Title :
Log-Likelihood Ratios for LDPC Codes with Pilot-Symbol-Assisted BPSK Transmission over Flat Rayleigh Fading Channels
Author :
Yuan, Haifeng ; Kam, Pooi Yuen
Author_Institution :
Dept. of Electr. & Comput. Eng., Nat. Univ. of Singapore, Singapore, Singapore
Abstract :
We derive the exact log-likelihood ratio (LLR) for iterative decoding of low-density parity-check codes for pilot-symbol-assisted BPSK transmission over flat Rayleigh fading channels. The bit-error rate (BER) performances of this metric are studied for various interleavers and different pilot spacings. We further compare this metric with the approximate metric, which has been commonly used in the literature. Simulation results show that the newly derived LLR metric results in better BER performances. In addition, the effect of signal-to-noise ratio estimation error is investigated and our new LLR shows more robustness.
Keywords :
Rayleigh channels; error statistics; iterative decoding; parity check codes; phase shift keying; BER performance; LDPC codes; binary phase shift keying; bit error rate; flat Rayleigh fading channels; iterative decoding; log-likelihood ratios; low density parity check codes; pilot-symbol-assisted BPSK transmission; signal-to-noise ratio estimation error; AWGN; Binary phase shift keying; Bit error rate; Channel estimation; Fading; Iterative algorithms; Iterative decoding; Maximum likelihood decoding; Parity check codes; Signal to noise ratio;
Conference_Titel :
Vehicular Technology Conference Fall (VTC 2009-Fall), 2009 IEEE 70th
Conference_Location :
Anchorage, AK
Print_ISBN :
978-1-4244-2514-3
Electronic_ISBN :
1090-3038
DOI :
10.1109/VETECF.2009.5378688
