Real-time high-definition (HD) video transmission for long distances (≥1 km) between an unmanned aerial vehicle (UAV) and a ground station is a challenging problem. The existing real-time solutions are limited to relatively low-quality video streaming, whereas an HD video, which is stored in the local memory, is accessible only when the UAV returns to the ground. In this study, a real-time HD video transmission system (VTS) with a multiple-input multiple-output (MIMO) antenna configuration and state-of-the-art coverage is proposed for security and inspection applications. The proposed VTS employs ultrathin, lightweight antennas that are suitable for seamless integration with a UAV’s body without any protrusion. A $3\times3$ MIMO configuration with large antenna bandwidths (3.9% at 2.4 GHz and 6.9% at 5.2 GHz) enables the simultaneous transmission of multiple data streams with high data rates (>30 Mbps), and a high antenna gain (~10 dBi) allows a relatively long communication range (>3 km). In field experiments, the UAV module (comprising thin conformal antennas, embedded electronics, an RF transceiver, and an HD camera) is attached to a commercial drone DJI Matrice 600 Pro. The HD video’s reception performance is investigated for operation in two frequency bands (2.4 and 5.2 GHz) for both horizontal and vertical antenna orientations. The maximum and average data rates for various distances are reported. Based on the conducted field experiments, it is found that the proposed VTS is capable of transmitting real-time HD video up to a 3.56-km distance with a receiver sensitivity of −76 dBm. The maximum achieved data rates at a 500-m distance are ~10 and ~43 Mbps for operation in the 2.4- and 5.2-GHz frequency bands, respectively.

中文翻译：

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采用 3 × 3 MIMO 天线系统为无人机自主开发的高清视频传输系统

无人机（UAV）和地面站之间长距离（≥1 km）的实时高清（HD）视频传输是一个具有挑战性的问题。现有的实时解决方案仅限于质量相对较低的视频流，而存储在本地内存中的高清视频只有在无人机返回地面时才能访问。在这项研究中，为安全和检查应用提出了一种具有多输入多输出 (MIMO) 天线配置和最先进覆盖范围的实时高清视频传输系统 (VTS)。提议的 VTS 采用超薄、轻量级的天线，适合与无人机机身无缝集成，没有任何突出。一个 $3\times3$具有大天线带宽（2.4 GHz 时为 3.9%，5.2 GHz 时为 6.9%）的 MIMO 配置能够以高数据速率（>30 Mbps）同时传输多个数据流，并且高天线增益（~10 dBi）允许相对通信距离远（> 3 km）。在现场实验中，无人机模块（包括薄保形天线、嵌入式电子设备、RF 收发器和高清摄像头）连接到商用无人机 DJI Matrice 600 Pro。针对水平和垂直天线方向的两个频段（2.4 和 5.2 GHz）操作，研究了高清视频的接收性能。报告了各种距离的最大和平均数据速率。基于进行的现场实验，发现所提出的 VTS 能够传输高达 3.5 倍的实时高清视频。56 公里距离，接收器灵敏度为 -76 dBm。在 2.4- 和 5.2-GHz 频带中运行时，在 500 米距离上实现的最大数据速率分别为 ~10 和 ~43 Mbps。