Entries |
Document | Title | Date |
20080207155 | Receiver system - A receiver system includes an antenna to receive a high-frequency signal; a first band pass filter circuit to eliminate unnecessary frequency components from the high-frequency signal; a low-noise amplifier to amplify signal output from the first band pass filter circuit; a local oscillator to produce a local oscillation signal; a mixer to mix signal output from the low-noise amplifier and the local oscillation signal to produce an intermediate signal; a second band pass filter circuit to eliminate unnecessary frequency components from the intermediate signal; an amplifier to amplify signal output from the second band pass filter circuit; a demodulator circuit to demodulate signal output from the amplifier; an analog-to-digital converter circuit to convert signal output from the demodulator into digital signal. | 08-28-2008 |
20080207156 | DETECT-AND-AVOID METHOD AND ARCHITECTURE FOR ULTRA-WIDEBAND SYSTEM - A method and system for detecting the presence of narrowband transmitters utilizing frequencies also utilized by wider band communication systems. In some embodiments an ultrawideband transceiver detects signals at specific frequencies within a spectrum of frequencies, and analyzes the signals to determine if the signals indicate transmissions by a narrowband transmitter in a narrowband communication system. In further embodiments transmission circuitry reduces signal components at frequencies occupied by the narrowband transmitters. | 08-28-2008 |
20080214137 | Receiver For Wireless Communications - An RF filtering and amplifying apparatus is proposed, comprising: a plurality of RF filters, connected with each other in a manner of cascade, for filtering the received radio signal level by level; a LNA (low noise amplifier), for amplifying the filtered signal to output an amplified and filtered signal. The RF filtering and amplifying apparatus in the present invention can not only meet the requirement for the selectivity of the filters, but also achieve desirable in-band distortion and insertion loss meanwhile. | 09-04-2008 |
20080214138 | Integrated tracking filters for direct conversion and low-IF single conversion broadband filters - A radio frequency (RF) tuner includes a programmable tracking filter bank receiving an RF input and outputting a filtered RF signal. A mixer stage receives the filtered RF signal and outputs a first quadrature component of the filtered RF signal and a second quadrature component of the filtered RF signal. Two variable gain amplifiers receive the first and second quadrature components and output amplitude-controlled I and Q components of the filtered RF signal. In one embodiment, the programmable tracking filter bank includes a plurality of tank circuits each connected to the RF input through an impedance. Each tank circuit include an inductor and a capacitor connected in parallel thereby forming an LC network, and a plurality of switched capacitors in parallel with the LC network and switched in and out of the tank circuit by programmable switches. In another embodiment, the programmable tracking filter bank includes a plurality of peaked low-pass circuits each connected to the RF input through an impedance. Each peaked low-pass circuit includes a capacitor connected to ground, and a plurality of switched capacitors in parallel with the capacitor and switched in and out of the peaked low-pass circuit by programmable switches. | 09-04-2008 |
20080220737 | NOISE SHAPED NTH ORDER FILTER - A low noise nth order filter, system, and method includes a plurality of nested general immittance converters (GICs) operatively connected to one another in successive GIC stages; and a capacitor operatively connected to each of the GICs, wherein a first successive GIC stage begins at a first node located in between a previous GIC stage and a corresponding capacitor operatively connected to the previous GIC stage. A second successive GIC stage begins at a second node located in between the first node and the first successive GIC stage. The filter may further comprise a resistor operatively connected to at least one successive GIC stage, wherein the resistor is preferably located in between the first node and the first successive GIC stage. | 09-11-2008 |
20080242252 | WIDEBAND RESISTIVE IMPUT MIXER WITH NOISE-CANCELLED IMPEDANCE - A radio frequency (RF) mixing circuit including a quadrature mixer that receives non-overlapping in-phase and quadrature local oscillator (LO) signals, and a plurality of low noise amplifiers (LNAs) operatively connected to the quadrature mixer, the plurality of LNAs presenting an input impedance at a baseband. A first voltage at an input node of the quadrature mixer is equal to a second voltage across the (noise cancelled) impedance up-converted to a frequency of a LO signal received by the quadrature mixer. The second voltage across the LNA input impedance includes a frequency of an input signal of the quadrature mixer down-converted by a frequency of the in-phase and quadrature LO signals and filtered by the (noise cancelled) impedance. The quadrature mixer down-converts an input signal by a frequency of the in-phase and quadrature LO signals and transfers the noise cancelled impedance to a RF to achieve a noise cancelled match. | 10-02-2008 |
20080299933 | FLICKER NOISE REDUCTION - Systems, devices, and methods are described for reducing flicker noise in a wireless multimode receiver. A radio frequency signal may be tuned to a frequency offset from baseband, the tuning generating flicker noise. The tuned signal and flicker noise may be digitized. The digitized signal and flicker noise may be frequency shifted, resulting in the digitized signal being shifted to baseband. The shifted flicker noise may then be filtered, producing a digitized, baseband version of the received signal. | 12-04-2008 |
20090004991 | RECEIVING APPARATUS WITH ENHANCED ISOLATION - A receiving apparatus with enhanced isolation is provided. The receiving apparatus includes a wireless detection unit, a switch connector and a receiver. The wireless detection unit includes an internal antenna and an amplifier. When the receiving apparatus is coupled to an external antenna through the switch connector, the isolation is increased through disabling the amplifier between the external antenna and the internal antenna. Therefore, the effect of co-channel interference and multi-path interference on the receiver is effectively reduced. | 01-01-2009 |
20090004992 | RADIO COMMUNICATION APPARATUS - A radio communication apparatus using a direct conversion method capable of receiving a radio signal having a predetermined frequency band. The radio communication apparatus includes: a low-noise amplifier section including one or a plurality of low-noise amplifiers receiving input of a receiving signal having a predetermined frequency band; and a mixer section including in-phase and quadrature mixers demodulating an output of the low-noise amplifier into in-phase-component and quadrature-component signals, respectively, wherein the mixer section includes a capacitor in an input section, separates the in-phase component and the quadrature component by the capacitor, and supplies the components to the corresponding in-phase and quadrature mixers, respectively. | 01-01-2009 |
20090011736 | Switching Channel Pass Receive Filter - A switchable channel-pass filter may be used on the receiver path of a multichannel radio system. The channel-pass filter may have several filter elements that may be switched in and out of the circuit to narrowly filter the incoming signal outside of the channel spectrum, which may be significantly narrower than the normal spectrum of the radio. The switchable channel-pass filter may be downstream from at least one low noise amplifier and may operate within the intermediate frequency area of the receiver path. Common applications for the switchable channel-pass filter may be IEEE 802.11 and IEEE 802.16 radio systems. | 01-08-2009 |
20090017785 | METHOD AND APPARATUS FOR SAMPLING RF SIGNALS - The invention provides a method and apparatus used in a receiver for sampling RF signals, particularly to provide a method and apparatus for greatly decrease the sampling rate performed in RF band. The invention provides an apparatus for sampling a RF signal including a plurality of interference frequency components and a useful frequency component, comprising: a filtering unit for filtering out at least one preset interference frequency component from the RF signal to generate a notch-filtered RF signal; a sampling unit for sampling the notch-filtered RF signal at a preset sampling rate to generate a discrete analog signal. The sampling unit can be implemented by a plurality of notch filters. RF sampling can be simply and conveniently implemented by using the method and apparatus according the invention, and the sampling rate can be decreased to about 1/N of the carrier frequency of the useful frequency component, which is much lower than the sampling rate in existing RF sampling scheme. The method and apparatus according the invention can greatly decrease power dissipation when sampling. | 01-15-2009 |
20090023411 | RECEIVING CIRCUIT - The present invention is a receiving circuit used for a cellular phone that is reduced in size and can realize low power consumption. In a signal reception circuit that is used in a cellular phone that perform transmission and reception of a plurality of band wireless signals and includes a low-pass filter for removing blockers unnecessary for signal reception, the low-pass filter | 01-22-2009 |
20090036086 | REDUCING SPECTRAL ROLL-OFF FACTORS TO INCREASE SPECTRAL EFFICIENCY - Systems for delivering a plurality of broadcast programs where the transmitter and receiver roll-off factors are mismatched. A system in accordance with the present invention comprises a transmitter comprising a modulator, and a plurality of receivers, each receiver in the plurality of receivers receiving the plurality of broadcast programs, each receiver in the plurality of receivers further comprising a demodulator; wherein the modulator has a first root-raised cosine filter having a first roll-off factor and each receiver has a second root-raised cosine filter having a second roll-off factor, the first roll-off factor being smaller than the second roll-off factor. | 02-05-2009 |
20090088117 | Receiver capable of reducing local oscillation leakage and in-phase/quadrature-phase (I/Q) mismatch and an adjusting method thereof - An adjusting method for reducing local oscillation leakage or I/Q mismatch in a receiver includes the steps of: (a) detecting a current extent of local oscillation leakage or I/Q mismatch; (b) determining if an adjusting direction is correct with reference to the current extent of local oscillation leakage or I/Q mismatch thus detected, maintaining the adjusting direction if correct, and reversing the adjusting direction upon determining that the adjusting direction is incorrect; and (c) adjusting a control signal according to the adjusting direction. | 04-02-2009 |
