An interleaver optimization for BICM-OFDM with convolutional codes over frequency-selective block fading channels

Abstract

Bit-interleaved coded modulation (BICM) system combined with orthogonal frequency-division multiplexing (OFDM) has been adopted in many recent wireless standards, where the random interleaver is commonly assumed due to its simplicity of analysis for BICM. On the other hand, the recent results have shown that BICM using convolutional code without any interleaving shows better performance than that with bit interleaving over an AWGN channel without fading. Nevertheless, the interleaver design suitable for BICM with convolutional code over general fading channels has not been well studied. In this paper, we propose an approach for optimizing conventional block interleavers in the framework of BICM-OFDM and demonstrate its effectiveness over frequency-selective Rayleigh and Ricean fading channels.