Simplified trellis min-max decoder architecture for nonbinary low-density parity-check codes

Abstract

© 2015 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.Nonbinary low-density parity-check (NB-LDPC) codes have become an efficient alternative to their binary counterparts in different scenarios, such as moderate codeword lengths, high-order modulations, and burst error correction. Unfortunately, the complexity of NB-LDPC decoders is still too high for practical applications, especially for the check node (CN) processing, which limits the maximum achievable throughput. Although a great effort has been made in the recent literature to overcome this disadvantage, the proposed decoders are still not ready for high-speed implementations for high-order fields. In this paper, a simplified trellis min max algorithm is proposed, where the CN messages are computed in a parallel way using only the most reliable information. The proposed CN algorithm is implemented using a horizontal layered schedule. The overall decoder architecture has been implemented in a 90-nm CMOS process for a ((N=837) and (K=726)) NB-LDPC code over GF(32), achieving a throughput of 660 Mb/s at nine iterations based on postlayout results. This decoder increases hardware efficiency compared with the existing recent solutions for the same code.This work was supported in part by the Spanish Ministerio de Ciencia e Innovacion under Grant TEC2011-27916; in part by the Universitat Politecnica de Valencia, Gandia, Spain, under Grant PAID-06-2012-SP20120625; and in part by the Institut Universitaire de France, Rennes, France. The work of F. Garcia-Herrero was supported in part by the Spanish Ministerio de Educacion under Grant AP2010-5178 and in part by the Institute Universitaire de France.Lacruz Jucht, JO.; García Herrero, FM.; Declercq, D.; Valls Coquillat, J. (2015). Simplified trellis min-max decoder architecture for nonbinary low-density parity-check codes. IEEE Transactions on Very Large Scale Integration (VLSI) Systems. 23(9):1783-1792. https://doi.org/10.1109/TVLSI.2014.2344113S1783179223