Research On Signal Processing Method For Surveillance Radar Against Active Jamming

Surveillance radar echo energy needs enough to discover distant targets, and in order toachieve the requirements of low probability of intercept, requiring large width pulse signaltransmitter to increase the average power, but by pulse compression processing to obtain thenecessary range resolution and low intercept performance. Because FM signals with large plotwith good time-frequency characteristics and the distribution characteristics of radar cansimultaneously take into account the resolution and detection range of requirements, widelyused in surveillance radar.Radar interference pathway more from the signal processing point of view, anti-jammingradar signature-based technology has been a major research direction. In addition, the radarsignal blind separation technology has increasingly become a hot issue, but for anti-activejamming of not much. Therefore, this system for routine surveillance radar to study theanti-active radar FM signal interference repressive methods. The contents of the researchmainly include the following several aspects:(1) Active radar interference mechanism is analyzed. Mainly for the active interferenceof the repressive interference, focused on the different types of interference signal form, therole of theory and interference characteristics, and introduces an oppressive interference typerecognition method.(2) Introduced based on radar signature anti-jamming methods and interferenceconditions, radar signal processing model. On surveillance radar used large wide radar signalcharacteristics are analyzed and discussed, and introduces two traditional radar-based signalcharacteristics of signal detection and anti-jamming algorithm.(3) Conventional methods for nonlinear FM signal detection accuracy rate is not high,anti-active jamming problem of poor performance, the application of short-time Fouriertransform based on the instantaneous frequency estimation and signal detection methods werestudied. Depth study of the short-time Fourier transform window function selection problemwhen the application based on a generalized wide-bandwidth product optimization windowfunction. The simulation results show that optimized short-time Fourier transform of thelinear FM signal instantaneous frequency estimation is better than the traditional short-timeFourier transform, interference is better than traditional methods.(4) Studied the blind signal separation technology, and the technology used in activesurveillance radar anti-interference method, applied to the serial FastICA separation algorithmseparate target signal and the interference signal adaptively to avoid overlapping radar signalsand active interference signals, to achieve the active interference signal suppression orelimination. As can be seen from the simulation results, the common processing of activeinterference signal suppression, the method may be the target echo signal and an interferencesignal for effective separation to achieve the purpose of active jamming resistance.