Base Station Timing Offset Refinement for Unlicensed Positioning
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing positioning solutions in unlicensed spectrum face accuracy issues due to time synchronization offsets among base stations, leading to LBT blocking and deteriorated positioning accuracy, especially in methods like DL-TDOA, UL-TDOA, E-CID, DL-AOD, UL-AoA, and Multi-RTT.
Innovation Solution
Network devices perform Clear Channel Assessment (CCA) procedures to identify and adjust timing synchronization offsets by adjusting forward or backward based on LBT outcomes, using anchor and normal base stations to synchronize with each other, and measuring interference levels to refine synchronization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If base stations transmit reference signals simultaneously in unlicensed spectrum, then positioning accuracy is improved, but time synchronization offsets cause LBT blocking and deteriorate positioning accuracy
Solution Approach 1:
The patent performs Clear Channel Assessment (CCA) procedures before transmitting reference signals to identify time synchronization offsets. By detecting the channel status in advance and identifying synchronization issues before they cause LBT blocking, the system can adjust timing to ensure simultaneous transmission. This preliminary detection and adjustment prevents the harmful effect of LBT blocking while maintaining positioning accuracy.
2Reliability
If base stations adjust timing to synchronize transmission, then LBT blocking is reduced, but timing synchronization offset identification complexity increases
Solution Approach 1:
The patent enables base stations to autonomously identify their own time synchronization offsets by analyzing CCA procedure outcomes. Each base station compares its CCA results with expected outcomes and independently determines whether it has a timing offset relative to other base stations. This self-service approach reduces the need for complex centralized coordination while maintaining reliable synchronization.
3Reliability
If multiple CCAs are performed to accurately identify synchronization offset, then positioning reliability is improved, but time consumption increases
Solution Approach 1:
The patent performs at least two CCA procedures to identify time synchronization offsets, which may seem excessive but ensures reliable detection. By conducting multiple CCAs and analyzing the patterns of outcomes, the system can confidently identify synchronization issues without requiring exhaustive measurements. This partial excess action provides sufficient reliability while avoiding unnecessary time consumption from overly extensive testing.
Data Source
AI summary
Disclosed are devices for time synchronization offset identification and refinement for network based positioning in an unlicensed spectrum. An example network device may comprise at least one processor and at least one memory including computer program code. The at least one memory and the computer program code may be configured to, with the at least one processor, cause the network device to receive listen-before-talk (LBT) outcomes from a plurality of base stations (BSs), and identify whether one or more of the plurality of BSs have a time synchronization offset based on the LBT outcomes. The LBT may be related to a reference signal (RS) configured on the BSs. The related methods, apparatuses and computer program product are also disclosed.