Research On The Feature Recognition Technology Of Radar Jamming And Its Implementation

Combined with a project of weapon development closely, technology research is investigated which is used for reconnaissance and processing of radar signals. It includes some algorithms which are used for modulation recognition of radar signals,and the implementation technology of a wideband radar jamming digital receiver. This dissertation is composed of three parts as follows:In part I, time-domain and frequency-domain features of Carrier Frequency(CF)、Liner Frequency Modulation(LFM) signal 、Binary Phase Shift Keying(BPSK) signal、 Quadrature Phase Shift Keying(QPSK) signal and Frequency Shift Keying(FSK) signal are analyzed. Firstly study the time-domain features of radar signals by time-domain methods. Then analyze them in frequency domain. Finally its time-frequency features are studied by Liner Time-frequency Distribution and Wigner-Ville Distribution.In part II, feature recognition technology of radar jamming, especially modulation recognition algorithms of radar deception jamming signal is studied. The algorithm based on instantaneous autocorrelation、the algorithm based on autocorrelation and the algorithm based on STFT are analyzed and compared. To precisely recognize phase modulation signal, a new algorithm based on instantaneous autocorrelation to get phase difference is proposed.The algorithm is able to distinguish different phase modulation types at low SNR. In order to automatically recognize different modulation types of radar pulses in EW digital receiver, a practical method of modulation recognition is proposed. The method has good real-time performance and high reliability and can meet the need of high sampling rate receivers. The performance of this method is simulated.In part III, the system implementation of wideband radar jamming digital receiver on FPGA is studied,and achieve some creative design such as the optimized structure of parallel FIR filter、high-precision and real-time logarithm calculation、the spectrum analyze technology of DPX. Combined with the Xilinx V6 FPGA,detailed theory analysis is made and effective implementation structures are proposed.