Research And Implementation Of Enhanced Waveform Design Based On Link16

Link16 data link has many abilities such as command,control,communication,navigation and data exchange.It is a common information distribution system for message interaction between aircraft.It plays an important role in command coordination.However,with the development of new technology and the application of new equipment,the theoretical transmission rate of Link16 with the highest 238kbps can not meet the transmission requirements of practical applications for image,video and other services.Therefore,this thesis proposes an enhanced waveform transmission scheme based on Link16,so as to realize the joint optimization of data link transmission rate and anti-interference performance,and meet the service requirements of higher transmission rate.This thesis focuses on the design method of enhanced waveform,gives the design scheme of enhanced waveform transmission,and realizes the enhanced waveform transmission link based on the hardware platform.First of all,the transmission scheme of enhanced waveform is designed in this thesis.Firstly,the time slot structure of Link16 data link and the working principle of transmission waveform are introduced.Then,based on Link16 waveform,the time slot structure and message packaging format of enhanced waveform are designed,and the transmission link scheme of enhanced waveform is proposed.Finally,the working parameters of the enhanced waveform communication system in this thesis are given.The transmission rate of enhanced waveform can reach 1.48Mbps,which is more than 6times higher than that of Link16 data link.In the next part,this thesis studies the modulation technology of enhanced waveform and interference suppression technology.Firstly,the channel model and interference pattern of enhanced waveform communication system are given,and then the FH-DFT-S-OFDM（Frequency Hopping Discrete Fourier Transform Spread OFDM）modulation mode of enhanced waveform is studied.Then,the interference suppression technology of enhanced waveform is studied,and the performance of different time-domain and frequency-domain interference suppression algorithms is simulated and analyzed.Finally,the transmission performance of Link16 waveform is simulated.The simulation results show that under AWGN and fading channel,the ability of enhancing the waveform to resist time-domain pulse interference,multi tone interference and partial band noise interference is better than Link16 data link,and the anti-interference performance is improved by more than 25d B.Afterwards,the FPGA implementation scheme of enhanced waveform is designed in this thesis.Firstly,the implementation scheme of enhanced waveform transmitter and receiver is given,then the design method and test results of each key module are given,and finally the resource utilization of transceiver link is evaluated.In the end,the transmission performance of enhanced waveform is tested.Firstly,the interference free transmission performance of enhanced waveform in AWGN and fading channel is tested.The test results are about 1d B lower than the simulation results.Then the anti-interference performance of the enhanced waveform under AWGN and fading channel is tested.The results show that the measured bit error rate can reach 10^-6when SJR=-35d B.The error of test and simulation is mainly caused by the fixed-point of floating-point data and hardware deviation.Finally,the video service transmission ability of enhanced waveform is tested in the laboratory.