Radar Phase Noise Reduction via Signal Correlation

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Solution Overview

Problem

Distributed radar systems face challenges in achieving coherent signal distribution and reducing phase noise interference, particularly with increasing aperture size, which affects angular resolution and accuracy due to independent signal generation in non-coherent transmitting and receiving devices.

Innovation Solution

A method that involves synchronizing signals between non-coherent transceiver units by forming comparison signals, compensating for systematic deviations, and using addition instead of multiplication to combine complex signals, thereby reducing phase noise without introducing additional interference and requiring less computational effort.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of moving object

If distributed radar systems use independent signal generation in non-coherent transceiver units to achieve spatial aperture and angular resolution, then the spatial aperture and angular resolution are improved, but phase noise interference increases and measurement accuracy deteriorates

Engineering Contradiction:
Improvespatial apertureVSAvoidmeasurement accuracy
Core Design Contradiction:
Area of moving objectVSMeasurement precision

Solution Approach 1:

The patent converts the harmful phase noise from independent signal generators into a beneficial synchronization mechanism. By using the phase noise itself as a reference signal through comparison signal generation and correlation processing, the system transforms the disturbance into useful information for achieving coherent signal combination across distributed transceiver units, thereby maintaining measurement accuracy while preserving spatial aperture advantages

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

Solution Approach 2:

The patent introduces comparison signals as an intermediary between independently generated signals from different transceiver units. These comparison signals serve as mediators that enable synchronization and coherent combination by providing a common reference framework, allowing the system to combine signals from multiple independent sources while maintaining phase coherence for accurate measurements

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of manufacture

If distributed radar systems use independent signal generation to allow separate high-frequency signal generation in each unit, then device complexity is reduced and ease of manufacture is improved, but synchronization difficulty increases and phase noise interference worsens

Engineering Contradiction:
Improveease of manufactureVSAvoidsynchronization complexity
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The patent implements self-service synchronization where each transceiver unit independently generates its own high-frequency signal and comparison signals, then uses local correlation processing to achieve synchronization without requiring complex external synchronization infrastructure. This allows completely independent signal generators to be used while maintaining coherent combination through self-contained synchronization mechanisms in each unit

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent replaces complex mechanical or hardware-based synchronization systems with signal-processing-based correlation methods. Instead of using precise mechanical clock distribution or phase-locked loops that require tight coupling, the system uses computational correlation of comparison signals to achieve synchronization, thereby simplifying the physical hardware while maintaining synchronization accuracy

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Measurement precision

If traditional multiplication methods are used to combine comparison signals for phase noise reduction, then phase noise suppression is achieved, but computational effort increases and additional interference is introduced

Engineering Contradiction:
Improvephase noise suppressionVSAvoidcomputational efficiency
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The patent extracts only the essential phase information from comparison signals through correlation processing, separating the useful phase coherence information from the harmful phase noise. By taking out only the necessary synchronization information through correlation rather than full multiplication, the system achieves phase noise suppression while minimizing computational effort and avoiding the generation of additional interference components that would arise from complete signal multiplication

Inventive Principle:
Principle #2Taking out (Extraction)

Data Source

PatentEP3400458B1Method and system for the reduction of disturbance through phase noise in a radar system
Publication Date: 2021.10.13 SYMEO
  • EP3400458B1 patent drawingFigure 1~2
  • EP3400458B1 patent drawingFigure 3~4
  • EP3400458B1 patent drawing

AI summary

A method for reducing interference caused by phase noise in a radar system is described in particular, in which a first signal (sigTX1) is generated in a first non-coherent transceiving unit (NKSE1) and is transmitted, in particular emitted, via a path (SP), a first signal (sigTX2) is generated in a further, in particular second non-coherent transceiving unit (NKSE2) and is transmitted, in particular emitted, via the path (SP), the signals (sigTX1 and sigTX2) are directly or indirectly received in the respective other transceiving stations and are processed there as reception signals sigRX12 and sigRX21, a comparison signal (sigC12) is formed in the first transceiving unit (NKSE1) from its first signal (sigTX1) and from such a first signal (sigTX2) received from the further transceiving unit (NKSE2) via the path (SP), and a further comparison signal (sigC21) is formed in the further transceiving unit (NKSE2) from its first signal (sigTX2) and from such a first signal (sigTX1) received from the first transceiving unit (NKSE1) via the path (SP), wherein the further comparison signal (sigC21) is transmitted, in particular communicated, from the further transceiving unit (NKSE2) to the first transceiving unit (NKSE1), wherein in a first step deviations of the signals sigC21 and sigC12 which are caused by systematic deviations in the transceiving units (NKSE2, NKSE1) are compensated for, wherein in a second step at least one complex value from a first of the two comparison signals or from a signal which has been derived from this first comparison signal is used to adapt at least one complex value of the second of the two comparison signals or a value of a signal which has been derived from this second comparison signal and to therefore form a signal (sigCC), wherein the adaptation is carried out using a mathematical operation to form the vectorial sum or the difference of the complex values or the sum or the difference of the phases of the complex values.