PRS Configuration for Propagation Delay Compensation in Multi-TRP Sync
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Solution Overview
Problem
Current 3GPP technologies face challenges in accurately compensating for propagation delays in ultra-reliable and low-latency communication systems, particularly in industrial IoT applications, due to limitations in timing advance and round-trip-time based methods, and the need for improved synchronization across multiple TRPs.
Innovation Solution
Enhanced PRS and TRS configurations, including semi-persistent and a-periodic transmission, coordinated muting patterns, and flexible periodicity, are introduced to improve time synchronization and propagation delay compensation, leveraging existing multi-RTT positioning methods.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If Timing Advance based propagation delay estimation is used, then propagation delay compensation is achieved, but timing synchronization accuracy is insufficient for ultra-reliable low latency communication
Solution Approach 1:
The patent changes the measurement parameters from legacy Timing Advance to enhanced RTT-based measurements with finer granularity. It introduces new measurement quantities (Rx-Tx time difference) with higher resolution (k values for different reporting resolutions) to achieve more accurate propagation delay estimation while maintaining reliability for URLLC applications
Solution Approach 2:
The patent replaces the legacy TA-based mechanical timing adjustment mechanism with an RTT-based measurement system that uses bidirectional time difference measurements between UE and gNB. This substitution enables more precise propagation delay compensation through dual-directional measurement rather than unidirectional TA adjustment
2Measurement precision
If Round-Trip-Time based delay compensation is used, then propagation delay compensation is achieved, but measurement precision and reporting resolution need improvement
Solution Approach 1:
The patent implements partial action by providing multiple reporting resolution options (k=0 to k=5) instead of forcing full high-resolution measurements always. The network can select appropriate resolution based on service requirements, reducing unnecessary measurement overhead while maintaining precision where needed
Solution Approach 2:
The patent introduces dynamic measurement and reporting configurations where the gNB can select different k values (reporting resolutions) based on current network conditions and service requirements. The measurement configuration is adaptable, allowing the system to optimize between precision and overhead dynamically rather than using fixed parameters
3Measurement precision
If PRS and TRS transmissions are increased for better time synchronization, then time synchronization accuracy is improved, but interference and resource conflict increase
Solution Approach 1:
The patent uses periodic transmission of PRS and TRS reference signals with configurable periodicities. By transmitting these signals periodically rather than continuously, the system achieves necessary time synchronization accuracy while reducing overall interference and resource consumption compared to continuous transmission
Solution Approach 2:
The patent segments the reference signal resources by separating PRS and TRS transmissions in time and frequency domains. It introduces coordinated muting patterns that divide the transmission space into active and muted regions, allowing multiple UEs and TRPs to share resources with reduced interference while maintaining synchronization accuracy
4Reliability
If multiple TRPs are coordinated for time synchronization, then synchronization coverage is improved, but device complexity and coordination overhead increase
Solution Approach 1:
The patent merges the time synchronization measurements from multiple TRPs into a unified RTT measurement framework. By combining the measurement processes and using a common reference time delivery mechanism through the PCell, the system achieves improved synchronization reliability across multiple TRPs while reducing the complexity of independent coordination for each TRP
Data Source
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AI summary
A method (500) performed by a UE. The method includes the UE receiving a configuration message that comprises positioning reference signal (PRS) resource configuration information defining a PRS resource configuration. The method also includes the UE receiving a trigger message transmitted by a base station, the trigger message comprising information for identifying the PRS resource configuration. The method also includes, after receiving the trigger message, the UE receiving a PRS transmitted by the base station according to the PRS resource configuration, wherein The PRS is a semi-persistently or an a-periodically transmitted DL reference signal.