SRS Timing Advance Handling for UE Positioning Across Cell Boundaries
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Solution Overview
Problem
Existing wireless communication systems face challenges in accurately and efficiently transmitting and receiving signals, particularly in scenarios where timing advance (TA) values are not valid at the boundaries of cells, leading to inefficiencies in signal transmission and reception.
Innovation Solution
A method and apparatus for transmitting and receiving sounding reference signals (SRS) in a wireless communication system, where a user equipment (UE) determines its timing advance (TA) value autonomously based on an SRS configuration, allowing SRS transmission in a radio resource control (RRC) inactive state, and includes a processor-readable medium and devices with memory and processors to facilitate this process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the UE uses a TA value configured by the network in the first cell, then the SRS transmission timing is synchronized in the first cell, but the TA value becomes invalid when the UE moves to a second cell boundary
Solution Approach 1:
The UE autonomously determines its own TA value for the second cell based on the SRS configuration received from the first cell and the measured timing difference, without requiring network configuration or intervention. This self-service approach allows the UE to adapt to cell boundaries independently, resolving the contradiction between maintaining TA validity and adapting to cell mobility.
Solution Approach 2:
The network pre-configures the UE with SRS configuration information in the first cell that includes parameters necessary for autonomous TA determination. This preliminary configuration enables the UE to calculate and apply the correct TA value when moving to the second cell, ensuring continuous timing synchronization without network intervention at the boundary.
2Adaptability or versatility
If the UE autonomously determines TA value in the second cell, then the SRS transmission remains valid at cell boundaries, but the UE requires additional capability to perform autonomous determination
Solution Approach 1:
The UE performs autonomous TA value determination for the second cell by measuring the timing difference of SRS signals and calculating the appropriate TA adjustment. This self-service mechanism enables the UE to handle cell boundary transitions independently, achieving high adaptability while keeping the additional processing requirements minimal and focused on timing measurements.
3Measurement precision
If the network configures TA value for each cell, then the TA timing is accurate for each specific cell, but the signaling overhead and network complexity increase
Solution Approach 1:
The SRS configuration received from the first cell is designed to be universally applicable for autonomous TA determination across multiple cells including the second cell. This multi-functional configuration allows the same SRS parameters to serve both the first cell operation and the autonomous TA calculation for the second cell, eliminating the need for separate network configurations for each cell while maintaining timing accuracy.
Data Source
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AI summary
According to at least one of the embodiments disclosed in the present specification, a method of transmitting a sounding reference signal (SRS) by a user equipment (UE) in a wireless communication system includes: receiving an SRS configuration related to a plurality of cells including a first cell through the first cell; and transmitting an SRS for positioning based on the SRS configuration in a radio resource control (RRC) inactive state, wherein a timing advance (TA) value for the SRS transmission may be determined based on whether a cell in which the UE locates at a current time that the SRS is transmitted is the first cell which has provided the SRS configuration.