Residue Cancellation in Automated Vehicle MIMO Radar
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Pseudo-Random Phase Modulation (PRPM) MIMO radar systems face limitations in detection dynamic range due to signal residue from non-orthogonal transmit signals, which can mask smaller objects in the presence of larger ones, and existing methods to reduce residue are either costly or computationally complex.
Innovation Solution
The Residue Estimation and Subtraction Technique (REST) is employed, where a controller generates sub-channel outputs using complex conjugates of PRPM-codes, estimates residue signals through cross-correlation and frequency transformations, and subtracts these from the original sub-channel outputs to improve detection dynamic range.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If Pseudo-Random Phase Modulation (PRPM) is used to transmit orthogonal signals from multiple transmit antennas, then signal orthogonality is achieved, but signal residue from non-orthogonal signals masks smaller objects and detection dynamic range is limited
Solution Approach 1:
The patent segments the detection process into multiple stages: initial detection using PRPM signals, residue estimation based on detected signal characteristics, and residue subtraction to produce a cleaned signal for final detection. This segmentation allows the system to handle the dynamic range limitation by processing signals in discrete steps rather than attempting single-stage detection.
Solution Approach 2:
The patent converts the harmful residue signal into a beneficial estimation target. By using the detected signal characteristics to estimate and model the residue, the system transforms the masking effect into a quantifiable parameter that can be measured, modeled, and subsequently removed, improving overall detection capability.
2Measurement precision
If existing methods are used to reduce residue, then detection dynamic range improves, but system cost and computational complexity increase
Solution Approach 1:
The patent implements a self-service approach where the system uses its own detected signal outputs to generate residue estimates, which are then subtracted to improve detection. The residue estimation leverages the already-detected signal characteristics and cross-correlation functions that are naturally available in the signal processing chain, eliminating the need for external complex processing systems.
Solution Approach 2:
The patent changes the processing parameters dynamically based on detected signal characteristics. By adjusting the residue estimation and subtraction operations based on the actual detected signal properties (amplitude, phase, frequency), the system adapts to varying conditions without requiring fixed complex processing architectures for all scenarios.
Data Source
AI summary
ABSTRACT OF THE DISCLOSURE A Pseudo-Random Phase Modulation (PRPM) multiple-input-multiple-output (MIMO) radar system (10) suitable for use on an automated vehicle includes a first transmit-antenna (12A) that transmits a first transmit-signal (38A) generated by a first PRPM-code (40A), a second transmit-antenna (12B) that transmits a second transmit-signal (38B) generated by a second PRPM-code (40B), a receive-antenna (14) used to detect a first reflected-signal (42A) arising from the first transmit-signal (38A) and a second reflected-signal (42B) arising from the second transmit-signal (38B), and a controller (46). The controller (46) is in communication with the receive-antenna (14) and is operable to generate the first PRPM-code (40A) and the second PRPM-code (40B). The controller (46) is configured to generate a first sub-channel-output (18A) based on a down-converted-signal (48) from the receive-antenna (14) and the first PRPM-code (40A), generate a second sub-channel-output (18B) based on the down-converted-signal (48) from the receive-antenna (14) and the second PRPM-code (40B), determine a first residue-signal (50A) based on the second sub-channel-output (18B), and determine a first residue-removed-signal (36A) by subtracting the first residue-signal (50A) from the first sub-channel-output (18A).