Dual-Frequency CW Radar Multipath Interference Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional dual-frequency CW radar systems face challenges in accurately and quickly distinguishing between synthetic and non-synthetic components in received signals, leading to erroneous distance and azimuth detection when multiple targets with the same speed are present, due to multipath interference.
Innovation Solution
A dual-frequency CW radar apparatus that includes an emitting means, receiving and outputting means, transforming means, peak detecting means, eigenvalue calculating means, and judging means, which generates frequency-spatial data from received signals, detects peak frequencies, calculates eigenvalues of a correlation matrix, and judges whether reflection components are synthetic based on eigenvalue magnitude, thereby inhibiting distance detection if synthetic components are identified.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If signal intensity comparison is performed multiple times to improve judgement accuracy on multipath interference, then measurement precision is improved, but loss of time increases
Solution Approach 1:
The patent extracts the harmful synthetic components from the received signals by using eigenvalue analysis of the correlation matrix. By calculating eigenvalues and comparing them against threshold values, the system identifies and separates synthetic components generated by multipath interference from genuine target reflections, enabling accurate detection without requiring multiple repeated measurements
Solution Approach 2:
The patent replaces the conventional mechanical approach of repeated signal intensity comparisons with an eigenvalue-based mathematical analysis method. By constructing a correlation matrix from received signals and analyzing its eigenvalue distribution, the system achieves rapid and accurate identification of multipath interference conditions in a single measurement cycle, substituting iterative mechanical comparison with direct mathematical computation
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables quick and accurate judgement of synthetic components in received signals, enhancing the performance of the radar system by avoiding errors in distance and azimuth detection, and allowing for precise target tracking.
Implementation Method 1
based on the received signals of the reflected waves, the distance to the target that has reflected the radar waves, and the speed and the azimuth of the target are detected
Implementation Method 2
the Doppler frequencies of the reflected waves that are generated by these targets may coincide with one another
Data Source
AI summary
In a dual-frequency CW radar apparatus, first/second beat signals that include reflection components of radar waves conforming to transmission signals of first/second frequencies are generated for each antenna element and the generated signals are Fourier transformed. A power spectrum average of the beat signals is used as a basis for the detection of a peak frequency fp corresponding to the frequency of the reflection components. A second eigenvalue λ2 of a correlation matrix: Ry=(½)·[y1,y2][y1,y2]H is calculated, the matrix being based on first received vector y1/second received vector y2 having elements that are Fourier transformed values of the peak frequency fp. Based on the magnitude of the eigenvalue λ2, whether or not the reflection components corresponding to the peak frequency fp are synthetic components of the reflected waves from a plurality of targets is decided.