Cooperative user relaying assisted load balancing scheme for OFDMA based cellular networks

Load balancing is one of the radio resource management functionalities for tackling the hotspot problem caused by bursty and unevenly distributed traffic. In the conventional handover based load balancing schemes, the shifted cell edge users will suffer Signal to Noise (SNR) degradation problem due to the poorer channel condition of the new link. In this paper, a cooperative user relaying assisted load balancing scheme is proposed to address this problem. In the proposed scheme, an edge user of a heavy-loaded hotspot cell can be handed over to a light-loaded neighbour cell by selecting an appropriate inactive user in the light-loaded cell as the user relay for cooperative transmission. The intention is to take the advantage of the cooperative diversity gain to counter act the SNR degradation. In the paper, the concept and procedures of the proposed cooperative user relay assisted load balancing scheme is presented. The theoretical analysis and simulation evaluations of the scheme are undertaken. Simulation results show that the proposed scheme can effectively balance the load between cells, improve SNR of the shifted cell edge users, enhance the system throughput and deduce the system call blocking probability.