20090117869 | Digital tunning error correction for intergrated receivers and associated methods - A digital tuning error correction system for an integrated receiver and associated method are disclosed that provide an advantageous solution for combining digital signal processing (DSP) circuitry on the same integrated circuit as mixer and local oscillator (LO) generation circuitry. | 05-07-2009 |
20090149148 | SYSTEM AND METHOD FOR ADAPTIVE STIMULUS-RESPONSE SIGNAL FILTERING - A system and method for filtering a signal comprising: receiving a signal of interest; receiving a signal indicating that a stimulus has been applied; receiving the synchronized stimulus signal and signal of interest; recursively selecting a portion of the signal of interest associated with a stimulus being applied and assign the selected portion of the signal of interest to one of the plurality of buffers; combining all responses in each of said plurality of buffers; transforming the combination of all responses in each buffer to a transform space; comparing the transform components of the buffers to determine a scaling factor; applying the scaling factor to the spectral components of the buffers; performing an inverse transform on the result of combining the buffers to return to the time domain to produce a filtered signal, and outputting the filtered signal received from the processor. | 06-11-2009 |
20090156154 | Satellite-band spectrum utilization using receiver filters to reduce interference - A first and/or a second communications system may provide communications service over a geographic area. A method of operating the first and/or the second communications systems may include generating a measure of aggregate interference reaching a satellite of the second communications system substantially from devices of the first communications system. The measure of aggregate interference reaching the satellite of the second communications system may be transmitted to an element of the first communications system. | 06-18-2009 |
20090163168 | EFFICIENT INITIALIZATION OF ITERATIVE PARAMETER ESTIMATION - The invention provides a method to initialize an iterative signal estimation algorithm, such as an expectation-maximization type algorithm, the method including the step of performing a non-parametric noise reduction method. Preferably, the non-parametric noise reduction method includes performing a spectral subtraction such as a power spectral subtraction and more preferably a weighted power spectral subtraction. Method according to any of the preceding claims, wherein the iterative signal estimation algorithm includes performing an expectation-maximization algorithm. Especially, the initialization may be used for an iterative signal estimation algorithm that includes performing a prediction error Kalman filtering followed by a local variance estimation. Preferably, the iterative signal estimation algorithm includes performing a signal estimation step including a Kalman filtering, and the iterations in the iterative signal estimation algorithm are preferably performed inter-frame sequentially. The invention also provides a noise reduction method based on performing the initialization method and an iterative signal estimation algorithm thus providing a noise suppressed signal. In addition, the methods may form part of a speech enhancement for enhancing speech in a noisy signal. In addition, the invention provides a device such as a headset, a hearing aid, or a mobile phone including a processor adapted to perform the described methods. | 06-25-2009 |
20090203343 | DEVICE AND METHODS FOR ENHANCED MATCHED FILTERING BASED ON CORRENTROPY - A signal processing device is provided, the device having a signal input for receiving a signal conveyed over a channel and defining a received signal. The device further includes one or more filters for generating a signal response based upon the received signal. The signal response includes an estimated value of a correntropy statistic. Additionally, the device includes a decision module connected to at least one of the filters for probabilistically deciding whether the received signal contains an information signal component based upon the estimated value of the correntropy statistic. The device further includes a signal output to convey a signal output indicating the received signal corresponds to a known signal template if the decision module decides that the received signal contains the information signal component. | 08-13-2009 |
20090221256 | Method and Apparatus for Filtering Narrow band Interference in a Pulsed Radio Signal - Narrow band interference in a received pulsed radio signal is removed by first shifting the narrow band interference to a lower frequency using a non-linear filter, and the passing the shifted signal through a high pass filter before detecting energy in the pulsed radio signal. The pulsed radio signal can be an ultra-wideband signal, and the non-linear filter can use a Teager-Kaiser energy operator. | 09-03-2009 |
20090247107 | SIMPLIFIED INTERFERENCE SUPPRESSION IN MULTI-ANTENNA RECEIVERS - A signal received via a plurality of antennas, and containing an interference component and a desired communication component, is processed to suppress the interference component. The interference component is suppressed based on an inverse of a spatial covariance matrix, which inverse is produced without performing a matrix inversion operation. | 10-01-2009 |
20090247108 | Signal Processing Device and Method, and Signal Processing Program - Provided is a signal processing device performing filter processing operations on an input signal using a plurality of filters to generate an output signal, including a filter processing unit configured to perform a filter processing operation on the input signal using a filter and a generating unit configured to generate the output signal by adding a correction value determined on the basis of each sign and each absolute value of each difference between each of filtered output signals obtained by the filter processing operations performed using a plurality of the above mentioned filter processing units and the input signal, to the input signal. | 10-01-2009 |
20090275303 | Receiving Apparatus - A receiving apparatus | 11-05-2009 |
20090275304 | MULTIMODE RECEIVER WITH ACTIVE BLOCKER SUPPRESSION - Various embodiments of a wireless multimode receiver having an off-chip duplex filter associated with a multimode band, and a blocker cancellation circuit disposed on a semiconductor chip are described in the present disclosure. | 11-05-2009 |
20090325531 | Method and circuit arrangement for prevention of interference in an intermediate frequency signal and am receiver comprising such a method of circuit arrangement - In a method and a circuit arrangement for preventing interference pulses in the intermediate frequency signal in an AM receiver comprising a mixer, in which a high frequency signal fed to the mixer is blanked out when interference occurs, it is provided that, while the high frequency signal is blanked out, a filter provided for the intermediate frequency signal is undamped. | 12-31-2009 |
20090325532 | Systems and methods for DC component recovery in a Zero-IF radio receiver - Methods and systems for recovering a DC component in a zero-IF radio receiver are disclosed that involve receiving a frequency modulated radio frequency broadcast signal, down-converting the frequency modulated radio frequency broadcast signal directly to an original baseband frequency signal, wherein the original baseband frequency signal includes an original DC component, filtering the original baseband signal to obtain a filtered baseband signal, wherein the original DC component is removed, analyzing modulus values of the filtered baseband signal to determine an estimated quantity for the original DC component, and adding the estimated quantity for the original DC component to the filtered baseband signal to compensate for removal of the original DC component such that a reconstructed baseband signal is obtained. | 12-31-2009 |
20100048157 | RECEIVER AND METHOD FOR RECEIVING A FIRST USABLE FREQUENCY BAND AND A SECOND USABLE FREQUENCY BAND - A receiver for receiving a first usable frequency band and a second usable frequency band includes a band-pass filter device for filtering one or several receiving signals, a mixer device for converting the combination signal or the first band-pass filter signal and the second band-pass filter signal with a local oscillator signal, for obtaining a first intermediate frequency signal and a second intermediate frequency signal, and an intermediate frequency filter device for filtering the first intermediate frequency signal and the second intermediate frequency signal. Further, the receiver includes an analog/digital converter device for analog/digital converting the first filtered intermediate frequency signal and the second filtered intermediate frequency signal by using a single sampling frequency for obtaining a first digitized intermediate frequency signal and a second digitized intermediate frequency signal. | 02-25-2010 |
20100069033 | Method and Apparatus for Optimizing Signal Processing - An booster/amplifier receives a plurality of RF signals, including a subject RF signal. A location-based signal spectrum is determined by performing either a frequency scan or an information lookup operation. An initial filter bandwidth for the booster/amplifier is set based at least in part on the determined signal spectrum and a target time delay interference. In one embodiment, the initial filter bandwidth is set such that both the TDI and ACI are optimized/minimized. The initial filter bandwidth subsequently may be adjusted from its initial value based on actual measured ACI and/or TDI values. | 03-18-2010 |
20100081407 | High-Frequency Prestage and Receiver - A filter stage for use in a receiver includes a switch with an input coupled to an antenna terminal, a first output and a second output; a first filter of a first type coupled to the first output; and a second filter of a second type different from the first type, coupled to the second output. A receiver includes a filter stage as mentioned above; and a switching unit coupled to the filter stage for controlling a switching state of the switch, to selectively connect the antenna terminal to the second output, depending on a selection signal. | 04-01-2010 |
20100136940 | SYSTEM AND METHOD OF JOINT SYNCHRONIZATION AND NOISE COVARIANCE ESTIMATION - A system and method in a radio receiver for joint synchronization and noise covariance estimation of a received signal. A spatially and temporally stacked signal model, whereby successive samples of temporally adjacent received signal vectors and corresponding training vectors are stacked, is used in the derivation of the estimation problem. The Toeplitz structure of the channel response matrix is neglected in the formulation of the estimation problem. The resulting estimator jointly estimates a synchronization position, a channel response matrix, and a noise covariance matrix. An estimate of a whitened channel is then computed based on the noise covariance matrix and the estimate of the channel response matrix. | 06-03-2010 |
