A comparison of orthogonal and overlapped relay subchannel allocation schemes for OFDMA based systems

This paper investigates the comparison of two different channelization schemes of relay links in the relay aided cellular network for different transmit power and the number of relays. One is the orthogonal relay subchannel allocation (ORRSA) which assigns each relay links to mobiles with orthogonal subchannels, leading to no interference between relays in the same cell. The other is the overlapped relay subchannel allocation (OVRSA) that maximizes spectral efficiency by allowing each relay to share same subchannels among them. Simulation results show that ORRSA provides slightly better cell throughput over OVRSA in multiple cell environment and both schemes of being investigated show cell throughput increases as the number of RSs per cell increases. Finally, it is observed that RS transmit power has little influence on the cell throughput performance.