Distributed Spatially-Modulated Space-Time-Block-Codes

In this paper, a novel energy-efficient protocol, intended for wireless networks with large number of relay nodes, is proposed. The main distinguishable feature of the proposed protocol is that it offers throughput enhancement, by having the same diversity-gain and having to activate the same number of relay nodes at any given time-instance, as the the conventional distributed space-time-block-codes (D-STBC). The proposed protocol applies the recently introduced idea of Spatially-Modulated Space-Time-Block-Codes (SM-STBC) devised for multiple-input-multiple-output (MIMO) systems to cooperative relay networks. The specific contributions of this paper are: i) an error-aware Maximum-Likelihood (ML) demodulator, which is robust to demodulation errors at the relays is developed; ii) a low-complexity error-aware demodulator is also developed; and iii) it is shown, with the help of Monte Carlo simulations, that the proposed protocol outperforms state-of-the-art relaying protocols.