TY  - JOUR
T1  - Construction of LDPC Codes for Non-Uniform Rayleigh Fading Channels Using PEXIT Analysis
AU  - Jeong, Hong-Jae 
AU  - Kim, Jae-Won 
JO  - The Journal of Korean Institute of Communications and Information Sciences
PY  - 2023
DA  - 2023/1/14
DO  - 10.7840/kics.2023.48.8.906
KW  - Differential evolution (DE)
KW  - low-density parity-check (LDPC) code
KW  - non-uniform channel
KW  - protograph extrinsic information transfer (PEXIT)
KW  - Rayleigh fading channel
AB  - In this paper, we propose a low-density parity-check (LDPC) code design algorithm in non-uniform Rayleigh fading channels. Specifically, protographs with superior decoding thresholds are designed using a protograph extrinsic information transfer (PEXIT) analysis algorithm and a differential evolution (DE) algorithm. In general, a fading channel is the same as an additive white Gaussian noise (AWGN) channel in which the size of the signal is modified for a fixed fading factor. If the fading factor is not fixed, the decoding threshold can be calculated by performing some intermediate calculations of the PEXIT analysis by the number of fading factors based on the Rayleigh fading distribution and averaging them. However, using multiple fading factors makes it impossible to utilize differential evolution algorithms in terms of computational complexity. Therefore, in this paper, we employ a small number of fading factors in differential evolution algorithms to alleviate the computational complexity in the most steps and design a protograph with an accurate and excellent decoding threshold by utilizing a large number of fading factors in the final step. Results on decoding thresholds and frame error rates (FERs) in various code rates show that the proposed design algorithm is effective for non-uniform Rayleigh fading channels.