Optimization of beamforming and path planning for UAV-assisted wireless relay networks  

作　　者：Ouyang Jian Zhuang Yi Lin Min Liu Jia 

机构地区：[1]College of Computer Science and Technology, Nanjing University of Aeronautics and Astronautics [2]PLA University of Science and Technology [3]National Mobile Communications Research Laboratory, Southeast University [4]Computer Center, Nanjing University of Aeronautics and Astronautics

出　　处：《Chinese Journal of Aeronautics》2014年第2期313-320,共8页中国航空学报（英文版）

基　　金：supported by the National Natural Science Foundation of China (Nos. 61202351, 61271255);the Natural Science Foundation of Jiangsu Province (No. BK20131068);the Open Research Fund of National Mobile Communications Research Laboratory in Southeast University (No. 2012D15);the Funding of Jiangsu Innovation Program for Graduate Education (No. CXLX11_0202);the Fundamental Research Funds for the Central Universities

摘　　要：Recently, unmanned aerial vehicles （UAVs） acting as relay platforms have attracted considerable attention due to the advantages of extending coverage and improving connectivity for long-range communications. Specifically, in the scenario where the access point （AP） is mobile, a UAV needs to find an efficient path to guarantee the connectivity of the relay link. Motivated by this fact, this paper proposes an optimal design for beamforming （BF） and UAV path planning. First of all, we study a dual-hop amplify-and-forward （AF） wireless relay network, in which a UAV is used as relay between a mobile AP and a fixed base station （BS）. In the network, both of the AP and the BS are equipped with multiple antennas, whereas the UAV has a single antenna. Then, we obtain the output signal^to-noise ratio （SNR） of the dual-hop relay network. Based on the criterion of maximizing the output SNR, we develop an optimal design to obtain the solution of the optimal BF weight vector and the UAV heading angle. Next, we derive the closed-form outage probability （OP） expression to investigate the performance of the dual-hop relay network conveniently. Finally, computer simulations show that the proposed approach can obtain nearly optimal flying path and OP performance, indicating the effectiveness of the proposed algorithm. Furthermore, we find that increasing the antenna number at the BS or the maximal heading angle can significantly improve the performance of the considered relay network.Recently, unmanned aerial vehicles （UAVs） acting as relay platforms have attracted considerable attention due to the advantages of extending coverage and improving connectivity for long-range communications. Specifically, in the scenario where the access point （AP） is mobile, a UAV needs to find an efficient path to guarantee the connectivity of the relay link. Motivated by this fact, this paper proposes an optimal design for beamforming （BF） and UAV path planning. First of all, we study a dual-hop amplify-and-forward （AF） wireless relay network, in which a UAV is used as relay between a mobile AP and a fixed base station （BS）. In the network, both of the AP and the BS are equipped with multiple antennas, whereas the UAV has a single antenna. Then, we obtain the output signal^to-noise ratio （SNR） of the dual-hop relay network. Based on the criterion of maximizing the output SNR, we develop an optimal design to obtain the solution of the optimal BF weight vector and the UAV heading angle. Next, we derive the closed-form outage probability （OP） expression to investigate the performance of the dual-hop relay network conveniently. Finally, computer simulations show that the proposed approach can obtain nearly optimal flying path and OP performance, indicating the effectiveness of the proposed algorithm. Furthermore, we find that increasing the antenna number at the BS or the maximal heading angle can significantly improve the performance of the considered relay network.

关 键 词：Aircraft communication Beam forming Path planning Unmanned aerial vehicles Wireless relay networks 

分 类 号：V279[航空宇航科学与技术—飞行器设计]