Abstract: A method of soft decoding received signals. The method comprises defining quantisation intervals for a signal value range, determining a number of bits detected in each quantisation interval, a number of bits in each quantisation interval that are connected to unsatisfied constraints and a probability that the error correction code is unsatisfied, determining an overall bit error rate based on the probability that the error correction code is unsatisfied, determining a log likelihood ratio for each quantisation interval based on the overall bit error rate, the number of bits detected in each quantisation interval and the number of bits in each quantisation interval that are connected to unsatisfied constraints and performing soft decoding using the log likelihood ratios.

Abstract: In an embodiment a method of feeding back channel state information from a beamformee device to a beamformer device is disclosed. The method comprises receiving, at a plurality of antennas of the beamformee device, signals from the beamformer device; constructing a beamforming matrix, the beamforming matrix spanning a vector subspace and indicating the signals received by each of the plurality of antennas of the beamformee device; determining a first feedback matrix that spans the vector subspace of the beamforming feedback matrix such that it can be compressed with a lower number of non-zero coefficients than the beamforming feedback matrix; compressing the first feedback matrix into a plurality of coefficients; and transmitting an indication of the plurality of coefficients to the beamformer device.

Abstract: In an embodiment, a wireless communication method of transmitting a plurality of data streams from a transmitter to a receiver is disclosed. The transmitter comprises a plurality of antennas.

Abstract: In an embodiment, a method of managing distributed storage in a wireless network is disclosed. The wireless network comprises a plurality of data generating nodes, each data generating node configured to generate and store data symbols and parity symbols. The parity symbols depend on data symbols stored on other data generating nodes.

Abstract: A method of transmitting a plurality of data streams across a MIMO channel from a transmitter to a receiver, the transmitter comprising an array of antennas, the method comprising acquiring channel state information for a plurality of subcarrier frequencies, determining a mapping that defines, for each frequency, how each data stream is to be mapped to each antenna in the array, and for each antenna in the array, adjusting the power allocated to each data stream that is to be transmitted from the antenna, so as to maximize a measure of throughput; wherein for each data stream, the power allocated to transmitting that data stream at each frequency is greater than or equal to zero, and for each frequency, the power transmitted by any one antenna does not exceed a threshold, and for each data stream, the same power is allocated to each subcarrier used for transmitting that data stream.

Abstract: A method of selecting a carrier frequency offset tracking pilot signal in an access point of a wireless network is disclosed. The wireless network includes the access point and a plurality of terminals. The method includes receiving, at a plurality of antennas of the access point, signals from each of the plurality of terminals; estimating, from the received signals, a spatial channel signature for each of the plurality of terminals; selecting, for each terminal of the plurality of terminals, using the spatial channel signatures, a carrier frequency offset tracking pilot signal for that terminal from a plurality of pre-coded pilot signals; and transmitting an indication of the selected carrier frequency offset tracking pilot signals to the respective terminal.

Abstract: An OFDM transmitter comprising an input for acquiring or receiving a signal to be transmitted, an output for transmitting a PAPR reduced version of the signal, a processor and memory storing code for execution by the processor. The processor, when executing the code, is configure to determine a plurality of possible values of tone reservation, hereinafter referred to as TR, tones for use in TR based PAPR reduction and to perform a tree search over some or all of the possible values under a first constraint that the average power per TR tone does not exceed the average power per tone used for data transmission and a second constraint that selected values for the TR tones reduce PAPR.

Abstract: A decoder for decoding a received set of blocks each including a plurality of data symbols and a plurality of parity symbols, wherein the received set of blocks is a subset of a complete set of blocks, the complete set of blocks including at least one erased block not included in the received set of blocks, the decoder including: a storage for a coding matrix which is the kronecker product of a totally non-singular matrix with an antidiagonal matrix; and a processor operable to determine data symbols of the at least one erased block using the encoding matrix.

Abstract: There is provided a device and method for demodulating a pulse amplitude modulated, hereinafter referred to as PAM, signal. The device comprises memory storing a set of boundaries of regions in which the log likelihood ratio, hereinafter referred to as LLR, for each bit to be determined is represented by a linear function of the received signal, along with the properties of the linear function for each bit for each region; and a controller. The controller is configured to: receive a PAM signal to be demodulated; determine which region the signal falls within; for each bit to be determined, retrieve the properties of the linear function for the LLR for the bit within the determined region and determine, from this linear function, the LLR value for the bit; and demodulate the signal based on the determined LLR values.

