Throughput Maximization of Mixed FSO/RF UAV-Aided Mobile Relaying With a Buffer

In this paper, we investigate a mobile relaying system assisted by an unmanned aerial vehicle (UAV) with finite size of the buffer. Under buffer limit and delay constraints at UAV relay, consider dual-hop mixed free-space optical/radio frequency (FSO/RF) (i.e., source-to-relay relay-to-destination links employ FSO RF links, respectively). Taking imbalance in transmission rate between into consideration, address trajectory design relay node to obtain maximum data throughput ground user terminal. Specifically, classify two schemes according requirements, i.e., i) delay-limited ii) delay-tolerant transmission. Accordingly, propose iterative algorithm effectively locally optimal solution our optimization problems further present complexity analysis algorithm. Through algorithm, resulting trajectories over atmospheric condition, size, requirement. addition, show optimum throughput-delay tradeoff for given system. The numerical results validate that proposed buffer-aided delay-considered scheme obtains 223.33% gain compared conventional static scheme.