MIMO Device Location via Multipath Component Evaluation
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Solution Overview
Problem
In massive MIMO systems, determining the location of a device is challenging due to the complexity of signal phases and multipath components, especially with obstructions affecting signal amplitude, making traditional methods less accurate.
Innovation Solution
A method is developed where a base station identifies a multipath component with a figure of merit based on time delay and angular spread, determining the angle of arrival and location of the device, even with obstructions, by focusing on the component with the shortest delay and lowest angular spread, and combining this information with other positioning methods.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional triangulation methods are used in massive MIMO systems, then the positioning capability is provided, but the accuracy deteriorates due to signal phase complexity and multipath components
Solution Approach 1:
The patent segments the complex multipath signal into individual multipath components (MPCs) and evaluates each component separately using figure of merit based on time delay and angular spread. This segmentation allows the system to identify the direct path component among multiple reflected components, thereby improving positioning accuracy without being overwhelmed by the overall signal complexity.
Solution Approach 2:
The patent changes the evaluation parameters from traditional signal phase alone to a composite figure of merit that includes time delay and angular spread. By evaluating MPCs based on these parameters, the system can distinguish the direct path component (which has minimal time delay and narrow angular spread) from reflected components, thus improving positioning accuracy in massive MIMO systems.
2Reliability
If all multipath components are considered for positioning, then more signal information is available, but the reliability deteriorates due to obstructions affecting signal amplitude
Solution Approach 1:
The patent shifts from relying on signal amplitude to using time delay and angular spread as primary evaluation parameters. This parameter change makes the positioning more reliable because time delay and angular spread are less affected by obstructions that attenuate signal amplitude, allowing the system to maintain positioning reliability even when some MPCs are weakened by obstacles.
Solution Approach 2:
The patent converts the harmful effect of multipath components (which traditionally cause positioning errors) into a beneficial resource by systematically evaluating each MPC's figure of merit. By doing so, the system can identify and select the direct path component even among multiple reflected components, turning the complex multipath environment into an opportunity for more robust positioning.
3Measurement precision
If fingerprinting methods are used to enhance location accuracy, then the positioning precision improves, but the device complexity increases due to covariance matrix processing
Solution Approach 1:
The patent extracts the essential positioning information (time delay and angular spread) from each multipath component and uses these extracted parameters to compute a figure of merit. This extraction approach provides location accuracy enhancement similar to fingerprinting methods but with reduced computational complexity by focusing only on the most relevant parameters rather than processing the complete covariance matrix.
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
This approach enables accurate device location determination in both closed and open environments, including indoors and outdoors, and supports emergency call requirements by providing precise positioning despite signal obstructions.
Implementation Method 1
a signal comprising several multipath components (MPCs) transmitted either omnidirectionally or with limited directivity
Implementation Method 2
determining, by the base station, an angle of arrival (AoA) of the MPC
Implementation Method 3
based on a time delay and an angular spread
Data Source
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AI summary
The invention is directed to systems, methods and computer program products for determining a location of a device (101) on a massive MIMO (multiple-input multiple- output) network. The device (101) transmits a signal comprising several multipath components (MPCs) either omnidirectionally or with limited directivity. The method comprises identifying, by a base station (103), that receives MPCs, an MPC with a figure of merit, based on a time delay and an angular spread, better than that of other MPCs; determining, by the base station (103), an angle of arrival (AoA) of the MPC is different from the AoAs of the other MPCs; and determining, by the base station (103), a location of the device (101) based on the time delay and the AoA.