Linear frequency modulation continuous wave time-width ratio estimation method based on fractional Fourier transform and minimum pulse width detection

Abstract

The invention relates to a linear frequency modulation continuous wave time-width ratio estimation method based on fractional Fourier transform and minimum pulse width detection. The method comprises:fractional Fourier transform is carried out on linear frequency modulation continuous wave signal data at different rotation factors to obtain a transformed sequence corresponding to each rotation factor; and Hilbert transform is carried out on the transformed sequence to obtain an envelope curve, a false alarm decision threshold is set and a minimum pulse width length is calculated, and a time-width ratio parameter estimation value of a target signal is obtained. According to the invention, high-dimensional complex calculation is not needed; the method is simple and is easy to realize; problems of multi-path delay and spectrum expansion caused by mutual interference between a direct wave and an indirect wave are solved effectively; a multi-path delay problem caused by multi-times reflection of the radar signal is solved; the operation load is reduced effectively and the estimation precision is improved; and the method has advantages of great practical application value, stable performance, and high reliability and efficiency.

Description

technical field [0001] The invention belongs to the technical field of radar signal processing, in particular to a method for estimating the time-width ratio of linear frequency modulation continuous waves based on fractional Fourier transform and minimum pulse width detection. Background technique [0002] Nowadays, electronic countermeasures have become an important part of modern warfare under the condition of informationization. Reconnaissance activities through technical means are also becoming more and more mature. While reconnaissance of local location information, traditional active signal detection also exposes a large amount of location information of one's own side, and the vicious consequences are self-evident. Using the signal of opportunity reflected by the non-coordinated external illumination source to irradiate the target for reconnaissance and positioning can well overcome the adverse consequences of active detection. [0003] To use an external signal sou...

AI Technical Summary

Problems solved by technology

The common radar signal is mainly LFMCW (Linear Frequency Modulation Continuous Wave) signal system. The time-to-width ratio parameter of the LFMCW estimated signal is a characteristic parameter that can obtain the most useful information of the signal. The commonly used methods for LFMCW signals are based on the FRFT algorithm. The method of parameter estimation, the calculation process is cumbersome and difficult to implement, and the amount of calculation is large

The existing methods for estimating LFMCW signals based on fractional-order Fourier transform are all based on high-order estimators, which have high computational complexity and program complexity, and the actual channel environment is very complex, and multipath effects and spectrum spread etc. The results have had serious repercussions

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