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.

A sequence detector is provided for detecting symbol values corresponding to a sequence of input samples obtained from a transmission channel. The sequence detector comprises a branch metric unit (BMU), a path metric unit (PMU) and a survivor memory unit. The branch metric unit calculates branch metrics for respective possible transitions between states of a trellis. The path metric unit accumulates branch metrics provided by the branch metric unit in order to establish path metrics. The survivor memory unit selects a survivor path based on the path metrics and outputs a survivor sequence of the detected symbols corresponding to the survivor path. The sequence detector is configured such that the synchronization length is different than the survivor path memory length.

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.

A sequence detector is provided for detecting symbol values corresponding to a sequence of input samples obtained from a transmission channel. The sequence detector comprises a branch metric unit (BMU), a path metric unit (PMU) and a survivor memory unit. The branch metric unit calculates branch metrics for respective possible transitions between states of a trellis. The path metric unit accumulates branch metrics provided by the branch metric unit in order to establish path metrics. The survivor memory unit selects a survivor path based on the path metrics and outputs a survivor sequence of the detected symbols corresponding to the survivor path. The sequence detector is configured such that the synchronization length is different than the survivor path memory length.

A system and techniques for decoding a message received over a communication channel comprises a receiver for receiving an encoded message. A sorting module is configured to organize candidate messages into a number of bins, sort the candidate messages within each bin, and output a group of candidate messages, the group comprising a number of most likely candidate messages from each message bin. A traceback module is configured to receive the most likely candidate message, and to walk through the tree of candidate messages to generate a decoded message.

A system and techniques for decoding a message received over a communication channel comprises a receiver for receiving an encoded message. A sorting module is configured to organize candidate messages into a number of bins, sort the candidate messages within each bin, and output a group of candidate messages, the group comprising a number of most likely candidate messages from each message bin. A traceback module is configured to receive the most likely candidate message, and to walk through the tree of candidate messages to generate a decoded message.

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.

Link capacity or data rate on a wired or wireless communication link such as WiFi, 5G, 6G, etc. may be increased by using two implicit transmission techniques, namely, implicit transmission with bit flipping (ITBF) and implicit transmission with collection decoding (ITCD) to transmit an independent second coded sequence implicitly while transmitting a first coded sequence explicitly over the channel. For instance, a novel generalized implicit transmission (GIT) technique that can transmit any number of independent implicit sequences implicitly while transmitting a single explicit sequence over the channel may be utilized, and GIT with multiple implicit sequences can increase the transmission rate significantly.