20100136941 | Quadratic amplitude control circuit for cosite interference cancellation - A quadratic amplitude matching system and associated method with an associated tuning control system is provided for continuously and automatically tuning a quadratic amplitude matching filter (QAMF) to a band center of an interfering signal to provide improved rejection of an interfering signal coupled from a transmission antenna into a local receive antenna in the presence of local multi-path, thereby providing improved interference cancellation system performance. The matching control system is provided as an element of an interference cancellation system. | 06-03-2010 |
20100167681 | INTERFERENCE-ROBUST RECEIVER FOR A WIRELESS COMMUNICATION SYSTEM - An interference-robust receiver includes an RF signal processor, a frequency conversion interface and an analog signal processor. The RF signal processor provides an RF signal. The frequency conversion interface includes a passive mixer for generating an intermediate frequency signal by down-converting an in-band part of the RF signal to a passband of a filter and down-converting an out-of-band part of the RF signal to a stopband of the filter. The filter can thus filter the intermediate frequency signal with the passband and the stopband. | 07-01-2010 |
20100178893 | Radio receiver and radio receiver front-end - A radio receiver front-end includes first and second RF receiver sections and an RF combining module. The first RF receiver section is coupled to receive an inbound RF signal and provide to a first representation of the inbound RF signal, wherein the inbound RF signal includes a desired signal component and an undesired signal component. The second RF receiver section is coupled to receive the inbound RF signal and to provide a second representation of the inbound RF signal. The RF combining module is coupled to combine the first and second representations of the inbound RF signal to produce a desired RF signal, wherein the desired RF signal includes the desired signal component and an attenuated representation of the undesired signal component. | 07-15-2010 |
20100233984 | INTERFERENCE CANCELLATION CIRCUIT FOR A RECEIVER - The invention discloses an interference cancellation circuit for a receiver to process an input signal which is carried on a first carrier frequency and includes a transmitted signal and at least one interference signals. The interference cancellation circuit comprises a down-converter for converting the input signal to dc location to generate a down-converted signal; a first path circuit for processing the down-converted signal to generate a first processed signal which includes the transmitted signal and the interference signals; a second path circuit for processing the down-converted signal to generate a second processed signal which includes only the interference signals; and a combiner for generating an output signal by combining the first processed signal and the second processed signal. | 09-16-2010 |
20100233985 | SYSTEMS AND METHODS FOR RECEIVING AND PROCESSING MULTIPLE CARRIER COMMUNICATIONS AND NAVIGATION SIGNALS - Methods and systems for signal analysis in multiple radio carrier environments are provided. In one embodiment, a radio receiver comprises: an adaptive pass band filter that operates over a pass band of frequencies, the adaptive pass band filter subdividing the pass band into a plurality of sub-channels each comprising a narrower bandwidth than the pass band; and a signal analyzer receiving the plurality of sub-channels, the signal analyzer providing feedback to the adaptive pass band filter, wherein the adaptive pass band filter divides the pass band into the plurality of sub-channels based on the feedback; wherein the signal analyzer selectively generates an output comprising of at least one of the plurality of sub-channels. | 09-16-2010 |
20100267354 | Frequency Translated Filter - Embodiments of a frequency translated filter (FTF) are presented. An FTF includes a passive mixer and a baseband impedance. The baseband impedance includes a network of one or more passive components (e.g., resistors, inductors, and capacitors) that form a low-Q filter. The passive mixer is configured to translate the baseband impedance to a higher frequency. The translated baseband impedance forms a high-Q filter and is presented at the input of the FTF. The FTF can be fully integrated in CMOS IC technology (or others, e.g., Bipolar, BiCMOS, and SiGe) and applied in wireless receiver systems including GSM, Wideband Code Division Multiple Access (WCDMA), Bluetooth, and wireless LANs (e.g., IEEE 802.11). | 10-21-2010 |
20100285768 | RECEIVING APPARATUS - A receiving apparatus comprising: a frequency-fluctuation-detection unit to detect a frequency difference between a received and desired signals; a first-undesired-level-detection unit to output as a first-undesired level an amplitude-level-difference between the signals having passed through first-and-second-band-pass filters in the received signals; one or a plurality of second-undesired-level-detection units to output amplitude levels of signals having passed through third-and-fourth-band-pass filters in the received signals as second-and-third-undesired levels, respectively, and output a sum of the second-and-third-undesired levels as a fourth-undesired level; and a determination unit to determine whether an undesired state, where an adjacent-undesired signal is present, occurs according to the fourth-undesired level if an absolute value of the frequency difference is equal to or greater than a predetermined-reference value, and select any one of the first-to-third-undesired levels to be outputted according to at least one of the frequency difference and the fourth-undesired level if determining that the undesired state occurs. | 11-11-2010 |
20100297975 | SIGNAL PROCESSOR AND METHOD FOR PROCESSING A RECEIVING SIGNAL - A signal processor for processing a receiving signal having a first usable frequency band and a second usable frequency band includes a first mixer for mixing the receiving signal with a first local oscillator signal, wherein a frequency of the first local oscillator signal is asymmetrical between the first usable frequency band and the second usable frequency band. The first mixer is implemented to obtain an in-phase signal and a quadrature signal, having a first signal portion representing a mixed image of the first usable frequency band, and having a second signal portion representing a mixed image of the second usable frequency band. The signal processor comprises a second mixer) for mixing the in-phase signal and the quadrature signal by using the second local oscillator signal. A frequency of the second local oscillator signal is selected such that the mixed image of the first usable frequency band and the mixed image of the second usable frequency band are at least partly image bands of each other with regard to the second local oscillator signal. The second mixer is implemented to separately provide information content of the first usable frequency band and the second usable frequency band at its output, for obtaining a first output signal, which substantially comprises information content of the first usable frequency band, and for obtaining a second output signal which substantially comprises information content of the second usable frequency band. | 11-25-2010 |
20100297976 | METHOD AND SYSTEM FOR AN INTERMEDIATE FREQUENCY (IF) CHANNEL SELECT FILTER WITH AN INTEGRATED ALTERNATE ADJACENT CHANNEL INTERFERENCE (AACI) FILTER - An alternate adjacent channel interference (AACI) filter is integrated into an intermediate frequency (IF) channel select filter to filter received RF signals. The IF channel select filter is an IF staged structure comprising successive IF stages. Each of the successive IF stages is a 2-biquad integrator. The AACI filter is integrated into the first IF stage of the IF channel select filter by re-using circuit components such as an operational amplifier, an input resistor, and a shunt capacitor of the first IF stage. The shunt capacitor is coupled between a middle point of the input resistor and ground. The AACI filter is realized via different equivalent implementations of the re-used circuit components of the first IF stage. A value of the shunt capacitor of the AACI filter becomes a fixed-value when a value the input resistor is inversely proportional to the bandwidth of the AACI filter. | 11-25-2010 |
20100297977 | FILTERING COMMUNICATIONS CHANNELS WITHIN TELECOMMUNICATIONS SATELLITES - A method is disclosed for filtering communications channels in a telecommunications satellite to remove large unwanted interfering signals, which includes monitoring channels of an uplink signal by stepping across a channel with a first analog agile filter having a narrow bandwidth in relation to the channel, and at each step monitoring the signal within the channel step, in order to determine the presence of interfering signals, and configuring a second analog agile filter having an adjustable band stop function to block the interfering signals. The uplink signal has first and second signal paths for the uplink signal, and the method includes demultiplexing the channels of the uplink signal onto separate lines in the first path, carrying out the band stop function within the second signal path, and replacing with the remaining filtered part of the channel, by a switching operation, the demultiplexed version of the channel. | 11-25-2010 |
20100311379 | Method and System for a Voltage-Controlled Oscillator with a Leaky Wave Antenna - Methods and systems for a voltage-controlled oscillator (VCO) with a leaky wave antenna are disclosed and may include transmitting wireless signals via one or more leaky wave antennas in one or more tank circuits coupled to one or more VCOs. The VCOs may be two-point modulated. Two modulating signals may be communicated to the one or more VCOs via varactors coupled to tank circuits on the one or more VCOs. The varactors may include CMOS transistors with source and drain terminals shorted together. The one or more leaky wave antennas may be integrated on the chip, on a package to which the chip is affixed, or on a printed circuit board to which the chip is affixed. The VCOs may be integrated in a phase-locked loop and an output of the one or more VCOs in the phase-locked loop may be fed back via a multi-modulus detector. | 12-09-2010 |
20100311380 | Method and System for Amplitude Modulation Utilizing a Leaky Wave Antenna - Methods and systems for amplitude modulation using a leaky wave antenna are disclosed and may include amplitude modulating an output of one or more power amplifiers in a wireless device by modulating a bias current in the power amplifiers that are coupled to one or more leaky wave antennas. The leaky wave antennas may include a balun that may be integrated on the chip, on a package to which the chip may be affixed, and/or integrated on a printed circuit board to which the chip may be affixed. An output power of the power amplifiers may be adjusted by configuring a bias voltage on the leaky wave antennas. The bias voltage may be configured utilizing a DC to DC voltage controller. The bias current may be modulated via one or more switched current sources. The switched current sources may be binary weighted and/or may be current mirrors. | 12-09-2010 |
