Design, analysis, and performance evaluation for BICM-ID withsquare QAM constellations in Rayleigh fading channels

摘要

We consider bit-interleaved coded modulation with iterativendecoding (BICM-ID) for bandwidth-efficient transmission over Rayleighnfading channels. We propose the design criteria that utilize a largenHamming distance inherited in a low-rate code and a new labelingntechnique designed specifically for fading channels. This results in anlarge coding gain over noniterative coded modulation and performancenclose to that of “turbo” coded modulation with lessncomplexity. We also show that BICM-ID designed for fading channelsnusually has a very good performance over the additive white Gaussiannnoise (AWGN) channel while the converse is difficult to achieve. Whenncombined with signal space diversity, diversity order can be improved tontwice the diversity order of conventional BICM-ID; therefore, the codencomplexity can further be reduced while maintaining the same level ofnperformance. Specifically, with the bandwidth efficiency of 2 bits/s/Hznover Rayleigh fading channels, a bit error rate (BER) of 10-6ncan be achieved with 16-QAM, a four-state rate 1/2 code atnEb/N0 of about seven dB. We also derivenperformance bounds for BICM-ID with and without signal space diversitynover Rayleigh fading channels, which can be easily extended for otherntypes of fading channels