Methods, systems, and devices for wireless communication are described. In a new radio (NR) system, a wireless device may identify a candidate codeword for a channel employing polar coding. The wireless device may perform a decoding operation on the candidate codeword to determine candidate decoding paths corresponding to encoded information bits. The decoding operation may include multiple decoding path candidates, each of which is associated with a path metric. The wireless device may evaluate a spread metric to determine if a decoding hypothesis is incorrect or if the received codeword is too corrupted for decoding. The spread metric may be based on the path metrics of the decoding paths or soft metrics of the decoding paths determined based on a subset of bit channels of the polar code. The wireless device may normalize the spread metric to compensate for signal-to-noise ratio (SNR) variation.

This application relates to a decoding method and a decoder. The decoding method includes: calculating, based on a path selection result of a second hit group in a current code block to be decoded, LLRs (log-likelihood ratios) of a first bit group in the code block, where the path selection result includes L paths; calculating BMs (branch metrics) of the first bit group based on the LLRs; selecting at least L BMs for each of the L paths; determining PMs (path metrics) of the first bit group based on the at least L BMs and a path selection result of a previous hit group of the first bit group; and determining a path selection result of the first bit group based on the PMs. In an entire decoding process, other phases before the PM calculation phase can be performed in parallel, thereby reducing a decoding delay, and improving decoding efficiency.

Sequence detectors and detection methods are provided for detecting symbol values corresponding to a sequence of input samples obtained from an ISI channel. The sequence detector comprises a branch metric unit (BMU) and a path metric unit (PMU). The BMU, which comprises an initial set of pipeline stages, is adapted to calculate, for each input sample, branch metrics for respective possible transitions between states of a trellis. To calculate these branch metrics, the BMU selects hypothesized input values, each dependent on a possible symbol value for the input sample and L>0 previous symbol values corresponding to possible transitions between states of the trellis. The BMU then calculates differences between the input sample and each hypothesized input value. The BMU compares these differences and selects, as the branch metric for each possible transition, an optimum difference in dependence on a predetermined state in a survivor path through the trellis.

The invention discloses a convolutional code decoder and a convolutional code decoding method. The convolutional code decoder performs decoding operation according to a received data and an auxiliary data to obtain a target data and includes an error detection data generation circuit, a channel coding circuit, a selection circuit, and a Viterbi decoding circuit. The error detection data generation circuit performs an error detection operation on the auxiliary data to obtain an error detection data. The channel coding circuit, coupled to the error detection data generation circuit, performs channel coding on the auxiliary data and the error detection data to obtain an intermediate data. The selection circuit, coupled to the channel coding circuit, generates a to-be-decoded data according to the received data and the intermediate data. The Viterbi decoding circuit, coupled to the selection circuit, decodes the to-be-decoded data to obtain the target data.

An apparatus including at least one processor configured to execute instructions and cause the apparatus to perform, obtaining for a first possible state (s) of a received sample at the current time step (k), log-likelihood ratio, Ilr, values Ilr.sub.old,min, Ilr.sub.old,max of a first transmitted bit (b.sub.j), wherein, the Ilr values Ilr.sub.old,min, Ilr.sub.old,max are respectively associated with a most likely state and a less likely state related to a received sample at the previous time step (k?1); determining based on path metrics and branch metrics corresponding to the received sample at the current time step (k); a first parameter (Q) related to a difference between likelihoods of the most likely state and the less likely state; updating magnitude of the Ilr value Ilr.sub.old,min at least based on the Ilr value Ilr.sub.old,min, the Ilr value Ilr.sub.old,max, and the first parameter, to obtain an updated Ilr value Ilr.sub.old,updated.

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 ?=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.

A mobile device includes a display, a mobile-communication modem including a Viterbi decoder (VD) configured to decode a tail biting convolutional code (TBCC)-encoded data, a memory coupled to the mobile-communication modem, and a wireless antenna coupled to the mobile-communication modem and to receive a Physical Downlink Control Channel (PDCCH). The VD is configured to: receive data encoded by TBCC; select a candidate to initiate a training section; determine final path metric (PM) values of possible states at a last step of the training section; determine a PM-related value based on the final PM values of the possible states; and determine an early termination of a decoding for the candidate based on the PM-related value.

Concepts and examples pertaining to combined coding design for efficient codeblock extension are described. A processor of a communication apparatus may combine channel polarization of a communication channel with a first coding scheme for first codeblocks of a smaller size to generate a second coding scheme. The processor may also code second codeblocks of a larger size using the second coding scheme.

Methods and apparatus are provided for calculating branch metrics, associated with possible transitions between states of a trellis, in a sequence detector for detecting symbol values corresponding to samples of an analog signal transmitted over a channel. For each sample and each transition, the method calculates a plurality of distance values indicative of distance between that sample and respective hypothesized sample values for that transition. In parallel with calculation of the distance values, the sample is compared with a set of thresholds, each defined between a pair of successive hypothesized symbol values arranged in value order, to produce a comparison result. An optimum distance value is selected as a branch metric for the transition in dependence on the comparison result.

In an aspect of the disclosure, a method, a computer-readable medium, and an apparatus are provided. The apparatus may receive a data packet that includes at least in part a preamble, an encoded block, and a payload. The apparatus may detect the preamble of the data packet at a last symbol of the preamble or prior to the last symbol of the preamble. The apparatus may compute a branch metric for each of a plurality of transitions between states. The apparatus may initialize a path metric for each of a plurality of non-synchronization states and synchronization states. In certain aspects, each of the synchronization states may be associated with the preamble. The apparatus may determine a survivor path for each of the non-synchronization states and synchronization states based at least in part on a respective path metric. The apparatus may determine a traceback timing.