Pseudo-code Phase Modulation Sfm Combined Detection Signal Processing Technology

The serrated signal of pseudo-code phase modulation and sine frequency modulation has both low acquisition probability and good anti-jamming ability of the pseudo-code and the characteristics of suppressing the close divulgence and reducing the doppler sensitivity which is the characteristics of sine frequency modulation, the complex detection system of pseudo-code phase modulation and sinusoidal frequency modulation decides the distance using the related processing of pseudo-code in echo signal and measures the target's speed by extracting the doppler signal in the difference frequency signal of the sine frequency modulation in echo signal.This thesis first analyzes the characteristics of pseudo-code phase modulation signal and sinusoidal frequency modulation signal, then analyzes the signal processings on the complex detection system of pseudo-code and sine frequency modulation. This thesis analyzes the complex signal's characteristics in time domain and in frequency domain based on the principles of the complex detection system, and analyzes the characteristics about ambiguity functions of the composite signal, followed by a discussion of parameters' choice about the composite signal, and simulates the whole signal processings of the complex system based on the choice of the parameters, analyzes each step of the signal processing combined with the pictures in time domain and in the form of spectrum, and the system can extract the information about the target's distance and speed from the echoes. Finally, this thesis discusses the anti-jamming performance of the composite signal by calculating the gain of the receiver about noise, frequency-modulation noise and amplitude-modulation noise, and gives the advantages of the complex detection system, this thesis confirms the realizability of the complex detection system.