Bit-interleaved coded modulation for delay-constrained mobile communication channels

The role of the interleaver in a bit-interleaved coded modulation (BICM) system is investigated. Square block interleavers and convolutional interleavers are compared to the random interleaver originally used by Zehavi (1992). It is shown that for short latencies (20 ms) the square block interleaver performs better than the random interleaver. However, when the side of the square block interleaver, √N is a multiple of n, the coded bits are grouped in such a way that the diversity, and hence performance is reduced. For short delays, the convolutional interleaver outperforms both the random and square block interleaver as the vehicle speed varies from pedestrian to freeway speeds