FPGA Implementation Of Helicopter Rotor Blocking Statellite Communication System

Helicopters have the characteristics of flexible maneuverability and fast response speed,and have played a very important role in disaster relief,emergency rescue and special operations.When the communication between the helicopter and the ground is interrupted,the ground communication network itself is not perfect,or the ground communication is damaged,the helicopter can communicate with the satellite to achieve the purpose of long-distance information transmission.Therefore,combining the flexibility of helicopter maneuvering with the long distance of satellite communication and the large coverage area has great practical value in special applications.However,in the process of helicopter-to-satellite communication,the antenna will be blocked by the helicopter rotor,resulting in a reduction in transmission efficiency.Therefore,in the case of rotor occlusion,it is of great practical significance to study related algorithms and design implementations to improve the communication efficiency between helicopters and satellites.First,we study the key algorithms to improve the transmission efficiency of helicopter satellite communications,and performs simulation and analysis.Firstly,the influence of helicopter rotor occlusion on communication is analyzed,and then the traditional anti-occlusion technology based on time diversity is introduced.Then,a rotor gap burst transmission method based on Kalman filter occlusion prediction technology was proposed,and simulation verification was carried out.Compared with the traditional occlusion prediction,the prediction accuracy is improved.Finally,sparse code division multiple access?SCMA?technology is introduced,and SCMA?6?4 codebook?and low density parity check code?LDPC?widely used in helicopter satellite communications joint simulation,after analysis,when the signal-to-noise ratio is 3dB,the system bit error rate is less than 10^5-,and the spectral efficiency is increased by 50%,indicating that SCMA is an effective method to improve helicopter satellite communications.Then,we optimize the original fixed-rate helicopter satellite communication system program,and the optimized system can support variable rate transmission of 64Kbps¹024Kbps,then improve the system program and complete the design of related software and hardware architecture.Firstly,the waveform structure was optimized,and the simulation platform of helicopter satellite communication system was built based on Matlab and performance simulation was carried out.In order to further improve the transmission efficiency,the rotor gap burst transmission technology based on Kalman filtering is used to increase the communication rate to 4096Kbps,and the corresponding system design and performance simulation are improved.After analysis,before and after the program change,under the signal-to-noise ratio of 3dB,the system bit error rate is less than 10^5-.Then introduce the software architecture and hardware architecture design of the key modules of the 64Kbps¹024Kbps rate scheme.In addition,we introduce the design and implementation of field-programmable gate array?FPGA?based helicopter field communication system,related system testing and performance analysis.First,based on the designed hardware architecture,FPGA design and simulation of key modules based on XC7K325T chip were carried out.Then the board-level test of the simulated helicopter rotor occlusion channel and the test of the real satellite channel are introduced,and the performance of the test results is analyzed and compared.The rate is less than 10^5-,which achieves the purpose of design.