Hybrid RTDM-DDM MIMO Radar for Peak Power Reduction
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Solution Overview
Problem
Conventional radar systems face challenges in accurately detecting the position and movement of objects, particularly in automotive applications, due to limitations in peak power, power consumption, heat management, and excessive Doppler spectrum overlap.
Innovation Solution
The implementation of a hybrid Random Time Division Multiplexing (RTDM) - Doppler Domain Multiplexing (DDM) Multiple-Input Multiple-Output (MIMO) radar system, which randomly selects transmitter groups for transmission and uses phase rotators to apply progressive phase shifts based on a co-prime coded (CPC) coding technique.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional DDM radar systems transmit all transmitters simultaneously, then Doppler spectrum coverage is maximized, but peak power, power consumption, and heat generation increase excessively
Solution Approach 1:
The patent divides the set of transmitters into multiple groups and transmits them in alternating time periods rather than simultaneously. This segmentation allows the radar system to achieve comprehensive Doppler spectrum coverage over time while limiting the number of active transmitters at any given moment, thereby reducing peak power requirements and heat generation.
Solution Approach 2:
The patent implements periodic transmission cycles where different transmitter groups are activated in alternating time periods. This periodic action enables the system to cycle through all transmitter groups, achieving full Doppler spectrum coverage across the measurement interval, while ensuring that only a subset of transmitters operates at any instant, thus controlling peak power and power consumption.
2Power
If conventional TDM radar systems use alternating transmission periods, then peak power is reduced, but velocity measurement aliasing and ambiguity increase
Solution Approach 1:
The patent segments transmitters into multiple groups and assigns each group to specific time periods, ensuring that the segmentation pattern preserves the temporal structure needed for accurate velocity measurements. This prevents velocity aliasing by maintaining appropriate pulse repetition intervals for each transmitter group while still achieving power reduction through alternating transmission.
Solution Approach 2:
The patent employs periodic transmission with carefully designed cycle structures that maintain the pulse repetition frequency relationships necessary for unambiguous velocity measurement. The periodic activation of different transmitter groups follows patterns that prevent Doppler ambiguity, allowing accurate velocity measurement while reducing peak power through time-division operation.
3Measurement precision
If conventional DDM radar systems transmit all transmitters simultaneously, then measurement capability is maximized, but Doppler spectrum overlap occurs excessively
Solution Approach 1:
The patent segments the transmitter operation into distinct time-period groups, where each group transmits during specific intervals. This temporal segmentation separates the Doppler spectra of different transmitter groups in the time domain, preventing spectral overlap while maintaining the ability to detect and measure multiple objects across the full Doppler range through the complete transmission cycle.
Solution Approach 2:
The patent uses periodic transmission cycles with alternating active and inactive periods for different transmitter groups. This periodic structure creates distinct temporal windows for each transmitter group, separating their Doppler spectra and eliminating overlap. The complete set of Doppler information is recovered by processing data from all periods, maintaining full measurement capability without spectral contamination.
4Measurement precision
If MIMO radar systems use multiple transmit and receive antennas, then angular resolution is improved, but device complexity increases
Solution Approach 1:
The patent segments the MIMO antenna array into multiple transmitter groups that are activated alternately. This segmentation allows the system to form a virtual array with high angular resolution capability while reducing the effective number of simultaneously active transmitters. The virtual array geometry is maintained through careful group assignment, preserving angular resolution while simplifying the instantaneous transmission complexity.
Solution Approach 2:
The patent implements periodic activation of different transmitter groups in the MIMO system. This periodic operation allows the full MIMO virtual array to be synthesized over time, achieving high angular resolution through the complete set of transmitted signals, while reducing instantaneous complexity by activating only a subset of transmitters at any given period. The periodic cycling through all groups reconstructs the full angular information.
Data Source
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AI summary
A radar system and methods of operating radar system are provided. The radar system includes transmitter groups, each including transmitter modules, configured to transmit multiple transmit signals in accordance with a Random Time Division Multiplexing (RTDM) - Doppler Domain Multiplexing (DDM) scheme, a receiver modules configured to receive reflections of the transmit signals reflected by at least one object and to generate digital signals based on the received reflections, and a controller that includes a signal processor configured to generate multiple range-Doppler antenna cubes (RDACs) based on the reflections of the plurality of transmit signals, each of the multiple RDACs corresponding to a respective transmitter group of the transmitter groups, generate a combined range-Doppler map (RDM) by integrating the multiple RDACs, and generate object position data based on the combined RDM.