As a newly emerging communication assistant equipment, unmanned aerial vehicles (UAVs) can be exploited to dispatch data files quickly to specific areas and support rapid deployment of communication links in complex terrain, which is of great significance for specific communication demands in disaster and remote areas. Nonorthogonal multiple access (NOMA), as a rosy technology in the fifth generation (5G) and future mobile communication systems, has been widely studied because of its ability in improving spectral efficiency and reducing transmission latency to enhance the overall Quality of Service (QoS) and meet the strict communication requirements. Based on these, in this article, we propose a device-to-device (D2D)-enhanced UAV-NOMA network architecture, in which D2D is introduced to increase the file dispatching efficiency. In our proposed D2D-enhanced UAV-NOMA network, the ground users (GUEs) that have already received file blocks (FBs) are allowed to reuse the time-frequency resources assigned to NOMA links to share their FBs with other GUEs, which significantly improves the efficiency of file dispatching. But this also leads to a complicated interference environment. In order to effectively manage the interference and minimize the UAV-assisted file dispatching mission time, we propose a graph-based file dispatching (GFD) protocol, in which the complicated joint optimization problem is decomposed to be solved efficiently and graph theory-based algorithms are proposed for resource allocation. The simulation results verify the advantages of our proposed D2D-enhanced UAV-NOMA network architecture and the efficiency of our designed GFD protocol in minimizing the total UAV-assisted file dispatching mission time.
Bibliographical noteFunding Information:
Manuscript received October 30, 2019; revised February 27, 2020, April 6, 2020, and April 20, 2020; accepted April 30, 2020. Date of publication May 15, 2020; date of current version September 15, 2020. This work was supported in part by the Ministry National Key Research and Development Project under Grant 2017YFE0121400, in part by the National Science Foundation under Grant CNS-1932413 and Grant ECCS-1935915, in part by the National Natural Science Foundation of China under Grant 61901302, in part by the Open Research Fund of National Mobile Communications Research Laboratory, Southeast University under Grant 2020D01, and in part by the Open Research Fund from Shenzhen Research Institute of Big Data under Grant 2019ORF01006. (Corresponding author: Rongqing Zhang.) Baoji Wang is with the State Key Laboratory of Advanced Optical Communication Systems and Networks, Department of Electronics, School of Electronics Engineering and Computer Science, Peking University, Beijing 100871, China, and also with the National Mobile Communications Research Laboratory, Southeast University, Nanjing 211189, China (e-mail: email@example.com).
© 2014 IEEE.
- Device to device (D2D)
- file dispatching
- nonorthogonal multiple access (NOMA)
- unmanned-aerial-vehicle (UAV) communications