Research And Verification On Key Techniques For High-Precision Time-Frequency Synchronization Of Cooperative Interference Signals

Modern wireless communication technique is increasingly extensive in military application.Fighting of both parties is increasingly fierce in communication control power.It is urgent to block communication of enemy and maintain communication system of our party,so as to introduce the cooperative interference rejection technology.The core principle is that the jammer launches interference signals to interdict communication.The receiver reconstructs the interference signals to restrain the interference.To estimate time-frequency amplitude 3D information accurately is the key to reconstruct interference signals accurately.The paper is targeted at high-precision time-frequency synchronization in cooperative interference rejection of digital domain to do algorithm design and simulation.At last,it is realized and verified on the hardware platform.The specific tasks are stated as follows:Firstly,the author systematically summarizes cooperative interference rejection and time-frequency synchronization methods,introduces radio frequency and digital domain's interference rejection and time-frequency synchronization technology,elaborates model structure and features,gives the developmental history of cooperative interference suppression,and summarizes the domestic and overseas studies and achievements in cooperative interference suppression techniques,laying a foundation on the subsequent design.Secondly,the author conducts demand analysis for cooperative interference suppression,gives the signal waveform,communication signals and interference signals to respectively use Frequency Modulation voice signals and Pseudo-Noise signals,analyzes the influences of frequency deviation and time migration on inhibition performance,proposes the synchronization precision demands,calculates signal attenuation,and provides basis for cooperative interference rejection chain in accordance with hardware conditions and estimated data bit signal to noise ratio.Thirdly,the author conducts algorithm design and simulation analysis for high-precision time-frequency synchronization.First of all,the author respectively gives the chain structure of interference signal transmitter,communication signal transmitter and receiver.Then,the author gives the theoretical deduction and analysis of frequency synchronization and time synchronization algorithm and finally conducts simulation analysis for time-frequency synchronization performance and suppression performance.Through simulation,with 25kHz of band width,frequency synchronization error is 0.4 Hz below and time synchronization error is 0.0016 symbols.The signal to interference rejection is 50dB.Fourthly,the author completes the realization of cooperative interference suppression and conducts verification analysis on the hardware platform,and introduces the chain realization methods of interference signal transmitter,communication signal transmitter,and receiver,including signal processing and parameter design.The author focuses on giving the realization details of time-frequency synchronization.In the lab,the author measure's the cooperative interferenee communication system.The findings indicate that with 25kHz of band width and 100MHz of carrier frequency,the signal to interference rejection is up to 50dB.The study on time-frequency synchronization technology of cooperative interference rejection can provide a reference for the subsequent study.