An iterative two dimension equalizer usable in a receiver of orthogonal time frequency space (OTFS) modulated signals is described. In one configuration of the equalizer, a forward path generates, from received time-frequency domain samples and a channel estimate, estimates of data bits and likelihood numbers associated with the estimates of data bits, generated by delay-Doppler domain processing. In the feedback direction, the estimates of data bits are used to generate symbol estimates and autocorrelation matrix estimate in the time domain. In another configuration, a soft symbol mapper is used in the feedback direction for directly generating the feedback input symbol estimate without having to generate estimates of data bits.

A receiver to generate a first vector of a first sequence of a portion of symbols of a signal. The receiver further generates a second vector of a second sequence of the portion of symbols, wherein the second sequence comprises a flipped version of the first sequence. Based at least in part on the first vector and the second vector, a decision including a sequence of one or more bits that represent at least a portion of the signal and a confidence level corresponding to the decision are generated.

Methods, systems, and devices for wireless communications are described. For instance, first one or more wireless devices may receive or obtain a set of reference signals from second one or more wireless devices. The first one or more wireless devices may estimate a set of channel state information parameters, where each channel state parameter is based on a respective reference signal of the set of reference signals. The first one or more wireless devices may output or transmit a set of transmissions, where each transmission of the set of transmissions is based on a different gain parameter of the set of gain parameters, where each gain parameter of the set of gain parameters is based on a different channel state information parameter, and where each gain parameter of the set of gain parameters is less than a first threshold and greater than a second threshold.

A method of processing a digitally encoded radio signal (102) comprising a bit to be determined is disclosed. The method comprises correlating a first bit sequence (103) comprising the bit with a plurality of predetermined filters (104a-h) to create a first set of filter coefficients (110a-h); calculating (120) a first likelihood data set (124) comprising a likelihood of said bit having a given value for each bit position from the first set of filter coefficients. A second bit sequence (103) comprising the bit at a different position is then correlated with the filters to create a second set of filter coefficients (10a-h), from which a second likelihood data set (124) is calculated. A soft output bit (26) comprising a probability weighted bit value from data corresponding to the bit at a first and second bit positions from the first and second likelihood data sets respectively is then calculated.

Provided is a data transmitting and receiving apparatus that may process a signal to be transmitted using a faster-than-Nyquist (FTN) method. The data transmitting and receiving apparatus may perform low-density parity-check (LDPC) encoding on data to be transmitted using a first matrix having a first degree based on a preset reference and a second matrix having a single diagonal matrix structure, independently perform interleaving and symbol mapping on each of an information bit and a parity bit of the data, accelerate an output signal by a transmission rate based on the FTN method, and transmit the data.

A method of digital signal processing includes modeling a digitally-modulated radio frequency (RF) communication stream using a set of incoming samples of the stream collected from a single antenna. The stream includes a first signal, the first signal including a sequence of first digital symbols having a previous symbol and a current symbol. Each first digital symbol is chosen from a plurality of first possible values. The first signal is modulated by a first known RF communication protocol having unknown time-varying parameters, the parameters having estimated previous values from modeling the previous symbol using a previous interval of the samples corresponding to the previous symbol. The method further includes collecting a current interval of the samples, predicting current values of the parameters, deciding a value of the current symbol using maximum likelihood estimation, and estimating the current values of the parameters using maximum likelihood estimation.

The present invention concerns a method for computing a soft estimate of coded bits forming transmitted symbol vectors of a multi-dimentional constellation, the transmitted vectors being received by a receiver from a source through a channel, characterized in that the method comprises the steps of: obtaining from the receiver memory a predetermined list of vectors with integer or gaussian integer entries, obtaining a channel matrix estimation between the source and the receiver and received symbols, obtaining a reduced channel matrix and a change of basis matrix from the channel matrix estimation, computing a vector with integer coordinates at least from the reduced channel matrix and the received symbols, shifting the predetermined list of vectors around the vector with integer coordinates and obtaining a shifted list of vectors, computing a soft estimation of the coded bits according to vectors belonging to the shifted list of vectors and to a transformed multi-dimentional constellation obtained from the multi-dimentional constellation and the change of basis matrix.

An apparatus and method are provided for processing a received input signal comprising a sequence of data blocks. Counter circuitry within the apparatus is arranged to receive a digital representation of the input signal, and for each data block generates a count value indicative of occurrences of a property of the digital representation (for example a rising edge or a falling edge) during an associated data block transmission period. Quantization circuitry then maps each count value to a soft decision value from amongst a predetermined set of soft decision values, where the number of soft decision values in the predetermined set exceeds a number of possible data values of the data block. The output circuitry then generates a digital output signal in dependence on the soft decision values. Such an apparatus has been found to provide a low power technique for a receiver, whilst still enabling the improved sensitivity benefits of using soft decisions to be achieved, and allows the apparatus to be constructed using all digital components.

An operating method of a modem chip includes receiving a first Euclidean distance (ED) set including an ED of first symbol vector candidates, comparing magnitudes of the EDs of the first ED set, calculating each of a first minimum ED corresponding to a bit value of a first bit being 1 and a second minimum ED corresponding to the bit value of the first bit being 0, the first bit being from among a plurality of bits of a plurality of layers of the transmission symbol, based on first index information including results of the comparing the magnitudes of the EDs of the first ED set, updating the first minimum ED and the second minimum ED with a smallest first minimum ED and a smallest second minimum ED, respectively, and detecting the transmission symbol based on the updated first minimum ED and the updated second minimum ED.

In certain embodiments, a method may include receiving one or more equalized samples of an input signal. The method may further include mitigating one or more excursions in the one or more equalized samples based on one or more current decisions of an iterative decoding process to generate compensated equalized samples. In addition, the method may include performing iterative decoding operations based on the compensated equalized samples, updating the current decisions of the iterative decoding process and outputting the current decisions as a converged result when the iterative decoding operations have converged for the compensated equalized samples.