An improved SOVA algorithm for turbo codes over AWGN and fading channels

Chuan Xiu Huang, Ali Ghrayeb

Research output: Contribution to conferencePaper

3 Citations (Scopus)

Abstract

In this paper, we present a modified soft-output Viterbi algorithm (MSOVA) that performs as good as the a posteriori probability (APP) algorithm with a complexity similar to that of the conventional SOVA algorithm. The idea behind the MSOVA centers around reducing the inherent correlation between the intrinsic information (input to the SOVA) and extrinsic information (output of the SOVA), where the latter is typically much higher than its APP counterpart. The proposed algorithm employs two attenuators, one applied directly to the output of the SOVA and another applied to the extrinsic information before it is passed to the other decoder (assuming iterative decoding). We examine the MSOVA on additive white Gaussian noise (AWGN) and fading channels. We show that the MSOVA provides improvements of about 0.8 to 1.0 dB at Pb = 10-5 in AWGN over the conventional SOVA, and is only about 0.1 dB away from the APP. It also provides improvements of 1.4 to 2.0 dB at P b = 10-5 on fading channels.

Original languageEnglish
Pages1121-1125
Number of pages5
Publication statusPublished - 1 Dec 2004
Event2004 IEEE 15th International Symposium on Personal, Indoor and Mobile Radio Communications, PIMRC 2004 - Barcelona, Spain
Duration: 5 Sep 20048 Sep 2004

Other

Other2004 IEEE 15th International Symposium on Personal, Indoor and Mobile Radio Communications, PIMRC 2004
CountrySpain
CityBarcelona
Period5/9/048/9/04

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Keywords

  • Fading channels
  • Iterative decoding
  • SOVA algorithm
  • Turbo codes

ASJC Scopus subject areas

  • Electrical and Electronic Engineering

Cite this

Huang, C. X., & Ghrayeb, A. (2004). An improved SOVA algorithm for turbo codes over AWGN and fading channels. 1121-1125. Paper presented at 2004 IEEE 15th International Symposium on Personal, Indoor and Mobile Radio Communications, PIMRC 2004, Barcelona, Spain.