Semi-Analytical Evaluation of Concatenated RS/LDPC Coding Performance With Finite Block Interleaving

Abstract

The Monte Carlo (MC) simulation of the error performance of a concatenated coding system with finite interleaving depth between the outer and inner codes is time-consuming, especially when targeting low error rates and examining several interleaver settings. In this letter, we present a semi-analytical evaluation of the word error rate (WER) performance of a system with Reed–Solomon (RS) outer coding, finite block interleaving and systematic low-density parity check (LDPC) inner coding. The proposed evaluation method relies on a simple semi-analytical statistical model for the number of bit errors in a segment of the information word after LDPC decoding on the AWGN channel. Only the WER and bit error rate of the inner subsystem (LDPC code and the considered constellation) are required to compute the WER of the concatenated code, corresponding to different parameters of the RS code and the interleaver. We show that the semi-analytical WER of the concatenated system closely matches the WER resulting from MC simulations for both the AWGN and Rayleigh block-fading channels.