Method for identifying frequency-shift interference of linear frequency modulated signal

A technology of linear frequency modulation signal and frequency shift interference, applied in radio wave measurement systems, instruments, etc., can solve the problems of large pulse pressure of frequency shift interference, difficult to identify quickly and effectively, and high fidelity of false targets. Real-time identification, easy engineering effect

CN109541556AActive Publication Date: 2019-03-29NO 8511 RES INST OF CASIC
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
Publication Date
2019-03-29

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Abstract

The invention discloses a method for identifying frequency-shift interference of a linear frequency modulated signal. The method comprises the following steps of: preprocessing the signals received bya radar, and dividing the signals into three paths before matching filters; passing the three signals through a complete matching filter and a designed half-bandwidth filter, and extracting a peak value of the output voltage of each half-bandwidth matching filter; setting a threshold; and determining whether the target is a frequency-shift interference false target according to the ratio of the matched output peaks of the target under different half-bandwidth matching filters and the set threshold. The invention has the following advantages: the radar can be used for real-time recognition ofmulti-targets; the application range is wide, and various false targets in an interference system can be identified; the shortcomings of the radar front-end tracking anti-interference method are compensated, and the detection and identification of the interference of an active advancing false target can be realized. The invention has few implementation steps and small calculation amount, can meetthe real-time identification of the radar for multiple targets, has no additional requirements on the hardware system, and is easy to implement in engineering.
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Description

technical field

[0001] The invention belongs to the field of radar anti-interference, and in particular relates to a method for identifying frequency-shift interference of linear frequency modulation signals. Background technique

[0002] Chirp signal (also known as chirp signal abroad) is widely used in various pulse compression radars because of its long range and high range resolution. However, the coupling characteristics of its existing distance and Doppler frequency shift make the radar of this system extremely susceptible to frequency shift interference. Immediately after the frequency modulation signal, the frequency-shifting jamming technology will be used to generate long-distance realistic false targets in front of and behind itself, making it difficult for the radar to identify the real target. The target group will greatly consume radar resources. The major survival challenge faced by LFM radar makes it of great military application value to seek real-time and...

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Embodiment Construction

[0037] The present invention will be described in further detail below in conjunction with the accompanying drawings.

[0038] In order to enable the radar to identify false targets generated by frequency-shifting jamming in a timely and effective manner, and provide support for subsequent anti-jamming methods, this is also an important key point in radar anti-frequency shifting jamming (false target recognition). The present invention utilizes the difference in frequency characteristics between the target echo signal, the frequency-shifting interference signal and the matched filter, adopts the method of combining half-bandwidth matching and full matching, after the radar receives and detects the target, compares the radar received The ratio of the output peaks of the signal passing through two half-bandwidth matched filters, under ideal conditions, the ratio of the target echo will be strictly 1:1, while the ratio of the frequency shift interference will be greater than or le...