Patent application number | Description | Published |
20090041109 | Compact floating point delta encoding for complex data - A method and apparatus for compression of complex data signals within a telecommunications base station. The method includes representing a sample of a complex value discrete time signal using 2(L−N)−S mantissa bits and 2N+S exponent bits to realize peak output signal to noise ratios over a wider dynamic range compared to a conventional L-bit uniform quantization format. The increases in dynamic range and peak output SNR is achieved without increasing the average number of data bits per sample and with relatively simple computational effort. | 02-12-2009 |
20090092195 | METHOD AND SYSTEM FOR ADAPTIVE PEAK TO AVERAGE POWER RATIO REDUCTION IN ORTHOGONAL FREQUENCY DIVISION MULTIPLEXING COMMUNICATION NETWORKS - A method and system adaptively reduce a peak-to-average power ratio in a communication system. Energy is clipped from at least one peak of a modulated signal. The modulated signal includes a plurality of sub-carriers. At least one data sub-carrier is adaptively selected for peak-to-average power ratio reduction use based on known scheduling information. The clipped energy is distributed among at least one data sub-carrier. | 04-09-2009 |
20100173639 | PROVIDING SPACE DIVISION MULTIPLE ACCESS IN A WIRELESS NETWORK - To provide space division multiple access in a wireless network, plural beams are transmitted within a cell segment. Different information sets are sent in the corresponding plural beams, where one or more of the information sets are detectable by a mobile station depending upon a location of the mobile station in the cell segment. An indication responsive to which of the different information sets is detected by the mobile station is received, and beam selection from among the plural beams is performed according to the received indication. | 07-08-2010 |
20100272089 | METHOD AND APPARATUS FOR PROCESSING MULTIPLE COMMON FREQUENCY SIGNALS THROUGH A SINGLE CABLE USING CIRCULATORS - A method and apparatus for processing multiple signals at a common frequency combined into a single radio frequency cable and subsequently recovering the signals without significant losses, distortion, or cross-talk. The method and apparatus includes processing multiple signals at a common frequency fed through a single radio frequency (RF) cable with or without one or more amplifiers and utilized for either forward or reverse link transmissions. The invention enables a single power amplifier to amplify multiple RF signals that occupy a common frequency channel and after amplification splitting these signals into amplified copies of the originals. The amplified signals may be sent to different antenna ports to illuminate different base station sectors if required. The signal splitting function is performed at the antenna masthead such that this method reduces the number of feeder cables running up the antenna tower by a factor of N, where N is the number of common frequency signals (e.g., the number of sectors) amplified by the single power amplifier. This invention enables a single power amplifier to simultaneously provide all the radio frequency signals necessary to feed a general N input phased array antenna system and form multiple antenna beams uniquely for several individual users simultaneously. | 10-28-2010 |
20100278288 | CHANNEL ESTIMATION METHOD AND SYSTEM FOR INTER-CARRIER INTERFERENCE-LIMITED WIRELESS COMMUNICATION NETWORK - A method and system for wireless communication channel estimation. A frequency offset hypothesis is determined. An interchannel interference (“ICI”) matrix based on the frequency offset hypothesis is generated. Pilot channel estimates based on the ICI matrix are obtained. A correlation error of the pilot channel estimates to the frequency offset hypothesis is calculated. The correlation error is compared with a predetermined correlation error value. The frequency offset hypothesis is updated and the aforementioned steps are iteratively repeated if the correlation error is greater than the predetermined correlation error value. The pilot channel estimates are used to estimate the wireless communication channel. | 11-04-2010 |
20120064848 | Low Sample Rate Peak Power Reduction - Peak power reduction in transmit chains of radiocommunication devices is performed using a low sample rate. Filtering and, optionally, interpolation of a signal being processed for peak power reduction can be performed only in an error signal path or in both an error signal path and a primary signal path. | 03-15-2012 |
20120076019 | Methods, Testing Apparatuses and Devices for Removing Cross Coupling Effects in Antenna Arrays - Methods and devices for removing cross coupling effects between elements of an antenna array ( | 03-29-2012 |
