Joint transmit antenna selection and precoding for millimeter wave massive MIMO systems

Millimeter wave (mmW) communication coupled with massive MIMO architecture is attaining considerable attention to overcome the huge data rate requirements. Increasing the dimensions of a massive MIMO architecture provides spatial multiplexing gains, but at the cost of decrease in hardware efficiency. To optimize the energy efficiency of massive MIMO systems, in this paper, focusing on a sub-connected hybrid architecture, we propose a joint transmit antenna selection and precoding technique. Low Complexity heuristic algorithms are used to perform the antenna selection in order to limit the number of active antennas, hence, decreasing the power consumption which subsequently increases the energy efficiency. Precoding for the selected transmit antennas is performed using successive interference cancellation (SIC) based scheme. Simulation results show that the heuristic algorithms based transmit antenna selection scheme requires less computations and its performance is close to exhaustive search algorithm. Furthermore, SIC based precoding enables to overcome serious signal attenuation of mmW systems and performs best in terms of spectral efficiency for a partially connected hybrid structure. The joint solution is optimal in-terms of computational complexity and energy efficiency, which optimizes the performance of mmW massive MIMO systems.