Signal processing method for calibrating direct current offset of single-frequency continuous wave Doppler radar

Abstract

The invention discloses a signal processing method for calibrating direct-current offset of a single-frequency continuous-wave Doppler rada. The method comprises steps of determining the sampling frequency of a Doppler radar signal, and obtaining an IQ signal of the Doppler radar; performing down-sampling processing on the original data of the IQ signals of the Doppler radar in parallel to obtain radar data after down-sampling; performing signal real-time calibration based on an improved gradient descent algorithm on the down-sampled radar data, and when IQ direct current offset in a set error range is met, calibrating the radar data by using a Gramer-Schmidt orthogonalization formula to obtain calibrated arc data; phase information related to target motion being recovered from the calibrated IQ signal through an arc tangent demodulation algorithm; and obtaining the motion information of the target object according to the recovered phase information related to the target motion.

Description

technical field [0001] The invention belongs to the field of continuous wave radar signal processing, in particular to a signal processing method for calibrating the DC offset of a single-frequency continuous wave Doppler radar. Background technique [0002] The detection principle of Doppler radar is to use the Doppler frequency shift effect to obtain the radial velocity of the moving object. The zero-IF receiver of the radar mixes the echo signal and the carrier signal of the same frequency, and directly converts the signal To the baseband, the conversion process does not pass through the intermediate frequency, and there is no image frequency interference; the radar system uses a zero-IF receiver, which will make its communication system have the advantages of low cost, small size, low power consumption, and high integration. [0003] However, zero-IF receivers have unique DC offset problems; first, the isolation between the LO signal port and the input of the mixer and L...

AI Technical Summary

Problems solved by technology

Alexander M.Vergara of the University of Hawaii at Manoa uses a digitally controlled voltage source to remove the DC offset of the hardware and the environment. The system needs to add an additional data acquisition system, including digital signal processing modules, digital-to-analog conversion modules, precision voltage sources, and system Complex design, high hardware cost

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