Interference Cancellation Using Precoding Design for UAV Systems with LOS Channels

This work studies a multi-user interference system consisting of multiple ground base stations (BSs) and multiple unmanned aerial vehicle (UAV) users. Each BS is equipped with a uniform linear array (ULA) of antennas and sends signals to its associated UAV user under co-channel interference and with line-of-sight (LOS) channels. A precoding scheme fully cancelling the interference to its unassociated UAVs is proposed for each ground BS. The signal-to-interference-plusnoise ratio (SINR) of the design is also analyzed. By connecting the precoding vectors with polynomials, we derive the precoding solution and the SINR expression in closed-forms. Simulation results are provided to demonstrate the superior performance of the proposed design to benchmark schemes and to validate the SINR derivations.