Virtual Antenna DOA Estimation for Vehicle Radar Arrays
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Solution Overview
Problem
Existing vehicle radar systems face challenges in accurately estimating the direction of arrival (DOA) of signals from multiple targets with similar speeds and ranges, particularly when using uniform linear arrays (ULAs), as they require a wide aperture that occupies excessive space and can result in grating lobes and side lobes, limiting resolution and accuracy.
Innovation Solution
The method involves generating virtual antennas at preset positions using actual antennas, with the virtual antennas disposed between or outside the actual antennas, and employing a Bartlett pseudo algorithm to estimate DOA, which increases the effective number of antennas without expanding the physical array, thereby improving resolution and suppressing grating lobes while maintaining a narrow beam width.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the number of actual physical antennas is increased to improve DOA resolution, then the measurement precision is improved, but the area occupied by the antenna array becomes excessively large
Solution Approach 1:
The patent creates virtual antenna copies by processing signals from actual antennas through phase rotation and signal combination. These virtual antennas are mathematical constructs that simulate additional physical antenna positions, allowing the system to achieve the resolution benefits of a larger array without physically expanding the antenna structure. The virtual antenna signals are generated by applying phase shifts and combining signals in ways that mimic what additional physical antennas would receive.
2Measurement precision
If the aperture of the antenna array is widened to narrow the main beam width for precise target identification, then the measurement precision is improved, but grating lobes and side lobes occur which prevent accurate target positioning
Solution Approach 1:
The patent applies different phase rotation operations to different virtual antenna elements, creating localized signal characteristics that suppress grating and side lobes. By assigning specific phase rotation values to different virtual antenna positions, the system optimizes the beam pattern locally at each element, resulting in a combined pattern with reduced unwanted lobes while maintaining narrow main beam width for accurate target identification.
3Productivity
If virtual antennas are used to increase the effective number of antennas, then the productivity is improved, but the number of virtual antennas that can be increased is limited by the number of actual antennas in related art
Solution Approach 1:
The patent extends the virtual antenna generation beyond the traditional limitation where the number of virtual antennas is constrained by the number of actual antennas. By introducing phase rotation operations and creating virtual antennas both between and outside the actual antenna positions, the system effectively adds a new dimension to virtual antenna placement. This allows generating a larger number of virtual antennas than the number of actual antennas, breaking the previous dimensional constraint.
Data Source
AI summary
A received signal DOA estimation method using generation of virtual received signals includes: generating a preset number of virtual antennas at preset positions of a plurality of actual antennas; generating received signals received from the virtual antennas; and generating a DOA estimation value through a DOA estimation algorithm using the received signals received from the virtual antennas and the received signals received from the actual antennas.