Automotive Radar Transceiver Angular Separability via Multi-Frequency Analysis
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Solution Overview
Problem
Automotive radar systems face challenges in achieving high angular resolution while minimizing computational complexity and hardware costs, particularly in distinguishing close targets due to grating lobes caused by undersampling, which can lead to misinterpretation of traffic situations.
Innovation Solution
The system employs an automotive radar transceiver with an antenna array and a processing device that generates and transmits radar signals in multiple frequency bands, allowing for the differentiation of true signals from grating lobes by determining spectral positions that remain constant across frequency bands, enabling high-resolution and unambiguous angle estimation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a large antenna array with many transmit and receive elements is used to improve angular resolution, then angular separability is improved, but computational complexity and hardware cost increase prohibitively
Solution Approach 1:
The patent segments the large antenna array into multiple sub-arrays, each with fewer elements. By processing each sub-array separately and combining results, the computational complexity is reduced from O(N²) for a full N-element array to O(k·m²) where the array is divided into k sub-arrays of m elements each, making the system feasible while maintaining angular resolution
Solution Approach 2:
The patent introduces a new dimension by using multiple frequency bands. By transmitting radar signals at different frequencies and analyzing the spectral positions across frequency bands, the system can resolve angular ambiguities and distinguish grating lobes from true targets, effectively adding a frequency dimension to the angular measurement space
2Measurement precision
If the highest possible frequency is used to improve measurement precision, then angular resolution is improved, but grating lobes appear causing false targets
Solution Approach 1:
The patent uses multiple frequency bands as intermediaries to resolve the grating lobe problem. By analyzing spectral positions across different frequency bands, true targets maintain consistent spectral positions while grating lobes appear at different positions, allowing the system to distinguish between them and eliminate false targets
Solution Approach 2:
The patent changes the frequency parameter by operating in multiple frequency bands. This allows the system to maintain high angular resolution benefits of high frequency while using frequency diversity to identify and eliminate grating lobe artifacts through spectral position analysis
3Measurement precision
If a large aperture antenna array is used to improve angular separability, then angular resolution is improved, but the number of transmit/receive antenna pairs increases computational load
Solution Approach 1:
The patent divides the large aperture array into multiple smaller sub-arrays, reducing the number of transmit/receive pairs that must be processed simultaneously. This segmentation maintains the effective aperture for angular resolution while making the computational load manageable through parallel processing of sub-arrays
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
This approach enhances angular separability, allowing for the accurate distinction of close targets, reducing the risk of misinterpretation and improving the reliability of higher-level control functions in autonomous driving scenarios.
Implementation Method 1
an automotive radar transceiver system with increased angular separability comprising a radar transceiver adapted to generate and transmit radar signals
Implementation Method 2
an antenna array and a processing device adapted to process received reflected radar signals received via the antenna array
Data Source
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AI summary
The present disclosure relates to automotive radar transceiver system (120) comprising a radar transceiver (130) adapted to generate and transmit radar signals, an antenna array (140) and a processing device (150) adapted to process received reflected radar signals received via the antenna array (140). The antenna array (140) comprises a plurality of antenna elements (141) where adjacent antenna elements (141) are separated by a corresponding distance (d1, d2, d3). The processing device (150) is adapted to - control the radar transceiver (130) to generate and transmit first radar signals (170) in a first frequency band (B1) having a first center frequency (fc1) that corresponds to a first wavelength (λ1) that exceeds two times at least one of said distances (d1, d2, d3). The processing device (150) is further adapted to - generate and transmit second radar signals (171) in a second frequency band (B2) having a second center frequency (fc2) that differs from the first center frequency (fc1) and corresponds to a second wavelength (λ2) that exceeds two times at least one of said distances (d1, d2, d3), and to - determine spectral positions (θ1A, θ1B, θ2A, θ2B; θ3, θ4; θ5, θ6; θ7, θ8; θ9, θ10; θ11, θ12) of determined amplitude peaks (205, 206; 210, 211; 212, 213) in the received reflected signals (172, 173); - determine which of the spectral positions (θ1A, θ1B, θ2A, θ2B; θ3, θ4; θ5, θ6; θ7, θ8; θ9, θ10; θ11, θ12) that are considered to remain constant for both frequency bands (B1, B2).