Design And Implementation Of Signal Processing For Security Radar

Security Radar is a hot research direction at home and abroad. By the discovering and identifying intrusion targets,it is able to achieve early warning function and provide security guarantee for important facilites and places in terms of surrounding environment. Catering to all-weather, all-time security demand, the thesis designs and realizes security radar signal processing system.1、This thesis briefly introduces the structure of the LFMCW radar and makes a detailed analysis of the principle in measuring range and velocity for frequency modulated continuous wave in two different kinds of systems, namely symmetrical triangle wave and sawtooth wave According to the application scenarios and specific indicators of security radar, the thesis designs the whole system and system of signal processing and verify the related indicators, and with respect to the high velocity ambiguity existed in LFMCW radar modulated by sawtooth, it employs two different sweep cycles to resolve the ambiguity problem.2、The signal processing algorithms, such as 2-D FFT, CFAR, velocity ambiguity, etc., is simulated with Matlab software. The signal processing system is designed based on DSP+FPGA architecture and the hardware and software design of the signal processing system are introduced in detail. Besides, the thesis achieves the function of such modules as data acquisition, data transmission, I2C communication and signal processing algorithm.3、Outdoor tests are conducted to verify the correctness and validity of the signal processing system and the radar system.4、A new algorithm is proposed to apply to the LFMCW radar which is modulated by symmetrical triangle. By using the ARMA model to estimate the beat signal’s spectrum, It successfully overcomes the shortcomings of invalidation to low-speed targets and retains the advantages of measuring target distance and speed at only one cycle. The simulation results demonstrate the effectiveness of this algorithm.5、It puts forward a new idea that comparing amplitude clear up excessive angle which the weakness of measuring angle by comparing phase, thus improving effectively the system angular measurement accuracy.6、Finally, the thesis is summarized, and the further improvements are advised.