June 09, 2017

Semi-analytical evaluation of concatenated RS/LDPC coding performance with finite block interleaving

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 contribution we present a semianalytical evaluation of the word error rate (WER) performance of a system with Reed-Solomon (RS) outer coding, finite block interleaving, low-density parity check (LDPC) inner coding and mapping to a symbol constellation. The proposed evaluation method relies on a simple single-parameter statistical mixture model for the number of byte errors in the LDPC codeword after the inner decoding. Only the WER and byte error rate (ByteER) of the inner subsystem, determined by the LDPC code and the considered constellation, are required to compute the error performance 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 channel and the Rayleigh block-fading channel.