Doppler Signal Processing for Interference Spectrum Tracking
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Solution Overview
Problem
Radar devices face significant challenges in accurately detecting objects due to background interference, leading to incorrect detection results, particularly when used to detect vital signs or human bodies, as existing methods for signal energy threshold and frequency energy detection do not provide high accuracy.
Innovation Solution
A Doppler signal processing device equipped with a frequency analysis unit, interference suppression unit, interference estimation unit, detection unit, and error detection unit, which generates a frequency domain signal vector, suppresses interference, and adjusts the rate of updating the interference estimation signal vector based on error detection control signals to improve detection accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If signal energy threshold device or frequency energy detection method is used to reduce background interference impact, then detection accuracy is improved, but the system cannot effectively track and suppress time-varying interference
Solution Approach 1:
The interference estimation unit performs preliminary estimation of interference spectrum before the suppression operation is applied. By estimating the interference characteristics in advance and then applying suppression based on this estimation, the system effectively removes time-varying interference while preserving target signals, resolving the contradiction between detection accuracy and interference suppression effectiveness.
Solution Approach 2:
The system implements a feedback mechanism where the interference estimation unit continuously monitors and estimates interference characteristics, and this estimation is fed back to the suppression unit for real-time adjustment. This closed-loop feedback enables the system to adapt to changing interference conditions, maintaining both high detection accuracy and effective interference suppression.
2Device complexity
If existing detection methods are used, then the system structure is simple, but detection accuracy deteriorates in high interference environments
Solution Approach 1:
The detection system is segmented into distinct functional units: frequency analysis unit, interference estimation unit, interference suppression unit, and detection unit. Each unit performs a specific function, allowing the system to achieve high detection accuracy through specialized processing while maintaining clear modular structure that manages complexity.
Solution Approach 2:
The interference estimation unit acts as an intermediary between the frequency analysis unit and the detection unit. It processes the frequency domain signal to estimate interference characteristics, which are then used by the suppression unit to clean the signal before detection. This intermediary processing step significantly improves detection accuracy without requiring complete redesign of the entire system.
3Measurement precision
If interference suppression is applied, then detection accuracy is improved, but the system may incorrectly suppress target signals along with interference
Solution Approach 1:
The interference suppression is applied locally in the frequency domain rather than uniformly across all frequencies. The interference estimation unit identifies specific frequency components that contain interference, and the suppression unit applies suppression only to those identified components. This localized approach preserves target signals at other frequencies while effectively removing interference, thus improving detection accuracy without causing signal loss.
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
The solution effectively suppresses background interference, enhancing the accuracy of object detection and vital sign monitoring by isolating movement information from interference, thereby improving the reliability of radar systems in noisy environments.
Implementation Method 1
a frequency analysis unit, configured to generate a frequency domain signal vector according to at least one digital signal
Implementation Method 2
The interference suppression unit is configured to perform a suppression operation according to the frequency domain signal vector and a frequency domain interference estimation signal vector to generate an interference suppressed frequency domain signal vector
Implementation Method 3
a Doppler signal processing device for a Doppler radar capable of interference spectrum tracking and suppression
Data Source
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AI summary
Doppler signal processing device (100) detects an object (Obj) according to a received wireless signal (Sr). The Doppler signal processing device (100) includes a frequency analysis unit (110) for generating a frequency domain signal vector (X(n)) according to at least one digital signal (Sd), an interference suppression unit (120) for performing a suppression operation according to the frequency domain signal vector (X(n)) and a frequency domain interference estimation signal vector (U(n)) to generate an interference suppressed frequency domain signal vector (Y(n)), an interference estimation unit (130) for generating the frequency domain interference estimation signal vector (U(n)) according to the frequency domain signal vector (X(n)), a detection unit (140) for generating a result signal (Shuman_presence) according to the interference suppressed frequency domain signal vector (Y(n)), an error detection unit (150) for optionally providing an error detection control signal (Snegative_amplitude_detected) to the interference estimation unit (130) to adjust a rate of updating the frequency domain interference estimation signal vector (U(n)).