User Clustering and Scheduling in UAV Systems Exploiting Channel Correlation

Unmanned aerial vehicle (UAV) communication system equipped with multiple input and multiple output (MIMO) antennas has been recognized as an efficient technique for obtaining high spectral efficiency. To improve the system capacity in UAV communication scenario, this paper investigates the user clustering and downlink user scheduling strategy. We first develop a channel correlation based K-means algorithm for user clustering. Furthermore, to diminish intergroup interference, a greedy user scheduling algorithm driven by the K-means clustering strategy, is devised to appropriately select the users with low-correlated channels to schedule at the same time slot. Simulation results are provided to demonstrate the superior performance of the proposed scheduling algorithm over conventional method. It is observed that the presented K-means aided algorithm can achieve near maximum average sum rate with much lower computational complexity.