Optimization of Resource Allocation in Multihop HARQ Relay Networks with a Delay Constraint

By minimizing the outage probability, optimization is carried out in this paper to find joint optimal power allocation (OPA) and relay placement (ORP) for multihop relay networks adopting Hybrid Automatic Repeat reQuest (HARQ). Different from previous works, the joint OPA and ORP is analysed under generalized fading channels with the constraint on total transmit power, end-to-end relaying distance and maximum transmission number (delay). The simulation results demonstrate that for different fixed number of nodes and fading models, there are preferred deployments depending on path loss exponent and power retransmission strategy. By employing multiple retransmission round which can improve the reliability and energy efficiency without significant overhead, the end-to-end outage probability is no longer bounded by that of the weaker hop, i.e., the hop with a poor channel condition. The proposed strategy provides a dramatic improvement for the end-to-end outage probability by compensating the channel difference