标题： 一种用于无人机移动中继的新存储-然后放大-转发协议 显示英文标题

标题： A New Store-then-Amplify-and-Forward Protocol for UAV Mobile Relaying

摘要： 在本文中，我们考虑使用无人机（UAV）作为移动中继，以协助两个无直接链路的地面用户之间的通信。 我们提出了一种新颖的存储-放大-转发（SAF）中继协议，使无人机能够结合其移动性与低复杂度的AF中继。 具体来说，来自源的接收信号首先在无人机的缓冲区中存储，然后当无人机飞近目的地时进行放大并转发到目的地。 通过联合优化源/UAV发射功率、无人机轨迹以及无人机接收和转发的每个数据包的时间槽配对，我们旨在通过这种新的SAF协议最大化无人机启用的中继系统的吞吐量。 由于该问题是一个难以解决的非凸混合整数优化问题，我们通过应用匈牙利算法、交替优化和连续凸逼近技术，提出了一种高效算法来获得其次优解。 数值结果表明，所提出的移动SAF中继优于没有信号存储的传统AF中继。 显示英文摘要

摘要： In this letter, we consider the use of an unmanned aerial vehicle (UAV) as a mobile relay to assist the communication between two ground users without a direct link. We propose a novel store-then-amplify-and-forward (SAF) relaying protocol for the UAV to exploit its mobility jointly with the low-complexity AF relaying. Specifically, the received signal from the source is first stored in a buffer at the UAV, then amplified and forwarded to the destination when the UAV flies closer to the destination. With this new SAF protocol, we aim to maximize the throughput of the UAV-enabled relaying system by jointly optimizing the source/UAV transmit power and the UAV trajectory, as well as the time-slot pairing for each data packet received and forwarded by the UAV. As this problem is a non-convex mixed integer optimization problem that is difficult to solve, we propose an efficient algorithm for obtaining a suboptimal solution for it by applying the techniques of Hungary algorithm, alternating optimization and successive convex approximation. Numerical results show that the proposed mobile SAF relaying outperforms the conventional AF relaying without signal storing.