Radar Interference Signal Frequency Avoidance
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Solution Overview
Problem
Conventional FMCW radar systems face challenges in accurately detecting targets due to interference from signals within the same frequency band, leading to reduced signal-to-noise ratio and increased false alarm rates or missed detections.
Innovation Solution
The method involves detecting interfering signals within the RF return signal, selecting a sweep range to avoid these signals, and processing time samples to generate arrays and thresholds for identifying and removing the interfering signal, thereby enhancing the radar system's ability to accurately detect targets.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the radar transmits signals within a frequency band, then it can detect targets in that band, but interfering signals within the same band corrupt the received signals and reduce detection accuracy
Solution Approach 1:
The patent extracts and removes interfering signals from the received radar return signal by analyzing the frequency spectrum, identifying interfering frequency components, and eliminating them before target detection. This separates the harmful interference from the useful target signal, resolving the contradiction between operating in a frequency band and avoiding interference within that band.
Solution Approach 2:
The patent converts the harmful interfering signals into useful information by analyzing their frequency characteristics in the spectrum. By identifying the frequency components and patterns of interference, the system can selectively remove only the interfering portions while preserving the target signals, thus transforming the harmful interference into a detectable and removable artifact.
2Measurement precision
If the radar uses a wide frequency sweep range, then it can detect targets at multiple ranges with good resolution, but it becomes more susceptible to interfering signals within that band
Solution Approach 1:
The patent maintains the wide frequency sweep range for good range resolution while extracting and removing interfering frequency components from the received signal. By performing interference removal in the frequency domain after FFT processing, the system preserves the benefits of wide bandwidth for range resolution while eliminating the harmful effects of interference within that band.
3Reliability
If the radar processes all received frequency components, then it can maintain sensitivity to weak target signals, but interfering signals at high power levels overwhelm the frequency spectrum and mask target signals
Solution Approach 1:
The patent converts the overwhelming interfering signals into identifiable frequency components in the spectrum. By analyzing the frequency domain representation of the received signal, the system identifies interfering components based on their power levels and frequency characteristics, then selectively removes them to reveal the masked target signals that would otherwise be lost.
Solution Approach 2:
The patent extracts and removes the interfering signal components from the frequency spectrum, separating them from the target signal components. This extraction process prevents the high-power interfering signals from overwhelming and masking the weaker target signals, thereby preserving the detection capability for weak targets.
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
This approach effectively reduces the impact of interfering signals, improving the accuracy and reliability of target detection by isolating the target signal from noise and interference, thus enhancing the radar system's precision and reducing false alarms.
Implementation Method 1
A conventional FMCW radar uses a mixer, which mixes (i.e., multiplies) the transmitted and received signals. One of the outputs of the mixer is the above-described difference in frequency between the transmitted and received signals, which is also referred to herein as a 'downconverted signal' or a 'video signal,' which can have a 'beat frequency.'
Data Source
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AI summary
A radar system and method determine the frequency of an interfering signal and then avoiding transmitting power in that portion of the frequency spectrum where the interfering signal is present.