Hybrid SIMO-MIMO Radar Chirp Signaling for Velocity Range
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Solution Overview
Problem
Conventional velocity measurement methods using SIMO and MIMO modes face challenges in maximizing the velocity measurement range while maintaining a large virtual aperture and minimizing signal duration, leading to reduced angular resolution and ambiguous velocity estimation.
Innovation Solution
A combined SIMO and MIMO method is employed, where chirp signals are transmitted in a time division multiplexing repetition cycle using multiple antennas, with optimized parameters to increase the maximum velocity measurement range and minimize signal duration while retaining a large virtual aperture.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If MIMO mode is used to increase virtual aperture and angular resolution, then angular resolution is improved, but sampling cycle increases to M_T * T_c which decreases maximum velocity measurement range by M_T multiple
Solution Approach 1:
The patent divides the MIMO transmission into multiple sub-cycles, where each sub-cycle uses a different subset of transmit antennas. This segmentation allows the system to maintain virtual aperture benefits while reducing the effective sampling cycle for velocity measurement, thereby resolving the contradiction between angular resolution and maximum velocity measurement range.
Solution Approach 2:
The patent dynamically configures the transmit antenna activation pattern across different sub-cycles within a repetition cycle. By dynamically switching which antennas are active in each sub-cycle, the system adapts the virtual aperture configuration to maintain both high angular resolution and extended velocity measurement range without the full MIMO penalty.
2Speed
If SIMO mode is used to maximize velocity measurement range, then maximum velocity measurement range is largest, but additional virtual array aperture cannot be obtained resulting in reduced angular resolution
Solution Approach 1:
The patent merges SIMO and MIMO modes into a hybrid configuration where multiple transmit antennas are used in a time-division manner. This combination allows the system to achieve both the extended velocity measurement range characteristic of SIMO mode and the virtual aperture benefits of MIMO mode for improved angular resolution.
3Measurement precision
If multiple transmit antennas transmit chirp signals in turn to obtain large virtual aperture, then angular resolution is greatly improved, but sampling cycle increases causing decrease of maximum velocity measurement range and velocity estimation ambiguity
Solution Approach 1:
The patent segments the multi-antenna transmission into multiple sub-cycles, where each sub-cycle uses a portion of the available antennas. This segmentation reduces the effective sampling cycle compared to full MIMO operation, thereby minimizing velocity estimation ambiguity while still providing sufficient virtual aperture for good angular resolution.
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 method achieves a competitive maximum velocity measurement range comparable to SIMO modes with reduced signal duration and improved angular resolution, while maintaining a large virtual aperture, enhancing signal-to-noise ratio and reducing target ambiguity.
Implementation Method 1
The velocity measurement mainly uses the Doppler effect principle: When the target approaches the sensor, a reflected signal frequency is higher than a transmit frequency. Conversely, when the target moves away from the sensor, a reflected signal frequency is lower than a transmit frequency.
Implementation Method 2
Frequency mixing is performed on a transmitted signal and a reflected signal, and output of a frequency mixer is represented as:
Data Source
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AI summary
A velocity measurement signal transmission method and receiving method are provided, which may be applied to an intelligent driving system including autonomous driving and assisted driving, so that a maximum velocity measurement range can be increased and entire velocity measurement signal duration can be minimized while a relatively large virtual aperture is retained. The transmission method includes: generating a plurality of chirp signals for measuring moving velocities of one or more moving targets (301); and transmitting the plurality of chirp signals in a time division multiplexing repetition cycle by using M antennas (302), where the time division multiplexing repetition cycle includes one single-antenna transmit mode sub-cycle and L consecutive multi-antenna transmit mode sub-cycles.