Optimum aerial BS deployment for moving users based on quicksort and ZF-SIC techniques: Uplink and downlink scenarios

Abstract

This paper proposes a single UAV acting as a base station (BS) for downlink users (DUs). The UAV follows the Gauss–Markov (GM) mobility model and accounts for interference from device-to-device (D2D) communications. In the uplink, users transmit their coordinates to the UAV via NOMA, where interference is mitigated using the ZF-SIC technique. Candidate UAV locations are randomly generated within the coverage area. For each location, Algorithm 1 evaluates the average user distance, coverage probability (ACP), and achievable rate (AAR). The following step includes sorting the calculated values in increasing order using QuickSort algorithm (Algorithm 2). In the end, Algorithm 3 obtains the optimal drone positions at each time interval. The MATLAB simulation outcomes show that when the drone’s best position is found, the ACP, representing the total number of service users, reaches 95 out of 100, with the AAR of DUs recorded at 0.15 Gbps. MATLAB simulations demonstrate that the proposed method achieves an ACP of 95% (95 out of 100 users served) and an AAR of 0.15 Gbps, outperforming existing approaches. Its value is the greatest when comparing with other methods.