Throughput Maximization of Dynamic TDD Networks with a Full-Duplex UAV-BS

Dynamic time division duplex (D-TDD) is a promising technology for the future networks, enabling communication nodes to change uplink and downlink traffic opportunistically in the time domain to improve communication resource management. In this article, we propose an innovative system architecture where a full-duplex unmanned aerial vehicle (UAV) serves as a base station (BS) to enhance the performance of D-TDD networks composed of multiple full-duplex ground users and provides essential mobility and duplexing flexibility. We theoretically and numerically analyze two typical communication scenarios under this architecture, namely single transceiver pair (single-pair case) and multiple transceiver pairs (multi-pair case), at any time slot. In the single-pair case, the full-duplex UAV-BS communicates with at most one uplink user and one downlink user at the same time. In the multi-pair case, the UAV-BS supports multiple uplink and downlink users simultaneously. We formulate the throughput optimization problems for each case by jointly considering the uplink/downlink scheduling, power allocation, energy consumption and UAV-BS trajectory. Efficient algorithms are developed to deal with the non-convex problems and proved to be convergent. In addition, extensive simulation results show that our algorithms can cater to asymmetric uplink and downlink traffic and outperform other competitive benchmarks.