Adaptive method and a radar receiver for suppression of disturbing portions of the Doppler spectrum
AssigneeSiemens Aktiengesellschaft
InventorRichard Klemm
Life of this patent
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Abstract
Disturbing components of the Doppler frequency spectrum in a radar receiver, having coherent integration, are suppressed. In this technique, the order of interference suppression and coherent integration is changed such that the echo values are first fed to a circuit to effect a Fourier transformation. Then, the disturbing components in the frequency band are deliberately suppressed, and a sub-optimal detection method suitable for real-time operation is derived from the optimum detection model in that sub-matrices symmetrical with the principle diagonal are formed from the power spectrum matrix, through which approximate decorrelation of the disturbing components is achieved.
Claims11
A method for adaptive suppression of disturbing components of the Doppler frequency spectrum in a radar receiver having coherent integration, comprising the steps of:
- receiving modulated echo signals in a plurality of frequency bands;
- demodulating the echo signals in each frequency band and converting the same to digital signals;
- performing a Fourier transformation on the digital echo values;
- then comparing the echo value of a band with the echo value of at least one other band to measure the disturbing components and suppressing the disturbing components in the frequency band;
- and then
- performing an approximate decorrelation by forming submatrices symmetrical with the principal diagonal from the power spectrum matrix in a suboptimal detection technique suitable for real-time operation, and detecting a Doppler frequency from a decorrelation value which is above a predetermined threshold.
A radar receiver for suppressing disturbing components in the Doppler frequency spectrum, comprising:
- a Fourier transformer for receiving scanning values and including a plurality of channel outputs;
- filter coefficient means including a plurality of inputs and a plurality of outputs, said inputs connected to said channel outputs, for calculating a plurality of filter coefficients;
- level detection threshold means, including a plurality of inputs and a plurality of outputs, said inputs connected to said outputs of said filter coefficient means, for calculating a plurality levels of detection thresholds;
- and
- an interference suppression circuit including a plurality of switching means, each of said switching means comprising a first input connected to a respective channel output, a second input connected to and controlled by a respective output of said filter coefficient means and a third input connected to and controlled by a respective output of said detection threshold means, and operable to suppress interference in the respective channels in response to the respective filter coefficients and detection thresholds.
Dependencies are inferred from the claim text.