Research On Suppression Of Characteristic Domain Interference In Space Tracking,Telemetering And Command System

The measurement and control system tracks,moniters and measures the trajectory,pose and the working states of subsystems in order to gurantee the predetermined operation of spacecraft.When the measurement and control system is under interferance,it may block the receive channels of transponder and degrade the SNR of received signal.The interference may even send false instructions to deceive the satellite and lead to false response which have serious consequences.Based on the need in protecting the aerospace measurement and control links from interference,this thesis raises a feature transformation domain interference suppression algorithm.The performance of this algorithm is verified with FPGA implementation.The main works are as follows:First,the main functions of aerospace measurement and control links and common techniques for interference suppression are stated.The history of the development of artificial satellites and aerospace measurement and control links are discussed.The importance of interference suppression to the safty of aerospace measurement and control links are analysed.Common techniques for interference suppression are stated as certain reference for interference suppression scheme design.Second,the principle of interference suppression in the feature transformation domain is introduced and an interference suppression scheme in the feature transform domain is designed.The relationship between the packet length,the update rate of the autocorrelation matrix,the convergence speed of the matrix and the interference suppression performance are verified based on the simulations.Also,the relationship of the initial matrix to the fixed-point range and the convergence speed of the matrix is analyzed based on simulations.The feature transformation domain interference suppression scheme is compared with the frequency domain interference suppression scheme and the time domain interference suppression scheme,and the advantages and disadvantages of these schemes are analyzed.Third,the overall framework of the feature transformation domain interference suppression software is designed and implemented with FPGA.Based on the introduced FPGA platform,the whole system is divided into several sub-modules and the interface is defined accordingly.Then,detailed design is performed for each sub-module in FPGA.The pre-layout simulation,logic synthesis and implementation,static timing analysis are performed.Then the design is optimized based on the timing report.Also,resource consumptions are analyzed.Fourth,field test is performed with the whole measurement and control link to verify the performance of the designed scheme.By varying the power of usful signal and interference,five scenarios are tested according to the requirements,which are narrow band interference,single-tone interference,multi-tone interference,co-location interference and broad band interference.The result shows that the required performance is met with processing loss less than 2dB and the system bit error rate less than 10"5.This thesis designed a feature transformation domain interference suppression scheme and verified it through FPGA implementation and field test.It gives theoretical and methodological support for the use of feature transformation domain interference suppression in protecting measurement and control links of aerospace systems and effectively improves the protective ability of measurement and control links.