DocumentCode :
3069083
Title :
LLR Approximation for Wireless Channels Based on Taylor Series and Its Application to BICM with LDPC Codes
Author :
Asvadi, Reza ; Banihashemi, Amir H. ; Ahmadian-Attari, Mahmoud ; Saeedi, Hamid
Author_Institution :
Dept. of Electr. & Comput. Eng., K.N. Toosi Univ. of Technol., Tehran, Iran
fYear :
2011
fDate :
5-9 Dec. 2011
Firstpage :
1
Lastpage :
6
Abstract :
A new approach for the approximation of the channel log-likelihood ratio (LLR) for wireless channels based on Taylor series is proposed. The approximation is applied to the uncorrelated flat Rayleigh fading channel with unknown channel state information at the receiver. It is shown that the proposed approximation greatly simplifies the calculation of channel LLRs, and yet provides results almost identical to those based on the exact calculation of channel LLRs. The results are obtained in the context of bit-interleaved coded modulation (BICM) schemes with low-density parity-check (LDPC) codes, and include threshold calculations and error rate performance of finite-length codes. Compared to the existing approximations, the proposed method is either significantly less complex, or considerably more accurate.
Keywords :
Rayleigh channels; channel coding; error statistics; interleaved codes; parity check codes; radio receivers; series (mathematics); wireless channels; BICM schemes; LDPC codes; LLR approximation; Taylor series; bit-interleaved coded modulation schemes; channel LLR; channel log-likelihood ratio; channel state information; error rate performance; exact calculation; finite-length codes; low-density parity-check codes; receiver; threshold calculations; uncorrelated flat Rayleigh fading channel; wireless channels; Fading; Linear approximation; Parity check codes; Polynomials; Signal to noise ratio; Taylor series;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Global Telecommunications Conference (GLOBECOM 2011), 2011 IEEE
Conference_Location :
Houston, TX, USA
ISSN :
1930-529X
Print_ISBN :
978-1-4244-9266-4
Electronic_ISBN :
1930-529X
Type :
conf
DOI :
10.1109/GLOCOM.2011.6133575
Filename :
6133575
Link To Document :
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