Linear frequency modulation signal parameter evaluation method based on LVD (Lv's distribution)

Abstract

The invention discloses a linear frequency modulation signal parameter evaluation method based on LVD (Lv's distribution). A linear frequency modulation signal has energy impulse characteristic in an LVD domain, so the relative inhibition of cross items is realized, and the parameter values of the center frequency and frequency modulation slope of the linear frequency modulation signal are accurately evaluated. The method comprises the following specific steps of 1, collecting signals; 2, judging if pulse noise is contained or not; 3, carrying out order-reduction preprocessing; 4, extracting a self-correlation feature; 5, converting phase dimensions; 6, extracting an LVD spectrum feature; 7, searching an LVD spectrum peak. The method overcomes the defect that in the prior art, cross item inhibition and resolution enhancement cannot be combined, a decoupling self-correlation signal is converted into the independently distributed LVD spectrum, the signal parameter evaluation precision in complicated noise environment is improved, and a new path is provided for the design of a future signal phase feature extracting technology.

Description

technical field [0001] The invention belongs to the technical field of communication, and further relates to a method for estimating parameters of linear frequency modulation signals based on LVD (Lv's Distribution LVD) in the technical field of radar signal processing. The invention uses a low-order preprocessing method to suppress pulse noise, and LVD transforms to estimate the center frequency and frequency modulation slope parameters of the linear frequency modulation signal, so as to realize phase feature extraction of the linear frequency modulation signal in a complex noise environment. Background technique [0002] The chirp signal has a large time-width-bandwidth product, and the use of pulse compression technology can significantly reduce the peak transmit power of the radar, thereby lowering the sensitivity of the intercepting receiver and achieving the purpose of low interception of the transmitted signal. As one of the most mature low probability of intercept ra...

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Problems solved by technology

However, the disadvantage of this patented technology is that because the narrow observation window of the short-time Fourier transform reduces the resolution of the time-frequency domain, the estimation performance of the signal parameters is reduced under the condition of low signal-to-noise ratio, and the fraction of each component mutual masking

[0007] To sum up, for the parameter estimation method of chirp signal, the existing time-frequency analysis method only considers the time-frequency characteristics of chirp signal changing with time, and does not consider the unique certainty of the center frequency and FM slope on the instantaneous frequency of the signal. The extracted time-frequency features cannot directly reflect the changing characteristics of the chirp signal, and the estimation accuracy is not high by using this method for parameter estimation

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