A Novel Multiple Relay Selection Strategy for LTE-Advanced Relay Systems

This paper considers a multiple decode-and-forward (DF) relay assisted network in the Long Term Evolution Advanced (LTE-A) system. Multiple relay nodes (RNs) joint transmission is applied to enhance the fairness of capacity for edge user (UE). But a number of RNs activated in the same time-frequency block group (TFBG) will let inter-cell interference (ICI) be stronger, and will reduce the system average capacity. In order to reconcile this contradiction between average capacity and fairness, this paper proposes an utility function (UF) which takes "RN-UE\´s demand" and "RNs\´ efficiency" into account. Besides, a low complexity greedy multi-RN selection (GMRS) scheme based on the UF (GMRS-UF) also be proposed. The simulation results show that GMRS has low complexity but outstanding performance. Compared with previous RN selection strategy, GMRS-UF could reduce ICI by discarding in efficient RNs, thereby promoting the average system throughput. And GMRS-UF can achieve any compromise between average capacity and fairness.