20100311381 | RECEIVING CIRCUIT - A receiving circuit is provided for performing reception of a plurality of band signals and suppression of blockers that remain in the plurality of band signals being received and converted in frequency. The receiving circuit includes a first low-pass filter that has a first pole position to suppress blockers remaining in a received signal by the first pole position, and a second low-pass filter that has a second pole position to suppress blockers remaining in a signal that has passed through said first low-pass filter by the second pole position. A switch that switches on/off an input-output path including the filters so that the received signal passes through said first filter without passing through the second filter when receiving a first band signal, while the received signal passes through both filters when receiving a second band signal different from the first band signal. | 12-09-2010 |
20100317311 | Protection for SAW-Less Receivers - Embodiments of a SAW-less RF receiver front-end that includes a frequency translated notch filter (FTNF) are presented. An FTNF includes a passive mixer and a baseband impedance. The baseband impedance includes capacitors that form a low-Q band-stop filter. The passive mixer is configured to translate the baseband impedance to a higher frequency. The translated baseband impedance forms a high-Q notch filter and is presented at the input of the FTNF. The FTNF can be fully integrated in CMOS IC technology (or others, e.g., Bipolar, BiCMOS, and SiGe) and applied in wireless receiver systems including GSM, EDGE, Wideband Code Division Multiple Access (WCDMA), Bluetooth, and wireless LANs (e.g., IEEE 802.11). In addition, embodiments of an apparatus to protect SAW-less RF receiver front-ends are presented. | 12-16-2010 |
20100323654 | HIGH DYNAMIC RANGE RECEIVER FRONT-END WITH Q-ENHANCEMENT - A preselect circuit maintains the dynamic range of a received RF input signal during bandpass filtering of the received RF input signal. The preselect circuit includes a Q-deficient passive bandpass filter for coupling to an antenna to receive a received RF input signal. The preselect circuit further includes a Q-enhancement circuit coupled to the Q-deficient passive bandpass filter, wherein the Q-enhancement circuit increases a Q-value of the Q-deficient passive bandpass filter by compensating for resistive inductive losses in the bandpass filter. | 12-23-2010 |
20110003572 | Layout Techniques For Frequency Translated Filters - Embodiments of a SAW-less RF receiver front-end that includes a frequency translated notch filter (FTNF) are presented. An FTNF includes a passive mixer and a baseband impedance. The baseband impedance includes capacitors that form a low-Q band-stop filter. The passive mixer is configured to translate the baseband impedance to a higher frequency. The translated baseband impedance forms a high-Q notch filter and is presented at the input of the FTNF. In an embodiment, the capacitors are implemented using MOS capacitors. In another embodiment, the capacitors are partially formed from MOS capacitors and fringe capacitors. The FTNF can be fully integrated in CMOS IC technology (or others, e.g., Bipolar, BiCMOS, and SiGe) and applied in wireless receiver systems including EDGE/GSM, Wideband Code Division Multiple Access (WCDMA), Bluetooth, and wireless LANs (e.g., IEEE 802.11). | 01-06-2011 |
20110003573 | System and Method for Performing RF Filtering - A method of filtering and a RF filtering circuit comprising a LO adapted to generate in-phase and quadrature LO signals; a quadrature passive mixer operatively connected to the LO; a filtering impedance operatively connected to the quadrature passive mixer, wherein the voltage at an input node of the quadrature passive mixer comprises the voltage across the filtering impedance up-converted to a frequency of a LO signal received by the quadrature passive mixer. Preferably, the voltage across the filtering impedance comprises a frequency of an input signal of the quadrature passive mixer down-converted by a frequency of the in-phase and quadrature LO signals and filtered by the filtering impedance. | 01-06-2011 |
20110065409 | FREQUENCY SHIFTING BASED INTERFERENCE CANCELLATION DEVICE AND METHOD - An interference cancellation device comprises an input for a disturbed signal, a first frequency shifter, a bandpass filter, and a signal combiner. The first frequency shifter shifts the disturbed signal from an original frequency range to a filtering frequency range. The frequency-shifted signal is filtered by the bandpass filter. The filtered signal is supplied to the signal combiner which combines the filtered signal with the disturbed signal to substantially reduce the interference signal that is present in the disturbed signal. A method for interference signal cancellation is also proposed. Furthermore, a computer program product with instructions for the manufacture and a computer program product enabling a processor to carry out the method for interference signal cancellation are also proposed. | 03-17-2011 |
20110076978 | FILTER DEVICE FOR DETECTING AND/OR REMOVING ERRONEOUS COMPONENTS IN AND/OR FROM A SIGNAL - The invention relates to a filter device (341, 342) for detecting and/or removing erroneous components like noise, deformations, glitch components or other errors in and/or from a signal, to a demodulation device using the filter device, to an information transmission system using the demodulation device and to a method for detecting a noise impulse in an input signal (Cα(t), Cα[k]). The filter device includes a summing element (510-51N, 610) connected to a correction element (540, 640). The summing element (510-51N, 610) sums the input signal (Cα(t), Cα[k]) within a reference interval (N) and the correction element (540, 640) verifies the summed input signal (IS[k]) with at least one signal condition (0, N+1, ΔCα[k]). Finally, the correction element (540, 640) outputs a predetermined signal (Cα | 03-31-2011 |
20110098014 | DYNAMIC SPUR AVOIDANCE FOR HIGH SPEED RECEIVERS - A system and method for implementing dynamic spur avoidance in a high speed receiver environment is provided. For a plurality of radio frequency (RF) input signal ranges, a range of intermediate frequency (IF) signals and a noise floor for each IF signal is determined. An identification of spurs that will affect the noise floor is also determined from a look up table for each range of the RF inputs. A frequency plan that sets local oscillator and constituent oscillator signals is selected such that the IF signals generated from the RF input will avoid lower order spurious responses of the identified spurs within the IF signal range. | 04-28-2011 |
20110117870 | ADJACENT CHANNEL OPTIMIZED RECEIVER - The present invention offers significant improvements in the performance of a radio receiver operating in an environment with high desired band interference. The present invention comprises a high selectivity RF circuit that is located between the antenna and the radio receiver, and utilizes superheterodyne technology to filter adjacent channel interference in the desired band frequency spectrum. This type of interference is problematic for IEEE 802.11 radio receivers that are implemented with the popular direct conversion radio receiver architectures. The present invention may be utilized in many types of radio receivers. | 05-19-2011 |
20110124308 | SYSTEM AND METHOD FOR ZERO INTERMEDIATE FREQUENCY FILTERING OF INFORMATION COMMUNICATED IN WIRELESS NETWORKS - A circuit for communicating information in a wireless network includes a filtering circuit in communication with a zero intermediate frequency (ZIF) transceiver circuit. The filtering circuit includes a first mixer in communication with an output of the ZIF transceiver circuit. The filtering circuit includes a first Surface Acoustic Wave (SAW) filter circuit in communication with an output of the first mixer. The filtering circuit includes a second mixer in communication with an output of the first SAW filter circuit. The filtering circuit includes a third mixer, and a second SAW filter circuit in communication with an output of the third mixer. The filtering circuit includes a fourth mixer in communication with an output of the second SAW filter circuit and an input of the ZIF transceiver circuit. The filtering circuit also includes a local oscillator circuit in communication with the first, second, third and fourth mixers. | 05-26-2011 |
20110159834 | BROADBAND INPUT FREQUENCY ADAPTIVE TECHNIQUE FOR FILTER TUNING AND QUADRATURE GENERATION - A method for tuning a filter is provided. The amplitude of a first signal (I | 06-30-2011 |
20110171922 | SYSTEMS, METHODS, AND APPARATUSES FOR REDUCING INTERFERENCE AT THE FRONT-END OF A COMMUNICATIONS RECEIVING DEVICE - Embodiments of the invention may provide for reducing interference in the front-end of a communications receiver. The cancellation circuitry may be utilized in conjunction with a preliminary rejection filter for improved rejection of out-of-band interference from other radio services or circuitry. The cancellation circuit may be placed in parallel with the preliminary rejection filter and may enhance suppression at the interference frequency by matching the gain and phase of the preliminary rejection filter prior to subtracting the matched signal from the preliminary rejection filter output. The cancellation circuit need not necessary know beforehand the characteristics of the preliminary rejection filter, the interference source, or the coupling mechanism, as it may adapt to unknown or varying interferers by adapting the matching gain and phase values based on the output of the preliminary rejection filter at tap points occurring both before and after application of the cancellation signal. | 07-14-2011 |
20110244821 | ELECTRONIC DEVICES HAVING INTERFERERS ALIGNED WITH RECEIVER FILTERS - Electronic devices contain radio-frequency receivers such as direct conversion receivers. A receiver may receive radio-frequency antenna signals from an antenna in an electronic device. The receiver may include notch filters that attenuate signals in the center of the communications channel that is being received by the receiver. An electronic device may include a clock source. The clock source may be used to clock electrical components in the electronic device. During operation, the clock source may produce radio-frequency interference signals at an associated interferer frequency. The potential for the interference signals to disrupt operation of the receiver can be reduced by configuring the electronic device so that the interferer frequency is aligned with the center of the communications channel. The clock source may be adjusted dynamically to accommodate changes in the communications channel. | 10-06-2011 |
20110244822 | RECEIVER - A receiver | 10-06-2011 |
