Radar DOA Estimation Using Virtual Antenna Extrapolation
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Solution Overview
Problem
Existing DOA estimation algorithms, such as the Bartlett and MUSIC algorithms, struggle to accurately distinguish multiple targets close to each other due to limitations in antenna array resolution and the generation of grating lobes, especially when using a small number of physical antennas.
Innovation Solution
The method employs antenna array extrapolation to create virtual antennas, increasing the number of effective antennas through a transformation matrix based on phase relationships, allowing for improved DOA resolution without increasing physical antenna space or generating grating lobes, by recursively generating virtual reception signals until a predetermined threshold is reached.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the number of physical antennas is increased to improve DOA resolution, then the resolution for distinguishing adjacent targets is improved, but the space occupied by the antenna array increases
Solution Approach 1:
The patent creates virtual antenna copies by extrapolating phase information from existing physical antennas. The transformation matrix generates synthetic reception signals that mimic what additional physical antennas would produce, effectively copying the functionality of extra antennas without the physical space requirements
Solution Approach 2:
The patent transitions from the physical spatial dimension to the signal processing dimension by creating virtual antennas through mathematical transformation. Instead of adding antennas in physical space, the system extends the antenna array into the signal domain using phase extrapolation techniques
2Measurement precision
If the antenna aperture size is increased to improve DOA estimation performance, then the measurement precision is improved, but grating lobes occur within the field of view range
Solution Approach 1:
The patent changes the effective aperture parameters by creating virtual antennas that extend beyond the physical array boundaries. This parameter transformation allows the system to achieve large-aperture performance without physically expanding the antenna structure, thereby avoiding grating lobe formation
3Device complexity
If existing DOA estimation algorithms are used with a small number of antennas, then the device complexity is reduced, but the ability to distinguish multiple adjacent targets is insufficient
Solution Approach 1:
The patent performs preliminary phase extrapolation to create virtual antennas before the actual DOA estimation process. This preliminary action of generating synthetic reception signals enhances the effective array aperture, enabling better target distinction capability while maintaining the simplicity of using a small number of physical antennas
Data Source
AI summary
A method and an apparatus for estimating direction of arrival of radar reception signal using antenna array extrapolation. Obtained is a transformation matrix representing a relationship between phases of reception signals received through ith to (N−2+i)th antennas and a phase of a reception signal received through (N−1+i)th antenna in a ULA antenna unit including N actual antennas. A phase of a virtual reception signal received through a new (N+i)th virtual antenna is generated by multiplying values corresponding to phases of the reception signals received through (i+1)th to (N−1+i)th antennas by the transformation matrix. A magnitude of the virtual reception signal received through the (N+i)th virtual antenna is obtained by averaging magnitudes of the reception signals received through ith to (N−1+i)th antennas.