TDMA Phase Correction in Radar Object Detection

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Solution Overview

Problem

Time division multiplexing (TDMA) in radar and wireless communication systems introduces phase shifts that can skew object detection information, especially when detecting moving objects, due to unknown velocities, complicating signal processing.

Innovation Solution

A system and method that use a processor to determine the existence of a transmission timing phase shift by analyzing the relationship between covariance matrices of received signals, allowing for compensation and accurate signal processing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If TDMA is used to transmit multiple signals, then the number of signals available for object detection is increased, but transmission timing phase shifts are introduced that skew detection information

Engineering Contradiction:
Improvenumber of signalsVSAvoiddetection accuracy
Core Design Contradiction:
Quantity of substanceVSMeasurement precision

Solution Approach 1:

The patent segments the detection process into distinct phases: signal transmission using TDMA, reception of signals with potential phase shifts, covariance matrix computation for each signal group, and comparison of trace values to determine phase shift existence. This segmentation allows systematic handling of phase shift issues while maintaining multiple signal transmission capability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent changes the parameter representation by computing covariance matrices from received signals and comparing their trace values. This parameter transformation enables detection of phase shift conditions without directly measuring phase shifts, allowing accurate object detection despite TDMA-induced timing differences.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If TDMA is used to separate signal transmissions in time, then signal orthogonality is achieved, but additional phase shifts are introduced that complicate processing

Engineering Contradiction:
Improvesignal orthogonalityVSAvoidsignal processing complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent introduces covariance matrices as an intermediary representation between raw received signals and final detection results. By computing covariance matrices for each signal group and comparing their trace values, the system mediates the complex phase shift issues, simplifying the processing while maintaining signal orthogonality benefits.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Ease of operation

If multiple transmitters transmit at different times, then processing difficulties are reduced through TDMA, but phase shifts related to unknown object velocity increase processing complexity

Engineering Contradiction:
Improvesignal transmission managementVSAvoidphase shift detection difficulty
Core Design Contradiction:
Ease of operationVSDifficulty of detecting and measuring

Solution Approach 1:

The patent implements a feedback mechanism where the system computes covariance matrices from received signals, compares trace values to determine phase shift existence, and uses this information to guide further processing. This feedback loop enables adaptive handling of phase shifts related to unknown object velocities, making detection more manageable despite TDMA timing differences.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP3572830A1Phase correction for object detection including TDMA
Publication Date: 2019.11.27 APTIV TECHNOLOGIES AG
  • EP3572830A1 patent drawingFigure 1
  • EP3572830A1 patent drawingFigure 2
  • EP3572830A1 patent drawingFigure 3

AI summary

An illustrative example object detection system (20) includes a plurality of first transmitters (24) that respectively transmit a first signal at a first time, a plurality of second transmitters (26) that respectively transmit a second signal at a second time, a plurality of receivers (28) that receive the signals, and a processor (30) that is configured to determine whether a transmission timing phase shift exists between the received first signals and the received second signals based on a relationship between matrices including the received signals.