Radar Signal Phase Correction for Accurate Elevation Estimation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Advanced driver-assistance systems (ADAS) face challenges in accurately determining the elevation angle of objects using radar signals, particularly due to the limitations of existing antenna array configurations which result in low resolution and noise interference from phase components, affecting the precision of direction of arrival (DOA) estimation.
Innovation Solution
The method involves generating a correction radar signal by correcting the phase of the initial radar signal based on the target azimuth angle, using a virtual array antenna with specific antenna element arrangements, allowing for independent estimation of both azimuth and elevation angles, thereby improving the accuracy of DOA estimation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a non-uniform or overlapping array of antenna elements is used to provide both elevation and azimuth information, then the radar system can achieve comprehensive directional coverage, but the resolution and measurement precision deteriorate due to grating lobe and sidelobe effects
Solution Approach 1:
The patent segments the antenna array into multiple sub-arrays arranged along different axes (first axis for azimuth, second axis for elevation). Each sub-array independently processes signals for its specific directional component, avoiding the interference problems of unified overlapping arrays while maintaining comprehensive coverage.
Solution Approach 2:
The patent transitions from a two-dimensional planar array to a three-dimensional spatial arrangement with antenna elements distributed along multiple axes. This dimensional expansion allows independent estimation of azimuth and elevation angles by exploiting the spatial separation along different axes, thereby improving measurement precision while maintaining versatility.
2Loss of information
If phase components are included in the radar signal for directional estimation, then both azimuth and elevation information can be extracted, but noise interference increases affecting DOA estimation accuracy
Solution Approach 1:
The patent segments the phase information processing by assigning different axes to different angular estimations. The first axis processes phase components for azimuth estimation while the second axis processes phase components for elevation estimation. This segmentation isolates the noise interference to specific processing channels, preventing cumulative noise effects while preserving complete directional information.
Solution Approach 2:
The patent introduces axis-aligned virtual antenna elements as intermediaries between the physical antenna array and the DOA estimation process. These virtual elements serve as mediators that separate and organize phase component processing along specific axes, thereby reducing noise interference while maintaining information completeness.
3Measurement precision
If a virtual array antenna with multiple axes is used for independent angle estimation, then the resolution and accuracy of elevation determination are improved, but the device complexity increases
Solution Approach 1:
The patent creates virtual antenna elements that replicate the functional capabilities of physical elements along different axes. These virtual copies allow independent elevation and azimuth processing without requiring duplicate physical antenna sets, thereby improving measurement precision while limiting the increase in actual device complexity.
Solution Approach 2:
The patent designs the multi-axis antenna array to serve multiple functions simultaneously: the same physical elements contribute to both azimuth and elevation estimation through their different axis alignments. This multi-functionality reduces the need for separate dedicated antenna sets for each measurement, thereby improving precision without proportionally increasing device complexity.
Data Source
AI summary
A processor implement method may include determining a target azimuth angle of the target object based on an initial radar signal received through an array antenna of a radar sensor, generating a correction radar signal by correcting a phase of the initial radar signal based on the target azimuth angle, and determining an elevation angle of the target object based on the correction radar signal.