User Equipment Rotation for Resolving PDOA Angle Ambiguity
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Solution Overview
Problem
Existing methods for determining the Angle of Arrival (AoA) using wireless signals face ambiguity when the separation between antennas is greater than half the wavelength, leading to angle ambiguity in phase difference of arrival (PDOA) measurements.
Innovation Solution
A method to resolve angle ambiguities by determining a plurality of candidate unwrapped PDOAs, comparing them, and identifying the true PDOA based on consistent measurements across different orientations of the user equipment (UE), leveraging the fact that the true PDOA remains consistent while untrue PDOAs diverge, or by projecting PDOAs onto a subspace defined by a measurement matrix.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the separation distance between antennas is increased to improve the baseline for AoA measurement, then the measurement capability is enhanced, but angle ambiguity occurs in PDOA measurements
Solution Approach 1:
The system dynamically changes the orientation of the user equipment to collect PDOA measurements from multiple angles. By rotating the UE and gathering measurements at different orientations, the system creates a dynamic data collection process that enables resolution of angle ambiguity through comparative analysis of measurements taken at different orientations.
Solution Approach 2:
The system transitions from single-orientation PDOA measurement to multi-orientation measurement by adding the orientation dimension. Instead of relying solely on spatial separation, the invention introduces temporal and angular dimensions by measuring PDOA at multiple UE orientations, thereby resolving ambiguity through dimensional expansion of the measurement space.
2Length of stationary object
If the separation distance between antennas is greater than half the wavelength, then the baseline for AoA determination is improved, but angle ambiguity arises in PDOA measurements
Solution Approach 1:
The system uses feedback from multiple PDOA measurements taken at different orientations to resolve angle ambiguity. By comparing measurements from different UE orientations and using the consistency or inconsistency of results as feedback, the system can identify and eliminate ambiguous angle solutions, thereby recovering accurate angle information.
Solution Approach 2:
The system performs preliminary measurements at multiple orientations before final AoA determination. By collecting PDOA data at different UE orientations in advance, the system prepares a set of measurements that can be used to resolve angle ambiguity and identify the true AoA, rather than relying on a single measurement that may be ambiguous.
3Reliability
If multiple candidate unwrapped PDOAs are generated for different orientations, then angle ambiguity can be resolved, but computational complexity increases
Solution Approach 1:
The system segments the angle ambiguity resolution problem into multiple discrete candidate PDOAs, each corresponding to a specific UE orientation. By dividing the continuous angle space into discrete candidates based on measured orientations, the system makes the computation tractable while still achieving accurate angle determination through comparison of these segmented candidates.
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
Resolves angle ambiguities in PDOA measurements for antennas separated by more than half the wavelength, enabling accurate determination of the AoA and location of a target object using wireless ranging signals.
Implementation Method 1
measuring a first phase difference of arrival (PDOA) between the first antenna and the second antenna for a first orientation of the UE and measuring a second PDOA between the first antenna and the second antenna for a second orientation of the UE
Data Source
AI summary
A method for determining a true phase difference of arrival (PDOA), includes: determining a plurality of candidate unwrapped PDOAs for a signal transmitted by a target object and received by at least a first antenna and a second antenna of a user equipment (UE), where the plurality of candidate unwrapped PDOAs corresponds to a plurality of orientations of the UE, where a separation distance between the first antenna and the second antenna is greater than or equal to half of a wavelength of the signal; comparing the plurality of unwrapped candidate PDOAs; and identifying a true PDOA based on the comparison.