Fair Integrated Sensing and Communication for Multi-UAV-Enabled Internet of Things: Joint 3-D Trajectory and Resource Optimization

Unmanned aerial vehicle (UAV) has been widely used as an aerial base station (BS) to assist the ground communications for Internet of Things (IoT) due to its wide-area coverage, high-mobility, and Line-of-Sight (LoS) communication link. In this article, a multi-UAV enabled IoT is considered, where the UAVs provide integrated sensing and communication (ISAC) services to the IoT nodes. The radar mutual information (MI) is introduced to measure the sensing performance of ISAC from the information theory perspective. To achieve fair communications, we seek to maximize the minimum communication rate per IoT node by jointly optimizing node scheduling, transmit power and 3-D trajectory of the UAV under the constraint of radar MI for each IoT node. The formulated nonconvex multivariable optimization problem is divided into three subproblems, including UAV scheduling optimization, UAV transmit power optimization, and UAV 3-D trajectory optimization. The near-optimal solutions of the original optimization problem can be achieved by proposing a three-layer iterative optimization algorithm to optimize the three subproblems iteratively. The simulation results demonstrate that the proposed optimization scheme can obviously improve communication rate under the constraint of radar MI as well as achieve fair communication for each node.

I. Introduction

Internet of Things (IoT) is a huge network of things that connects various physical devices and objects via the Internet so that they can communicate and interact with each other [1]. The IoT has the functions of data collection, information sharing and data analysis through sensors and network connections, which can be applied in various fields, such as agriculture, healthcare, transport, etc. [2], [3], [4]. By establishing IoT base stations (BSs), the IoT nodes can share their sensing information with the surrounding devices [5], [6]. However, the IoT faces challenges in efficiently exchanging information when the number of IoT nodes is too large [7]. To address this issue, unmanned aerial vehicles (UAVs) are utilized as aerial BSs to assist the ground IoT communications in remote areas or emergency situations [8].