Icera, Inc.

Nvidia Corporation

Nvidia Technology UK Limited

Steve Allpress

Carlo Luschi

Philip Jones

Simon Nicholas Walker

Simon Huckett

Stephen Felix

Tarik Tabet

Abdelkader Medles

Steve Felix

Colman Hegarty

Donal Price

Laolu Lijofi

Jonathan Peter Lucas

Dinkar Vasudevan

Robert Buckley

Edward Charles John Andrews

Simon Walker

One aspect provides a method of processing a signal transmitted over a channel in a wireless communication system. In one embodiment, the method comprises receiving at a receiver the signal transmitted over the channel, estimating at intervals at least one parameter of a time varying communication environment of the system, monitoring at least one processor-related criterion of a processor at the receiver, and selecting a signal processing function from a plurality of signal processing functions implementable by the processor. The selecting of the signal processing function is based on both the at least one parameter and the at least one processor-related criterion. Each signal processing function comprises a plurality of code blocks which process the received signal. Each code block of the plurality of code blocks comprises a sequence of instructions for execution by on a processor platform of the processor.

Processing signals in a wireless communications environment

Wireless receivers are described for receiving signals from a transmitter. A receiver can include a plurality of antennas each for receiving a version of a signal via a different propagation channel and providing that version to a respective input. Signal processing means can be included and configured to operate diversity processing of a supplied number of said inputs for use in performing detection of said signal. The receiver can include channel parameter estimation means, configured to estimate one or more channel parameters on the propagation channels. The receiver can also include selection means configured to select only a subset of said inputs to implement a specific dimensionality of the receiver diversity processing, in dependence on the one or more channel parameters indicative of channel conditions on said propagation channels. The diversity processing can be linear or non-linear. Related methods and software implementations and computer program products are also described.

Wireless receiver with receive diversity

A method of processing digital samples of a signal received at a receiver of a wireless communication system includes monitoring channel conditions and generating a channel indicator including at least one channel parameter by performing at least one of: estimating a channel mobility parameter and comparing it with a threshold; estimating a channel parameter of the energy of the channel outside a predefined temporal window, and comparing it with a threshold; estimating a channel temporal duration parameter and establishing if it meets predetermined criteria; estimating a channel-zero location parameter and establishing if it meets predetermined criteria; estimating a received-signal signal-to-disturbance power ratio, and comparing it to a threshold; estimating an estimated-channel-response signal-to-disturbance power ratio; estimating the degree of non-stationarity of the disturbance at the receiver input; and selecting one of a plurality of processing routines for processing the digital samples based on said channel indicator. Related receivers are also described.

Processing digital samples in a wireless receiver

Techniques are described for optimizing the processing facilities of a receiver in a wireless communication environment, taking into account processing performance set against the computing resources and/or power consumption required to obtain that processing performance. A radio receiver for a wireless communications system can include channel equalization means arranged to receive samples of an incoming signal and to generate an equalized output, said channel equalization means including means for processing said digital samples in accordance with an equalizer algorithm. The receiver includes means for estimating parameters of a channel over which the incoming signal has been transmitted. The receiver can also include means for selecting from a plurality of equalizer algorithms an equalizer algorithm for execution by the processing means based on at least one said estimated channel parameter. Related methods and algorithms are described. Related computer program products are also described.

Radio receiver in a wireless communications system

Method, receiver and computer program product for decoding a coded data block received at the receiver are disclosed. A first plurality of coded data bits representing the coded data block are received. First soft information values are determined corresponding to respective ones of the received first plurality of coded data bits, wherein each of the soft information values indicates a likelihood of a corresponding coded data bit having a particular value. An attempt is made to decode the coded data block using the first soft information values. The first soft information values are compressed. The compressed first soft information values are stored in a data store. A second plurality of coded data bits representing the coded data block is received and second soft information values corresponding to respective ones of the received second plurality of coded data bits are determined. The compressed first soft information values are retrieved from the data store and decompressed. The decompressed first soft information values are combined with the second soft information values, and an attempt is made to decode the coded data block using the combined soft information values.

Decoding a coded data block

Method and receiver for processing a signal in a wireless communication system in which the signal comprises a sequence of chips. The signal is receive data at least one rake finger and sampled. There is a time spacing tbetween successive samples less than the time spacing tbetween successive chips in the signal. Channel conditions on the channel are estimated and based on estimated channel conditions by the following steps: monitoring timing of the signal on one of the at least one rake finger to determine a time difference between the timing of the signal on the one of the at least one rake finger and the timing of the generation of the samples, the determined time difference being a multiple of t, where t&#x3c;t; aligning the timing of the generation of the samples with the timing of the signal on the one of the at least one rake finger to within a timing range t.

