FMCW Radar Signal Segmentation for Interference Mitigation
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Solution Overview
Problem
Automotive radar systems face interference issues due to multiple sensors operating on the same vehicle or nearby, affecting detection performance by mixing radar return signals from different sources, leading to decreased accuracy in range, bearing, and velocity determination.
Innovation Solution
The method involves rearranging the sections of a linear ramp signal in a FMCW radar system to create a transmit control signal that varies piecewise-linearly with time, generating a radar transmission signal, and processing an intermediate frequency signal after low-pass filtering to reduce interference by distinguishing between relevant and interfering signals based on frequency components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multiple radar sensors operate simultaneously using conventional linear ramp signals, then the radar system can perform detection in the region of interest, but interference between sensors degrades detection performance and parameter accuracy
Solution Approach 1:
The linear ramp signal is divided into multiple time sections that are rearranged in a non-consecutive order. This segmentation of the frequency modulation waveform allows the radar system to maintain detection capability while creating distinctive signal patterns that reduce interference between multiple sensors operating simultaneously.
Solution Approach 2:
The patent changes the temporal parameter of the frequency-modulated signal by rearranging the time sections in a non-consecutive order. This parameter modification creates a piecewise-linear frequency trajectory that distinguishes the signal from conventional linear ramp signals, enabling interference mitigation while preserving detection functionality.
2Ease of operation
If radar return signals are processed using conventional methods, then processing is straightforward, but interference from other sensors mixes with relevant signals making accurate detection difficult
Solution Approach 1:
The low-pass filter extracts and retains only the low-frequency components of the intermediate frequency signal that correspond to relevant radar returns, while removing high-frequency components that represent interference from other sensors. This extraction process maintains processing simplicity while improving detection reliability by eliminating interfering signals.
Solution Approach 2:
The low-pass filter acts as an intermediary element between the mixed radar signals and the detection processing stage. It mediates by selectively passing desired low-frequency components while blocking unwanted high-frequency interference, thereby protecting the detection system from interference without complicating the overall processing architecture.
3Device complexity
If the transmit signal uses a conventional linear ramp, then frequency variation is simple and continuous, but interfering signals produce overlapping frequency components that cannot be easily distinguished
Solution Approach 1:
The continuous linear ramp signal is segmented into discrete time sections that are rearranged in a non-consecutive sequence. This creates a piecewise-linear frequency trajectory with distinctive temporal characteristics that reduce frequency overlap and interference between multiple radar sensors while maintaining relatively simple signal generation circuitry.
Solution Approach 2:
The rearranged time sections create a periodic pattern in the frequency modulation that differs from conventional linear ramps. This periodic structure with specific temporal characteristics enables the radar system to distinguish its signals from interfering signals through frequency analysis, reducing the harmful effects of interference.
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 or eliminates interference from other radar sensors by filtering out high-frequency components caused by interfering transmitters, allowing for accurate radar detection and parameter determination by focusing on low-frequency components from the relevant transmitter.
Implementation Method 1
The IF signal is low-pass filtered to generate a low-pass-filtered IF signal
Data Source
AI summary
In a frequency-modulated continuous-wave radar processing system and method, a linear frequency ramp signal is defined. The linear ramp signal is divided into a plurality of time sections. The sections of the linear ramp signal are rearranged in time such that the plurality of sections define a transmit control signal different than the linear ramp signal. A radar transmission signal is generated having a frequency varying with time according to the transmit control signal, and the radar transmission signal is transmitted into the region of interest. An intermediate frequency (IF) signal is generated using the radar transmission signal and radar receive signals received from the region of interest, a frequency of the IF signal being a difference between the frequency of the radar transmission signal and a frequency of the radar receive signals. The IF signal is low-pass filtered. Radar processing is performed on the low-pass-filtered IF signal.