Performance Comparison of Iterative Decoding Algorithm Using the Extrinsic Information Transfer Chart

The Extrinsic Information Transfer (EXIT) chart is a powerful tool to design and optimize iterative systems, which visualizes the exchange of mutual information in an iterative system. Bit-interleaved coded modulation with iterative decoding (BICM-ID) is a bandwidth efficient transmission scheme. We study the performance and iterative behavior of the decoding algorithm for BICM-ID system with the tool of EXIT chart. Analysis and simulation results show that fixed-const-log-APP algorithm has the lowest decoding complexity in terms of number of iterations, max-log-APP follows it and log-APP has the highest decoding complexity, but their performance is in inverse order. With the increase of the channel signal-to-noise ratio, their performances come close to each other and it takes fewer iterations for them to get a low bit error rate performance.