Power Allocation for CoMP in LTE-advanced system

CoMP is one of key technologies in LTE-Advanced system to eliminate inter-cell interference, enhance system throughput and cell-edge spectrum efficiency. CS/CB (Coordinated Scheduling/Coordinated Beamforming) and JT (Joint Transmission) are two main technologies of CoMP. In this paper, cell-edge users transmit data by JT scheme, and cell-center users adopt CB scheme to eliminate interference. Precoding algorithm based on SLNR (Signal to Leakage and Noise Ratio) is adopted to improve quality of desired signal and restrain interference from adjacent cells. The proposed CoMP system gets more than 80% gain on both throughput and spectrum efficiency than single-point transmission. Based on the proposed coordinated system above, CoPA (Convex Optimization Power Allocation) power allocation scheme is proposed to maximize cell total data rates, subjected to maximum transmit power of each eNodeB. The proposed power allocation scheme achieves 2.3% gain on both throughput and spectrum efficiency compared with EPA (Equal Power Allocation).