20110281541 | Reconfigurable Receiver Architectures - An adaptive front-end architecture for a receiver is disclosed. In one embodiment, the adaptive front-end architecture includes an input configured to receive an input signal and a linear low-noise amplifier connected to the input and configured to amplify the input signal to produce an amplified input signal. The adaptive front-end architecture further includes a first passive mixer arrangement configured to generate first a local oscillator signal and mix the first local oscillator signal with the amplified input signal to produce a first baseband output signal. The adaptive front-end architecture further includes a second passive mixer arrangement configured to generate a second local oscillator signal and mix the second local oscillator signal with the input signal to produce a second baseband output signal. The adaptive front-end architecture further includes a baseband impedance component configured to filter the first baseband signal and/or the second baseband signal using impedance translation. | 11-17-2011 |
20110312294 | AUDIO HOLE SUPPRESSION METHOD AND APPARATUS FOR A TWO-WAY RADIO - A channel scanning technique and apparatus provides audio hole suppression in two-way radio communications. Upon detecting the absence of a carrier signal on a priority channel during a priority scan mode of operation, a training waveform is constructed upon returning to the home-channel. The training waveform is applied to audio shaping filters within an audio lineup to suppress transients and minimize or eliminate the occurrence of audio pops at a speaker output thereby reducing the audio hole. | 12-22-2011 |
20110319046 | Quadratic Amplitude Control Circuit For Cosite Interference Cancellation - A quadratic amplitude matching system and associated method with an associated tuning control system is provided for continuously and automatically tuning a quadratic amplitude matching filter (QAMF) to a band center of an interfering signal to provide improved rejection of an interfering signal coupled from a transmission antenna into a local receive antenna in the presence of local multi-path, thereby providing improved interference cancellation system performance. The matching control system is provided as an element of an interference cancellation system. | 12-29-2011 |
20110319047 | OFF-LINE CHANNEL TUNING AMPLITUDE SLOPE MATCHED FILTER ARCHITECTURE - A tuning control system and associated method is provided for continuously and automatically tuning a lobed amplitude slope matching filter (ASMF) to a band center of an interfering signal to provide improved rejection of an interfering signal coupled from a transmission antenna into a local receive antenna in the presence of local multi-path, thereby providing improved interference cancellation system performance. The tuning control system is provided as an element of an interference cancellation system. | 12-29-2011 |
20120157031 | Circuits and Methods of Low-Frequency Noise Filtering - A circuit includes an input terminal for receiving a radio frequency (RF) signal and a noise mitigation circuit coupled to the input terminal. The noise mitigation circuit is configured to detect a low-frequency noise signature in the RF signal and to automatically adjust an attenuation network to filter low-frequency noise from the RF signal in response to detecting the low-frequency noise signature. | 06-21-2012 |
20120190323 | SMOOTHING FILTER FOR IRREGULAR UPDATE INTERVALS - A technique for determining a received signal strength from multiple messages filters noise from the received signal to provide an accurate signal strength value. Advantageously, the more accurate output signal strength value can be used to identify movement of a station as well as estimate locations and direction of movement. | 07-26-2012 |
20120264388 | Adaptive Interference Nulling for MIMO Receiver Based on Interference Characteristics - Interference in an unlicensed frequency band is spatially filtered out from received signals at a wireless device operating in the unlicensed frequency band. Energy received at a plurality of antennas of the wireless is device is analyzed to detect interference in the unlicensed frequency band. The detected interference is classified by type. Parameters for a nulling filter are generated or selected based on the type of interference detected in the received energy. During a time interval when it is expected to receive desired signals, the nulling filter is applied using the parameters to signals obtained from energy received at the plurality of antennas during the time interval. | 10-18-2012 |
20120264389 | METHOD OF DETECTING THE POSITION, IN A SIGNAL RECEIVED BY A DETECTOR, OF A WAVEFRONT CORRESPONDING TO AN EVENT - A method of detecting the position of a wavefront in a time-varying signal corresponding to an event is disclosed. According to one aspect, the method includes digitizing a signal received by a detector to produce a working signal, filtering the working signal N4 times with a band-pass filter to obtain N4 filtered working signals with different pass-bands, detecting a peak of the N4 filtered working signals to detect the position of a first wavefront as a function of time of occurrence. The N4 points are plotted such that an ordinate is one of the times of occurrence and an abscissa is the width of the associated band. An exponential asymptote that fits a maximum number of the N4 points is applied, and the position of the wavefront is determined as the ordinate of the point that has the maximum abscissa and substantially fits the exponential asymptote. | 10-18-2012 |
20120329419 | APPARATUS AND METHOD FOR ELIMINATING OUTBAND INTERFERENCE SIGNAL - Provided is an apparatus and method for eliminating an outband interference signal. An apparatus for eliminating an interference signal includes a first mixer, a filter unit, a second mixer, and an operation unit. The first mixer downconverts a received signal containing an outband interference signal. The filter unit extracts the downconverted outband interference signal from the downconverted received signal. The second mixer upconverts the downconverted outband interference signal to restore the outband interference signal to the original frequency band. The operation unit subtracts and eliminates the restored outband interference signal from the received signal. | 12-27-2012 |
20130040595 | Circuit For A Front-End Tunable Filter of A Communication and Broadcast Receiver and A tuning Method thereof - A circuit for a front-end tunable filter of a communication and broadcast receiver and a tuning method thereof are described herein. In one aspect, the circuit of the tunable filter may be independent of the signal reception link of the receiver. The pre-filter ( | 02-14-2013 |
20130045705 | Filtering Interference Detected at Wireless Receiver - A wireless receiver for UWB or other format receives a useful signal in a particular band of frequencies in spite of interference components. The wireless receiver has two or more different types of tunable band reject filter, involves detecting interference in the received signal, and selecting which of the different types of filter to use according to thresholds of parameters of the detected interference. The filter is then tuned according to the detected interference and the useful signal is then received with the interference suppressed using the selected BRF. As the different types of filters have different drawbacks and benefits, by having multiple types, and selecting which to use according to the detected interference, the filtering can be better matched to the detected interference, or the drawbacks can be reduced for example. | 02-21-2013 |
20130072143 | NARROWBAND INTERFERENCE CANCELLATION METHOD AND CIRCUIT - A narrowband interference (NBI) canceller is coupled to an A/D converter to receive an input signal and supply an NBI-canceled signal to an error correcting decoder. In the NBI canceller, a first arithmetic unit receives the input signal and a predicted- interference signal, and supplies a difference thereof as the interference-canceled signal. A slicer receives the interference-canceled signal and supplies a decision signal. A second arithmetic unit subtracts the decision signal from the input signal to generate a noise signal. A coarse frequency estimator receives the noise signal and analyzes the frequency spectrum to generate a coarse estimate of a fundamental frequency of the NBI. The coarse estimate is used by an adaptive narrowband interference predictor to generate the predicted-interference signal while adaptively tracking the narrowband interference. Use of the NBI canceller in a transceiver can eliminate link drop caused by operation of wireless devices that generate EMI in a cable. | 03-21-2013 |
20130084820 | Device and Method for Cascading Filters of Different Materials - Some embodiments of the invention provide a filter having at least one first filter, each first filter being a band-reject type filter having a first set of filter parameters that are a function of a first material used to fabricate the at least one first filter, and at least one second filter, each second filter having a second set of filter parameters that are a function of a second material used to fabricate the at least one second filter, each second filter being one of a band-reject type filter and a band pass type filter. The at least one first filter and the at least one second filter are then cascaded together to form the filter. The cascaded filter has a new third set of filter parameters that are a function of both the first material and the second material. | 04-04-2013 |
20130084821 | Detecting Interference in Wireless Receiver - A wireless receiver ( | 04-04-2013 |
20130090080 | FILTER ARRANGEMENT - A filter arrangement for filtering a radio signal comprising at least a first filter stage is presented wherein the at least first filter stage comprises a divide stage for dividing a filter stage input signal into several signal portions. The signal portions are filtered in at least two parallel filter elements. A combine stage combines the separate filter output signals into a single filter stage output signal. | 04-11-2013 |
20130149982 | FREQUENCY AGILE FILTER USING A DIGITAL FILTER AND BANDSTOP FILTERING - A method of providing frequency dependent signal attenuation. An RF input signal is split into a first signal portion and a second signal portion. Discrete time filtering, a negative group delay and bandstop filtering are applied to the first signal portion to provide a filtered signal portion. The second signal portion is applied to a component, and a component output signal portion is received from the component. The component output signal portion is combined with the filtered signal portion to provide an RF output signal having frequency dependent attenuation. | 06-13-2013 |
20130157606 | SYSTEM FOR RECEIVING SATELLITE SIGNALS - System for receiving satellite signals jammed by at least one source of interference and by a thermal noise comprising means for receiving the said satellite signals, means for filtering the said satellite signals, in order to remove the disruption from the said sources of interference. The system also comprises first means for determining a first covariance matrix of the satellite signals, adding means for adding respectively a first coefficient to at least one element of the diagonal of the said first covariance matrix in order to obtain a second covariance matrix, second means for determining, on the basis of the said second covariance matrix, second coefficients used by the said filtering means. The system also comprises means for detecting a first power of the said thermal noise, third means for dynamic determination of the value of the said first coefficients, on the basis of the first power. | 06-20-2013 |
