External radiation source radar polarization filtering method based on subcarrier processing

Abstract

The invention provides an external radiation source radar polarization filtering method based on subcarrier processing. The external radiation source radar polarization filtering method based on subcarrier processing comprises the steps of: obtaining a reference signal according to the OFDM signal broadcasted by a digital television; taking an external radiation source radar signal based on the signal broadcasted by the digital television as a received signal, performing subcarrier processing on the received signal, and obtaining a polarization signal according to the received signal after subcarrier processing; performing estimating according to the polarization signal, so that a clutter estimation polarization angle and a clutter estimation polarization difference are separately obtained, constructing an interference signal sub-space according to the clutter estimation polarization angle and the clutter estimation polarization difference, constructing a clutter polarization suppression vector according to the interference signal sub-space, and obtaining an output signal by calculation according to the clutter polarization suppression vector and the received signal; and performinginverse discrete Fourier transform on the output signal and performing matched filtering processing with the reference signal, so that a signal distance Doppler spectrum is obtained. By means of theexternal radiation source radar polarization filtering method based on subcarrier processing in the invention, the interference polarization state estimation precision is increased; and the interference suppression performance of a polarization filter is improved.

Description

technical field [0001] The invention belongs to the field of radar signal processing, in particular to a method for polarization filtering of external radiation source radar based on subcarrier processing. Background technique [0002] External radiation source radar, as a new radar system, has become a research hotspot in recent years because of its characteristics of no radiation and low cost. Most of the researches on radar detection of external radiation sources focus on the filtering, detection and tracking of external radiation sources such as civil radio and television signals. For civilian radio and television signal systems, most of them are deployed in urban areas, so this determines that radar detection of external radiation sources must face severe clutter environments. As a new filtering method different from time domain filtering, spatial filtering and frequency domain filtering, polarization filtering technology has attracted people's attention. The polariza...

AI Technical Summary

Problems solved by technology

The traditional polarization filter is based on the orthogonal projection technology, which has a good suppression effect on the interference signal, but the interference suppression performance depends on the estimation accuracy of the interference polarization state. The higher the accuracy, the better the interference suppression performance, and the lower the accuracy The worse the suppression performance

[0004] Complex multipath propagation environment in cities brings difficulties to polarization state estimation

Since the strength of the direct wave interference signal is greater than that of the multipath interference signal, when the traditional polarization filtering method is used to estimate the interference polarization state, the disturbance caused by the multipath propagation environment will have a great impact on the polarization state estimation, and the weak target signal cannot highlight

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