Radar Signal Processing Phase Error Compensation Staggered Trigger

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Solution Overview

Problem

Radar apparatuses using a staggered trigger scheme face challenges in achieving improved signal-to-clutter ratio (S/C) and signal-to-noise ratio (S/N) due to phase errors caused by varying relative speeds of target objects and stagger processing, which disrupt the effectiveness of Doppler processing.

Innovation Solution

A signal processing device that includes an echo signal input unit, a complex reception signal generator, a phase calculator to determine phase changes based on moving speeds, and a phase corrector to adjust the complex reception signals, thereby performing Doppler processing while considering phase changes from both the transmission source and target object speeds, effectively mitigating phase errors introduced by staggered trigger schemes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If stagger processing is applied to avoid mutual interference between radar apparatuses, then the ability to discriminate echo signals from transmission signals of other radars is improved, but the signal-to-clutter ratio and signal-to-noise ratio cannot be improved as sufficiently as expected in Doppler processing when relative speed increases

Engineering Contradiction:
Improvediscrimination capabilityVSAvoidsignal-to-clutter ratio
Core Design Contradiction:
ReliabilityVSMeasurement precision

Solution Approach 1:

The patent changes the timing parameters of pulse transmission by applying stagger processing, where the transmission interval is varied between different pulse repetitions. This parameter change allows the radar to distinguish its own echo signals from those of other radars by creating unique timing patterns, while the patent further compensates for the resulting phase errors through additional correction mechanisms to maintain Doppler processing effectiveness

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent applies preliminary phase correction based on predicted phase errors caused by stagger processing. By calculating and compensating for the expected phase deviations before Doppler processing, the system prevents the degradation of signal-to-clutter ratio that would otherwise occur due to the staggered transmission intervals

Inventive Principle:
Principle #9Preliminary anti-action

2Reliability

If stagger processing is applied to avoid mutual interference between radar apparatuses, then the ability to discriminate echo signals from transmission signals of other radars is improved, but phase errors occur due to varying relative speeds and stagger processing

Engineering Contradiction:
Improvediscrimination capabilityVSAvoidphase accuracy
Core Design Contradiction:
ReliabilityVSLoss of information

Solution Approach 1:

The patent modifies the transmission timing parameters through stagger processing, creating variable intervals between pulses. This parameter change enables discrimination of radar signals from multiple sources while introducing phase variations that the patent subsequently corrects through predictive phase error compensation mechanisms

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent implements a feedback mechanism where phase errors predicted from stagger processing parameters are calculated and used to adjust the phase of received signals. This closed-loop approach compensates for the phase information loss introduced by staggered transmission, maintaining accurate Doppler velocity measurements

Inventive Principle:
Principle #23Feedback

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 reduces interruptions in S/C and S/N improvements, ensuring that Doppler processing can effectively enhance radar detection accuracy even under conditions of unequal pulse signal transmission intervals between sweeps.

Implementation Method 1

Radar apparatuses detect target objects (e.g., aircrafts and ships) generally by transmitting pulses of electromagnetic waves from antennas and receiving reflection waves from the target objects from the antennas

Methodology Applied
Scientific EffectRadar: Radar

Implementation Method 2

receiving reflection waves from the target objects

Methodology Applied
Scientific EffectReflection: Reflection

Implementation Method 3

performing Doppler processing on the corrected complex reception signals and outputting the Doppler-processed complex reception signals as Doppler echo signals of the object

Methodology Applied
Scientific EffectDoppler effect: Doppler Effect

Data Source

PatentEP2706374B1Signal processing device, radar apparatus, target object method
Publication Date: 2019.12.25 FURUNO ELECTRIC CO LTD
  • EP2706374B1 patent drawingFigure 1
  • EP2706374B1 patent drawingFigure 2A
  • EP2706374B1 patent drawingFigure 2B

AI summary

A signal processing device (40) is provided. The device includes an echo signal input unit (30) for receiving echo signals resulted from transmission signals reflected on an object. The transmission signals are transmitted from a transmission source (20) at transmission timings at predetermined time intervals, at least one of the transmission timings shifted from the other timings in time. The device includes a complex reception signal generator (42) for generating complex reception signals, a phase calculator (43) for calculating a phase change amount of the complex reception signals with respect to a reference phase, a phase corrector (44) for phase-correcting the complex reception signals and outputting the corrected signals, and a Doppler processor (45) for performing Doppler processing on the corrected signals and outputting the Doppler-processed signals as Doppler echo signals of the object.