MIMO Radar Signal Differentiation Using DDMA Phase Steps
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Solution Overview
Problem
Conventional radar devices face challenges in differentiating signals from multiple transmit antennas in FMCW radar systems with MIMO, leading to difficulties in target detection and angular resolution, particularly due to issues with signal-to-noise ratio (SNR) and computation load.
Innovation Solution
A radar device employing a monolithic microwave integrated circuit (MMIC) that transmits radar signals using Doppler division multiple access (DDMA) to differentiate among transmit antennas, with a uniform phase step to improve SNR and reduce computation, enabling accurate target detection and estimation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If MIMO technique is used to enlarge effective radar aperture size, then angular resolution is improved, but it becomes difficult to differentiate among signals transmitted from multiple transmit antennas
Solution Approach 1:
The patent applies Doppler division multiple access (DDMA) by modulating the phase of transmit signals with different Doppler frequencies. This parameter change in the frequency domain allows the radar to differentiate among signals from multiple transmit antennas while maintaining the MIMO configuration for improved angular resolution.
2Reliability
If multiple transmit antennas are used to improve target detection capability, then target detection probability is improved, but computation load increases
Solution Approach 1:
The patent transforms the signal differentiation problem into a frequency domain problem using DDMA. By applying uniform phase steps in the Doppler axis direction, the system can differentiate transmit antenna signals through frequency analysis rather than complex spatial processing, reducing computation load while maintaining multi-antenna target detection capability.
3Measurement precision
If FMCW radar with MIMO is used, then angular resolution is improved, but signal-to-noise ratio for peak detection deteriorates
Solution Approach 1:
The patent applies uniform phase steps specifically in the Doppler axis direction to concentrate signal energy at peak locations. This parameter adjustment in the frequency domain improves the signal-to-noise ratio for peak detection while preserving the angular resolution benefits of the MIMO configuration.
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
The solution enhances target detection probability and SNR, reduces computation load, and resolves Doppler ambiguities, improving angular resolution and target estimation accuracy.
Implementation Method 1
A radar device needs to have high angular resolution to detect or track the distance, velocity, and angle of a target device by transmitting and receiving electronic waves
Implementation Method 2
Due to the Doppler effect, the frequency difference also contains a component that results from the relative velocity of the target
Implementation Method 3
A frequency-modulated continuous wave (FMCW) radar device uses a transmit signal whose transmit frequency is ramp-modulated
Implementation Method 4
the FMCW radar device generates a baseband signal from a receive signal through mixing with the transmit signal. A frequency of the baseband signal corresponds to a frequency difference between a signal transmitted at a given time point and a signal received at the same time point
Data Source
AI summary
A radar device includes a plurality of transmit antennas, a plurality of receive antennas, and a monolithic microwave integrated circuit (MMIC) configured to control the plurality of transmit antennas and the plurality of receive antennas. The MIMIC is configured to, transmit a radar signal through the plurality of transmit antennas in accordance with a Doppler division multiple access (DDMA), receive a reflected signal, which is at least a part of the radar signal reflected from a target, through the plurality of receive antennas, estimate a transmit antenna corresponding to the reflected signal among the plurality of transmit antennas based on a phase corresponding to the received reflected signal, and obtain radar data corresponding to the target based on the estimated transmit antenna and the reflected signal.