Signal processing method for eliminating static clutter interference of FMCW radar

Abstract

The invention provides a signal processing method for eliminating static clutter interference of FMCW radar. The method comprises the following steps: step one, estimating amplitude a-hat of base-bandcomposite beat signals during each frequency sweep period; step two, obtaining a discrete point (R[i], I[i]) sequence on a complex plane on the basis of an estimated amplitude time sequence and a known initial phase time sequence; step three, performing circle center estimation fitting on the discrete point (R[i], I[i]) sequence on the complex plane; step four, performing correction compensationon offset of the circle center, and obtaining a corrected Ru[i] and a corrected Iu[i]; and step five, taking a phase angle of a complex discrete point (Ru[i], Iu[i]) sequence, and obtaining a corresponding phase time sequence. Correction compensation is conducted on the estimated phase time sequence on the basis of signal post-processing, so interference of static clutter in vibration monitoring of target object can be eliminated effectively and the extraction precision of vibration displacement amplitude can be improved.

Description

technical field [0001] The invention relates to the technical field of radar monitoring, in particular to a signal processing method for eliminating static clutter interference of FMCW radar. Background technique [0002] Generally, the radar emits a certain form of electromagnetic waves, receives the electromagnetic echo signals scattered by the target object, and obtains the baseband signal through frequency mixing and filtering. By analyzing the frequency and phase information of the baseband signal, the distance, speed and other information of the monitoring target can be extracted. Typically, a linear frequency modulation continuous wave (Linear Frequency Modulation Continuous Wave, LFMCW for short) radar transmits a linear frequency modulation continuous wave to obtain an intermediate frequency baseband beat signal. The corresponding distance information is obtained by estimating the frequency of the beat signal. However, due to the limitation of the radar transmissio...

AI Technical Summary

Problems solved by technology

Since it is difficult to separate the signal components caused by different scattering points from the baseband beat signal, the interference of static clutter is often eliminated from the perspective of hardware, such as placing strong reflection points on the target object or additional frequency shifting, frequency doubling devices, etc. , but increases the complexity of the system hardware and limits the application of this technology

Images