Coded Pulse Between The Pulse Inside The Fm Composite Radar Signal Detection Study

The binary phase-coded and linear frequency modulation (BC-LFM)signal, which combines the characteristic of the pseudo random code and the linear frequency modulation signal (LFM), has not only high range and velocity resolution and accuracy, but also good anti-jamming capability and low interception probability. At present this composite signal has been used in a few kinds of radar and microminiature detector, and the research for detecting the BC-LFM signal is of great significance. This dissertation investigates the method for detecting the BC-LFM signal, including the following several aspects:Firstly, the characteristic of the LFM signal and the binary phase-coded signal are analyzed briefly and the waveform and the ambiguity function of the BC-LFM signal are introduced.Secondly, the time-frequency analysis methods of multi-component LFM signal, including short time Fourier transformation, Wigner distribution, Cohen class time-frequency distribution are studied and compared. The results show that smoothed pseudo Wigner distribution (SPWVD) of Cohen class time-frequency is suitable to detect multi-component LFM signal.At last, the detection of the BC-LFM signal using smoothed pseudo Wigner distribution (SPWVD) of Cohen class time-frequency analysis is discussed thoroughly. For keeping the time and frequency resolution due to windowing, threshold segmentation is used. Correlation method for detecting code mode is also analyzed. The cross-correlation detection method and the SPWVD based on threshold segmentation are utilized to estimate the parameters of BC-LFM under various signal-to-noise ratio (SNR), time-bandwidth product (TBP). The effect of SNR and TBP for parameter estimation is discussed.In conclusion, the detection of the BC-LFM signal is feasible with the use of the cross-correlation detection method and the SPWVD based on threshold segmentation.