Method and system for processing a signal

One aspect provides a method of controlling transmit power in a wireless device, wherein a desired transmit power is determined as a result of detection of a receive signal parameter. The method comprises detecting a desired maximum transmit power and generating a sequence of attenuation factors. The sequence is generated by monotonically increasing a variable at a controlled rate between a starting value and the maximum transmit power. The method further comprises using each attenuation factor in turn to: (a) reduce the measured value of the received signal power; and (b) reduce a determined desired value of the transmit power, where the transmit power is continually reduced as the variable is increased.

Controlling transmit power in a wireless device

A method of generating a reliability indicator for decoding an encoded signal transmitted from a transmitter to a receiver via a wireless channel subject to fading. The method comprises: receiving symbols of the encoded signal; generating a reliability indicator for decoding at least some of the symbols selectively based on one or both of a statistical model representing additive white Gaussian noise (AWGN) in the encoded signal and a statistical model representing fading of the encoded signal; and selecting the statistical model based on signal characteristics of the wireless channel.

Method and device for decoding of signals transmitted over fading channels with multiplicative noise

A method, program and apparatus for transmitting from a transmitter to a receiver over a channel using a transmit diversity scheme. The method comprises: receiving power-related information fed back from the receiver to the transmitter; and at the transmitter, using the power-related information to generate channel state information. The method further comprises using the generated channel state information to control for subsequent transmission to the receiver from the multiple transmit antennas of the transmitter.

Adaptive transmission feedback

A method, receiver and program for equalizing digital samples of a radio signal received over a wireless communications channel. The method comprises: receiving digital samples of the radio signal; calculating equalizer coefficients in the frequency domain; transforming the equalizer coefficients from the frequency domain to the time domain; and equalizing the digital samples in the time domain using the transformed time domain equalizer coefficients.

Signal processing in wireless communication receivers

One aspect provides a method. The method comprises receiving a signal comprising a sequence of encoded symbols, each corresponding to one of a plurality of possible states. For each symbol in the sequence, the method further comprises determining a set of state metrics, each representing a probability that the respective symbol corresponds to the plurality of states. The method further comprises decoding the signal by processing runs of recursions using runs of forward recursions, whereby a later state metric in the sequence is updated based on a preceding state metric, and runs of recursions using runs of reverse recursions, whereby a preceding state metric in the sequence is updated based on a later state metric. The method further comprises outputting the decoded signal to a device. The decoding comprises performing a plurality of repeated iterations over the sequence.

Iterative decoding of signals received over a noisy channel using forward and backward recursions with warm-up initialization

A method, program and system for transmitting from a transmitter to a receiver over a wireless multiple-input-multiple-output channel. In one aspect, the method may comprise encoding precoding information fed back from the receiver to the transmitter according to a differential encoding scheme, and resetting the differential encoding scheme upon detecting a condition. In another aspect, the method may comprises encoding precoding matrices fed back from the receiver to the transmitter relative to a most-probable subset of precoding matrices. In another aspect, the method may comprise transmitting an indication of and/or the size of a preferred subset of precoding matrices for use in the encoding.

Method using differentially encoded feedback information in precoded MIMO-OFDM systems

Methods are described of processing a signal transmitted over a channel in a wireless communication system. A method includes estimating at intervals at least one parameter of a time varying communication environment of said system. At least one processor-related signal processing criterion can be monitored for implementing a signal processing activity. Based on said at least one parameter and said at least one processor-related criterion, a signal processing function can be selected from a plurality of signal processing functions implementable by a processor. Each signal processing function includes a plurality of code blocks having a sequence of instructions for execution on a processor platform, the processor platform including a set of configurable operators having a plurality of predetermined configurations, each sequence of instructions including at least one configuration instruction, which selects one of the plurality of predefined configurations for executing that code block. Related receivers and software implementations are described.

There is disclosed a method of determining one or more candidate frequencies for a carrier signal in a received signal, which method comprises: generating a narrowband spectrum of the received signal; detecting one or more peaks in the narrowband spectrum; generating a candidate frequency list, each frequency at which a peak occurs being included in the candidate frequency list. The method further comprises: removing the detected one or more peaks from the narrowband spectrum to generate a modified narrowband spectrum; detecting one or more further peaks in the modified narrowband spectrum; and modifying the candidate frequency list in dependence on the one or more further peaks.

Carrier detection

The invention relates to a method of feeding back information from a receiver to a transmitter, and also a corresponding receiver, transmitter, system comprising a receiver and transmitter, and computer program products for performing the steps of the receiver and transmitter respectively. The method comprises: receiving signals at the receiver from the transmitter over a wireless multiple-input-multiple-output channel; and, based on the received signals, transmitting back reports from the receiver to the transmitter including a report indicating a pre-coding matrix and a report indicating a rank of the pre-coding matrix. In the event that the report indicating the rank is not transmitted, the receiver instead uses a default rank to determine the report.

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Bristol, United Kingdom

Steve Allpress