Joint optimization of relay selection and power allocation in cooperative wireless networks

In cooperative wireless networks, it is often the case that multi-source and multi-relay cooperate to transmit their own data to the destination, namely, the access point. For the cooperative systems, the choice of relay and the allocation of power between the source and the relay are important design issues. In this paper, based on the optimal power allocation between one source and one relay under an outage constraint, the joint optimization of relay selection and power allocation is done efficiently by introducing a greedy and exchange algorithm (GAEA), which aims at minimizing the total transmission power in the multi-source and multi-relay wireless networks where one relay can only be allocated to one source. Simulation results and numerical analyses show that, the proposed algorithm, with low computational complexity, can achieve the similar performance as the exhaustive search algorithm and save transmission power significantly.