A Polarization Filtering Method for External Radiator Radar Based on Subcarrier Processing

Abstract

The invention proposes a polarization filtering method for external radiation source radar based on subcarrier processing. The present invention obtains the reference signal according to the OFDM signal of the digital television broadcast; according to the external radiation source radar signal based on the digital television broadcast signal as the received signal, the received signal is subjected to sub-carrier processing, and the received signal is processed according to the sub-carrier to obtain a polarized signal; according to The polarization signal is estimated, and the clutter estimated polarization angle and the clutter estimated polarization phase difference are respectively obtained, and the interference signal subspace is constructed according to the clutter estimated polarization angle and the clutter estimated polarization phase difference, and the clutter is constructed according to the interference signal subspace The polarization suppression weight vector is calculated according to the clutter polarization suppression weight vector and the received signal to obtain the output signal; the output signal is subjected to inverse discrete Fourier transform and matched filter processing on the reference signal to obtain the signal range Doppler spectrum. The invention improves the estimation accuracy of the interference polarization state and improves the interference suppression performance of the polarization filter.

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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