Beam Selection for Position Estimation Using Time of Arrival
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Solution Overview
Problem
In wireless communication systems, particularly in 5G networks operating at high frequency bands like mmW, propagation loss and multipath propagation complicate position estimation, as the beam with the highest received signal strength may not always be optimal due to longer propagation delays, affecting precise timing measurements.
Innovation Solution
A method where a node receives multiple beams, determines the time of arrival for each, identifies beams of interest for position estimation based on these times, and sends a report to adjust the transmission of position reference signals to align with the beams of interest, ensuring accurate position estimation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If beamforming is used to extend RF signal coverage and increase signal strength, then propagation loss is mitigated and data rate is improved, but the beam with the highest received signal strength may not correspond to the shortest propagation path, causing timing measurement errors for position estimation
Solution Approach 1:
The patent segments the beam selection process into two distinct functions: one for data communication (selecting beam with highest signal strength) and one for position estimation (selecting beam with shortest propagation delay). This segmentation allows the system to optimize for different objectives separately, resolving the contradiction between signal strength and timing accuracy.
Solution Approach 2:
Instead of using the conventional approach of selecting the beam with the highest received signal strength for position estimation, the patent inverts the selection criterion to identify beams with the shortest propagation delay. This inversion directly addresses the timing measurement error caused by conventional beam selection methods.
2Area of stationary object
If multiple beams are transmitted to cover all directions, then coverage is improved, but the complexity of identifying the correct beam for position estimation increases due to multipath propagation
Solution Approach 1:
The patent applies preliminary action by having the transmitting node send indication information about beam directions and timing advance values before the actual position estimation process. This preliminary information provides the receiving node with reference data to simplify the identification of correct beams, reducing the complexity of dealing with multipath propagation effects.
Solution Approach 2:
The patent introduces indication information as an intermediary that carries metadata about beam directions and timing characteristics. This intermediary layer simplifies the complex task of beam identification by providing pre-processed reference information that helps the receiving node distinguish between direct path and reflected path beams.
3Productivity
If beamforming is applied to transmit RF signals in specific directions, then spectral efficiency is enhanced, but the determination of which beam corresponds to the shortest path becomes more difficult due to multipath effects
Solution Approach 1:
The patent implements feedback by having the receiving node send a report back to the transmitting node, identifying which beams correspond to the shortest propagation path based on timing measurements. This feedback loop allows the system to learn and adapt, improving the accuracy of shortest path detection while maintaining the spectral efficiency benefits of beamforming.
Data Source
AI summary
Disclosed are techniques for identifying beams of interest for position estimation. In an aspect, a first node receives, from a second node, a plurality of beams, determines a time of arrival of each beam, identifies one or more beams of interest for determining a position estimate based on the times of arrival, and sends, to the second node, a report identifying each of the one or more beams of interest. A second node transmits, to a first node, a plurality of beams, receives a report identifying one or more beams of interest for determining a position estimate of the first node, wherein the one or more beams of interest are a subset of the plurality of beams, and transmits, in response to receiving the report, at least one beam carrying position reference signals for the second node in a same direction as the one or more beams of interest.