Intra-pulse Subtle Features Extraction Based On DSP In Electromagnetic Environment Monitoring System

With the development of radar technology, radar system towards diversification,complex and comprehensive direction, making electronic countermeasures facingincreasingly complex electromagnetic environment. Analysis is becomes particularlyimportant to correct sorting and punching subtle features of radar signals in a complexsignal environment.Electromagnetic environmental monitoring system is in the electromagneticenvironment, real-time collection of electromagnetic signals stored in the experimentalarea, and then stored data signal feature extraction, including the parameters to obtain andsubtle characteristics of the pulse, the conclusions from the analysis is to assess realelectromagnetic environmental data. Subtle characteristics of the signal pulse analysisresearch, mainly within the parameters of the pulse signal acquisition, of the pulse signaland the clock signal modulation characteristics selected for analysis.Pulse parameters generally include pulse amplitude, pulse width, pulse arrival time,carrier frequency, etc. The measurement of pulse arrival time is the premise of radar signalsorting. In this thesis, a new pulse parameter measurement method was proposed, that issliding window power detection method. According to the energy value of pulse signal indifferent sliding windows and the multi-level sliding window, the pulse arrival time can bemeasured efficiently. Because of low computation and full use of information of eachsampling point, sliding window power detection is suitable for low SNR.Then, the sequential difference histogram is adopted to complete deinterleaving afteranalysis of each deinterleaving methods of signals through simulation. Moreover theparallel processing method is purposed to improve the efficiency of the algorithm. Themethod has the low computation, t so it is widely used in practice and real-time system.In the analysis of the characteristic of signal modulation, a new algorithm combinationwas adopted in this thesis, which is SFFT-Haar to obtain the signal type of modulation andmodulation parameters. This algorithm is a combination of time and frequency domaincharacteristics of the signal. In the last, made a detailed presentation to the electromagnetic environmentmonitoring system and signal analysis unit, given pulse subtle feature extraction’s DSPalgorithms, conducted by CCS debugging and simulation, and experimental verificationwith actual field data.