Node Selection and Two-Hop Power Allocation in Multi-Source Cooperative Mesh Networks

This paper considers relay selection and power allocation in a two-hop multi-source multi-destination mesh network wherein fixed relay nodes use the decode-and-forward protocol. The jointly optimal solution is of exponential complexity. Introducing a set of time-sharing factors into the objective function, and relaxing the selection constraint, provides an upper bound to the original problem. We also provide a heuristic method to impose selection on each source-destination pair. Second, we propose a decentralized selection scheme in which each individual source-destination pair chooses its best relay independently followed by power allocation. Simulation results reveals that the performance of the decentralized selection scheme almost exactly tracks that of an upper bound for both max sum rate as well as max min rate metrics. The key difference from previous works on selection is that, throughout, we account for the source-relay channel and the need for the relay to decode the source.