Uplink Timing Correction for Carrier Aggregation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In telecommunications systems employing carrier aggregation, achieving precise timing alignment for uplink signals across multiple component carriers is challenging due to varying UE-eNodeB distances, leading to differences in signal arrival times and the need for individual timing corrections for each carrier.
Innovation Solution
A method and apparatus for determining a single uplink transmission timing correction for multiple component carriers, where the base station measures signal arrival times and sends a common timing correction to the user equipment, along with information on its validity across all applicable carriers, allowing for efficient alignment of UL signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If individual timing corrections are applied for each component carrier, then timing alignment precision is improved, but signaling overhead and processing complexity increase
Solution Approach 1:
The patent segments the timing correction information by associating it with specific component carriers through carrier indicator fields. This allows the system to send timing corrections selectively for only those carriers that need adjustment, rather than transmitting corrections for all carriers universally. The segmentation enables precise timing alignment where needed while reducing unnecessary signaling overhead for carriers that are already properly aligned.
Solution Approach 2:
The timing correction mechanism is designed to be universal across multiple component carriers. A single timing correction message can apply to one or multiple carriers depending on the carrier indicator field configuration. This multi-functionality allows the same signaling structure to serve both individual carrier timing correction and group-based timing correction, flexibly adapting to different network scenarios and reducing overall signaling complexity.
2Area of stationary object
If carrier aggregation is implemented to support wideband carriers, then bandwidth capacity is improved, but timing synchronization difficulty increases
Solution Approach 1:
The patent introduces carrier indicator fields as intermediaries between the timing correction data and the component carriers. These indicator fields act as mediators that link timing correction information to specific carriers or carrier groups, enabling the base station to efficiently manage timing synchronization across aggregated carriers without requiring separate complex synchronization mechanisms for each carrier.
Solution Approach 2:
Instead of applying timing corrections to all component carriers universally, the system applies timing corrections partially - only to the specific carriers or carrier groups indicated by the carrier indicator fields. This partial action approach reduces signaling overhead by avoiding redundant timing correction transmissions for carriers that do not require adjustment, while still maintaining proper synchronization where needed.
Data Source
AI summary
The present invention relates to methods and arrangements in a base station and a user equipment for determining an uplink transmission timing correction for communication in a telecommunication system in which aggregation of component carriers is applied. The base station receives a signal from the user equipment on an uplink (UL) component carrier and measures the arrival time of the signal. A timing correction of the UL transmission timing based on the arrival time of the signal is determined. Thereupon the base station determines for which of the uplink component carriers used by the user equipment the timing correction is valid. The timing correction and the validity information is sent to the user equipment. The user equipment adjusts the UL transmission timing for each UL component carrier the timing correction is valid for.