Bit error rate analysis of convolutionally coded BICM with specific interleaver structures

Bit-interleaved coded modulation (BICM) has found its application in various wireless communication systems due to its simplicity in the design of coding and modulation. In particular, the BICM combined with convolutional coding has been adopted by several recent standards due to its low complexity and low latency at the decoder side. The performance of the convolutionally coded BICM depends not only on the constraint length of the code but also significantly on the structure of the bit interleavers introduced mainly for the purpose of dispersing the correlated bits. To date, however, theoretical analysis of the performance that well captures its dependence on the interleaver structures has not been presented in conjunction with the convolutionally coded BICM due to its complexity in precise analysis. In this paper, we derive a tight approximate BER expression over AWGN channels to evaluate its performance for a given bit interleaver structure, and present a design guideline for an optimal interleaver structure with its performance over fading channels in mind.