Distributed Resource Allocation for Multi-Cell Relay-Aided OFDMA Systems

We propose an efficient resource allocation (RA) scheme for downlink of relay-aided orthogonal frequency division multiple access systems. To mitigate excessive computational complexity of the centralized RA where the base station (BS) is responsible for resource allocation of the entire cell, we take a distributed RA strategy with which each relay station (RS) and BS perform resource allocation for their respective receivers by themselves. The proposed RA scheme is composed of two parts, RS resource allocation (RS-RA) and BS resource allocation (BS-RA). Considering that multiple RSs compete for radio resource in a distributive manner, we design the RS-RA scheme according to noncooperative game framework. The proposed RS-RA scheme aims at allocating less resource to two-hop transmission via RS so that more resource can be used for one-hop (direct) transmission. This RA strategy greatly heightens the system performance. Simulation results show that the proposed RA scheme provides the high cell throughput and the low outage probability. In addition, we devise a heuristic RA scheme that can lower the computational complexity further with much smaller reporting overhead and also suggest an iterative algorithm that can easily implement the proposed RA scheme.