Title :
LLR metrics for LDPC codes with quadrature differential PSK transmission, and their performances
Author :
Mo, Elisa ; Kam, Pooi Yuen ; Armand, Marc A.
Author_Institution :
Dept. of Electr.&Comput. Eng., Nat. Univ. of Singapore, Singapore
Abstract :
Iterative decoding of low-density parity-check codes transmitted over noncoherent channels using quadrature differential phase-shift keying is investigated. The log-likelihood ratio for each of the two code bits sent over one transmission period, based on the joint probability of two consecutive received signal samples pertaining to these code bits, is derived. An approximation of this metric yields a less complex metric with negligible performance loss. Applications of these metrics to the decoding of binary and mixed alphabet LDPC codes are considered. In addition, performances of these metrics in the presence of signal-to-noise ratio estimation error are also studied.
Keywords :
parity check codes; quadrature phase shift keying; telecommunication channels; LDPC codes; LLR metrics; PSK transmission; estimation error; log-likelihood ratio; low-density parity-check codes; noncoherent channels; quadrature differential phase-shift keying; signal-to-noise ratio; AWGN; Application software; Differential phase shift keying; Estimation error; Information theory; Iterative decoding; Parity check codes; Phase shift keying; Signal to noise ratio; Turbo codes;
Conference_Titel :
Information Theory and Its Applications, 2008. ISITA 2008. International Symposium on
Conference_Location :
Auckland
Print_ISBN :
978-1-4244-2068-1
Electronic_ISBN :
978-1-4244-2069-8
DOI :
10.1109/ISITA.2008.4895388
