Optimization of BICM mutual information and bit error rate of 8-ary signal constellations using genetic algorithms

Abstract

We propose the use of genetic algorithms for optimizing 8-ary signal constellations. The constellations are either optimized for a high bit interleaved coded modulation (BICM) mutual information or a low bit error rate (BER) in the additive white Gaussian noise channel (AWGN). We obtained a constellation that outperforms the 8-cross by 0.25 dB for a BICM mutual information of 2 bit/symbol. The optimized constellation for a low bit error rate requires a 0.4 dB lower SNR compared to the 8-cross for a BER of 10-3.