Radio frequency interference suppression method based on FRFT frequency estimation subspace

Abstract

The invention provides a radio frequency interference suppression method based on an FRFT frequency estimation subspace. The method specifically comprises the steps of calculating an optimal order ofFRFT; calculating FRFT of a frame of original data under the optimal order through a kernel function, and obtaining an original signal of an FRFT frequency domain; detecting radio frequency interference of an FRFT frequency domain signal; if the radio frequency interference exists in the FRFT frequency domain signal, obtaining an FRFT time domain signal through inverse Fourier transform; constructing an orthogonal projection matrix by utilizing an FRFT frequency estimation subspace method, and performing projection transformation on the FRFT time domain signal to suppress the radio frequency interference; performing fast Fourier transformation to obtain the FRFT frequency domain signal after radio frequency interference suppression; and performing p-order inverse FRFT on the FRFT frequencydomain signal to obtain the original signal after radio frequency interference suppression. According to the method, steady-state and non-steady-state radio-frequency interferences can be suppressedat the same time; the integrity of useful signals can be kept on the basis of fully suppressing the radio frequency interferences; the effective detection distance of a radar is increased; and the precision of marine dynamics parameter inversion and target detection by the radar is improved.

Description

technical field [0001] The invention belongs to the field of radar signal processing, in particular to a radio frequency interference suppression method based on FRFT frequency estimation subspace. Background technique [0002] High-frequency surface wave radar obtains the distribution information of ocean surface dynamic parameters (wind, wave, current, etc.) in a non-contact manner, and is an important detection equipment used in marine radar environmental monitoring. Compared with the traditional fixed-point and calibration observation, high-frequency ground wave radar has the advantages of all-weather and wide coverage area, and can obtain more complete information on the temporal and spatial changes of dynamic parameters in the observed sea area. Compared with satellite observations, it has advantages in time and space resolution, and is not affected by weather factors such as rain and fog. my country has a vast ocean and land, and high-frequency radar remote sensing c...

AI Technical Summary

Problems solved by technology

The adaptive beamforming algorithm is not effective for the time-varying RFI suppression of the direction of arrival, and cannot suppress the RFI located in the main lobe

Orthogonal projection algorithms based on range coherence usually need to obtain several range unit signals that do not contain sea clutter as training matrices. Great signal attenuation

However, the time-domain detection and zeroing algorithms are often helpless in the case of continuous interference.

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