In this paper a system for automatic recognition of radar waveform is introduced. This technique is used in many spectrum management, surveillance, and cognitive radio and radar applications. For instance the transmit...In this paper a system for automatic recognition of radar waveform is introduced. This technique is used in many spectrum management, surveillance, and cognitive radio and radar applications. For instance the transmitted radar signal is coded into six codes based on pulse compression waveform such as linear frequency modulation (LFM), Frank code, P1, P2, P3 and P4 codes, the latter four are poly phase codes. The classification system is based on drawing Choi Willliams Distribution (CWD) picture and extracting features from it. In this study, various new types of features are extracted from CWD picture and then a pattern recognition method is used to recognize the spectrum. In fact, signals from CWD picture are defined using biometric techniques. We also employ false reject rate (FRR) and false accept rate (FAR) which are two types of fault measurement criteria that are deploy in biometric papers. Fairly good results are obtained for recognition of Signal to Noise Ratio (-11 dB).展开更多
This paper describes a pulse compressor implementation with DSP for small Time Bandwidth (TB) product Linear Frequency Modulation (LFM) waveform. It contains the digital generation of the LFM waveform and the dig...This paper describes a pulse compressor implementation with DSP for small Time Bandwidth (TB) product Linear Frequency Modulation (LFM) waveform. It contains the digital generation of the LFM waveform and the digital internally Hamming weighted compression filter. Two methods for suppression of time sidelobe of the digital pulse compressor are employed. First, the LFM waveform is modified by using cubic phase pre distortion for reducing the effect of Fresnel ripples in small TB product LFM waveform. Secondly, anti aliasing filter is used before A/D converter for reducing spectrum skirt level of the returned LFM waveform. The parameters of the compression filter implemented with IMSA100 DSP are programmable. The experiments show that the peak time sidelobe level of the digital pulse compressor is less than -32 dB for TB product of 20.展开更多
文摘In this paper a system for automatic recognition of radar waveform is introduced. This technique is used in many spectrum management, surveillance, and cognitive radio and radar applications. For instance the transmitted radar signal is coded into six codes based on pulse compression waveform such as linear frequency modulation (LFM), Frank code, P1, P2, P3 and P4 codes, the latter four are poly phase codes. The classification system is based on drawing Choi Willliams Distribution (CWD) picture and extracting features from it. In this study, various new types of features are extracted from CWD picture and then a pattern recognition method is used to recognize the spectrum. In fact, signals from CWD picture are defined using biometric techniques. We also employ false reject rate (FRR) and false accept rate (FAR) which are two types of fault measurement criteria that are deploy in biometric papers. Fairly good results are obtained for recognition of Signal to Noise Ratio (-11 dB).
文摘This paper describes a pulse compressor implementation with DSP for small Time Bandwidth (TB) product Linear Frequency Modulation (LFM) waveform. It contains the digital generation of the LFM waveform and the digital internally Hamming weighted compression filter. Two methods for suppression of time sidelobe of the digital pulse compressor are employed. First, the LFM waveform is modified by using cubic phase pre distortion for reducing the effect of Fresnel ripples in small TB product LFM waveform. Secondly, anti aliasing filter is used before A/D converter for reducing spectrum skirt level of the returned LFM waveform. The parameters of the compression filter implemented with IMSA100 DSP are programmable. The experiments show that the peak time sidelobe level of the digital pulse compressor is less than -32 dB for TB product of 20.
