Net Throughput of Centralized and Decentralized Cooperative Networks With Relay Selection

Relay selection is an attractive approach for achieving diversity gain in cooperative communications. In this letter, an optimal decentralized relay selection scheme that maximizes the net throughput is investigated. We compare the net throughput of centralized and decentralized relay selection schemes. The impact of overhead is included in our analysis. We show that the centralized scheme achieves a higher net throughput than the decentralized scheme if the number of relays is small and/or the channel is static. Although the decentralized scheme significantly reduces the amount of overhead, it suffers from unavoidable performance loss. For given system environments, the criterion for determining which scheme should be applied is also provided.