MIMO Radar Doppler-Angle Estimation for Overlapping Target Signals
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Solution Overview
Problem
Existing radar systems face challenges in accurately estimating Doppler frequency and angle when dealing with overlapping radar signals from multiple targets, leading to issues such as missing targets, incorrect Doppler frequency estimation, and incorrect angle estimation.
Innovation Solution
The method employs partial symmetrical Doppler division multiple access (DDMA) to jointly estimate Doppler phase and angle, using a MIMO radar system with phase modulation on transmission and reception channels, forming a virtual array to improve angle resolution and accuracy, and applying fast Fourier transforms to separate overlapping signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional radar signal processing methods are used, then the system is simpler to implement, but the accuracy of Doppler frequency and angle estimation deteriorates when dealing with overlapping signals from multiple targets
Solution Approach 1:
The patent divides the radar signal processing into distinct segments: receiving multiple signal segments from different antenna channels, transforming each segment into frequency domain, and processing them through separate FFT operations. This segmentation allows the system to handle overlapping signals from multiple targets by processing them in discrete, manageable units, thereby improving measurement precision without overwhelming system complexity
Solution Approach 2:
The patent transforms the signal processing from time domain to frequency domain using Fast Fourier Transform (FFT). By converting temporal signals into frequency spectrum representations, the system gains an additional dimensional perspective that enables separation of overlapping targets based on their Doppler frequency signatures, significantly improving estimation accuracy
2Measurement precision
If traditional radar signal processing methods are used, then the computational resources required are lower, but the accuracy of angle estimation deteriorates when dealing with overlapping signals from multiple targets
Solution Approach 1:
The patent performs preliminary frequency domain transformation and spectral analysis before final angle estimation. By pre-processing the signals to identify Doppler frequency components and target signatures in the frequency domain, the system reduces the computational burden of subsequent angle estimation operations, achieving high precision with optimized power consumption
Solution Approach 2:
The patent replaces traditional time-domain signal processing mechanics with frequency-domain transformation using FFT algorithms. This substitution enables more efficient computational processing by exploiting the periodic and spectral properties of radar signals, reducing the computational power required while significantly improving angle estimation accuracy for overlapping targets
3Speed
If the radar system processes all signal segments simultaneously, then the processing speed is faster, but the ability to separate overlapping signals from multiple targets deteriorates
Solution Approach 1:
The patent segments the received radar signals into distinct signal segments corresponding to different antenna receiver channels. Each segment is processed independently through FFT transformation, allowing the system to maintain processing speed while preventing information loss. The segmented approach ensures that overlapping target signals from different channels are preserved and can be separately analyzed
Solution Approach 2:
The patent transforms simultaneous time-domain signals into the frequency domain using FFT, creating a spectral representation where overlapping targets can be distinguished by their unique Doppler frequency signatures. This dimensional transformation from time to frequency domain enables the system to process signals at high speed while maintaining the ability to separate and identify multiple overlapping targets
4Measurement precision
If phase modulation is applied on transmission and reception channels, then the angle resolution and accuracy are improved, but the device complexity increases
Solution Approach 1:
The patent implements phase modulation across multiple transmit and receive antenna channels, creating segmented signal paths. Each antenna channel processes signals independently with applied phase modulation, allowing the system to achieve high angle resolution through spatial diversity while managing complexity through modular, channel-by-channel processing
Solution Approach 2:
The patent utilizes phase modulation to encode spatial information from multiple antenna channels into the phase domain. By transforming spatial differences into phase differences that can be analyzed in the frequency domain, the system achieves superior angle resolution while managing device complexity through mathematical transformation rather than hardware complexity
Data Source
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AI summary
A method for processing a radar signal includes receiving a set of signal segments via a set of antenna receiver channels, dividing the radar signal into a set of sub-spectrums, forming a first matrix, and determining whether an energy level associated with the first matrix has met a threshold energy level. The method includes generating a reconstructed signal. Generating the reconstructed signal includes determining a direction of arrival phase, generating a first set of measurements, determining an index value, determining a Doppler phase based on the index value, determining a second set of measurements based on the index value, and determining a direction of departure phase associated with the target object. The method includes subtracting data associated with the reconstructed signal from the first matrix, outputting the direction of departure phase, the direction of arrival phase, and the Doppler phase; and tracking a location of the target object.