The Research Of Method For The Echo Signal Processing Of Micro-motion Target Based On A Dual Frequency CW Radar

Because of micro-Doppler effect, the radar echoes of micro motion target have theinformation such as the frequency and amplitude. Through signal processing of radarechoes, we can get the attribute and perturbation frequency of target, such as thelocation information. There will be important application in no-contact medical,counter-terrorism operations, disaster relief and so on. Existing majority of through-wallradar in order to detect target behind something such as snow, earthquake ruins,concrete walls and opaque obstruction various form of signals have be employed suchas single frequency continuous wave signal, pulse signal,step frequency continuouswave signal, etc. Through the processing of target echo signal, we can obtain theinformation of target. Various signals on target detection have advantages anddisadvantages.For the applications of through-wall radar, this article proposed a method of signalprocessing based on dual frequency cw radar system for micro perturbation target suchas slightly undulating body caused by breathing or heartbeat; realize the function ofdetection and location for micro perturbation target.1. According to the characteristics of micro perturbation target and transmit signal,the target model of sine motion was established; based on the detection signals,introducesd several conventional processing methods for echo signal, and through thesimulation, the detection performance of different method were verified.2. Based on micro motion target model, the transmit signal model, and thedouble-sine FM echo signal model were established; Take the advantage of dualfrequency cw radar system, we can obtain data of the signals cross-correlation fromtwo channels. In a low SNR environment we can obtain the breathing rate. And throughthe comparison, we analyzed the strengths and weaknesses of different transmit signalswhich were adopted to detect the target.3. Combining with the target echo model, proposed the detection and localizationalgorithm use dual frequency cw radar for micro perturbation target. First of all the echosignals are analyzed in detail; Then put forward the basic phase differential ranging algorithm and FFT phase differential ranging algorithm, detected the distance betweenradar and target; Finally, trilateration localization algorithm was put forward, then wecan achieve the accurate positioning.4. Proposed phase differential ranging algorithm for error analysis from the drift infrequency and I/Q mismatch.5. The simulation experiments are carried out to verify the validity of the relevanttheories and algorithms. And the theory and algorithm can also be applied to thedetection and location for other micro motion target.