MIMO Radar Virtual Antenna Overlap for Multipath Angle Filtering
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Solution Overview
Problem
Conventional MIMO radar systems face accuracy degradation in estimating angular positions of objects outside their nominal field-of-view (FOV) and are susceptible to multipath propagation, leading to unreliable detection.
Innovation Solution
The MIMO radar apparatus arranges radar transmitters and receivers such that at least one virtual transceiver position coincides with another, allowing for the identification and classification of low-confidence estimated angular positions by analyzing phase or power differences between virtual transceiver signals, or through spatial spectra analysis, and discarding or reducing the weight of such positions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional MIMO radar systems use standard virtual transceiver array configurations, then the system can operate within a nominal field-of-view, but accuracy degrades for objects outside the FOV and multipath propagation causes unreliable detection
Solution Approach 1:
The patent segments the virtual transceiver array into multiple sub-arrays, where each sub-array is associated with a specific field-of-view region. By dividing the overall array into segments, the system can independently process signals from different spatial regions, allowing accurate detection even when objects are outside the nominal FOV of individual sub-arrays. This segmentation enables the system to identify and filter out erroneous estimates caused by multipath propagation in out-of-FOV regions.
Solution Approach 2:
The patent applies local quality by assigning different weights or confidence levels to estimates from different virtual transceiver sub-arrays based on their spatial coverage characteristics. Sub-arrays covering in-FOV regions are given higher weight, while those covering out-of-FOV regions are given lower weight or are discarded. This local differentiation of quality allows the system to maintain high accuracy for reliable detections while minimizing the impact of erroneous out-of-FOV estimates.
2Measurement precision
If the radar system increases the aperture by using multiple transmitters and receivers, then the capability to separate objects based on Direction of Arrival improves, but the complexity of the system increases
Solution Approach 1:
The patent makes the virtual transceiver array multi-functional by enabling it to serve multiple purposes: (1) detecting objects within the nominal FOV using standard processing, (2) detecting objects outside the FOV using extended processing, and (3) identifying multipath propagation conditions. The same array of M transmitters and N receivers performs all these functions, eliminating the need for separate systems for each detection task and thus managing complexity while maintaining high angular resolution.
Solution Approach 2:
The patent introduces a new dimension of processing by creating virtual transceiver sub-arrays that extend the effective aperture in additional spatial dimensions. Instead of simply increasing the physical aperture, the system creates virtual extensions through signal processing techniques, allowing the same physical array to achieve enhanced angular resolution and out-of-FOV detection capability without proportionally increasing hardware complexity.
Data Source
AI summary
A MIMO radar apparatus includes M simultaneously transmitting radar transmitters, N radar receivers, and control circuitry coupled thereto. Positions of the M transmitters and N receivers define M×N virtual transceiver positions; at least one virtual transceiver position coincides with another. The control circuitry transmits simultaneously radar output signals via the transmitters, receives radar return signals arising from the output signals via the receivers, and generates N corresponding electronic receiver signals, and can further generate M×N virtual transceiver signals and estimate angular positions of backscattering/backreflecting objects. Comparing signal characteristics arising from the same virtual transceiver position but from different corresponding transmitter/receiver pairs can enable identification of low-confidence estimated angular positions arising from out-of-field-of-view or multipath propagation of radar signals.