Base Station Selection Technique for MMSE Joint Transmission in Downlink Cooperative MIMO System

Cooperative multiple input multiple output (MIMO) system is capable in mitigating co-channel interference (CCI) that limits the downlink capacity of cellular network. Among the joint transmission designs for base station (BS) cooperation, the linear joint transmissions with per-base power constraint is preferred due to its computational simplicity and reality. However, since the transmissions with per-base power constraint sometimes make BSs cannot fully utilize their usable power, it leads considerable capacity loss. In this paper, we propose a BS selection technique for MMSE joint transmitter in downlink cooperative MIMO system to relive the inefficient usage of power under per-base power constraint. To find the BS group which yields the highest capacity, we compare the system capacity of all the possible BS groups. Simulation results show that the BS selection significantly improves the system capacity compared to the conventional linear joint transmissions by overcoming the aforementioned power allocation problem.