Study On Identification And Parameter Extraction Of Continuous-wave Radar Signal

In the modern extremely complex electromagnetic environment, as a special form of the signal, the signal identification and parameter extraction of continuous-wave radar signal obtain more and more attention. The radar detection system should have the analyzing and processing ability to the continuous-wave signal, so it's necessary to research on its signal modulation identification and modulation parameter extraction techniques.The modulation identification and modulation parameter extraction of continuous-wave radar signal are researched in this paper and then the computer simulation is given. Firstly, each modulation of the continuous-wave radar signals is introduced and the basic characteristic of each signal is talked about. And then the instantaneous frequency signal extraction algorithms is introduced and the short-time Fourier transform is adopted to extract the instantaneous frequency of continuous-wave radar signal in this paper.The non-modulated continuous-wave signal is identified according to the spectral width of the continuous-waves signal. The instantaneous frequency of the modulated continuous-wave signal is extracted to identify the frequency modulation or phase-coded modulation continuous wave signal by the analysis of spectral. Each kind of frequency-modulated signal is distinguished by the spectral analysis of instantaneous frequency. Two-phase and four-phase coded modulation continuous-wave signal is identified by the square spectral width analysis of original signal. According to the simulation, the recognition accuracy rate is still high in low signal-to-noise ratio condition.Modulation parameter extraction is based on correct modulation identification. For the non-modulated continuous-wave signal, amend Rife algorithm is used to estimates carrier frequency. Regarding frequency modulated continuous wave signal, the spectral analysis of instantaneous frequency is used to extract modulation parameter. For the phase-coded modulation continuous-wave signal, first estimates its carrier frequency and phase, then get a correlation operation, the element width and the code sequence is extracted by the output of correlation operation. By simulation, we can conclude that this algorithm has a high precision.