Spectrum reuse schemes for OFDMA cellular networks with fixed relay stations

This paper addresses the problem of spectrum reuse in the broadband Orthogonal Frequency Division Multiple Access (OFDMA) cellular system with two-hop fixed relay nodes operating in decode-and-forward and half-duplex mode. Two novel spectrum reuse schemes are proposed to improve the spectral efficiency, both of which have good trade-offs between multi-user diversity and interference coordination. One aims to exploit higher multi-user diversity and the other develops a novel spectrum reuse framework which can achieve much higher spectral efficiency. It is demonstrated through intensive system-level simulation the performance of our proposed spectrum reuse schemes are superior to several known spectrum reuse schemes. Besides, both proposed schemes support uniform and non-uniform traffic distribution.