20120290633 | SPECTRUM AGILE RADIO - A spectrum agile radio having one or more variable digital filters is described. To quickly, yet accurately, retune the digital filter(s) a windowing function is applied to an ideal filter characteristic for each of one or more desired frequency bands to generate filter coefficients. Transitioning between coefficients of a previous filter and a current filter is handled to avoid problems associated with discontinuities in the signal processing. | 11-15-2012 |
20120307743 | SYMBOL FFT RACH PROCESSING METHODS AND DEVICES - Methods and devices for extracting a RACH preamble using as input a number of Fast Fourier Transformed symbols, in order to extract a random access channel (RACH) preamble from a signal received in a base station from a user device, in a radio communication system, are provided. An initial cyclic prefix (symbol CP) is removed prior to performing FFT on symbols. After (1) selecting from the FFT of a symbol frequencies corresponding to the RACH band all other non-RACH frequency bins having been set to zero, (2) shifting the signal to baseband and (3) performing a FFT on the baseband signal, a phase adjustment is performed to compensate for group delays due to symbol CP gaps occurring when generating the baseband signal, the phase adjustment being determined individually for each symbol. | 12-06-2012 |
20120320948 | MULTI-CARRIER PEAK POWER REDUCTION IN FREQUENCY HOPPING SYSTEMS - Peak power reduction in transmit chains of frequency hopping, multi-band radiocommunication devices is performed. Filtering and, optionally, interpolation of a signal being processed for peak power reduction can be performed only in an error signal path or in both an error signal path and a primary signal path. Alternatively, a sufficiently high sample rate can be used in support of error signal generation. | 12-20-2012 |
20130022152 | ROBUST ANTENNA ARRAY - A wireless communication system that includes a robust transmitter array. The robust transmitter array includes an antenna array system with at least one column, at least one antenna element, and at least one polarization, a plurality of transmitter devices to transmit analog voice/data signals through the antenna array system, and a signal processor. The signal processor modifies two or more input signals in the event of a transmitter device failure such that substantially similar amounts of each of the two or more input signals are output from the transmitter system to the antenna array system, and wherein substantially less transmitted signal power is lost than in the case wherein the signal processor does not modify the two or more input signals in the event of a transmitter failure. | 01-24-2013 |
20130027090 | MULTI-BAND PEAK POWER REDUCTION - Peak power reduction in transmit chains of multi-band radiocommunication devices is performed. By using knowledge of the phase transformations which occur at the upconverter to determine how baseband signal samples will combine at the higher (upconverted) frequency, peak prediction and corresponding baseband signal modification can be performed in a way that reduces peak power of the combined signal. | 01-31-2013 |
20130207843 | DETERMINATION OF AN IMPAIRMENT COMPENSATION MATRIX FOR AN ANTENNA ARRAY - Determination of an impairment compensation matrix for compensation of impairments in an antenna array is disclosed. A plurality of different combinations of multi-signal transmissions which form at least one null at a respective location of a plurality of locations is determined. Each combination includes a multi-signal transmission that comprises at least two concurrent signal transmissions from at least two antenna subarrays of N antenna subarrays and the respective location. Based on signal characteristics associated with the plurality of different combinations of multi-signal transmissions and an expected signal reception at the plurality of locations, an impairment matrix that identifies an effect of impairments among the N antenna subarrays is determined. The impairment compensation matrix is determined based on the impairment matrix. | 08-15-2013 |
20130315320 | Multi-Carrier/Technology Peak Power Reduction - Disclosed is a system and method for peak power reduction on a plurality of frequency domain orthogonal frequency divisional multiplexing (OFDM) signal carriers and a plurality of time domain signal carriers in a communications system. The system includes a plurality of frequency domain carrier processing blocks configured to iteratively perform frequency domain processing of at least one frequency domain OFDM signal carrier to reduce peak power transmission and a plurality of time domain carrier processing blocks configured to iteratively perform time domain processing of at least one time domain signal carrier to reduce peak power transmission, wherein the system is further configured to perform the frequency domain processing and time domain processing substantially simultaneously, thereby spreading excess peak power to one or more of the plurality of frequency domain OFDM signal carriers and to one or more of the plurality of time domain signal carriers. | 11-28-2013 |
