Timing Advance Group Mapping for Carrier Aggregation
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Solution Overview
Problem
In wireless communication systems with carrier aggregation, User Equipment (UE) faces challenges in acquiring a Timing Advance (TA) for uplink transmission in newly configured cells, leading to potential data transmission errors due to uplink out-of-synchronization.
Innovation Solution
A method where the base station determines and sends mapping relationships between cells and TA groups to the UE, allowing the UE to determine the appropriate TA group for a newly added cell, using either stored mapping relationships or RRC signaling, and initiates a random access procedure if necessary to acquire the correct TA for uplink transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If carrier aggregation is introduced to improve peak rates and accommodate multiple cells, then the system can serve more users and utilize spectrum resources better, but the UE cannot correctly acquire TA for newly added cells leading to uplink out-of-synchronization and data transmission errors
Solution Approach 1:
The base station performs preliminary action by determining and notifying the TA group mapping relationship before the UE needs to access the newly added cell. This allows the UE to acquire the correct TA information in advance through the mapping relationship, preventing uplink out-of-synchronization and data transmission errors while enabling carrier aggregation for improved peak rates.
2Reliability
If the base station notifies TA group information for newly added cells, then the UE can correctly acquire TA and maintain uplink synchronization, but the system complexity increases due to additional mapping relationship management
Solution Approach 1:
The TA group mapping relationship serves multiple functions: it enables the UE to acquire TA for newly added cells, maintains uplink synchronization, and supports carrier aggregation operations. By making the mapping relationship universal and reusable across different cells and scenarios, the solution avoids the need for complex separate TA acquisition mechanisms for each cell, thus managing system complexity while ensuring reliable uplink synchronization.
3Reliability
If the UE performs random access procedure for every newly added cell, then the UE can acquire TA, but the access time increases and system efficiency decreases
Solution Approach 1:
The base station performs preliminary action by determining and notifying the TA group mapping relationship before the UE needs to access the newly added cell. This allows the UE to acquire the correct TA information in advance through the mapping relationship, eliminating the need for time-consuming random access procedures for TA acquisition while maintaining reliable TA acquisition.
Solution Approach 2:
Instead of performing a complete random access procedure for each newly added cell, the UE copies the TA group mapping relationship information from the notification and applies it to the new cell. This copying approach significantly reduces the time required for TA acquisition compared to performing full random access procedures while ensuring reliable TA acquisition.
Data Source
AI summary
Embodiments of the invention disclose an information notification and timing advance acquisition method, system and device, relate to the field of wireless communications and address the problem of how a UE acquires a Timing Advance (TA) for uplink transmission in a cell newly added in a set of cells configured for the UE. In the invention, a base station sends mapping relationships between cell and Timing Advance, TA, group to a UE, and the UE determines a TA group corresponding to a newly added cell configured for the UE by the base station according to the mapping relationships; determines whether there is a cell, having established uplink synchronization with the based station, in the TA group; and if so, then the UE regards a TA of the cell as a TA for uplink transmission in the newly added cell; otherwise, the UE acquires a TA for uplink transmission in the newly added cell by initiating a random access procedure. Apparently with the invention, the UE can acquire a TA for uplink transmission in the newly added cell.