includes a chip equalizer, a correction matrix calculating unit, and a correction unit. The chip equalizer equalizes a plurality of reception signal sequences received via an antenna. The correction matrix calculating unit calculates a correction matrix by using a channel matrix, a weight of an equalizer, a power ratio of a pilot signal to a reception signal, a number of multi codes, and a spreading factor of the reception signal sequences. The correction unit corrects, by using the correction matrix, the reception signal sequences equalized by the chip equalizer. | 03-03-2016 |
20160105257 | DATA RECEIVING METHOD AND APPARATUS - The present invention provides a data receiving method and apparatus. The method includes: receiving a data signal delivered by a base station, where the data signal includes at least two encoded data block groups, and each encoded data block group includes at least one encoded data block; decoding the data signal, and acquiring decoded data blocks obtained by decoding the encoded data blocks; and separately performing CRC detection on each decoded data block, and determining, according to a CRC, obtained through detection, of each decoded data block, whether to execute an SIC operation, and if it is determined to execute an SIC operation, executing CRC detection again on the decoded data block on which an SIC operation is performed, until a same CRC result occurs or all CRCs are zero. | 04-14-2016 |
20160119023 | ON CELL/FINGER ASSIGNMENT FOR REDUCED CELL DELAY SPREAD - Methods and apparatus for wireless communications are described. A method of wireless communications includes determining an energy for a first signal received at a first finger of a rake receiver after a reference signal is received at a second finger of the rake receiver, determining an energy for a second signal received at a third finger of a rake receiver before the reference signal is received at the second finger of the rake receiver, and selecting the first signal as a new reference signal when the energy of the first signal exceeds the energy of the second signal by a predefined threshold amount. In another aspect, a method includes assigning a signal received at a rake receiver to a finger of the rake receiver, and deassigning the finger if the signal has an energy level below a preselected lock threshold energy for a predefined time. | 04-28-2016 |
20160191114 | METHODS AND APPARATUSES USING FILTER BANKS FOR MULTI-CARRIER SPREAD SPECTRUM SIGNALS - A transmitter includes a synthesis filter bank to spread a data symbol to a plurality of frequencies by encoding the data symbol on each frequency, apply a common pulse-shaping filter, and apply gains to the frequencies such that a power level of each frequency is less than a noise level of other communication signals within the spectrum. Each frequency is modulated onto a different evenly spaced subcarrier. A demodulator in a receiver converts a radio frequency input to a spread-spectrum signal in a baseband. A matched filter filters the spread-spectrum signal with a common filter having characteristics matched to the synthesis filter bank in the transmitter by filtering each frequency to generate a sequence of narrow pulses. A carrier recovery unit generates control signals responsive to the sequence of narrow pulses suitable for generating a phase-locked loop between the demodulator, the matched filter, and the carrier recovery unit. | 06-30-2016 |
20160254840 | METHOD AND APPARATUS FOR MITIGATING SIGNAL INTERFERENCE IN A FEEDBACK SYSTEM | 09-01-2016 |
20160380672 | SATELLITE RADIO SIGNAL RECEIVER, ELECTRONIC TIMEPIECE, DATE AND TIME ACQUIRING METHOD AND RECORDING MEDIUM - A satellite radio signal receiver includes a receiving section which receives radio signals from satellites and demodulates the signals to identify bits of the demodulated signals as received bits; and a processor. The processor compares each received bit of the satellites with estimated bits which are estimated to be received within a possible deviation range from a current date and time acquired as a reception timing of the received bit to obtain comparison result information between the received bits and the estimated bits in relation to deviations within the possible deviation range with respect to each of the satellites, integrates the comparison result information on the received bits of the satellites, specifies a deviation that satisfies a match condition of the received bits and the estimated bits based on the integrated comparison result information, and acquires date and time information based on the deviation that satisfies the match condition. | 12-29-2016 |