Systems and methods are disclosed for performing polar encoding of a number of information bits for transmission in a wireless communication system in a manner that is optimized for a specific code length. In some embodiments, a method of operation of a transmit node in a wireless communication system comprises performing polar encoding of a set of K information bits to thereby generate a set of polar-encoded information bits where the K information bits are mapped to the first K information bit locations specified in an information sequence S.sub.N which is a ranked sequence of N information bit locations among a plurality of input bits for the polar encoding where N is equivalent to a code length, a size of the information sequence S.sub.N is greater than or equal to K, and the information sequence SN is optimized for a specific value of the code length N.

Methods and apparatus for training a Neural Network to recover a codeword of a Forward Error Correction code are provided. Trainable parameters of the Neural Network are optimised to minimise a loss function. The loss function is calculated by representing an estimated value of the message bit output from the Neural Network as a probability of the value of the bit in a predetermined real number domain and multiplying the representation of the estimated value of the message bit by a representation of a target value of the message bit. Training a neural network may be implemented via a loss function.

There is provided mechanisms for decoding an encoded sequence into a decoded sequence. A method is performed by an information decoder. The method comprises obtaining the encoded sequence. The encoded sequence has been encoded using a polar code. The method comprises successively decoding the encoded sequence into the decoded sequence. The decoding is performed for a given list size, LS, where LS>1, defining how many candidate decoded sequences in total the thus far decoded sequence is allowed to branch into during the decoding. The encoded sequence is decoded, until its first branching, by at least as many processing units in parallel as a factor, f, of the given list size. The factor is at least half the given list size, fLS/2.

There is provided a method of obtaining one or more parity symbols (PS) of an encoding of information symbols (IS) according to a linear cyclic code, the method comprising: upon a permutation of information symbols (IS), generating data indicative of parity coefficients of a row of a generator matrix associated with the linear cyclic code, computing, for each given parity coefficient, a first data in accordance with, at least, the given parity coefficient and the first IS; updating, by the processing circuitry, for each given parity coefficient of the one or more parity coefficients, the first data, in accordance with, at least, the given parity coefficient and the respective IS; and upon meeting a parity completion criterion for a given parity coefficient, deriving a parity symbol from the respective first data, thereby obtaining the one or more parity symbols of the codeword of the linear cyclic code.

There is provided a decoder for decoding a data signal received through a transmission channel in a communication system, the decoder (310) comprising a symbol estimation unit (311) configured to determine estimated symbols representative of the transmitted symbols carried by the received signal, the estimated symbols being determined from nodes of a decoding tree based on a weight metric associated with each of the node. The decoder further comprises a termination alarm monitoring unit (312) for monitoring a termination alarm depending on the current decoding computation complexity, the termination alarm being associated with a metric parameter, the symbol estimation unit being configured to reduce the weight metric of each node of the decoding tree by a quantity corresponding to a function of the metric parameter associated with the termination alarm, in response to the triggering of the termination alarm.

Systems and methods are provided for decoding a codeword having a first codeword length using a decoding system. The systems and methods include receiving a vector corresponding to the codeword at the decoding system, wherein the decoding system comprises a first decoder and a second decoder, the first decoder is available to concurrently process codewords up to the first codeword length, and the second decoder is available to concurrently process codewords up to a second codeword length. The systems and methods further include determining that the received vector is to be decoded using the second decoder, partitioning the received vector of the first codeword length into a plurality of segments having a size no larger than the second codeword length, and decoding the plurality of segments using the second decoder.

There is provided a method of recursive sequential list decoding of a codeword of a polar code comprising: obtaining an ordered sequence of constituent codes usable for the sequential decoding of the polar code, representable by a layered graph; generating a first candidate codeword (CCW) of a first constituent code, the first CCW being computed from an input model informative of a CCW of a second constituent code, the first constituent code and second constituent code being children of a third constituent code; using the first CCW and the second CCW to compute, by the decoder, a CCW of the third constituent code; using the CCW of the third constituent code to compute a group of symbol likelihoods indicating probabilities of symbols of a fourth (higher-layer) constituent code having been transmitted with a particular symbol value, and using the group of symbol likelihoods to decode the fourth constituent code.

A method is performed by an information decoder. The method comprises obtaining (S102) an encoded sequence having been encoded using a polar code. The method comprises successively decoding (S104) the encoded sequence into the successive bits of the decoded sequence. Successively decoding the encoded sequence comprises performing a threshold check (S106) for evaluating a bit uncertainty criterion. Successively decoding the encoded sequence comprises branching (S108) the decoded sequence into two candidate decoded sequences whenever the threshold check fails.

Certain aspects of the present disclosure relate to techniques and apparatus for improving decoding latency and performance of Polar codes. An exemplary method generally includes generating a codeword by encoding information bits, using a multi-dimensional interpretation of a polar code of length N, determining, based on one or more criteria, a plurality of locations within the codeword to insert error correction codes generating the error correction codes based on corresponding portions of the information bits, inserting the error correction codes at the determined plurality of locations, and transmitting the codeword. Other aspects, embodiments, and features are also claimed and described.

There is provided a decoder (310) for sequentially decoding a data signal received through a transmission channel in a communication system, the received data signal carrying transmitted symbols, the decoder comprising a symbol estimation unit (311) configured to determine estimated symbols representative of the transmitted symbols carried by the received signal from information stored in a stack, the stack being filled by iteratively expanding child nodes of a selected node of a decoding tree comprising a plurality of nodes, each node of the decoding tree corresponding to a candidate component of a symbol of the received data signal and each node being associated with a predetermined metric, the stack being filled at each iteration with at least some of the expanded child nodes and being ordered by increasing values of the metrics associated with the nodes, the selected node for each iteration corresponding to the node having the lowest metric in the stack. The decoder further comprises a stack reordering activation monitoring unit (313) configured to monitor at least one stack reordering activation condition and, in response to a stack reordering activation condition being verified, to cause the symbol estimation unit to: reduce the metric associated with each node stored in the stack by a quantity, reorder the stack by increasing value of the reduced metric, and remove a set of nodes from the reordered stack so as to maintain a number N of nodes in the reordered stack, the maintained nodes corresponding to the N nodes having the lowest metrics in the reordered stack.