Optimum relay location and power allocation of cooperative decode-and-forward dual-hop ARQ networks

In this paper, we consider a multi-relay cooperative network assisted by the Automatic Repeat reQuest mechanism. In particular, the source node broadcasts the encoded stream to a set of relaying nodes and a relay will be chosen at each retransmission round to assist the source to convey the same stream to the common destination. Afterwards, we develop a semi-analytical method to compute the exact end-to-end outage probability, average delay and throughput metrics for the general case where the relays are positioned at various locations. This analytical method is corroborated by extensive simulation results to prove the accuracy of the proposed formulation. Further, we assess the performance of several relay-placement and power allocation configurations to find the optimal scheme.