3D UAV Trajectory and Communication Design for Simultaneous Uplink and Downlink Transmission

In this paper, we investigate the unmanned aerial vehicle (UAV)-Aided simultaneous uplink and downlink transmission networks, where one UAV acting as a disseminator is connected to multiple access points (AP), and the other UAV acting as a base station (BS) collects data from numerous sensor nodes (SNs). The goal of this paper is to maximize the system throughput by jointly optimizing the 3D UAV trajectory, communication scheduling, and UAV-AP/SN transmit power. We first consider a special case where the UAV-BS and UAV-AP trajectories are pre-determined. Although the resulting problem is an integer and non-convex optimization problem, a globally optimal solution is obtained by applying the polyblock outer approximation (POA) method based on the problem's hidden monotonic structure. Subsequently, for the general case considering the 3D UAV trajectory optimization, an efficient iterative algorithm is proposed to alternately optimize the divided sub-problems based on the successive convex approximation (SCA) technique. Numerical results demonstrate that the proposed design is able to achieve significant system throughput gain over the benchmarks. In addition, the SCA-based method can achieve nearly the same performance as the POA-based method with much lower computational complexity

An Energy Efficient Data Collection Using Multiple UAVs in Wireless Sensor Network: A Survey Study

   اليوم، مع التقدم العلمي والتكنولوجي في الروبوتات، والذكاء الاصطناعي، والسيطرة والحواسيب، المركبات البرية والجوية والبحرية قد تم الاهتمام بها. كما تم تحسين الطائرات بدون طيار (UAVs) بشكل كبير وهي مفيدة جدا للعديد من التطبيقات الهامة في الأعمال التجارية والبيئة الحضرية والعسكرية. أحد أهم استخدامات الطائرات بدون طيار في شبكات الاستشعار اللاسلكية (WSNs)  التي لديها طاقة منخفضة وقد لا تكون قادرة على الاتصال في مناطق واسعة. في هذه الحالة ، يمكن أن توفر الطائرة بدون طيار وسيلة لجمع بيانات WSN من جهاز واحد ونقلها إلى المستلم المقصود تركز هذه المقالة على مجال البحث في التطبيقات العملية للطائرات بدون طيار كجامع متنقل لشبكات الاستشعار اللاسلكية. أولا التحقيقات حول الطائرات بدون طيار المقترحة تم دراستها ومقارنة نقاط ضعفها مع بعضها البعض. وكذلك التحديات التقنية لتطبيقات الطائرات بدون طيار في شبكة الاستشعار اللاسلكية تم استكشافها.Today, with scientific and technological advances in robotics, artificial intelligence, control and computers, land, air, and sea vehicles, they have been considered. Unmanned aerial vehicles (UAVs) have also significantly improved and are very useful for many important applications in the business, urban and military environment. One of the important uses of UAVs in Wireless Sensor Networks (WSNs) is that devices with low energy and may not be able to communicate in large areas. Nevertheless, a UAV can provide a tool for collecting the data of WSN from one device and transmitting it to another device. This article focuses on the field of research on practical applications of UAVs as mobile collectors for wireless sensor networks. First, the investigations of the proposed UAV were studied and compared their weaknesses with each other. Then, the technical challenges of the applications of UAVs in the wireless sensor network were explored

Securing UAV Communications Via Trajectory Optimization

Unmanned aerial vehicle (UAV) communications has drawn significant interest recently due to many advantages such as low cost, high mobility, and on-demand deployment. This paper addresses the issue of physical-layer security in a UAV communication system, where a UAV sends confidential information to a legitimate receiver in the presence of a potential eavesdropper which are both on the ground. We aim to maximize the secrecy rate of the system by jointly optimizing the UAV's trajectory and transmit power over a finite horizon. In contrast to the existing literature on wireless security with static nodes, we exploit the mobility of the UAV in this paper to enhance the secrecy rate via a new trajectory design. Although the formulated problem is non-convex and challenging to solve, we propose an iterative algorithm to solve the problem efficiently, based on the block coordinate descent and successive convex optimization methods. Specifically, the UAV's transmit power and trajectory are each optimized with the other fixed in an alternating manner until convergence. Numerical results show that the proposed algorithm significantly improves the secrecy rate of the UAV communication system, as compared to benchmark schemes without transmit power control or trajectory optimization.Comment: Accepted by IEEE GLOBECOM 201