Distributed space-time coding with decode-and-forward-amplify-and-forward selection relaying protocol in cooperative wireless sensor networks

Distributed space-time coding (DSTC) with an efficient relaying protocol, referred to as amplify-and-forward and decode-and-forward (DF-AF) selection relaying, has not received much attention yet. In the DF-AF selection relaying-aided DSTC transmissions, each relay could adaptively process the received signal according to its decoding state to improve the performance. In this study, the authors analyse the pairwise error probability (PEP) performance, the diversity order and the union bound on the error probability of the DSTC with DF-AF selection relaying in cooperative wireless sensor networks. More specifically, by introducing a random variable vector to denote the decoding state of the relays, the upper bounds of PEP are derived first for the DSTC with DF-AF selection relaying based on the Chernoff bound. Then, the diversity order and the union bound on the error probability are obtained based on the upper bounds of PEP. Finally, simulation results verify the theoretical analysis and demonstrate that the DSTC with DF-AF selection relaying has better error performance than the DSTC with DF protocol and the DSTC based on AF protocol.