Sequential decoding

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

Faulty Gallager-B decoding with optimal message repetition

Abstract: We consider the decoding of regular low density parity-check codes with a Gallager-B message-passing algorithm built exclusively from faulty computing devices. We propose an extension of the Gallager-B algorithm where messages can be repeated to provide increased fault tolerance, and use EXIT functions to derive its average performance. Thresholds are obtained both for the channel quality and the faultiness of the decoder. We argue that decoding complexity is central to the analysis of faulty decoding and compare the complexity of decoding with a faulty decoder instead of a reliable decoder, for a fixed channel condition and residual error rate. Finally, we show that when the message repetitions in the extended Gallager-B algorithm are scheduled optimally, a small complexity overhead with respect to a reliable decoder provides large gains in fault tolerance.

Multilevel trellis MPSK modulation codes for the Rayleigh fading channel

Abstract: The multilevel coding technique is used for constructing multilevel trellis M-ary phase-shift-keying (MPSK) modulation codes for the Rayleigh fading channel. In the construction of a code, all the factors which affect the code performance and its decoding complexity are considered. The error performance of some of these codes based on both one-stage optimum decoding and multistage suboptimum decoding has been simulated. The simulation results show that these codes achieve good error performance with small decoding complexity. >

A memory efficient belief propagation decoder for polar codes

Abstract: Polar codes have become increasingly popular recently because of their capacity achieving property. In this paper, a memory efficient stage-combined belief propagation (BP) decoder design for polar codes is presented. Firstly, we briefly reviewed the conventional BP decoding algorithm. Then a stage-combined BP decoding algorithm which combines two adjacent stages into one stage and the corresponding belief message updating rules are introduced. Based on this stage-combined decoding algorithm, a memory-efficient polar BP decoder is designed. The demonstrated decoder design achieves 50% memory and decoding latency reduction in the cost of some combinational logic complexity overhead. The proposed decoder is synthesized under TSMC 45nm Low Power CMOS technology. It achieves 0.96 Gb/s throughput with 14.2mm2 area when code length N=216 which reduces 51.5% decoder area compared with the conventional decoder design.

Pseudo-random recursive convolutional coding for near-capacity performance

Abstract: We consider recursive convolutional coding as a means for constructing codes whose distance distribution is close to that obtained in the average by random coding, hence whose performance is expected to closely approach the channel capacity. We especially consider convolutional codes where the encoder register taps are such that it generates maximum-length sequences. Two algorithms for decoding these codes are discussed. Since both involve implementation difficulties, we propose to generate such codes by means similar to turbo-codes which make their decoding easy. >

Trellis Decoding of Block Codes: A Practical Approach

Abstract: We present a number of techniques which promise to make the soft-decision trellis decoding of block codes as powerful and cost effective as that of convolutional codes. The techniques are based on the concept of generalised array codes (GACs) and enable sufficient simplification in the decoding complexity.