Antenna selection for downlink transmission in large scale green MIMO system

Large scale MIMO (multiple-input multiple-output) requires a large number (tens or hundreds) of base station antennas serving a much smaller number of terminals, with large gains in energy efficiency and spectral efficiency compared with traditional MIMO technology. Large scale antennas mean large scale radio frequency (RF) chains. Considering the plenty of power consumption and high cost of RF chains, antenna selection is necessary for large scale MIMO wireless communication systems in both transmitting end and receiving end. In this paper, an energy efficient antenna selection algorithm based on convex optimization is proposed for large scale MIMO wireless communication systems. On the condition that the channel capacity of the cell is larger than a certain threshold, the number of transmit antenna, the subset of transmit antenna and servable mobile terminals (MTs) are jointly optimized to maximize energy efficiency. The joint optimization problem is proved in detail. The proposed algorithm is verified by both mathematical analysis and numerical simulations. According to the simulation results, huge performance gain of energy efficiency is obtained comparing with no antenna selection.