Unmanned aerial vehicle (UAV) has been more and more widely used in military and civilian, with its unique advantages of flexibility, convenience, and wide coverage. As flying stations, UAVs can quickly set up relay communication links for different missions, to enhance the receiving signal power, increase the system capacity, and expand the communication coverage. In this article, we investigate a two-way multihop UAV relaying network, where there are two ground users as sources and multiple UAVs as relays to help the two ground sources exchange information. For the purpose of enhancing the efficiency of the investigated UAV-assisted relaying, we come up with a productive two-way multihop UAV relaying pattern, which can achieve a data rate of (1/2)({1}/{2}) data packets per time slot with the decode-and-forward protocol. Then, we further formulate a joint transmit power and trajectory optimization problem for the UAVs in this two-way multihop relaying scenario. The formulated problem is nonconvex which makes it difficult to solve directly; hence, we propose an iterative algorithm to obtain an approximate optimal solution based on block coordinate descent and successive convex optimization techniques. Numerical results demonstrate that our proposed two-way multihop UAV relaying network achieves significant throughput gains compared with other benchmark schemes.

中文翻译：

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双向多跳无人机中继网络的联合发射功率和轨迹优化


无人机以其灵活、便捷、覆盖范围广等独特优势，在军事和民用领域的应用越来越广泛。无人机作为飞行站，可以针对不同任务快速建立中继通信链路，增强接收信号功率，增加系统容量，扩大通信覆盖范围。在本文中，我们研究了一个双向多跳无人机中继网络，其中有两个地面用户作为源，多个无人机作为中继，以帮助两个地面源交换信息。为了提高所研究的无人机辅助中继的效率，我们提出了一种高效的双向多跳无人机中继模式，可以实现 (1/2)({1}/{2}) 的数据速率使用解码和转发协议的每个时隙的数据包。然后，我们进一步制定了双向多跳中继场景中无人机的联合发射功率和轨迹优化问题。所表述的问题是非凸的，这使得直接求解变得困难；因此，我们提出了一种基于块坐标下降和连续凸优化技术的迭代算法来获得近似最优解。数值结果表明，与其他基准方案相比，我们提出的双向多跳无人机中继网络实现了显着的吞吐量增益。