Design and analysis of eIRA codes on correlated fading channels

Abstract

We present a simple design technique for extended irregular repeat-accumulate (eIRA) codes (a class of efficiently encodable LDPC codes) for flat Rayleigh fading channels, using simple channels as surrogates in the design. We show that eIRA codes designed for the burst-erasure channel (BuEC) or the burst-erasure channel with AWGN (BuEC-G) achieve essentially the same performance over Rayleigh fading channels as codes designed for the fading channel. Thus, to design good codes for the Rayleigh fading channel, instead of implementing the complex design procedures targeted specifically for this channel, we propose the simple approach of designing codes over surrogate channels, the BuEC or the BuEC-G. We also derive a new channel statistic, the distribution of the number of faded bits per codeword which determines the difference between the performance of correlated and uncorrelated (ideally interleaved) fading channels.