Automotive Radar Direction of Arrival Estimation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional direction of arrival estimation in automotive radar systems requires precise synchronization of antennas on the scale of the radar carrier frequency, which is challenging, and displacement of antennas leads to ambiguity in angular reconstruction.
Innovation Solution
The method employs a multiple-input and multiple-output (MIMO) configuration with transceiver antenna units arranged at a priori known positions, using range gates to determine the direction of arrival by reading out and pattern-matching occupied range gates, eliminating the need for synchronization on the radar carrier frequency scale and utilizing time-of-flight profiles for refined angular resolution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional beamforming algorithms are used for direction of arrival estimation, then angular resolution can be achieved, but precise synchronization of antennas on the scale of radar carrier frequency is required
Solution Approach 1:
The patent replaces the conventional beamforming approach that requires precise temporal synchronization with a geometry-based range gate analysis method. Instead of using phase information and complex synchronization mechanisms, the invention uses the spatial geometry of antenna positions and range gate occupancy patterns to estimate direction of arrival, thereby eliminating the need for picosecond-level synchronization
Solution Approach 2:
The patent changes the fundamental parameters used for DoA estimation from phase-based measurements (requiring synchronization) to range-based measurements using occupancy patterns. By analyzing which range gates are occupied by different antenna units and comparing this to pre-calculated geometry-based expected patterns, the system achieves DoA estimation without requiring precise temporal synchronization
2Adaptability or versatility
If antennas are displaced to provide multi-functionality, then vehicle coverage and adaptability are improved, but ambiguity in angular reconstruction occurs
Solution Approach 1:
The patent pre-calculates expected occupancy patterns based on the known geometry of antenna positions before radar operation begins. These pre-calculated patterns serve as reference templates that are compared against actual measured occupancy patterns, allowing the system to resolve angular ambiguities that arise from antenna displacement
Solution Approach 2:
The patent adds a new dimension to DoA estimation by incorporating range gate occupancy patterns into the analysis. Instead of relying solely on angular information from beamforming, the invention uses the additional dimension of range gate occupancy across multiple antenna units to disambiguate angular reconstruction, particularly for displaced antenna configurations
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 allows for accurate direction of arrival estimation without the need for precise antenna synchronization, enhancing angular resolution and reducing ambiguity, particularly effective for targets in the far field, and enabling robust and reliable execution through a software module.
Implementation Method 1
radar technology, in particular in the millimeter wave range between 75 and 81 GHz
Implementation Method 2
determine the Direction of Arrival (DoA) of incoming radar waves which were transmitted towards and were reflected by targets
Implementation Method 3
determining a range of a target reflecting radar waves that have been transmitted by at least the specific transceiver antenna unit by reading out a plurality of range gates
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
A method of direction of arrival estimation with an automotive spread radar system (10). The automotive spread radar system (10) comprises a plurality of at least two transceiver antenna units (TRxk), which are configured to work in a MIMO configuration, wherein the transceiver antenna units (TRxk) are arranged at aprioriknown positions. The automotive spread radar system is configured to determine, for each transceiver unit antenna unit (TRxk) of the plurality of transceiver antenna units (TRxk), a range of a target (28) reflecting radar waves that have been transmitted by at least the specific transceiver antenna unit (TRxk) by reading out a plurality of range gates (12) assigned to a specific transceiver antenna unit (TRxk). The method and radar system are capable of estimating a direction of arrival without the need of ensuring a synchronization of antennas on the scale of a radar carrier frequency.