Subcarrier and Power Allocation in Multihop Relay System

Radio resource allocation is a key issue in multihop relay(MR) network.A subcarrier and power allocation algorithm for the downlink of two-hop relay systems was proposed,and the goal is to maximize the system throughput under a joint sum power constraint.The heuristic algorithm is composed of three steps:subcarriers allocation on the second hop,subcarrier pairing and power allocation.In power allocation,optimal power allocation(OPA) and equal power allocation(EPA) were proposed according to different computing complexities.Simulation results show that OPA always outperforms EPA and subcarrier pairing can improve the system performance effectively when the channel qualities of the first hop link and the second hop link are similar,moreover the proposed algorithm can exploit multiuser diversity gain.