A linear log-MAP algorithm for turbo decoding and turbo equalization

Author

Talakoub, Shahram ; Sabeti, Leila ; Shahrrava, Behnam ; Ahmadi, Majid

Author_Institution

Dept. of Electr. & Comput. Eng., Windsor Univ., Ont., Canada

Volume

1

fYear

2005

fDate

22-24 Aug. 2005

Firstpage

182

Abstract

A simplification of the log-MAP algorithm for use in turbo decoders and turbo equalizers is presented. The simplified algorithm is based on the MacLaurin series expansion of the logarithmic term in the Jacobian logarithmic function used in the log-MAP algorithm. In terms of complexity the proposed algorithm can easily be implemented using adders and comparators as this is the case for the max-log-MAP algorithm. Also, simulation results show that the proposed algorithm has performance very close to the log-MAP algorithm for both turbo decoding and turbo equalization, even in a high loss intersymbol interference (ISI) channel where there is a wide gap between the performance of the log-MAP and max log-MAP turbo equalizers.

Keywords

adders; comparators (circuits); equalisers; intersymbol interference; maximum likelihood decoding; turbo codes; Jacobian logarithmic function; MacLaurin series expansion; intersymbol interference channel; linear log-MAP algorithm; logarithmic term; max-log-MAP algorithm; turbo decoding; turbo equalization; Approximation algorithms; Binary phase shift keying; Equalizers; Frequency; Intersymbol interference; Iterative algorithms; Iterative decoding; Jacobian matrices; Performance gain; Performance loss;

fLanguage

English

Publisher

ieee

Conference_Titel

Wireless And Mobile Computing, Networking And Communications, 2005. (WiMob'2005), IEEE International Conference on

Print_ISBN

0-7803-9181-0

Type

conf

DOI

10.1109/WIMOB.2005.1512836

Filename

1512836