Signal Processing Sidelobe Suppression Technology

The master dissertation introduces passive correlative orientation system and base theory in signal dispose briefly in the first place.The system takes TV sound FM signal from TV satation signal. The power rate of TV station signal to sound signal is ten to one. In the case of submerged by mussy weave and machine's hot noise, dispersed target signal is feeble. Taking general pulse detect method is too difficult to detect distant target. The nonstop TV station signal is taked as reference and correlated with echo to detect target. The system signal correlation results sidelobe. The sidelobe of strong signal should impact the neaby feeble signal.That noise FM signal emalates TV sound FM signal researchs above two question about correlative detection and restrainning sidelobe. The research's result is compared with linear FM emulational research's. The specific research methods are listed:1.Matched filter taking the max ouput SNR as the best rule correlates nonstop divided signal and divided echo to detect low SNR target signal. Then all one dimension divided correlation outs and done FFT in portrait to leach interferential signal such as static or low rate mussy meaves,many pathway echo and so on and to take target's time difference and Doppler frequency that combine parameters that target's direction taken from antenna and so on to implement target's orientation and tracking.2.The signal correlation spectrum is corrected to rectangle spectrum by using spectrum correcting technique and then added window to restrain distance sidelobe, and all one dimension divided correlation outs are added diversified windows to restrain rate sidelobe.The fruits of emulational research are obtained:1 The method of divided planar correlation deal with wonderfully and can detect the target information of TV sound FM signal about time difference and Doppler frequency with this understanding of -20dB SNR.2.The spectrum correcting technique is applied in one dimension distance sidelobe restraining successly and deal with well with this understanding of zero or low Doppler frequency and without noise, mussy weaves.3.In the process of restraining distance and Doppler planar sidelobe, linear FM signal restrains sidelobe well, noise FM signal has definited impact on restrainning sidelobe in concrete circumstance by tring diversified methods.4.The signal data collected in expteriment are taken out in emulational research of system experiment. Many methods such as adding window in frequency field, eliminating static object and so on restrain the width and sidelobe of static mussy weaves and detect out the target availably.The text's creative fruits are many methods such as spectrum correcting technique that are applied to restrain sidelobe. The diversified methods such as moving signal's center frequency after low passing filter, spectrum correcting, adding windows and so on are analyzed and compared, those impacts on restraining sidelobes of noise FM and linear FM are observed, those are researched in applied process.