20130165067 | METHOD AND APPARATUS FOR INTERFERENCE MEASUREMENT AND RESPONSE - A radio frequency front end of a receiver including a tunable filter receiving a signal; a controller for tuning the tunable filter; and an interference detection circuit configured to detect interference and provide an input to a controller, wherein the controller tunes the tunable filter based on the input from the interference detection circuit. Also a method for removing interference at a radio frequency front end of a receiver, the method detecting interference at an interference detection circuit; and tuning at least one tunable filter to at least one frequency of the detected interference. | 06-27-2013 |
20130225109 | On-Demand Signal Notching in a Receiver - Aspects of a method and system for on-demand signal notching in a receiver. In this regard, signal strength measurements of a received signal may enable detection of unwanted signal component(s) and one or more filters in an on-chip receiver may be configured in response to the measurements. The filter(s) may additionally be configured based on power consumption of the filter(s). Signal measurements and/or the corresponding configuration may be performed real-time. The filter(s) may be configured such that a notch in a frequency response of the filter(s) is centered at or near the unwanted component. In this manner, the unwanted component(s) may be filtered out. The filter(s) may be configured, for example, by switching one or more filter stages and/or components into and/or out of a signal path and/or by tuning one or more variable circuit elements within the filter(s). | 08-29-2013 |
20130273871 | RADIO RECEIVER WITH RECONFIGURABLE BASEBAND CHANNEL FILTER - A radio receiver circuit configured to receive a radio frequency signal and produce a baseband signal as an output therefrom has a channel filter having a bandwidth, the channel filter configured to receive the baseband output at a filter input and produce a filtered output at a filter output thereof. A signal-to-noise ratio (SNR) estimator prior to or after the channel filter or both is configured to estimate a signal-to-noise ratio of the baseband signal. A filter controller is configured to receive the signal-to-noise ratio estimate and control the channel filter to adjust the bandwidth thereof in accord with the signal-to-noise ratio estimate. This process thereby assists in improving SNR after the channel filtering by varying the channel filter bandwidth. This abstract is not to be considered limiting, since other embodiments may deviate from the features described in this abstract. | 10-17-2013 |
20130337761 | METHOD AND APPARATUS FOR IN-CHANNEL INTERFERENCE CANCELLATION - A communication device includes a receiver that is capable of canceling in-channel interference. The receiver includes an antenna for receiving a wireless signal comprising in-channel components and an out-of-channel component, wherein the in-channel components comprise a desired component and an in-channel interference component. A first filter of the receiver filters the wireless signal by blocking at least a portion of the out-of-channel component to produce a first signal comprising the in-channel components, and at least a second filter of the receiver filters the wireless signal by blocking at least a portion of the in-channel components to produce a second signal comprising the out-of-channel component. An in-channel interference estimator of the receiver generates an in-channel interference estimation signal based on the second signal. And a combiner of the filter combines the first signal and the second signal to at least partially cancel the in-channel interference component of the first signal. | 12-19-2013 |
20130344835 | Mobile Communication Device - Embodiments provide a mobile communication device comprising an adaptive filter for filtering a RF signal and a controller. The adaptive filter comprises a first terminal, a second terminal, a reference terminal for providing a reference potential, a first filter structure connected in series between the first terminal and the second terminal, a second filter structure connected in series between the first terminal and the reference terminal, and a third filter structure connected in series between the second terminal and the reference terminal, wherein at least one filter structure of the first, second and third filter structures comprises at least one switchable filter element. The controller is configured to selectively activate or deactivate the at least one switchable filter element based on the RF signal or a baseband version thereof. | 12-26-2013 |
20130344836 | ADJUSTABLE RECEIVE FILTER RESPONSIVE TO FREQUENCY SPECTRUM INFORMATION - An adjustable filter is responsive to a control signal to change a frequency response of the adjustable filter based on frequency spectrum information. The control signal may shift a center of the pass band from a first center frequency to a second center frequency and/or change a pass band bandwidth from a first bandwidth to a second bandwidth. In one example, the frequency spectrum information includes a status of an internal secondary radio. The frequency spectrum information may also indicate a region of operation where the frequency response is selected in accordance with the region. | 12-26-2013 |
20130344837 | ADJUSTABLE RECEIVE FILTER RESPONSIVE TO FREQUENCY SPECTRUM INFORMATION - An adjustable filter is responsive to a control signal to change a frequency response of the adjustable filter based on frequency spectrum information. The control signal may shift a center of the pass band from a first center frequency to a second center frequency and/or change a pass band bandwidth from a first bandwidth to a second bandwidth. In one example, the frequency spectrum information includes a status of an internal secondary radio. The frequency spectrum information may also indicate a region of operation where the frequency response is selected in accordance with the region. | 12-26-2013 |
20140018029 | Method of Compensating Signal Imbalance of Wireless Communication System - Filter coefficients are generated by testing a wireless communication system using single-tone signals. While using the filter coefficients in a filter module, signal imbalance caused by a local oscillator or analog elements in a wireless communication system can be eliminated, so as to prevent the wireless communication system from being affected by the noises. | 01-16-2014 |
20140024329 | FRONT END RADIO ARCHITECTURE HAVING A SPLIT BAND ARRANGEMENT WITH CO-BANDING - A front end radio architecture is configured to provide a split band frequency arrangement that includes co-banding. The disclosed split band frequency arrangement combines a medium bandwidth filter with a small bandwidth filter to provide enough bandwidth to pass a relatively large communication band. The medium bandwidth filter has a bandwidth that is large enough to support co-banding of smaller communication bands, while also having a narrow enough bandwidth to realize a relatively steep roll-off that ensures coexistence with adjacent bands that are not co-banded. The bandwidths of the medium bandwidth filter and the small bandwidth filter overlap in bandwidth by an amount that is at least as large as the highest bandwidth signal expected to be received or transmitted. The split band frequency arrangement reduces the number of filters needed in the front end radio architecture by repurposing the small bandwidth filter, and by co-banding the smaller communication bands. | 01-23-2014 |
20140051378 | WIDEBAND INTERFERENCE MITIGATION FOR DEVICES WITH MULTIPLE RECEIVERS - Certain disclosed embodiments pertain to suppressing interference in a wireless communication system. For example, a method of suppressing interference can include receiving one or more first signals including components from a plurality of sub-channels. Each of the first signals can be converted into a respective plurality of first sub-band frequency components. A respective spatial filter can be determined for each frequency sub-band using one or more corresponding first sub-band components for each respective spatial filter. One or more second signals including components from the plurality of sub-channels can be received. Each of the second signals can be converted into a respective plurality of second sub-band frequency components. A corresponding plurality of filtered sub-band components can be generated by applying the respective spatial filters to the corresponding second sub-band components for each of the second signals. | 02-20-2014 |
20140073280 | RECIPROCAL MIXING NOISE CANCELLATION SYSTEM - A system for cancellation of a reciprocal-mixing noise may comprise a down-converter mixer that may be configured to down convert a radio-frequency (RF) signal and to generate a baseband signal. The RF signal may include a desired signal and a blocker signal. A first signal path may be configured to receive the baseband signal and to generate a first signal. A second signal path may be configured to receive the baseband signal and to generate a second signal. A subtraction module may be configured to subtract the second signal from the first signal and to generate an output signal. The second signal may comprise the reciprocal-mixing noise, and the output signal may comprise the desired signal substantially free from the reciprocal-mixing noise. | 03-13-2014 |
20140073281 | HIGH DYNAMIC RANGE RECEIVER FRONT-END WITH Q-ENHANCEMENT - A preselect circuit maintains the dynamic range of a received RF input signal during bandpass filtering of the received RF input signal. The preselect circuit includes a Q-deficient passive bandpass filter for coupling to an antenna to receive a received RF input signal. The preselect circuit further includes a Q-enhancement circuit coupled to the Q-deficient passive bandpass filter, wherein the Q-enhancement circuit increases a Q-value of the Q-deficient passive bandpass filter by compensating for resistive inductive losses in the bandpass filter. | 03-13-2014 |
20140080436 | HIGH-IF SUPERHETERODYNE RECEIVER INCORPORATING HIGH-Q COMPLEX BAND PASS FILTER - A novel and useful reconfigurable superheterodyne receiver that employs a 3 | 03-20-2014 |
