Title :
Design of irregular LDPC codes for BIAWGN channels with SNR mismatch
Author :
Saeedi, Hamid ; Banihashemi, Amir H.
Author_Institution :
Dept. of Syst. & Comput. Eng., Carleton Univ., Ottawa, ON
fDate :
1/1/2009 12:00:00 AM
Abstract :
Belief propagation (BP) algorithm for decoding low-density parity-check (LDPC) codes over a binary input additive white Gaussian noise (BIAWGN) channel requires the knowledge of the signal-to-noise ratio (SNR) at the receiver to achieve its ultimate performance. An erroneous estimation or the absence of a perfect knowledge of the SNR at the decoder is referred to as "SNR mismatch". SNR mismatch can significantly degrade the performance of LDPC codes decoded by the BP algorithm. In this paper, using extrinsic information transfer (EXIT) charts, we design irregular LDPC codes that perform better (have a lower SNR threshold) in the presence of mismatch compared to the conventionally designed irregular LDPC codes that are optimized for zero mismatch. Considering that min-sum (MS) algorithm is the limit of BP with infinite SNR over-estimation, the EXIT functions generated in this work can also be used for the efficient analysis and design of LDPC codes under the MS algorithm.
Keywords :
AWGN channels; binary codes; channel coding; channel estimation; decoding; parity check codes; BIAWGN channel; EXIT chart; belief propagation algorithm; binary input additive white Gaussian noise channel; channel estimation; decoding; extrinsic information transfer chart; irregular LDPC code design; min-sum algorithm; Additive white noise; Algorithm design and analysis; Belief propagation; Decoding; Degradation; Design optimization; Estimation error; Parity check codes; Robustness; Signal to noise ratio; Irregular LDPC codes, signal-to-noise ratio (SNR) mismatch, channel estimation error, LDPC code design, EXIT charts, belief propagation (BP) algorithm, min-sum algorithm;
Journal_Title :
Communications, IEEE Transactions on
DOI :
10.1109/TCOMM.2009.0901.060118