DocumentCode :
2826958
Title :
Concatenated coded modulation schemes for the Rayleigh fading channel
Author :
Bounaas, Sofiane ; Dany, Jean-Claude
Author_Institution :
Service Radioelectr. et Electron., SUPELEC, Gif-sur-Yvette, France
fYear :
1994
fDate :
2-3 Nov 1994
Firstpage :
1
Lastpage :
7
Abstract :
The purpose of the paper is to present a performance analysis of concatenated coded modulation schemes for the Rayleigh fading channel. This structure consists of concatenated codes using Reed-Solomon and Hamming codes respectively as outer and inner codes, incorporated into a multilevel code. In order to provide a large coding gain with a minimum complexity, the authors propose a new algorithm, with reduced complexity, for soft decoding the inner code. This algorithm is named DSCR (decodage souple a complexite reduite). The advantage of the proposed suboptimal algorithm lies in the significant reduction computation complexity compared to the classical Viterbi algorithm. This is obtained by associating reliability information to each received signal. In this algorithm which is based on the Chase algorithm (Chase, 1972), the authors have developed a reliability measurement method which uses four thresholds for the decision reliability. The proposed schemes coding 8-QAM and 16-QAM, provide in average a coding gain of 12 dB over uncoded 4-QAM at bit error rate of 10-3. The overall code rate of coded 8-QAM is not the same as the uncoded 4-QAM spectral efficiency which can be easily obtained by coding 16-QAM instead. The ratio of the average complexities of the DSCR algorithm versus the hard decoding Hamming code is in the range of 2 to 3
Keywords :
modulation coding; 16-QAM; 8-QAM; Chase algorithm; DSCR; Hamming codes; Rayleigh fading channel; Reed-Solomon codes; bit error rate; coding gain; computation complexity; concatenated coded modulation schemes; decision reliability; decodage souple a complexite reduite; inner codes; multilevel code; outer codes; performance analysis; received signal; reduced complexity; reliability information; soft decoding; suboptimal algorithm; Concatenated codes; Decoding; Fading; Gain; Modulation coding; Performance analysis; Quadrature phase shift keying; Rayleigh channels; Reed-Solomon codes; Viterbi algorithm;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Communications and Vehicular Technology in the Benelux, 1994., IEEE Second Symposium on
Conference_Location :
Louvain la Neuve
Type :
conf
DOI :
10.1109/SCVT.1994.574137
Filename :
574137
Link To Document :
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