Optimal UAV Deployment and Resource Management in UAV Relay Networks

Abstract

UAV equipped three-dimensional (3D) wireless networks can provide a solution for the requirements of 5G communications, such as enhanced Mobile Broadband (eMBB) and massive Machine Type Communications (mMTC). Especially, the introduction of an unmanned aerial vehicle (UAV) as a relay node can improve the connectivity, extend the terrestrial base station (BS) coverage and enhance the throughput by taking advantage of a strong air-to-ground line of sight (LOS) channel. In this paper, we consider the deployment and resource allocation of UAV relay network (URN) to maximize the throughput of user equipment (UE) within a cell, while guaranteeing a reliable transmission to UE outside the coverage of BS. To this end, we formulate joint UAV deployment and resource allocation problems, whose analytical solutions can be hardly obtained, in general. We propose a fast and practical algorithm to provide the optimal solution for the number of transmit time slots and the UAV relay location in a sequential manner. The transmit power at BS and UAV is determined in advance based on the availability of channel state information (CSI). Simulation results demonstrate that the proposed algorithms can significantly reduce the computational effort and complexity to determine the optimal UAV location and transmit time slots over an exhaustive search.

Resource Allocation of Multiple Base Stations for Throughput Enhancement in UAV Relay Networks

“…In the URNs, the SINR enhancement of a wireless backhaul link is the key to guaranteeing a reliable relay link to isolated user equipment (U o ) without throughput degradation of another UE in the URN. Several studies have focused on achieving a stronger backhaul link in the URN by focusing on optimal UAV placement and resource allocation [25][26][27][28][29][30][31]. In [25], the resource allocation of the transmission power, bandwidth and transmission rate, and the position of the UAV relay node are jointly investigated to maximize the system throughput.…”

“…Ref. [31] proposed UAV deployment and the time allocation algorithm for fast and optimal UAV deployment. It first determines the minimum required transmission time slots between ground BS and UAV and between UAV and a remote user to ensure a robust wireless backhaul and access link.…”

“…Studies in [25][26][27][28][29][30][31] considered a single transmission from a single BS to set up a wireless backhaul link without considering an adjacent BS. However, due to interference from a nearby BS, an outage of U o can occur because it cannot have a strong relay link, which results in the throughput degradation of other UE in the URN.…”

End-Cloud Collaboration Navigation Planning Method for Unmanned Aerial Vehicles Used in Small Areas

“…Navigation planning is one of the key technologies for UAVs to synergistically perform regional search [ 1 ], communication support [ 2 ], logistics transportation [ 3 ], forest prevention and control [ 4 ], and other tasks. Navigation planning refers to the formulation of the optimal flight path from the initial point to the target point via the UAV platform or background assistance after task assignment, meeting the constraints of the UAV performance and environmental conditions, and taking into account the terrain, threats and other factors [ 5 ].…”

Editorial: Special Issue “Unmanned Aerial Vehicle (UAV)-Enabled Wireless Communications and Networking”

“…Ref. [1] proposed a fast and practical algorithm for UAV relay networks to provide the optimal solution for the number of transmit time slots and the UAV relay location in a sequential manner. The transmit power at the base station and the UAV was determined in advanced based on the availability of channel state information (CSI).…”