DDMA Radar Signal Processing for Multi-Antenna Differentiation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional FMCW radar devices with MIMO technology face challenges in differentiating signals from multiple transmit antennas and suffer from low signal-to-noise ratio (SNR) and high computation load, affecting target detection probability and angular resolution.
Innovation Solution
A radar device employing Doppler division multiple access (DDMA) with a monolithic microwave integrated circuit (MMIC) to control transmit and receive antennas, using uniform phase steps to differentiate transmit antennas and improve SNR, and reduce data processing complexity.
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 segments the transmitted signal by assigning different phase codes to signals from different transmit antennas. Each transmit antenna imparts a unique phase code sequence to its transmitted signal, allowing the receiver to differentiate between signals from multiple antennas through correlation processing, thereby resolving the signal differentiation problem while maintaining MIMO's angular resolution advantage
Solution Approach 2:
The patent changes the phase parameter of the transmitted signal in a time-varying manner for each transmit antenna. By applying different phase code sequences to different transmit antennas, the system enables signal differentiation without requiring additional hardware complexity, thus resolving the contradiction between improved angular resolution and signal differentiation difficulty
2Measurement precision
If multiple transmit antennas are used to improve target detection probability, then measurement capability is enhanced, but computation load for data processing increases
Solution Approach 1:
The patent applies phase codes to transmit signals before transmission, preliminarily embedding identification information in the signal structure. This preliminary encoding allows the receiver to use simple correlation processing to separate and identify signals from different transmit antennas, significantly reducing the computation load compared to post-processing differentiation methods while maintaining enhanced target detection probability through multiple antenna diversity
3Reliability
If FMCW radar transmits continuous ramp-modulated signals, then target detection capability is maintained, but signals from different transmit antennas cannot be differentiated
Solution Approach 1:
The patent applies periodic phase coding to the FMCW radar signals transmitted from different antennas. Each transmit antenna uses a distinct periodic phase code sequence, which allows the receiver to differentiate between simultaneous continuous wave signals from multiple antennas through correlation processing, thereby maintaining continuous target detection capability while enabling signal differentiation
Solution Approach 2:
The patent dynamically changes the phase parameter of the continuous FMCW signal in a periodic manner for each transmit antenna. This time-varying phase modulation embeds antenna identification information into the continuous wave signal without interrupting transmission, enabling differentiation of simultaneous signals from multiple antennas while maintaining reliable target detection
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
Enhances target detection probability by improving SNR and reducing computation load, allowing accurate estimation of target angle and velocity through improved angular resolution.
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
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
Figure 1~2
Figure 3A
Figure 3B
AI summary
A radar device includes a plurality of transmit antennas (140), a plurality of receive antennas (150), and a monolithic microwave integrated circuit, MMIC (100), 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.