FMCW Radar Signal Processing with Adaptive Interference Extraction
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Solution Overview
Problem
Conventional FMCW radars experience performance degradation due to interference from other vehicles' radar signals, leading to non-detection and false detection, which can cause malfunctions during critical vehicle operations like braking or steering.
Innovation Solution
A system and method that includes a transmission module for transmitting radar signals with unique frequency variations and pulse repetition intervals, a variation module to adjust these parameters, an extraction module to identify interference signals using cumulative histograms, and an adjustment module to replace the interference signals with zeros, thereby reducing interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If FMCW radar transmits signals to detect objects and vehicles, then detection capability is improved, but interference from other radar signals causes performance degradation and false detection
Solution Approach 1:
The extraction module separates interference signals from valid radar signals by calculating cumulative histograms of signal intensities. Signals exceeding a dynamically determined threshold are identified as interference and extracted for removal, thereby isolating the harmful factor from the useful signal.
Solution Approach 2:
The system dynamically adjusts the threshold parameter based on the cumulative histogram distribution of signal intensities. By changing the threshold parameter adaptively rather than using a fixed value, the system can distinguish between valid weak signals and interference signals under varying operational conditions.
2Reliability
If radar signals are transmitted continuously to maintain detection, then detection coverage is improved, but interference accumulation increases causing malfunctions during critical operations
Solution Approach 1:
The system converts the harmful interference signal into a useful diagnostic indicator. By calculating the cumulative histogram of all received signals and identifying peaks that exceed the threshold, the system detects interference patterns and uses this information to adjust processing, thereby transforming the harmful accumulation into a basis for improved reliability.
Solution Approach 2:
The adjustment module uses feedback from the cumulative histogram analysis to dynamically modify signal processing parameters. When interference is detected through histogram peak analysis, the system adjusts the threshold and processing gain accordingly, creating a closed-loop system that maintains reliability despite continuous transmission and interference accumulation.
3Measurement precision
If threshold is set low to detect weak signals, then sensitivity is improved, but false detection increases due to noise and interference
Solution Approach 1:
The system applies partial action by processing signals in stages: first calculating the cumulative histogram to identify interference levels, then applying the threshold only to signals that exceed the dynamically determined level. This partial application of thresholding avoids false detection of noise while maintaining sensitivity to genuine weak signals.
Solution Approach 2:
Before applying the detection threshold to individual signals, the system performs preliminary action by calculating the cumulative histogram of all received signals to establish the interference baseline. This preliminary analysis enables the system to set an informed threshold that accounts for current interference conditions, preventing false detection before it occurs.
Data Source
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AI summary
Provided are a system and method for processing a radar signal for deriving a Doppler frequency from a sampled digital input signal radiated by a frequency modulation continuous wave (FMCW) radar. The system includes a transmission module that repeatedly transmits a radar signal having a unique frequency variation and a pulse repetition interval, a variation module that varies the frequency variation or pulse repetition interval of the radar signal transmitted by the transmission module, an extraction module that, upon occurrence of interference between the radar signal having the varied frequency variation or pulse repetition interval and another radar signal, extracts an interference signal from the varied radar signal, and an adjustment module that adjusts the radar signal to reduce the extracted interference signal.