FMCW Radar Processing Chain Clutter Removal
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Solution Overview
Problem
Radar processing chains face challenges in clutter-rich environments, particularly in detecting objects with small radar cross-sections like human beings, due to strong interference from clutter sources such as building structures and furniture, which dominate the received signal and obscure smaller RCS objects.
Innovation Solution
A radar processing chain that includes a clutter removal algorithm and allows for high-resolution directional-of-arrival (DoA) estimation and low-complexity Doppler estimation, using a signal processor to generate a frequency domain representation of beat-signal samples, correct for clutter, determine angular spectra, and apply spatial beamforming and FFT to extract Doppler information.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional radar processing is used in clutter-rich environments, then the system can operate with standard processing chains, but detection of objects with small radar cross-sections is obscured by strong clutter interference
Solution Approach 1:
The radar signal processing is divided into distinct stages: Fast Fourier Transform (FFT) for range processing, clutter removal stage, angular spectrum determination, and Doppler processing. Each stage handles specific aspects of signal decomposition, allowing clutter to be targeted and removed without affecting the entire processing chain.
Solution Approach 2:
The clutter component is explicitly extracted and removed from the received signal in a dedicated clutter removal stage. By identifying and separating the clutter signal from the total received signal, the processing chain eliminates the harmful interference while preserving signals from objects with small radar cross-sections.
2Measurement precision
If high-resolution directional-of-arrival estimation and Doppler estimation are implemented, then accurate angular and Doppler information can be obtained, but the processing complexity increases
Solution Approach 1:
Clutter removal is performed as a preliminary action before angular spectrum determination and Doppler processing. By eliminating clutter early in the processing chain, subsequent high-resolution estimation algorithms operate on cleaner data, achieving better accuracy without requiring overly complex processing in later stages.
Solution Approach 2:
The processing chain uses adaptive Fast Fourier Transform techniques and dynamic signal separation methods that adjust processing parameters based on the received signal characteristics. This allows the system to maintain high measurement precision while optimizing computational complexity according to actual operating conditions.
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
Enables effective detection of objects in clutter-rich environments by removing clutter interference and providing accurate angular and Doppler information, improving the ability to locate objects with small radar cross-sections.
Implementation Method 1
The received electromagnetic radiation for each chirp is mixed with the transmitted chirp to provide a beat signal
Implementation Method 2
A Fast Fourier transform (FFT) is applied to the beamformed signal block for the range bin to provide a Doppler spectral vector
Implementation Method 3
Spatial beamforming is applied to a dimensional spatial vector comprising all clutter corrected samples for a given range bin
Implementation Method 4
Doppler information is extracted or an object of the at least one object associated with the given range bin from the Doppler spectral vector
Data Source
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AI summary
In systems and methods for a radar processing chain for frequency-modulated continuous wave radar systems, a transmitter (102) transmits a plurality of chirps, each comprising an electromagnetic radiation signal, at a region of interest. A receiver front-end (104) receives reflected electromagnetic radiation for each chirp and generates a time series of beat-signal samples for each chirp at each antenna of a plurality of antennas. A signal processor (106) detects objects within the region of interest by providing a frequency domain representation of each time series of beat-signal samples as sample values for a set of range bins representing respective distances from the receiver, correcting the sample values for each of the set of range bins to provide a set of clutter corrected samples for each range bin, and determining an angular spectrum for each of a subset of the set of range bins from the clutter corrected samples.