Lfm Signal Detection And Parameter Estimation Techniques

Ultra-wideband radar is a new type of radar system, and it has high range resolution because of its wide bandwidth. Thus, UWB radar has extended application such as target identification, precise position, target imaging and discrimination.The research object is ultra-wideband LFM signal in low signal-to-noise ratio In this thesis, Study ultrawideband radar signal detection and parameter estimation, and obtain some valuable results.Ultra-wideband LFM signals are nonstationary. Traditionally Fourier analysis is a transform in full-time domain, and it can't describe the signal property in different time. LFM signal is analyzed based on the time-frequency distribution. The different time-frequency distribution chanracterist for LFM signal detection in different signal-to-noise ratio is also discussed in the paper. In this paper, offers a signal reception system, analyzes the detection of LFM signal, discusses the influence of imbalance of amplitude and phase of I,Q channel and match filtering of LFM signal. Based on the ideal of match, the signal correlation method for LFM signal realize the parameter estimation of LFM signal through the correlation of the signal. The computer simulation is done to test it. But the ambiguity condition limits the parameter estimation precision of LFM signal.In order to advance the capability of correlation signal detection method, a new method for LFM signal detection,based on the technology for ambiguity resolution of stagger repeated frequency, is proposed. Using the method, the signal in low signal-to-noise ratio can be detected very well and its parameters can be estimated more precisely too. Computer simulation shows the new method is effective, and its structure is so simple to be realized easily and have some practical value.