20140087679 | WIRELESS COMMUNICATION DEVICE, WIRELESS COMMUNICATION METHOD, AND WIRELESS COMMUNICATION PROGRAM - A wireless communication device includes a demodulation unit which demodulates a predetermined reception frequency, an S/N improvement processing unit which performs an S/N improvement process on a demodulated signal output from the demodulation unit, a first filter which performs an adaptive operation with respect to a frequency having a largest amplitude in a signal output from the S/N improvement processing unit, and outputs a filter coefficient updated by the adaptive operation, a controller which calculates the frequency of the largest amplitude defined by the filter coefficient output from the first filter, and controls the demodulation unit to update the reception frequency so as to reduce a difference between the frequency having the largest amplitude and a predetermined frequency, and a second filter which limits a range of a frequency bandwidth of the demodulated signal based on the frequency having the largest amplitude. | 03-27-2014 |
20140106697 | INTERFERENCE WAVE SIGNAL REMOVING DEVICE, GNSS RECEPTION APPARATUS, MOBILE TERMINAL, INTERFERENCE WAVE SIGNAL REMOVING PROGRAM AND INTERFERENCE WAVE REMOVING METHOD - An interference wave signal removing device that can surely remove an interference wave signal is provided. An interference wave signal remover includes a controller, a notch filter, an entire-range frequency scanner, and a local frequency scanner. The controller detects the interference wave signal based on a frequency scanning result by the entire-range frequency scanner, and sets the notch filter to attenuate the interference wave signal frequency. Based on input signals to the notch filter, the local frequency scanner frequency-scans in a local frequency band including an attenuation band of the notch filter. The controller detects a frequency drift of the interference wave signal frequency based on the frequency scanning result by the local frequency scanner, and updates the setting of the notch filter to attenuate the interference wave signal frequency after the frequency drift. | 04-17-2014 |
20140106698 | VARIABLE BAND PASS FILTER DEVICE - A variable filter device has: a first series arm which is serially connected to a signal line, includes a variable capacitance and an inductance, and constitutes a series resonator; first and second parallel arms, which are connected between the signal line and the ground on both sides of the first series arm, each of which includes a variable capacitance and an inductance, and constitutes a grounded series resonator. The first series arm defines the center frequency of the pass band, and the first and second parallel arms define attenuation poles sandwiching the pass band. | 04-17-2014 |
20140113580 | SPLITTER - In a splitter, a first band pass filter is connected between an antenna terminal and a first terminal, a high pass filter and a second band pass filter are connected between the antenna terminal and a second terminal, a pass band of the second band pass filter is higher than a pass band of the first band pass filter, a cut off frequency of the high pass filter is located closer to the high-frequency side than the pass band of the first band pass filter, the pass band of the second band pass filter is located closer to the high-frequency side than the cut off frequency, and the high pass filter also functions as a notch filter having an anti-resonant frequency in a transition region such that the steepness of the transition region between the pass band of the second band pass filter and the attenuated band is high. | 04-24-2014 |
20140120857 | MAGNITUDE AND PHASE RESPONSE CALIBRATION OF RECEIVERS - An integrated calibrator provides for magnitude and phase response calibration of RF receivers to produce amplitude flatness and phase linearity across the frequency range of the RF receiver by using a simple square law diode detector and a frequency-stepped two-tone source. A two-tone source generator provides two sinusoidal signals separated by a specified frequency delta about a center frequency. The center frequency is stepped across the bandwidth of the RF receiver. At each center frequency the two sinusoidal signals are input to the RF receiver and to the diode detector. The two sinusoidal signals are processed by both the receiver path and the calibrator path, and the results are used by the calibrator to generate coefficients for a correction filter in the receiver path at each of the stepped center frequencies. | 05-01-2014 |
20140120858 | Cyclic Redundancy Check Circuit And Semiconductor Device Having The Cyclic Redundancy Check Circuit - An object of the present invention is to provide a CRC circuit with more simple structure and low power consumption. The CRC circuit includes a first shift register to a p-th shift register, a first EXOR to a (p−1)th EXOR, and a switching circuit. A data signal, a select signal, and an output of a last stage of the p-th shift register are inputted to the switching circuit, and the switching circuit switches a first signal or a second signal in response to the select signal to be outputted. | 05-01-2014 |
20140187188 | FILTER HAVING SIGNAL DETECTION FUNCTION - A filter includes a base and a sidewall extending from the base. The base and the sidewall cooperatively define a cavity. The filter further includes a signal input unit, and a signal output unit having a signal output port. The signal output port is located on the sidewall and extends outside of the cavity. The signal output port is connected to a conductive post received within the cavity. The conductive post collects radio signals and outputs the collected radio signals via the signal output port. The signal output unit further includes a signal detection module. The signal detection module includes a coupling plate, a coupling signal output terminal, and a probe. The coupling plate is electrically connected to the probe. The probe is located adjacent to the conductive post to receive radio signals surrounding the conductive post and output the received radio signals via the coupling output terminal. | 07-03-2014 |
20140199956 | TUNABLE FILTER DEVICES AND METHODS - Analog interference filter devices and methods for isolation of desirable portions of a radio frequency signal. Signal compensation is used to provide desirable center frequency, passband width, ripple, rolloff, stopband and distortion performance. The filter is implemented with passive and/or active components. | 07-17-2014 |
20140242936 | Multichannel Radio Receiver with Overlapping Channel Filters - A radio may define a channel plan to include one or more channels, and each channel may include a plurality of overlapping filters. Each filter may overlap at least one other filter, such as by an expected bandwidth of an incoming signal. The overlapping filters may extend over a frequency range based in part on an expected frequency error of the incoming signal. Due in part to the overlapping nature of the filters, the incoming signal will be within at least one of the filters. Since only one of the filters must receive the incoming signal, the filters may be narrower than might otherwise be the case, particularly in an application that includes frequency error. Accordingly, the filters may be narrower than their respective channels, and therefore receive less noise and interference. This improves signal-to-noise and improves the quality of the link and range. | 08-28-2014 |
20140273907 | METHOD AND APPARATUS FOR CONFIGURING A FREQUENCY DEPENDENT I/Q IMBALANCE COMPENSATION FILTER - A method of configuring at least one frequency dependent (FD), in-phase/quadrature (I/Q), imbalance compensation filter within a radio frequency (RF) module is described. The method includes applying an input signal to an input of the RF module, receiving a filtered I-path signal for the RF module and deriving at least one I-path filtering estimate value therefrom, receiving a filtered Q-path signal for the RF module and deriving at least one Q-path filtering estimate value therefrom, and configuring the at least one FD I/Q imbalance compensation filter based at least partly on at least one ratio between the derived I-path and Q-path filtering estimate values. | 09-18-2014 |
20140302809 | DETECTION AND MITIGATION OF INTERFERENCE BASED ON INTERFERENCE LOCATION - Embodiments include a novel receiver architecture to optimize receiver performance in the presence of interference. In various embodiments, the presence of interference is detected, and the relative frequency location of the interference is detected. The relative frequency location specifies whether the frequency of the interference is high side (above the desired signal, i.e., at a higher frequency) or low side (below the desired signal). The receiver is configured based on the detected interference and relative location thereof. For a device such as a cellular phone that operates in a dynamic and changing environment where interference is variable, embodiments advantageously provide the capability to modify the receiver's operational state depending on the interference. | 10-09-2014 |
20140315509 | WIRELESS COMMUNICATION DEVICE - A wireless communication device includes a base board, a metal zone, and a filter. The metal zone and the filter are disposed on the base board. The metal zone defines a slot. The filter is connected to the slot to divide the slot into a first slot section and a second slot section. When a current having a first frequency flows through the first slot section and the second slot section, the filter is in an open circuit state, and the first slot section and the second slot section are activated to receive/transmit wireless signals having a first central frequency. When a current having a second frequency only flows through the first slot section, the filter is in a closed circuit state, and the first slot section is activated to receive/transmit wireless signals having a second central frequency. | 10-23-2014 |
20140323076 | WIDEBAND TUNABLE NOTCH CANCELLATION - A system and method for wideband tunable notch cancellation that is passive and does not require feedback or feed forward circuitry. An input spectrum containing interference is split into two signals that are 180 degrees out of phase with each other. The preferred signal is filtered out of the 180 degree out of phase signal using a notch filter while the original signal is sent through a delay line. Then the two signals are summed with a power summer so that the interference signals that are 180 degrees out of phase with those in the original signal are cancelled out and the preferred signal remains. The notch filter is tunable to different preferred signals. | 10-30-2014 |
20140335811 | METHOD, SYSTEM AND APPARATUS FOR FILTERING A SIGNAL WITH REDUCED DELAY - Undesired variations in a signal are removed by initializing two boundaries comprising an upper boundary and a lower boundary to track the signal level. At least one of the upper boundary and the lower boundary is adjusted encapsulate/track the received signal between the two boundaries when the signal level is outside of the two boundaries. A value computed with reference to at least one of the boundaries is provided as a filter output. As a result, the output comprises desired variations that cross the boundaries and the undesired variations that are within the boundaries are eliminated. In one embodiment, an altimeter sensor signal is filtered such that the undesired variations due to noise and instability of the altimeter are removed and the desired variations representing the change in the altitude are detected and provided without any delay to the navigation subsystem. | 11-13-2014 |
