Research And Verification On Key Techniques Of Data Transmission Waveform For Missile

Missile data-link technology is the hotspot and focus in the research of national defense science and technology,and the missile-borne data transmission technology is the key technology in missile data-link technology.In the missile-borne data transmission environment,the missile is in a high-speed motion state,the channel environment is variable,and the data transmission faces a series of problems such as high dynamics,large doppler frequency offset,and time selective fading.This thesis studies the key issues in the missile-borne data transmission system,and proposes a point-to-point communication model design and verification scheme for the missile-borne digital transmission waveform.Firstly,by systematically reviewing the wireless channel fading characteristics and the time-frequency synchronization technology,the basic model of the missile-borne digital transmission channel is determined,and the time-frequency synchronization technology adapted to the channel characteristics are selected.The thesis discusses the important characteristic parameters of wireless channel fading,then refers to the existing literature,and compares the advantages and disadvantages of the time-frequency synchronization technology in high-speed mobile scenes.The time and frequency synchronization technology based on repeated PN sequences is finally selected in the waveform.Secondly,the key performance indicators of the missile-borne data transmission waveform design are analyzed and demonstrated,and then the link design requirements with theoretical derivation is presented.For the index of 20 km transmission distance,the minimum transmission power requirement 16 dBm is calculated with the free space path loss and noise floor formula.The adverse effects of large frequency offset on time synchronization based on cross-correlation is exhaustively disserted,and the design criterion of digital transmission waveform time synchronization algorithm is proposed.Through the analysis for timing synchronization offset on the signal-to-interfere ratio between codes,the time synchronization timing accuracy should be no less than 1/8 chip.Thirdly,the transmitter and receiver links of the missile-borne data transmission waveform are designed,and the baseband signal processing link that meets the performance of the indicator is obtained through software and hardware simulation verification.Above all,the transmission frame format design is carried out,and the design principles and functions of key technologies such as coding,modulation and spread spectrum are elaborated.The detailed design and principle of the receiver's key baseband processing techniques are given,especially for the time synchronization and frequency synchronization techniques.The simulation results of key performance indicators such as bit error rate and synchronous capture rate of the full link design are given.Finally,based on the software scheme,the waveform development is completed on the software defined radio platform.The feasibility of this solution is verified by the main functions and performance laboratory test results at last.The research results of the waveform design of missile-borne data transmission have certain theoretical and practical reference value for reliable data transmission in high-speed environment.