Disclosed are devices, systems and methods for precoding and decoding polar codes using local feedback are described. One example method for improving an error correction capability of a decoder includes receiving a noisy codeword vector of length n, the codeword having been generated based on a concatenation of a convolutional encoding operation and a polar encoding operation and provided to a communication channel prior to reception by the decoder, performing a successive-cancellation decoding operation on the noisy codeword vector to generate a plurality of polar decoded symbols (n), generating a plurality of information symbols (k) by performing a convolutional decoding operation on the plurality of polar decoded symbols, wherein k/n is a rate of the concatenation of the convolutional encoding operation and the polar encoding operation, and performing a bidirectional communication between the successive-cancellation decoding operation and the convolutional decoding operation.

A method and system for error checking in a wireless communication are provided. The method includes: receiving a payload; determining a final decoding result of the payload, the final decoding result indicating a start state and an end state; determining whether the end state is identical to the start state based on a state circularity check; and determining to discard the final decoding result based on whether the end state is identical to the start state.

A method of soft-decision decoding including training a machine learning agent with communication signal training data; providing to the trained machine learning agent a signal that has been received via a communications channel; operating the machine learning agent to determine respective probabilities that the received signal corresponds to each of a plurality of symbols; and, based on the determined probabilities, performing soft decision decoding on the received signal.

A cyclo-stationary characteristic of a communications channel and/or storage media is determined. The cyclo-stationary characteristic has K-cycles, K > 1. Markov transition probabilities are determined that depend on a discrete phase ϕ=t mod K, wherein t is a discrete time value. An encoder to optimize the Markov transition probabilities for encoding data sent through the communications channel and/or stored on the storage media. The optimized Markov transition probabilities are used to decode the data from the communication channel and/or read from the storage media.

The present disclosure includes apparatus, systems, and techniques relating to noise-predictive detector adaptation. A described technique includes operating a decoder system to decode codewords that are based on a received encoded signal by processing the codewords and exchanging information between path and code decoders, operating the path decoder to use estimation parameters to produce first and second paths based on a codeword of the codewords, operating the code decoder to produce a decoded path based on the codeword; determining a winning path of first and second paths based on whether the decoded path matches the first path or the second path; and updating, based on one or more error terms and the winning path, the estimation parameters to favor selection of the winning path by the path decoder and to disfavor selection of a losing path of the first and second paths by the path decoder.

An ultra-wideband (“UWB”) communication system comprising a transmitter and a receiver. In one embodiment, the symbol mapper circuit in the transmitter is adapted, in a first mode, to develop symbols having the number of pulses as currently defined in the 4z Standard; and, in a second mode, to develop symbols having fewer pulses than as currently defined in the 4z Standard. In an optional third mode, each data bit is mapped to a single pulse.

An ultra-wideband (“UWB”) communication system comprising a transmitter and a receiver. In one embodiment, the symbol mapper circuit in the transmitter is adapted, in a first mode, to develop symbols having the number of pulses as currently defined in the 4z Standard; and, in a second mode, to develop symbols having fewer pulses than as currently defined in the 4z Standard. In an optional third mode, each data bit is mapped to a single pulse.

A soft decision audio decoding system for preserving audio continuity in a digital wireless audio receiver is provided that deduces the likelihood of errors in a received digital signal, based on generated hard bits and soft bits. The soft bits may be utilized by a soft audio decoder to determine whether the digital signal should be decoded or muted. The soft bits may be generated based on a degree of closeness of a detected phase trajectory to known legal phase trajectories determined from the running the phase trajectory through a soft-output Viterbi algorithm. The value of the soft bits may indicate confidence in the strength of the hard bit generation. The soft decision audio decoding system may infer errors and decode perceptually acceptable audio without requiring error detection, as in conventional systems, as well as have low latency and improved granularity.

The present invention discloses a decoding path selection device for decoding codewords generated by convolutional codes or turbo codes encoders in error correction codes, the decoding path selection device comprising: a branch metrics calculation unit for receiving incoming signals and calculating branch metrics values; a programmable generalized trellis router for generating a decoding path control signal according to the turbo code or convolutional code specification employed by one of communications standards; a multiplexer for receiving the branch metrics values from the branch metrics calculation unit and the decoding path control signal from the programmable generalized trellis router and selecting a corresponding branch metrics value; a recursive calculation unit, connected after the multiplexer and for receiving the corresponding branch metrics value from the multiplexer; and an a-posteriori probability calculation unit, connected after the recursive calculation unit and for calculating a final decoding result.

Methods and apparatus for efficient demapping of constellations are described. In an embodiment, these methods may be implemented within a digital communications receiver, such as a Digital Terrestrial Television receiver. The method reduces the number of distance metric calculations which are required to calculate soft information in the demapper by locating the closest constellation point to the received symbol. This closest constellation point is identified based on a comparison of distance metrics which are calculated parallel to either the I- or Q-axis. The number of distance metric calculations may be reduced still further by identifying a local minimum constellation point for each bit in the received symbol and these constellation points are identified using a similar method to the closest constellation point. Where the system uses rotated constellations, the received symbol may be unrotated before any constellation points are identified.