Research And Implementation Of UAV High-speed Data Transmission Technology

This paper introduces the current development of UAVs and points out that highspeed and real-time communication between UAVs and ground stations has become a research hotspot in the field of UAVs.The UAV communication link has become the key to high-speed and real-time communication Link.Further,for high-speed communication requirements,the representative of the multi-carrier technology,OFDM,is introduced.The anti-frequency selective fading and anti-multipath effect in this technology make it able to adapt to the environment between the UAV and the ground station,which has strong multi-path interference and severe Doppler shift.On the other hand,for antijamming performance requirements of UAV information transmission,an effective antijamming technology—frequency hopping technology—is introduced.This technology can significantly improve the anti-jamming capability of the communication system and has a strong security effect.Considering the dual requirements of the UAV communication link for data transmission rate and anti-jamming performance,this paper considers the effective combination of OFDM technology and frequency hopping technology to achieve both high-speed data transmission and improved anti-jamming capability.A two-to-one frequency hopping OFDM communication link is formed.This article starts with the related technical principles involved in frequency hopping OFDM,and separately introduces the technical ideas,basic principles and application advantages of the frequency hopping communication system and the OFDM communication system.Subsequently,two major types of frequency hopping OFDM systems,namely subcarrier frequency hopping OFDM and radio frequency hopping OFDM,were introduced,and their respective technical characteristics,advantages and disadvantages were analyzed.Finally,radio frequency hopping OFDM that was more suitable for the design was selected as our design scheme.Next,we introduced the various UAV channel scenarios involved in this design,and carried out three important indicators under the various channels of UAV signaling: Rice factor,Doppler spread,and delay spread.Targeted analysis these factors,we finally concluded the characteristics summary of the UAV communication channel in different scenarios,it is a preparation for the subsequent design of the OFDM baseband links.Since the beginning of Chapter 4,we have entered into the core work of this article.These sections aim at the radio frequency hopping OFDM scheme proposed in the previous section and studie how to achieve fast frequency hopping in the AD9361.In this process,the software radio(SDR)RF transceiver system architecture is introduced,which is combined of Microblaze(SOPC)and AD9361.Based on this architecture,we can not only validate that the AD9361 RF chip can be used for frequency hopping,but also derive the performance parameters of the AD9361 for fast frequency hopping.Through these parameters,a preliminary model of frequency hopping OFDM is constructed.In the following chapters,based on the UAV channel parameters obtained in Chapter 3 and the preliminary scheme of frequency hopping OFDM in Chapter 4,we propose a design scheme for OFDM baseband links and a scheme for implementing frequency hopping in OFDM links.In accordance with the actual problems and difficulties faced by the project,concrete and effective debugging and implementation were carried out,and the function and performance tests of the entire UAV frequency hopping OFDM link were finally completed.The innovation of this paper is that the AD9361,an RF chip that is not used for frequency hopping,is used to implement fast frequency hopping through SOPC-based software radio architecture.Based on this architecture,it also combines RF frequency hopping with OFDM baseband links.Finally,a complete UAV hopping OFDM link is formed,and the entire design has a certain market application prospects.