Bit-interleaved coded modulation with signal space diversity in Rayleigh fading

We present a combined method of bit-interleaved coded modulation (BICM) with coordinate interleaving and a rotated constellation, also known as signal space diversity. The diversity order can be increased to twice the diversity order of BICM, which is the minimum Hamming distance of a code. This greatly improves the performance over Rayleigh fading while preserving minimum squared Euclidean distance of BICM. Our simulation results show that the new combined scheme greatly outperforms BICM and bit-interleaved I-Q TCM as well as coordinate-interleaved TCM over Rayleigh fading channels. We first describe BICM and signal space diversity schemes, then follow with the design of BICM with signal space diversity. The complexity reduction technique is also investigated.