Pn Phase Modulation And Sine Frequency Modulated Continuous Wave Radar Key

Pseudo-Random Code CW (PRC-CW) radar is the realization of noise radar in digital way. Using this radar system,we can gain strong anti-clutter, no blind spot at close range , high resolution and accuracy advantages ,and so on . But like other continuous wave (CW), the interference of close-in targets is also a serious problem to PRC-CW radar, although PRC-CW radar have a very low residue for large N,a problem exists in that this residue is constant.Thus,a large target near the radar will have as large a residue in a distant range bin as it does in a nearby adjacent bin. When there is interference of nearby clutter and close-in targets,if we want to investigate far target, this radar is powerless.In order to suppress the returns from close-in targets,The effective measures is to modulate the carrier with sine wave.That is, Pseudo-random binary-phase coded and sine frequency modulated CW radar.This thesis studies the key technologies of this Composite modulation radar system in-depth.This paper analyses the performance of the m series phase encoded radar signal and the characteristics of sine FM signal.And then focus on the Pseudo-random binary-phase coded and sine frequency modulated signal.The working principle of Composite modulation radar system is described in detail. Finally focus on analyzing the correlation accumulation of echo and on the basis of research results, according to spread-spectrum communication solutions related to the principle of correlative despreading, a improved signal processing scheme is proposed.Through detailed analysis and feasibility studies, the Pseudo-random binary-phase coded and sine frequency modulated CW radar has a preferable tactical performance, possesses a preferable practicality and feasibility.