The Application Of Spread Spectrum Modulation Techniques In The Multi-carrier Spread Spectrum Radar System

Multi-carrier and spread spectrum modulating technology have the feature of low acquisition probability, and have predominant performance of anti-jamming, anti-interference, and anti-multipath capability. They also have high resolution of velocity, and have great potential applications in the research of new radar system.This thesis mainly discusses the multi-carrier phase code (MCPC) pulses signal, and the design of pulses trains with low peak-mean envelop power ratio (PMEPR).Firstly, we research the structure model of the multi-carrier radar system, and the basic performance of some phase code pulse signals used in this thesis. Secondly, we research the two designs of multi-carrier phase code pulses with low PMEPR: identical sequences (IS) and consecutive ordered cyclic shifts (COCS) of an ideal chirp-like sequence (CLS). Then analyze the measures of how to reduce the PMEPR of these two designs. After comparing autocorrelation function, ambiguity function and PMEPR of IS and CLS COCS designs, we get each characteristics of them. We also research the numbers of carriers and amplitude weighting affecting the side-lobes. Finally, we research the three design of pulses train, and analyze their performances of autocorrelation function, ambiguity function and spectrum.