Improvements in cooperative selection diversity based resource allocation in OFDMA relay-enhanced systems

Cooperative diversity methods are used to increase network throughput while considering fairness. By using these methods in OFDMA relay-enhanced systems, the best transmission link between direct transmission link and decode-and-forward relaying link is selected dynamically. In this paper, we improved the resource allocation algorithms introduced by Wang et. al. by proposing two new decision criteria for subchannel allocation process, called RA/NAS+ and RA/MAR+. Using these methods, the minimum resource requirements of each user is allocated by the number of required subchannels and end-to-end required data rate. Simulation results demonstrate that the RA/NAS+ achieves more system throughput especially in high varying channel conditions in comparison to previous method. Moreover, the comparison between RA/MAR+ and conventional resource allocation methods demonstrates that RA/MAR+ shows higher fairness level, while achieving an acceptable throughput.