Research On Signal Processing Techniques For Bistatic LFMCW Radar

This dissertation has completed the following research of signal processing theory and system key techniques for Bistatic Linear Frequency Modulation Continuous Wave (LFMCW) radar.1) From the geometry structure of Bistatic and the characteristic of LFMCW signal, the symmetrical triangle LFMCW signal applied in Bistatic radar is analyzed, which include the target echo signal, the beating signal of moving target with velocity and acceleration, as well as the signal optimal detection model in white Gaussian noise.2) The ambiguity function and its characteristic of monostatic symmetrical triangle and Bistatic single sweep frequency LFMCW signal are analyzed. By combining the above two signals, then the ambiguity function and its characteristic of Bistatic symmetrical triangle LFMCW signal is analyzed. The range resolution, velocity resolution and rang-velocity coupling characteristic are also derived and analyzed.3 ) Aiming at single target environment, a method of moving target's velocity and acceleration estimation using polynomial phase transform for Bistatic LFMCW radar is presented. Aiming at the velocity and acceleration estimation problem of multi-targets in the same range cell, a modified polynomial phase transform method is also presented. The simulation has tested the validity of the algorism.4) Aiming at the parameter estimation problem of velocity and acceleration of Bistatic LFMCW radar in color Gaussian noise, a general discrete Chirp-Fourier transform is presented. The algorithm efficiently makes use of the power spectrum information of color noise, which makes its capability obviously better than the existing discrete Chirp-Fourier transform in actual target detection and parameter estimation, In addition, the CRB of the chirp signal's parameter estimation under the condition of normal Gaussian noise is also derived, which can provide a precise lower bound for the variance of actual parameter estimation.5) A method of improving range precision of LFMCW radar based on frequency domain up-sampling-interpolating is presented. The simulation indicates that the...