Sequential decoding

About: Sequential decoding is a research topic. Over the lifetime, 8667 publications have been published within this topic receiving 204271 citations.

A Simple Proof of Threshold Saturation for Coupled Scalar Recursions

Abstract: Low-density parity-check (LDPC) convolutional codes (or spatially-coupled codes) have been shown to approach capacity on the binary erasure channel (BEC) and binary-input memoryless symmetric channels. The mechanism behind this spectacular performance is the threshold saturation phenomenon, which is characterized by the belief-propagation threshold of the spatially-coupled ensemble increasing to an intrinsic noise threshold defined by the uncoupled system. In this paper, we present a simple proof of threshold saturation that applies to a broad class of coupled scalar recursions. The conditions of the theorem are verified for the density-evolution (DE) equations of irregular LDPC codes on the BEC, a class of generalized LDPC codes, and the joint iterative decoding of LDPC codes on intersymbol-interference channels with erasure noise. Our approach is based on potential functions and was motivated mainly by the ideas of Takeuchi et al. The resulting proof is surprisingly simple when compared to previous methods.

Polar code decoding method and decoding device

Abstract: Embodiments of the present invention provide a method and a device for decoding Polar codes. A reliable subset is extracted from an information bit set of the Polar codes, where reliability of information bits in the reliable subset is higher than reliability of other information bits. The method includes: obtaining a probability value or an LLR of a current decoding bit of the Polar codes; when the current decoding bit belongs to the reliable subset, performing judgment according to the probability value or the LLR of the current decoding bit to determine a decoding value of the current decoding bit, keeping the number of decoding paths of the Polar codes unchanged, and modifying probability values of all the decoding paths by using the probability value or the LLR of the current decoding bit. The probability values of the decoding paths are obtained by calculation according to the probability value or the LLR of the decoding bit of the Polar codes. In the embodiments of the present invention, the information bits in the reliable subset are judged without splitting the decoding path, thereby reducing overall decoding complexity.

Robustly optimal rate one-half binary convolutional codes (Corresp.)

Abstract: Three optimality criteria for convolutional codes are considered in this correspondence: namely, free distance, minimum distance, and distance profile. Here we report the results of computer searches for rate one-half binary convolutional codes that are "robustly optimal" in the sense of being optimal for one criterion and optimal or near-optimal for the other two criteria. Comparisons with previously known codes are made. The results of a computer simulation are reported to show the importance of the distance profile to computational performance with sequential decoding.

Area-efficient high-speed decoding schemes for turbo decoders

Abstract: Turbo decoders inherently have large decoding latency and low throughput due to iterative decoding. To increase the throughput and reduce the latency, high-speed decoding schemes have to be employed. In this paper, following a discussion on basic parallel decoding architectures, the segmented sliding window approach and two other types of area-efficient parallel decoding schemes are proposed. Detailed comparison on storage requirement, number of computation units, and the overall decoding latency is provided for various decoding schemes with different levels of parallelism. Hybrid parallel decoding schemes are proposed as an attractive solution for very high level parallelism implementations. To reduce the storage bottleneck for each subdecoder, a modified version of the partial storage of state metrics approach is presented. The new approach achieves a better tradeoff between storage part and recomputation part in general. The application of the pipeline-interleaving technique to parallel turbo decoding architectures is also presented. Simulation results demonstrate that the proposed area-efficient parallel decoding schemes do not cause performance degradation.