Radiation Pattern Design for Reconfigurable MU-MISO System with Zero-Forcing Precoding

Pattern reconfigurable multi-antenna array can reshape the wireless channel with different radiation patterns to achieve performance gains. In this paper, we exploit the benefits of reconfigurable antennas to maximize the signal-to-noise-ratio (SNR) of users in the downlink of a multi-user multi-input singleoutput system, when zero-forcing (ZF) precoder is employed. We use the sampling vectors to reveal the physical mechanism of reconfigurable patterns on the wireless channel, and show that reconfigurable patterns can redistribute the channel gains of all scattering paths. We consider the practical case where all the antenna elements adopt the same radiation pattern, and we propose to optimize the radiation pattern of the reconfigurable array for received SNR maximization, where the Successive Convex Approximation (SCA) algorithm and Majorization-Minimization (MM) scheme are proposed to obtain a promising solution. Numerical results demonstrate that reconfigurable patterns can further improve the bit error rate and throughput performance over the legacy MU-MISO system.