Radar Interference Cancellation via Time-Frequency Analysis

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Radar devices face reduced detection accuracy due to interference from external disturbance electromagnetic waves, which can cause ripples in FFT processing results and lead to insufficient object detection when interference periods are excluded from sampling data.

Innovation Solution

A radar device with an interference signal processing unit that performs multiple resolution analysis on beat signals, detects interference plots in time-frequency plots, cancels interference signals, and reversely converts time-frequency plots back into time samples for object detection, ensuring accurate detection even with interference present.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-generated harmful factors

If interference periods are excluded from sampling data to remove interference signals, then interference signal removal is improved, but detection accuracy deteriorates due to insufficient sampling data

Engineering Contradiction:

Improveinterference signal removalVSAvoiddetection accuracy

Core Design Contradiction:

Object-generated harmful factorsVSMeasurement precision

Solution Approach 1:

The patent segments the signal processing into time-frequency domain analysis using Short-Time Fourier Transform (STFT), allowing interference signals to be identified and removed in specific time-frequency regions while preserving the rest of the sampling data for object detection

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent introduces an intermediary processing step using STFT to convert the time-domain signal into a time-frequency representation, which serves as a mediator to identify and remove interference signals without directly manipulating the original sampling data, thus preserving data integrity

Inventive Principle:

Principle #24Intermediary (Mediator)

2Ease of operation

If FFT processing is performed on time sample data, then object detection is enabled, but ripples appear in processing results due to interference signals

Engineering Contradiction:

Improveobject detection capabilityVSAvoidprocessing result accuracy

Core Design Contradiction:

Ease of operationVSManufacturing precision

Solution Approach 1:

The patent performs preliminary interference signal removal in the time-frequency domain before conducting FFT processing, by identifying interference components through STFT and removing them from specific time-frequency regions, thus preventing ripples in the subsequent FFT results

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent replaces the direct FFT processing of raw time-sample data with an intermediate STFT-based interference removal process, substituting the mechanical FFT operation with a more sophisticated signal processing approach that eliminates interference artifacts

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Data Source

PatentUS12158537B2Radar device

Publication Date: 2024.12.03 DENSO CORP

AI summary

A radar device includes: a transmission unit; a reception unit; an interference signal processing unit that cancels an influence of an interference signal from a beat signal; and an object detection unit that detects the object based on the beat signal. The interference signal processing unit includes: a digital converter that converts the beat signal into a time sample; a multiple resolution analysis unit that converts the time sample into time-frequency plots; an interference plot detection unit that detects an interference plot; an interference cancellation unit that cancels the influence of the interference signal; and a reverse converter that reverse converts the time-frequency plots into the time sample. The object detection unit detects the object using the reversely converted time sample.