Reseach On Ka-band Security LFMCW Radar Signal Processing

Compared to the camera, radar has more advantages. For example, it can detect distant targets day and night without being influenced by fog, clouds, and rains, which means that it has the capability of all-weather and all-time, and the ability to penetrate. Therefore, radar application is also popular in the field of security. Currently, the security perimeter surveillance radar is widely used in airport security zone detection, protection of pipelines and oil fields, as well as integration with the existing prison security video system.Security radars generally use LFMCW(Linear Frequency Modulated Continuous Wave) system. LFMCW radar has a good distance and speed resolution, high reliability, small blind distance and good anti-jamming performance. So it is widely used in radar range and velocity measurement.This thesis is based on Ka-band radar project on security, studied some LFMCW radar baseband signal processing algorithms. The main research work is as follows:First, introduced the background and current research situation of LFMCW radar, followed by a detailed analysis of its basic principles and signal model. Also, the advantages and disadvantages of LFMCW radar were introduced. Based on the above research and the specific requirements of Ka-band security radar, the baseband signal processing solution was proposed, among which several important radar signal processing modules were mainly studied, including moving target indicator(MTI), moving target detection(MTD), constant false alarm rate(CFAR) processing, and multi-target pairing. Simulations using MATLAB were done for each module in order to compare the performances of different algorithms. In MTI part, an adaptive novel MTI filter has been designed by applying Genetic Algorithm. In the process, an innovative fitness function and penalty function are used, and the simulation result shows that the designed filter has good performance. In MTD part, the paper compared two different kinds of filter designing algorithm based on FFT and FIR. As for CFAR processing, various one-dimensional two-dimensional scene processing algorithms were analyzed and compared. In multi-target pairing section, four algorithms are introduced: pairing method in frequency domain, MTD-pairing method in frequency domain, variable cycle method, and the method of adding a flat slope. Subsequently, completed the integration of the various algorithm modules and the simulation of the whole LFMCW radar system, and verified the simulation results.Another work that has been done is the field testing of the whole radar system. At the same time, two sets of data collected from different outfields was imported into the software MATLAB to verify the reliability of the actual performance of the simulated system. The final results show that the whole system works well, and it has achieved the measurement of multi-target speed and distance parameters.