On Cooperative Achievable Rates of UAV Assisted Cellular Networks

• Published in: IEEE transactions on vehicular technology Vol. 69; no. 9; pp. 9882 - 9895
• Main Authors: Song, Yujae, Lim, Sung Hoon, Jeon, Sang-Woon, Baek, Seungjae
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.09.2020; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Algorithms; Bandwidths; Base stations; Cellular communication; Cellular networks; Computational geometry; Convexity; Cooperative DF; Ground stations; Numerical methods; Optimization; Particle swarm optimization; Radio equipment; resource allocation; Resource management; Terminals; Three-dimensional displays; UAV; unlicensed band; Unmanned aerial vehicles; Wireless communication
• ISSN: 0018-9545; 1939-9359
• DOI: 10.1109/TVT.2020.3003301

In this paper, we study an UAV base station (UBS) assisted cellular network that consists of a single ground macro base station (MBS), multiple UBSs, and multiple ground terminals. We assume that the MBS transmits to the UBSs and the terminals in the licensed band while the UBSs use a separate unlicensed band (e.g., Wi-Fi) to transmit to the terminals. For the utilization of the UBSs, we propose a cooperative decode-forward (DF) protocol in which multiple UBSs assist the terminals simultaneously while maintaining a predetermined interference level on the coexisting unlicensed band users. For our network setup, we formulate a joint optimization problem for minimizing the aggregate gap between the target rates and the throughputs of terminals by optimizing over the 3D positions of the UBSs and the resources (power, time, bandwidth) of the network. To solve the optimization problem, we propose an efficient nested structured algorithm based on particle swarm optimization and convex optimization methods. Extensive numerical evaluations of the proposed algorithm is performed considering various aspects to demonstrate the performance of our algorithm and the gain for utilizing UBSs.