Low complexity algorithms for relay selection and power control in interference-limited environments

We consider an interference-limited wireless network, where multiple source-destination pairs compete for the same pool of relay nodes. In an attempt to maximize the sum rate of the system, we address the joint problem of relay assignment and power control. Initially, we study the autonomous scenario, where each source greedily selects the strategy (transmission power and relay) that maximizes its individual rate, leading to a simple one-shot algorithm of linear complexity. Then, we propose a more sophisticated algorithm of polynomial complexity that is amenable to distributed implementation through appropriate message passing. We evaluate the sum rate performance of the proposed algorithms and derive conditions for optimality. Our schemes incorporate two of the basic features of the LTE-Advanced broadband cellular system, namely interference management and relaying. We also provide guidelines on how our algorithms can be incorporated in such multichannel systems.