Joint Optimization of Power Allocation and Relay Deployment in Wireless Sensor Networks

We study the problem of optimizing the symbol error probability (SEP) performance of cluster-based cooperative wireless sensor networks (WSNs). It is shown in the literature that an efficient relay selection protocol based on simple geographical information of the nodes to execute the cooperative diversity transmission, can significantly improve the SEP performance at the destination of such networks. Also, a similar analysis on the optimal power allocation for the source and the relay exists in the literature. However, we propose that to achieve the minimum SEP at the destination, a joint optimization of power allocation and relay selection should be accomplished. To this aim, we reformulate the SEP performance at the destination of a simple cluster-based cooperative WSN in the general form and solve the mentioned joint optimization problem efficiently for a relay deployment scenario. Simulation results demonstrate that the proposed joint optimization can effectively improve the SEP performance of the network for both 1-hop and multi-hop scenarios in comparison with the previous disjoint optimal relay deployment scheme.