Abstract: A device for use in demodulating modulated signals by determining a value for a log likelihood ratio. The device has a storage device to store executable instructions and a processor to execute the instructions stored on the memory device.

Abstract: A device comprising an input for receiving an OFDM signal, a processor and a memory for storing code. The code is configured to, when executed by the processor, cause the processor to generate a modified signal with reduced PAPR based on the OFDM signal by performing first and second PAPR reduction methods. In the first PAPR reduction method an intermediate signal is generated so that the number of signal peaks above a predetermined threshold is substantially minimised. In the second PAPR reduction method the PAPR of the intermediate signal is reduced.

Abstract: In an embodiment, a method of managing distributed storage in a wireless network is disclosed. The wireless network comprises a plurality of data generating nodes, each data generating node configured to generate and store data symbols and parity symbols. The parity symbols depend on data symbols stored on other data generating nodes.

Abstract: There is provided a device and method for demodulating a pulse amplitude modulated, hereinafter referred to as PAM, signal. The device comprises memory storing a set of boundaries of regions in which the log likelihood ratio, hereinafter referred to as LLR, for each bit to be determined is represented by a linear function of the received signal, along with the properties of the linear function for each bit for each region; and a controller. The controller is configured to: receive a PAM signal to be demodulated; determine which region the signal falls within; for each bit to be determined, retrieve the properties of the linear function for the LLR for the bit within the determined region and determine, from this linear function, the LLR value for the bit; and demodulate the signal based on the determined LLR values.

Abstract: An OFDM transmitter comprising an input for acquiring or receiving a signal to be transmitted, an output for transmitting a PAPR reduced version of the signal, a processor and memory storing code for execution by the processor. The processor, when executing the code, is configure to determine a plurality of possible values of tone reservation, hereinafter referred to as TR, tones for use in TR based PAPR reduction and to perform a tree search over some or all of the possible values under a first constraint that the average power per TR tone does not exceed the average power per tone used for data transmission and a second constraint that selected values for the TR tones reduce PAPR.

Abstract: In an embodiment, a wireless communication method of transmitting a plurality of data streams from a transmitter to a receiver is disclosed. The transmitter comprises a plurality of antennas.

Abstract: A method of transmitting a plurality of data streams across a MIMO channel from a transmitter to a receiver, the transmitter comprising an array of antennas, the method comprising acquiring channel state information for a plurality of subcarrier frequencies, determining a mapping that defines, for each frequency, how each data stream is to be mapped to each antenna in the array, and for each antenna in the array, adjusting the power allocated to each data stream that is to be transmitted from the antenna, so as to maximise a measure of throughput; wherein for each data stream, the power allocated to transmitting that data stream at each frequency is greater than or equal to zero, and for each frequency, the power transmitted by any one antenna does not exceed a threshold, and for each data stream, the same power is allocated to each subcarrier used for transmitting that data stream.

Abstract: A device for use in demodulating modulated signals by determining a value for a log likelihood ratio. The device has a storage device to store executable instructions and a processor to execute the instructions stored on the memory device.

Abstract: In an embodiment a method of feeding back channel state information from a beamformee device to a beamformer device is disclosed. The method comprises receiving, at a plurality of antennas of the beamformee device, signals from the beam—former device; constructing a beamforming matrix, the beamforming matrix spanning a vector subspace and indicating the signals received by each of the plurality of antennas of the beamformee device;determining a first feedback matrix that spans the vector sub—space of the beamforming feedback matrix such that it can be compressed with a lower number of non-zero coefficients than the beamforming feedback matrix; compressing the first feedback matrix into a plurality of coefficients; and transmitting an indication of the plurality of coefficients to the beamformer device.

Abstract: In an embodiment a method in an access point of a wireless is disclosed. The wireless network comprises the access point and a plurality of terminals. The method comprises receiving, at a plurality of antennas of the access point, signals from each of the plurality of terminals; estimating, from the received signals, a spatial channel signature for each of the plurality of terminals; selecting, for each terminal of the plurality of terminals, using the spatial channel signatures, a carrier frequency offset tracking pilot signal for that terminal from a plurality of pre-coded pilot signals; and transmitting an indication of the selected carrier frequency offset tracking pilot signals to the respective terminal.

Abstract: In an embodiment a method of estimating a sparse signal from a measured signal using a transform matrix is disclosed. The method comprises determining a partial contribution to the sparse signal; determining a residual by subtracting the partial contribution from the measured signal; and iteratively determining further contributions to the sparse signal.