2016/07/07 by Trinh Van Chien, Emil Björnson, Van Chien, Trinh +3
Engineering · Computer Science · #Advanced MIMO Systems Optimization #Advanced Wireless Network Optimization #Cooperative Communication and Network Coding
paper · pdf · doi:10.48550/arxiv.1607.01908
This paper aims to minimize the total transmit power consumption for Massive\nMIMO (multiple-input multiple-output) downlink cellular systems when each user\nis served by the optimized subset of the base stations (BSs). We derive a lower\nbound on the ergodic spectral efficiency (SE) for Rayleigh fading channels and\nmaximum ratio transmission (MRT) when the BSs cooperate using non-coherent\njoint transmission. We solve the joint user association and downlink transmit\npower minimization problem optimally under fixed SE constraints. Furthermore,\nwe solve a max-min fairness problem with user specific weights that maximizes\nthe worst SE among the users. The optimal BS-user association rule is derived,\nwhich is different from maximum signal-to-noise-ratio (max-SNR) association.\nSimulation results manifest that the proposed methods can provide good SE for\nthe users using less transmit power than in small-scale systems and that the\noptimal user association can effectively balance the load between BSs when\nneeded.\n