Multi-Frequency PDoA Tracking for Ambiguous Wide Antenna Spacing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing wireless communication systems face challenges in accurately determining the angle-of-arrival (AoA) of radio signals when antenna separation exceeds half the wavelength, leading to ambiguity in positioning and tracking, especially for stationary devices that cannot easily move to resolve this issue.
Innovation Solution
A method using multiple frequencies to measure phase difference of arrival (PDoA) for radio links, enabling a tracking device with antenna separation greater than half the wavelength to determine a true AoA by optimizing a loss function across multiple AoA candidates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If antenna separation is increased beyond half the wavelength, then communication diversity and signal reception quality are improved, but angle-of-arrival estimation accuracy deteriorates due to phase ambiguity
Solution Approach 1:
The patent applies parameter changes by measuring phase differences at multiple frequencies (different wavelengths) rather than a single frequency. This allows the system to maintain large antenna separation for communication diversity while resolving the phase ambiguity that causes AoA estimation errors. By changing the frequency parameter and comparing measurements across multiple frequencies, the system can identify the true AoA despite the ambiguous phase measurements at individual frequencies.
2Reliability
If antenna separation is increased beyond half the wavelength, then signal reception quality is improved, but positioning accuracy deteriorates due to multiple candidate angles
Solution Approach 1:
The patent resolves the positioning accuracy problem by introducing frequency as an additional parameter. By measuring phase differences at multiple frequencies and analyzing how the candidate angles change with frequency, the system can distinguish between true and false AoA candidates. The true AoA will show consistent geometric relationships across frequencies, while false candidates will not, thereby enabling accurate positioning despite large antenna separation.
3Ease of operation
If device remains stationary to maintain positioning capability, then operational simplicity is improved, but ability to resolve AoA ambiguity deteriorates
Solution Approach 1:
The patent replaces the mechanical approach (moving the device to resolve ambiguity) with a signal processing approach using multiple frequencies. Instead of requiring physical movement to gather additional geometric information for resolving AoA ambiguity, the system uses electromagnetic field properties at different frequencies to obtain the necessary information, thereby maintaining operational simplicity while achieving accurate AoA estimation.
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
Enables accurate AoA estimation for stationary devices with separated antennas, improving positioning and tracking accuracy without requiring physical movement, and enhancing communication diversity.
Implementation Method 1
measuring a set of phase difference of arrivals (PDoAs) for a set of radio links between the first user equipment (UE) and a second UE
Implementation Method 2
a largest phase wrap for the set of PDoAs, where the largest phase wrap is based on a largest difference in phase between a first antenna and a second antenna of the at least two antennas
Data Source
AI summary
Aspects presented herein may enable a first UE to estimate the angle-of-arrival (AoA) of a second UE. In one aspect, a first UE measures a set of phase difference of arrivals (PDoAs) for a set of radio links between the first UE and a second UE, each radio link in the set of radio links is associated with a different wavelength. The first UE determines a general function that is associated with a probability in which the second UE is at a set of relative directions or a set of relative positions compared to the first UE. The first UE estimates a relative direction or a relative position of the second UE compared to the first UE, where the relative direction is included in the set of relative directions and the relative position is included in the set of relative positions.