Open AccessJoint detection/decoding algorithms for non‐binary low‐density parity‐check codes over inter‐symbol interference channels
Author(s) -
Zhao Shancheng,
Lu Zhifei,
Ma Xiao,
Bai Baoming
Publication year - 2013
Publication title -
iet communications
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.355
H-Index - 62
eISSN - 1751-8636
pISSN - 1751-8628
DOI - 10.1049/iet-com.2012.0616
Subject(s) - algorithm , low density parity check code , iterative viterbi decoding , viterbi algorithm , bcjr algorithm , factor graph , computer science , decoding methods , list decoding , soft output viterbi algorithm , sequential decoding , viterbi decoder , berlekamp–welch algorithm , computational complexity theory , concatenated error correction code , block code , error floor
This study is concerned with the application of non‐binary low‐density parity‐check (NB‐LDPC) codes to binary input inter‐symbol interference channels. Two low‐complexity joint detection/decoding algorithms are proposed. One is referred to as max‐log‐MAP/X‐EMS algorithm, which is implemented by exchanging soft messages between the max‐log‐MAP detector and the extended min‐sum (EMS) decoder. The max‐log‐MAP/ X ‐EMS algorithm is applicable to general NB‐LDPC codes. The other one, referred to as Viterbi/GMLGD algorithm, is designed in particular for majority‐logic decodable NB‐LDPC codes. The Viterbi/GMLGD algorithm works in an iterative manner by exchanging hard‐decisions between the Viterbi detector and the generalised majority‐logic decoder (GMLGD). As a by‐product, a variant of the original EMS algorithm is proposed, which is referred to as µ ‐EMS algorithm. In the µ ‐EMS algorithm, the messages are truncated according to an adaptive threshold, resulting in a more efficient algorithm. Simulations results show that the max‐log‐MAP/ X ‐EMS algorithm performs as well as the traditional iterative detection/decoding algorithm based on the BCJR algorithm and theQ‐ary sum–product algorithm, but with lower complexity. The complexity can be further reduced for majority‐logic decodable NB‐LDPC codes by executing the Viterbi/GMLGD algorithm with a performance degradation within one dB. These algorithms provide good candidates for trade‐offs between performance and complexity.