Performance Evaluation of Relay-Aided Multi-cell OFDMA System

In this paper, we consider the throughput performance in relay-aided multi-cell orthogonal frequency division multiple access (OFDMA) system, when mobile user (MS) is uniformly distributed and relay station (RS) is located at some typical positions, such as d_RS = 0:5 and d_RS = 0:85, where d_RS is the ratio between the distance from RS to base station (BS) and the cell radius. Although cooperative diversity and frequency reuse improve the throughput gain, more spectral and time resources will be occupied. Simulation results demonstrate that multi-cell system with RS deployed obtains very limited throughput gain compared with non-relay system. Whereas, if free space optics (FSO) or wired link is available between BS and RS, the throughput performance will be improved significantly.