Radar narrow-pulse rejecting out-band interference inhibition method

Abstract

The invention belongs to the field of radar signal processing. Radar out-band pulse signals generate residual signals after filtering processing of a receiver, and the residual signals are mainly concentrated at edges of pulses in a narrow pulse form to form interference. The interference signal inhibition method comprises the steps that after digital quadrature and low-pas filtering of a signal processing flow, a narrow-pulse rejecting out-band interference inhibition function module is added before a pulse compression module for calculating absolute values of an in-phase component I and a quadrature component Q of a radar echo signal of each distance unit, and an envelope signal of the echo is obtained and processed. Envelope anti-asynchronization is performed in an orientation slow time direction, by comparing echo envelope amplitudes of the same distance unit in adjacent radar repeated periods, asynchronous I and Q values are rejected, and value compensation is carried out. In a distance quick time direction, three adjacent distance units are selected in the same radar repeat period, I and Q values of the narrow pulse residual signals on the corresponding distance units are rejected based on fluctuation of the echo in near distance, and value compensation is carried out.

Description

technical field [0001] The invention belongs to the field of radar signal processing, and relates to a method for suppressing out-of-band interference of a pulse compression system radar. Background technique [0002] Modern radars achieve the purpose of anti-interference by changing the transmission frequency between radars, so that the carrier frequency of the transmission signal between radars is staggered in the intermediate frequency bandwidth. However, the way of staggering the operating frequency of the radar, in some cases, the anti-jamming performance will drop sharply. For example, for the traditional system radar with low transmitter frequency stability, the transmission harmonics are very serious; the pulsed high-power interference signal from the radar in the short range may not only block the receiving channel, but also the pulse edge spectrum is rich and the harmonic energy is high ; The existence of objective factors such as poor out-of-band rejection of rad...

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Problems solved by technology

Anti-asynchronous interference processing is usually placed after pulse compression in the radar signal processor, but it is difficult to perform anti-asynchronous anti-jamming formation based on anti-asynchronous processing only after pulse compression, because a large amount of interference received by the radar is filtered by the receiver The rest will be broadened in the time domain after the pulse compression without processing. The broadening makes it difficult to deal with the anti-asynchronous interference after the pulse compression. It will lead to a decline in the constant false alarm processing effect of the distance unit. Therefore, it is necessary to add a targeted radar signal processing module before the pulse pressure to suppress asynchronous signals and out-of-band residual interference signals, and to prevent the pulse pressure expansion of non-target signals.

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