Research On APSK Satellite Communication Signal Blind Analysis Technology

This paper focuses on the APSK satellite communication signal blind reconnaissance,and studies the modulation recognition,constellation diagram style recognition,symbol rate estimation,frequency offset estimation and other key technologies;Based on the Gaussian white noise channel,the correlation algorithm suitable for APSK signal is proposed,and its effectiveness is verified through analysis the masured data.The main research work and innovation of this paper are as follows:1.The modulation recognition of APSK signals is researched based on signal characteristic parameters;Here we put forward the new problem of APSK signal constellation pattern recognition,which is achieved through improved recognition algorithm based on constellation recovery and Kolmogorov-Smirnov(K-S)test,at moderate SNR conditions.2.For APSK signal,we focus on the joint estimation of SNR and modulation recognition.On the base of the joint estimation based on the K-S test,we propose a new joint estimation method combining the Method-of-Moment and the K-S test,with which the contradiction between SNR and modulation recognition is solved further.3.Based on the amplitude spectrum,M times involution spectrum and cyclic spectrum,the symbol rate estimation of APSK signal is researched;Based on the DFT and antocorrelation,the frequency offset estimation of APSK signal is researched.Based on the existing algorithm,through the derivation,analysis and improvement,the suitable algorithm of parameter estimation for APSK signal is determined.4.Based on MATLAB,the APSK blind analysis software is constructed and a corresponding graphical user interface was formed,which verifies the algorithm proposed in this paper.