20140335812 | RADIO RECEPTION DEVICE AND RADIO RECEPTION METHOD IN RADIO COMMUNICATION SYSTEM - A radio reception device and a radio receiving method are provided that, when a frequency band assigned to a different radio system is shared, can effectively suppress the influence of interfering waves from this different radio system. A radio reception device is one in a second radio system ( | 11-13-2014 |
20140364078 | 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 a composite signal, the composite signal comprising a UWB signal transmitted from within a monitored region and an interference signal transmitted from a source positioned outside the monitored region; filtering at least a first component of the composite signal representing the interference signal with a tunable notch filter to generate a filtered signal; determining an interference level in the filtered signal; and adjust the tunable notch filter to reduce the interference level. Corresponding systems, methods, and computer-readable storage medium are also provided. | 12-11-2014 |
20150017942 | SYSTEM AND METHOD FOR COMMUNICATION - A communication system includes an omnidirectional antenna to receive a wideband primary signal, a nulling antenna to receive a secondary signal and a controller. The nulling antenna is oriented to place a null in a direction of a desired communication signal and the controller subtracts a processed secondary signal from a processed wideband primary signal to produce a jamming cancelled signal. | 01-15-2015 |
20150044981 | Multi-Notch Filter and Method for Multi-Notch Filtering - A system and method for multi-notch filtering for a communication device are provided. The system includes an input node to receive a signal directed to the communication device; a time delay element to delay the signal by a predetermined time delay; a summation element to sum the signal and the time-delayed signal; and a gain element to output the summed signal to the communication device. | 02-12-2015 |
20150072635 | CIRCUIT AND METHOD FOR FILTERING ADJACENT CHANNEL INTERFERERS - A circuit and method for filtering adjacent channel interferers. One embodiment of an adjacent channel filtering circuit for reducing adjacent channel interference with an in-band signal, includes: (1) a radio frequency (RF) circuit configured to receive and down-convert an RF signal to a baseband signal containing an in-band signal and adjacent channel components, (2) a controlled single pole filter electrically coupled to the RF circuit and configured to reject the adjacent channel components and cause a predetermined attenuation in the in-band signal, (3) a baseband circuit coupled to the controlled single pole filter and configured to condition the baseband signal for conversion to a digital signal, and (4) a digital circuit coupled to the baseband circuit and configured to receive the digital signal and compensate for the predetermined attenuation. | 03-12-2015 |
20150094009 | BRANCH CIRCUIT AND BRANCH CABLE - A branch circuit includes a common antenna port and separates a first communication signal including a signal in a low band and a signal in a high band and a second communication signal that is a signal in a frequency band between the low band and the high band. The branch circuit includes a first-communication-signal-line-side band elimination filter and a second-communication-signal-line-side band elimination filter and SAW filter. | 04-02-2015 |
20150133069 | FM RECEIVER WITH FREQUENCY DEVIATION-DEPENDENT ADAPTIVE CHANNEL FILTER - Methods, systems, and devices are described for wireless communications in a frequency modulation (FM) receiver with a frequency deviation-dependent adaptive channel filter. A maximum frequency deviation of an FM broadcast signal may be estimated. One or more coefficients of a channel filter may be adapted based at least in part on the maximum frequency deviation. The coefficient adaptation may include identifying a set of coefficients corresponding to the maximum frequency deviation and applying the set of coefficients to the channel filter. The set of coefficients may be identified by selecting one of multiple sets of coefficients stored in memory. In some instances, a signal quality metric (e.g., signal-to-noise ratio (SNR)) may be identified and may be used to modify a value of one or more of the set of coefficients applied to the channel filter. | 05-14-2015 |
20150295606 | Method and system for filtering out adjacent frequency band interference - Provided are a method and a system for filtering out adjacent frequency band interference. The method includes that an RF MEMS switch control module receives a first transmitted coupling signal from a first frequency band RF module and a second received coupling signal from a second frequency band RF module; the RF MEMS switch control module determines whether interference exists between a first frequency band and a second frequency band according to the first transmitted coupling signal and the second received coupling signal; if interference exists, the RF MEMS switch control module filters out the interference by instructing a first frequency band RF MEMS radio frequency reconfigurable antenna working in the first frequency band to change a first antenna structure and/or by instructing a second frequency band RF MEMS radio frequency reconfigurable antenna working in the second frequency band to change a second antenna structure. By means of the disclosure, adjacent frequency bands can co-exist on hardware and mutual interference is effectively avoided. | 10-15-2015 |
20150349820 | Detection and Mitigation of Interference Based on Interference Location - Embodiments include a novel receiver architecture to optimize receiver performance in the presence of interference. In various embodiments, the presence of interference is detected, and the relative frequency location of the interference is detected. The relative frequency location specifies whether the frequency of the interference is high side (above the desired signal, i.e., at a higher frequency) or low side (below the desired signal). The receiver is configured based on the detected interference and relative location thereof. For a device such as a cellular phone that operates in a dynamic and changing environment where interference is variable, embodiments advantageously provide the capability to modify the receiver's operational state depending on the interference. | 12-03-2015 |
20150349821 | FEEDBACK RECEIVE PATH WITH RF FILTER - An apparatus includes an elliptical inductance-capacitance (LC) filter and a resistive-capacitive (RC) notch filter serially coupled to the elliptical LC filter. The elliptical LC filter and the RC notch filter are configured to filter a radio-frequency (RF) signal received by a feedback receive path. | 12-03-2015 |
20160020793 | REJECTION OF RF INTERFERERS AND NOISE IN A WIRELESS COMMUNICATIONS TRANSCEIVER - The invention provides a radio receiver or transceiver having one or more low noise amplifiers corresponding to one or more antenna inputs wherein one or more outputs of the one or more low noise amplifiers is/are combined at a single output current summing node, a tunable, shunt notch filter is coupled or connected to the summed output node that allows for the attenuation of a Tx blocker or interferer, an external blocker or interferer or an internal on-chip interferer. | 01-21-2016 |
20160028424 | RF Receiver - An RF receiver comprising: an RF signal processing unit for receiving an RF signal, wherein the RF signal processing unit comprises a dynamically reconfigurable RF filter for filtering the RF signal; an analog-to-digital converter for converting the filtered RF signal to a digital signal; and a digital signal processing unit for processing the digital signal to provide at least one channel; wherein the digital signal processing unit is adapted to adjust a respective transfer function of at least one said channel when the RF filter is reconfigured, to at least partially compensate a change in the transfer function of the RF filter. | 01-28-2016 |
20160087659 | METHODS, SYSTEMS, AND NON-TRANSITORY COMPUTER READABLE MEDIA FOR WIDEBAND FREQUENCY AND BANDWIDTH TUNABLE FILTERING - Methods, systems, and computer readable media for wideband frequency and bandwidth tunable filtering are disclosed. According to one aspect, the subject matter described herein includes a wideband frequency and bandwidth tunable filter that splits a filter input signal into first and second input signals, modifies the first input signal to produce a first output signal, modifies the second input signal to produce a second output signal having an intermediate frequency response, and combines the first and second output signals while adjusting their relative phases and/or amplitudes to produce a filter output signal with the target frequency response. Adjustment includes splitting the second input signal into third and fourth input signals, which are modified and then combined to produce the second output signal having the intermediate frequency response. | 03-24-2016 |
20160142229 | PROCESSING INTERFERENCE IN A WIRELESS NETWORK - Interference is processed in a waveform received at a device in a wireless network, the received interference comprising non-linear products of at least a first signal (C | 05-19-2016 |
20160164557 | Method and Apparatus Relating to Reception of Radio Signals - Method and multi carrier receiver for removing interference from a RF-signal. In a multi carrier receiver with a heterodyne receiver structure, the RF-signal is received from a multi carrier transmitting entity. The RF-signal comprises a data part an interference part. The interference part is detected by means of the interference unit, and a frequency and a power level of the interference part is determined. A frequency of a first LO is adjusted, such that an output signal of a first mixer is frequency shifted towards an upper edge or a lower edge of a first IF bandpass filter when the determined power level exceeds a predetermined threshold. By detecting an interference part of an incoming RF-signal and controlling a local oscillator based on the detected interference, an effective and flexible solution is achieved for removing interference from the RF-signal. | 06-09-2016 |
20160191092 | LOW NOISE AMPLIFIER MODULE AND METHOD OF IMPLEMENTATION - A high performance switch module to filter a radio frequency signal and to selectively connect to an output includes a filter unit and a plurality of switches. The filter unit has a filter configured to connect to the radio frequency signal and having a plurality of parallel output ports. The plurality of switches is connected between the plurality of parallel output ports and the output, the plurality of switches configured to connect to a control input to selectively connect an output port of the plurality of parallel output ports to the output and to selectively connect a remainder of the plurality of parallel output ports to a connection providing a substantially full reflection to the remainder of the plurality of parallel output ports of the filter unit. | 06-30-2016 |
20160254830 | Wideband Beamformer System | 09-01-2016 |