20130329817 | METHOD AND SYSTEM FOR ADAPTIVE PEAK TO AVERAGE POWER RATIO REDUCTION IN ORTHOGONAL FREQUENCY DIVISION MULTIPLEXING COMMUNICATION NETWORKS - A method and system adaptively reduce a peak-to-average power ratio in a communication system. Energy is clipped from at least one peak of a modulated signal. The modulated signal includes a plurality of sub-carriers. At least one data sub-carrier is adaptively selected for peak-to-average power ratio reduction use based on known scheduling information. The clipped energy is distributed among at least one data sub-carrier. | 12-12-2013 |
20140133470 | ANTENNA ARRAY CALIBRATION USING TRAFFIC SIGNALS - An antenna array of a base station is calibrated using outbound traffic signals. The antenna array includes a number of sub-arrays. A combiner in the antenna array combines the outbound traffic signals in the sub-arrays into a feedback signal. The outbound traffic signals are captured simultaneously for use as reference signals before the outbound traffic signals enter transmit paths in a radio unit of the base station. Each of the reference signals is one of the outbound traffic signals that is to be transmitted via one of the sub-arrays. An impairment estimator of the base station estimates the impairment for each of the outbound traffic signals based on the feedback signal and the reference signals. An approximate inverse of the impairment estimation is applied to the outbound traffic signals by a number of equalizers before the outbound traffic signals enter the transmit paths. | 05-15-2014 |
20140133543 | Method and Apparatus For Antenna Array Calibration Using Traffic Signals - An antenna array of a base station is calibrated using outbound traffic signals. The outbound traffic signals are captured for use as reference signals before the outbound traffic signals enter transmit paths in a radio unit of the base station. The outbound traffic signals are captured for use as a feedback after the outbound traffic signals exit the transmit paths. Each of the reference signals is one of the outbound traffic signals to be transmitted. An impairment estimator estimates the impairment for each of the outbound traffic signals based on the feedback signal and the reference signals. For each transmit path, a set of weights of an all-pass filter is determined, where the all-pass filter has a frequency response that approximates the impairment estimation in an occupied frequency region where reference signal power is above a threshold. The set of weights is inversed to obtain equalizer taps for each of the transmit paths. | 05-15-2014 |
20140153666 | DISTRIBUTED DIGITALLY CONVERTIBLE RADIO (DDCR) - Embodiments of a hybrid unit that supports a configurable number of radio units for a base station in a cellular communications network and embodiments of Distributed Digitally Convertible Radio Units (DDCRUs) for use with the hybrid unit are disclosed. In one embodiment, a hybrid unit for a base station in a cellular communications network is provided. The hybrid unit includes an analog hybrid matrix. The analog hybrid matrix includes a number of feeder ports operative to connect to at least one radio unit and up to a number of radio units that are external to and separate from the hybrid unit. In one preferred embodiment, the radio unit(s) is(are) DDCRU(s). The analog hybrid matrix also includes a number of antenna ports operative to connect to at least one and up to a corresponding number of antennas of the base station. | 06-05-2014 |
20140177563 | Symbol FFT RACH Processing Methods and Devices - Methods and devices for extracting a RACH preamble using as input a number of Fast Fourier Transformed symbols, in order to extract a random access channel (RACH) preamble from a signal received in a base station from a user device, in a radio communication system, are provided. An initial cyclic prefix (symbol CP) is removed prior to performing FFT on symbols. After (1) selecting from the FFT of a symbol frequencies corresponding to the RACH band all other non-RACH frequency bins having been set to zero, (2) shifting the signal to baseband and (3) performing a FFT on the baseband signal, a phase adjustment is performed to compensate for group delays due to symbol CP gaps occurring when generating the baseband signal, the phase adjustment being determined individually for each symbol. | 06-26-2014 |