Doppler Radar Narrowband Interference Suppression
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Continuous wave Doppler radar systems face false alarms due to narrowband interference from constant frequency sources, which complicates motion detection by mixing with Doppler signals.
Innovation Solution
A Doppler radar apparatus with a narrowband interference suppression device that uses a tapped delay line and interference estimating device to generate weighting coefficients for adjusting suppression strength, and optionally includes high-pass filtering and notch filters to isolate and filter out narrowband interference frequencies.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If continuous wave Doppler radar is used for motion detection, then the radar can detect moving objects, but narrowband interference from constant frequency sources causes false alarms
Solution Approach 1:
The patent extracts and separates the narrowband interference signal from the composite radar signal using a tapped delay line and interference estimation device. By identifying and isolating the constant frequency interference component, the system removes it from the detection signal, thereby eliminating false alarms while preserving the Doppler motion detection capability.
Solution Approach 2:
The patent implements a feedback mechanism where the interference estimation device continuously monitors the signal, updates interference templates based on detected interference patterns, and adjusts suppression parameters in real-time. This adaptive feedback loop enables the system to dynamically respond to varying interference conditions and maintain reliable motion detection.
2Measurement precision
If narrowband interference suppression is applied to eliminate false alarms, then detection accuracy improves, but device complexity increases due to additional components
Solution Approach 1:
The patent designs the interference suppression device to perform multiple functions: signal delay, interference estimation, template updating, and adaptive suppression all within a unified structure. The tapped delay line serves both as a signal processing element and as a basis for interference template generation, reducing the need for separate dedicated components and thereby limiting the increase in device complexity.
Solution Approach 2:
The patent employs parameter-based adaptation where the suppression characteristics are controlled by adjusting weighting coefficients and interference template parameters rather than changing the physical structure. This allows the system to adapt to different interference scenarios through parameter modification, maintaining measurement precision while avoiding structural complexity increases.
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
Effectively suppresses narrowband interference, reducing false alarms and enhancing the accuracy of Doppler motion detection by adaptively adjusting interference suppression strength based on signal intensity ratios.
Implementation Method 1
A first aspect of the embodiments of the disclosure provides a Doppler radar apparatus including a transmitting device configured to transmit a first wireless signal, a receiving device coupled to the transmitting device and configured to receive a second wireless signal to generate a first digital signal, where the first digital signal includes a Doppler signal component
Implementation Method 2
The narrowband interference suppression device is coupled to the receiving device and is configured to perform interference suppression on the first digital signal to suppress the narrowband interference signal component in the first digital signal to generate an output digital signal
Implementation Method 3
The narrowband interference suppression device includes a tapped delay line configured to obtain a delayed digital signal according to the first digital signal and an interference estimating device coupled to the tapped delay line
Implementation Method 4
The interference estimating device is configured to generate an interference estimation signal according to the delayed digital signal and multiple weighting coefficients, update the weighting coefficients according to an error signal
Implementation Method 5
The narrowband interference suppression device includes a high-pass filter configured to filter the Doppler signal component of the first digital signal to generate an interference tracking digital signal
Data Source
AI summary
A Doppler radar apparatus including a transmitting device, a receiving device and a narrowband interference suppression device is provided. The transmitting device is configured to transmit a first wireless signal. The receiving device is coupled to the transmitting device and is configured to receive a second wireless signal to generate a first digital signal. The first digital signal includes a Doppler signal component and a narrowband interference signal component, and a bandwidth of the narrowband interference signal component is smaller than a bandwidth of the Doppler signal component. The narrowband interference suppression device is coupled to the receiving device and is configured to perform interference suppression on the first digital signal to suppress the narrowband interference signal component in the first digital signal to generate an output digital signal.