Title :
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
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;
Conference_Titel :
Vehicular Technology Conference, 2007. VTC-2007 Fall. 2007 IEEE 66th
Conference_Location :
Baltimore, MD
Print_ISBN :
978-1-4244-0263-2
Electronic_ISBN :
1090-3038
DOI :
10.1109/VETECF.2007.243
