Research On Key Technologies Of UAV High-Speed Data Link

Unmanned Aerial Vehicles(UAVs)have become the weapon of hot research in today's countries.They have the advantages of small size,flexible deployment,and zero casualties,which are in line with modern operational concepts.UAVs become a wonder soldier of the information battlefield.The data link is an important part of the UAV platform.It is the link between the UAV platform and the accusation center,and is the core means for information sharing,monitoring and command,and feedback of strike effect.The high-speed data link is the key research field of the current world military power in the field of military communications.With the changes in the battlefield environment,the development trend of UAV synergy and stealth,and the performance improvement of photoelectric sensors and radar devices,the data link faces many challenges such as real-time interaction of big data video information,low interception,high reliability,etc.It is no longer able to meet the military needs of future high-intensity confrontation.High-speed,real-time and reliable data link has become the hot research content of current UAV related technologies.The paper analyzes and summarizes the existing architecture and shortcomings of UAV high-speed data link,optimum design of its architecture,and the related technologies such as source data compression for large-capacity video data,high-speed and reliable channel coding and multi-carrier technology,microwave filter and anti-interference,low-intercept directional communication are studied.The main work and innovative achievements of this paper are as follows:(1)In view of the requirements of anti-interference,low interception,large-capacity realtime transmission and stealth in future high-intensity wars,the existing data-link technology architecture is analyzed.A new architecture of high-speed data-link for UAV is proposed and the key technologies are analyzed.(2)Research on high efficiency video information coding and rate allocation algorithms is carried out.For the real-time and reliable transmission demand of high-capacity video data of the UAV high-speed data link,H.265/HEVC with higher compression efficiency is selected as the source coding.A frame layer bit allocation algorithm based on correlation information between video frames is proposed.The rate distortion performance increment is about 0.131 d B.The algorithm improves the coding performance and can maintain the consistency of the compressed data rate and target rate.(3)LT codes and OFDM multi-carrier transmission technology are studied.Combining the advantages of LT code and OFDM modulation technology,a data link coding and modulation system based on OFDM multi-carrier modulation and LT codes is constructed,which fits well with the transmission requirements of high-speed data link of UAV.The scheme improves the robustness of the UAV high-speed data link communication and reduces the system complexity.Combining the grouping and phase rotation vectors,the PAPR is reduced by transmitting the symbol with the smallest PAPR.When the CCDF is 10-4,the PAPR is reduced from 12.2d B to 8.9d B.(4)To meet the miniaturization requirements of the UAV data link,a dual-mode resonator structure is designed,which has the advantages of small size and light weight,and is decomposed by the odd-even mode analysis method.The resonant frequency can be controlled freely,making the design of the filter more flexible.In order to further improve the isolation suppression degree outside the filter passband,the filter has independent controllable transmission zero point by introducing source-load coupling technology.3d B relative bandwidth is 15.7%.The performance of out-of-band rejection of band-pass filter is improved.The volume is small and the performance is excellent.(5)In order to improve the anti-interference,low interception and high-rate capability of the high-speed data link of the drone,the system adopts directional communication as the main communication link.A reflective surface antenna based on the spatter plate feed is studied and designed.By shaping the sub-reflective surface and using the spatter plate feed medium support mirror,the far-field radiation pattern of the feed is equalized within a certain range.At the same time,the main surface of the spatter plate feed antenna is evenly distributed,and the phase is equal-phase distributed.The gain is 27.42 d Bi,the sidelobe level is-23.48 d B,and the maximum standing wave ratio is 1.09.The antenna has the advantages of high gain,low side lobes,and good standing wave performance.