Unmanned aerial vehicle (UAV)-aided two-way relaying networks are designed, where a UAV is deployed to assist multiple pairs of users in their information exchange. There are two basic approaches for the user pairs’ information exchange within a single time slot via the UAV relay. The first approach is based on full-duplex, where all participants operate in the full-duplex mode to transmit and receive signals simultaneously. However, all transceivers have to operate in the face of severe self-interference, which cannot be completely suppressed. The second approach is based on conventional half-duplex, where the users send their information to the UAV within a certain fraction of the time slot, and the UAV relays them within the remaining fraction to avoid the self-interference. In either approach, the joint bandwidth and power allocation maximizing the sum information exchange throughput under realistic resource and user throughput constraints poses a complex nonconvex problem. New inner approximations are proposed for developing path-following algorithms for their computation. Our numerical results show that the time-fraction-based half-duplex approach clearly outperforms the high-complexity full-duplex approach.

中文翻译：

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无人机辅助双向多用户中继

设计了无人机 (UAV) 辅助的双向中继网络，其中部署了无人机以协助多对用户进行信息交换。用户对在单个时隙内通过无人机中继交换信息有两种基本方法。第一种方法基于全双工，其中所有参与者都以全双工模式运行，以同时发送和接收信号。然而，所有收发器都必须在严重的自干扰面前工作，而这种自干扰是无法完全抑制的。第二种方法基于传统的半双工，用户在时隙的某个部分内将他们的信息发送给无人机，无人机在剩余的部分内中继它们以避免自干扰。在任何一种方法中，在现实的资源和用户吞吐量限制下，联合带宽和功率分配使总信息交换吞吐量最大化，这提出了一个复杂的非凸问题。提出了新的内部近似，以开发用于其计算的路径跟踪算法。我们的数值结果表明，基于时间分数的半双工方法明显优于高复杂度的全双工方法。