The Research And Implementation Of Radar Modulation Mode Recognition Technology

In the modern electronic warfare environment, the electromagnetic signals are more and more complex,the signal density is big,and the type of the signals is too many. the new system of radar signals emerges, then extract the various parameters from the incident radiation quickly and efficiently is the key factor to identify radiation sources successfully.The new system of radar signals can not be recognized only based on conventional signal characteristic parameter, the new radiation characteristics are analysed and extracted effectivly,we can achieve the recognition of a new radar system. In this paper, radar modulation recognition technology has been studied in three areas, namely, the recognition of the radar pulse modulation mode, the recognition of radar signal fingerprint identification and the recognition of radar signal polarization characteristics, in these three areas, the mrthods that are can be realized in the project are proposed. The simulation verifies the correctness and feasibility of the method, and some methods are applied to actual projects ultimately based on a high-speed digital receiver.Firstly, the characteristics of the radar pulse modulation recognition methods were studied, a coarse -to-fine methods of the modulation type identification was found. Firstly, it calculates the bandwidth of the signal spectrum. The signal roughly divided into two types:the phase-modulated signal and frequency-modulated (FM) signals. and based on the category refinement menthod, two-phase encoded signals (BPSK), quadrature phase encoded signals(QPSK), frequency encoding signal (FSK), chirp signal (LFM), non-linear FM signal(NLFM), V-type FM signal (VLFM) are identified. By implementing the digital receiver, the effectiveness of the method is verified, which has a high value in engineering application.Secondly, through the defination of the characteristics of the radar signal fingerprint,several parameters that can represent the characteristics of the fingerprint are extracted. and by comparing the stability and interference suppression ability of several parameters, the rising edge of the pulse envelope is confirmed as the radiation source fingerprint characteristic finally. By calculating the resemblance coefficient between the incident radiation signal and the template signal, the purpose of identifying the radiation source is achieved.Again, through the different ways of the radar signal polarization characteristic, the different characteristics of each polarization signal is analyzed. Based on the actual test, two polarization identification methods are proposed: the minimum magnitude output criteria amplitude ratio and phase difference identification. Comparing the realization difficulty of these two methods, the final selection criteria is the minimum magnitude output criteria,which is used for hardware implementation.Then,the hardware design of high-speed seven -channel digital receiver is described in this paper. The chip selection, power supply design, chip peripheral circuit design are described in detail, the paper finally devised a universalization and platform high-speed multi-channel digital receiver board.Finally, the system selected method which is used in the high-speed seven -channel digital receiver software and the actual test results are introduced, the VHDL program is written. Through the joint simulation using Quartus ? and Modelsim,as well as another combination of online observation base on SignalTap ? logic analyzer, and the software program designed is completed to verify the correctness and feasibility of the proposed method.