Automotive Radar Joint DoA-DoD Estimation in Multipath

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Solution Overview

Problem

Radar systems struggle to accurately detect direction-of-arrival (DoA) and direction-of-departure (DoD) angles in multipath scenarios due to DoD-DoA mismatches, leading to errors in object detection and tracking, particularly in automotive applications, which can result in unsafe driving conditions.

Innovation Solution

A radar system that generates a two-dimensional data matrix to jointly determine DoA and DoD estimates using a sparse transmitter and receiver array, allowing for improved angular resolution and reduced cost without requiring expensive polarimetric antennas or multiple data snapshots.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a MIMO radar system uses a synthetic array to improve angular resolution, then measurement precision is improved, but the system requires DoD to equal DoA which limits applicability in multipath scenarios

Engineering Contradiction:
Improveangular resolutionVSAvoidapplicability in multipath scenarios
Core Design Contradiction:
Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The patent transitions from traditional 1D DoA estimation to 2D joint DoA-DoD estimation by organizing received signals into a two-dimensional data matrix where rows correspond to receiver antenna elements and columns correspond to transmitter antenna elements. This dimensional expansion enables independent estimation of both departure and arrival angles, resolving the contradiction by allowing synthetic array formation without requiring DoD to equal DoA.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Measurement precision

If expensive polarimetric antennas or multiple data snapshots are used to resolve multipath reflections, then measurement precision is improved, but device complexity and cost increase

Engineering Contradiction:
Improveobject detection accuracyVSAvoidantenna configuration complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent creates a virtual synthetic array through signal processing that copies the functionality of a larger physical array without requiring additional hardware. By forming a 2D data matrix from existing transmitter and receiver antenna elements, the system achieves enhanced angular resolution equivalent to a larger antenna configuration without the corresponding increase in physical complexity or cost.

Inventive Principle:
Principle #26Copying

3Ease of operation

If traditional radar systems ignore multipath reflections, then ease of operation is maintained, but reliability deteriorates due to detection errors

Engineering Contradiction:
Improvesystem operation simplicityVSAvoidobject detection reliability
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent converts the harmful effect of multipath reflections into a beneficial signal source for joint DoA-DoD estimation. Instead of treating reflected signals as noise to be filtered out, the system utilizes them to populate the 2D data matrix, enabling accurate angle estimation even in multipath environments. This approach maintains operational simplicity while significantly improving detection reliability.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

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

Enables accurate detection of objects in multipath scenarios with improved angular resolution and reduced computational resources, suitable for automotive applications, by determining DoA and DoD angles effectively, thus enhancing safety and reliability in vehicle navigation systems.

Implementation Method 1

Radar systems use antennas to transmit and receive electromagnetic (EM) signals for detecting and tracking objects. In automotive applications, radar systems operate in dynamic environments that can cause EM signals to have multipath reflections.

Methodology Applied
Scientific EffectElectromagnetic radiation reflection: Reflection

Data Source

PatentUS12560695B2Radar system to jointly detect direction-of-arrival and direction-of-departure angles in multipath scenarios
Publication Date: 2026.02.24 APTIV TECHNOLOGIES AG
  • US12560695B2 patent drawing
  • US12560695B2 patent drawing
  • US12560695B2 patent drawing

AI summary

This document describes techniques and systems to enable a radar system to jointly detect DoA and DoD angles in multipath scenarios. In some examples, an automotive radar system includes one or more processors. The processors obtain electromagnetic (EM) energy reflected by objects and generate, based on the reflected EM energy, a two-dimensional (2D) data matrix. The 2D data matrix has a number of rows corresponding to the number of antenna elements in a transmitter array and a number of columns corresponding to the number of antenna elements in a receiver array. Using the 2D data matrix, the processors can determine DoA estimates and DoD estimates in both monostatic and bistatic reflection scenarios. By comparing the DoA estimates to the DoD estimates, the processors determine angles associated with the objects with improved angular resolution and reduced cost.