Uplink Synchronization in Multi-Component Carrier Systems
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In multiple component carrier systems, the existing signaling protocols for informing a terminal about the Timing Advance Group (TAG) configuration for secondary serving cells are unclear, and methods for updating TAGs based on channel conditions are not well-defined, leading to increased overhead and complexity in uplink synchronization.
Innovation Solution
The implementation of a method and apparatus for UE to obtain uplink synchronization, involving a random access processing unit, transmission unit, and RRC processing unit to send and receive random access preambles, secondary serving cell configuration information, and TAG configuration information, allowing reorganization of TAGs based on RRC connection reconfiguration procedures and random access procedures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multiple component carriers are used for carrier aggregation, then bandwidth utilization is improved, but uplink synchronization complexity increases
Solution Approach 1:
The patent segments the multiple component carriers into separate Timing Advance Groups (TAGs), where each TAG contains one or more serving cells that share the same timing advance value. This segmentation allows independent timing management for each group, reducing the overall synchronization complexity while maintaining efficient bandwidth utilization across all carriers.
Solution Approach 2:
The patent introduces a new dimension of organization by grouping serving cells into TAGs based on their timing advance relationships. This dimensional organization (grouping cells with same TA values) transforms the complex many-to-many timing relationships into a structured many-to-few mapping, where multiple cells map to a limited number of TAGs, thereby simplifying synchronization management.
2Reliability
If TAG configuration signaling is implemented for secondary serving cells, then uplink synchronization is improved, but signaling overhead increases
Solution Approach 1:
The patent merges the configuration of multiple serving cells into a single TAG structure, where one TAG configuration message can simultaneously configure timing advance parameters for multiple secondary serving cells. This merging approach maintains reliable uplink synchronization across all cells while significantly reducing the total signaling overhead compared to configuring each cell individually.
Solution Approach 2:
The TAG configuration mechanism serves multiple functions simultaneously: it establishes timing advance values, groups serving cells with identical timing characteristics, and provides a scalable framework for managing any number of secondary cells. This multi-functionality reduces the need for separate signaling mechanisms for different synchronization aspects.
3Measurement precision
If TAG reorganization is performed based on channel conditions, then uplink synchronization accuracy is improved, but system complexity increases
Solution Approach 1:
The patent implements dynamic TAG reorganization that allows the network to adaptively adjust TAG configurations based on changing channel conditions. Serving cells can be moved between TAGs or new TAGs can be created as needed, enabling the system to respond to varying timing requirements while maintaining a manageable structure through the TAG abstraction layer.
Solution Approach 2:
The system incorporates feedback mechanisms where the network monitors uplink synchronization performance and channel conditions, then uses this information to make informed decisions about TAG reorganization. This feedback-driven approach ensures high synchronization accuracy while avoiding unnecessary reorganizations that would increase system complexity.
Data Source
AI summary
A user equipment (UE) of re-organizing a timing advance group (TAG) is provided. The UE includes: a receiving unit for receiving, from a serving base station, secondary serving cell (SCell) configuration information which includes a first field and a second field, the first field including an ScellIndex of an SCell to indicate a removal of the SCell, the second field including at least one of the ScellIndex to indicate an addition of the SCell and a TAG ID indicating a TAG of the SCell, and a radio resource control (RRC) processing unit for performing the addition of the SCell after performing the removal of the SCell from one or more SCells configured in the UE, and for reorganizing the TAG by including the SCell in the TAG.