A New Distributed-STBC Scheme for Cooperative Relaying in Wireless Networks

Space-time encoded communications aim at improving the quality and reliability of a wireless high-data rate link by exploiting both the temporal and spatial signal dimensions. However, these techniques are impeded by typically low profile requirement of the terminals, making impractical the deployment of multiple antennas, more particularly at the relay side. In this paper, we propose a new and simplified distributed space-time block Coding (D-STBC) scheme in which the STBC code is artificially generated by relying on three single-antenna nodes in the cooperative network and using less time slots than the conventional counterpart. The proposed scheme is then generalized to encompass both multiple cooperative relays and multiple receive antennas cases. Furthermore, our proposal is investigated with both decode- and-forward (DaF) and amplify-and-forward (AaF) relaying protocols. At the destination, zero-forcing detector is adopted for the D-STBC decoding, and maximum ratio combining (MRC) of the relays signals is performed when retaining multiple relays configuration. It is shown that, with one relay, our proposed scheme exhibits similar performance in terms of data reliability with the conventional STBC alternative, with the advantage of resorting to only one antenna per transmitting/retransmitting node. Moreover, the viable capabilities of the proposed scheme are fully pointed out with an increased number of relays.