Radar Device Pulse Timing Shift for Resolution

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Solution Overview

Problem

Current radar technologies face limitations in achieving high separation resolution due to the constraints of AD conversion circuits, which restrict the sampling frequency and result in complex circuit configurations when attempting to shorten pulse widths for improved accuracy in multipath environments.

Innovation Solution

The radar device employs a pulse transmission position adjuster to shift the timing of each pulse signal relative to the AD conversion sampling timing, allowing for pseudo oversampling without increasing the sampling frequency or circuit complexity, thereby enhancing the separation resolution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the pulse width is shortened to increase separation resolution, then the separation resolution is improved, but the processing speed requirement of AD conversion circuit increases beyond current limits

Engineering Contradiction:
Improveseparation resolutionVSAvoidprocessing speed of AD conversion circuit
Core Design Contradiction:
Measurement precisionVSSpeed

Solution Approach 1:

The transmission timing of pulse signals is shifted in advance by a time shorter than the sampling interval before transmission. This preliminary timing adjustment enables the reception signal to be sampled at effectively shorter intervals without requiring the AD conversion circuit to operate at higher speeds, thus resolving the contradiction between separation resolution and processing speed requirements

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

A pulse transmission position adjuster is introduced as an intermediary component between the pulse generator and the transmission path. This adjuster shifts the transmission timing of pulse signals without affecting the AD conversion circuit's sampling operation, enabling higher separation resolution while maintaining the circuit within its current processing speed capabilities

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If the sampling frequency is increased to achieve higher separation resolution, then the separation resolution is improved, but the device complexity and power consumption increase

Engineering Contradiction:
Improveseparation resolutionVSAvoidcircuit configuration complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

Instead of increasing the sampling frequency of the AD conversion circuit, the transmission timing of pulse signals is shifted in advance by a time shorter than the sampling interval. This approach achieves higher separation resolution by effectively increasing the sampling density without modifying the AD conversion circuit's operating frequency, thereby avoiding increased device complexity

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

Rather than increasing the sampling frequency to improve separation resolution, the invention inverts the approach by shifting the transmission timing of pulse signals. This reverse strategy achieves the same effect of higher resolution while maintaining the original sampling frequency and avoiding circuit complexity increases

Inventive Principle:
Principle #13The other way round (Inversion)

Data Source

PatentEP2618173B1Radar device
Publication Date: 2021.04.14 PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO LTD
  • EP2618173B1 patent drawingFigure 1
  • EP2618173B1 patent drawingFigure 2
  • EP2618173B1 patent drawingFigure 3

AI summary

It is intended to make it possible to acquire a digital signal at an interval that is shorter than the sampling interval of an AD conversion circuit and to thereby increase the distance resolution of a radar device. Based on a pulse signal having a constant interval that is generated by and output from a pulse generator 101, a pulse transmission position adjuster 102 generates a transmission signal in which transmission positions are adjusted by shifting the timing of the pulse signal in units of a time adjustment amount α that is shorter than a sampling interval of an AD converter 114 of a receiver. In doing so, the pulse transmission position adjuster 102 delays transmission positions of respective pulses of the pulse signal in units of the time adjustment amount α in a pattern that ends when the transmission timing becomes equal to the timing of the original pulse signal. A distance detector 115 generates a reception signal through pseudo oversampling having an interval that is equal to the time adjustment amount α according to transmission position information indicating the transmission positions of the respective pulses of the pulse signal on the basis of a digital signal generated by sampling a reception signal corresponding to the transmission signal with the AD converter 114.