Multi-dimensional MPSK for iterative demapping over AWGN and Rayleigh fading channels

We intend to investigate the performance of multi-dimensional (MD) MPSK modulation for iterative demapping. Design criteria of MD MPSK constellation labeling for AWGN channels and Rayleigh fading channels are proposed based on the extrinsic information transfer (EXIT) chart. Based on our criteria, we have established bit-interleaved coded modulation with iterative decoding (BICM-ID) schemes with QPSK and 8PSK of different dimensions. Simulation results show that optimized MD modulations have a good EXIT characteristic over the two channels and can improve the system´s performance in both the waterfall and the error floor region of the bit error rate (BER) curve. Specially, with a bandwidth efficiency of 1 bit/s/Hz over the AWGN channel, a BER of 10^-5 can be achieved with 6-D QPSK and a 4-state rate 1/2 convolutional code at SNR of 0.9 dB.