A Reliability-Based SNR Estimation Method in Turbo Detection Systems

Author

Qiang, Li ; Li, Shaoqian

Author_Institution

Univ. of Electron. Sci. & Technol. of China, Chengdu

fYear

2007

Firstpage

1122

Lastpage

1126

Abstract

In this paper, we analyze the sensitivity of MAP algorithm and its reduced ones, as max-log-MAP and scaled max-log-map, to SNR mismatch in turbo detection systems. And then, we propose a new reliability-based SNR estimation method using the soft extrinsic information output from SMLM decoder. Next, a new turbo equalization scheme is also provided with the new SNR estimation algorithm. Finally, the performance of turbo equalization systems are evaluated using our new scheme. The simulation results show that our equalization scheme performs very close to the LM algorithm with known channel SNR, although it does not need pilot symbols.

Keywords

equalisers; maximum likelihood detection; maximum likelihood estimation; turbo codes; LM algorithm; MAP algorithm; SMLM decoder; log maximum a posteriori algorithm; reliability-based SNR estimation method; scaled max-log-map; soft extrinsic information output; turbo detection systems; turbo equalization scheme; Algorithm design and analysis; Bit error rate; Communication switching; Detectors; Equalizers; Estimation error; Iterative algorithms; Iterative decoding; Mobile communication; Robustness;

fLanguage

English

Publisher

ieee

Conference_Titel

Vehicular Technology Conference, 2007. VTC-2007 Fall. 2007 IEEE 66th

Conference_Location

Baltimore, MD

ISSN

1090-3038

Print_ISBN

978-1-4244-0263-2

Electronic_ISBN

1090-3038

Type

conf

DOI

10.1109/VETECF.2007.243

Filename

4349892