Block-Markov encoding with network coding for cooperative communications

In this paper, we propose network coding as an operational implementation of information theoretic block-Markov coding for cooperative communications. This is a transmission strategy where users act as a relay for each other to help reliable recovery of the message at the destination(s). With analytical results, we show that even with this very simple implementation, we can outperform cooperative transmission schemes using legacy space–time (ST) and the repetition codes. We take outage probability and the diversity-multiplexing tradeoff curve as a performance measures to evaluate the gains offered by this so called cooperative communications using network coding scheme. The results show that, under block-fading channel, network coding based cooperative communications offers diversity order of 3 while ST and the repetition coding based cooperative transmission offers diversity order of 2 only. When the performance is compared in terms of diversity-multiplexing tradeoff, block-Markov codebook structure inspired, network coding based cooperative communications outperforms by 33%, in terms of multiplexing gain, both ST and the repetition coding based cooperative transmission schemes.