Carrier Aggregation Timing Advance Group Segmentation
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Solution Overview
Problem
In carrier aggregation systems, managing multiple uplink transmission timings efficiently is challenging, particularly in scenarios where antennas for primary and secondary carriers are located at different sites, leading to potential interference and decoding failures due to mismatched uplink symbol reception timings.
Innovation Solution
The method involves sorting carriers with the same uplink timings into Timing Advance Groups (TAGs) and using explicit signaling to manage uplink transmission timing synchronization, where the terminal either maintains synchronization or suspends transmissions until synchronization is achieved through a random access procedure, ensuring orthogonal uplink symbol reception.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multiple carriers are aggregated with different uplink transmission timings, then data rate is improved, but interference and decoding failures occur due to mismatched uplink symbol reception timings
Solution Approach 1:
The patent segments carriers with different uplink transmission timings into separate Timing Advance Groups (TAGs). Each TAG manages a specific group of carriers with identical uplink timing, preventing interference between carriers with different timings while maintaining the benefits of carrier aggregation for improved data rate.
2Area of stationary object
If antennas for primary and secondary carriers are located at different sites, then coverage is improved, but managing multiple uplink transmission timings becomes complex
Solution Approach 1:
The patent divides carriers into separate TAGs based on their uplink timing characteristics. This segmentation simplifies timing management by organizing carriers with identical timing into groups, reducing the complexity of managing multiple uplink transmission timings while enabling distributed antenna deployment for extended coverage.
Solution Approach 2:
The patent introduces TAG identifiers as an intermediary mechanism to manage timing relationships between carriers. The TAG ID serves as a mediator that associates carriers with specific uplink timing configurations, simplifying the management of multiple timing scenarios in distributed antenna deployments.
3Adaptability or versatility
If uplink transmission timing is not synchronized, then transmission flexibility is improved, but interference occurs and uplink symbols cannot be decoded correctly
Solution Approach 1:
The patent segments carriers into TAGs where each TAG maintains synchronized uplink timing for its member carriers. This segmentation allows the system to maintain transmission flexibility across different carrier groups while ensuring that carriers within each group remain synchronized, preventing interference and enabling correct decoding.
Data Source
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AI summary
A method for establishing time alignment by a user equipment (UE) in a wireless communication system. The method comprises: receiving, from a base station, a radio resource control (RRC) message including information on a timing advance group (TAG); determining whether a timer associated with the TAG to which a serving cell belongs is running; and performing an uplink transmission on the serving cell according to whether the timer associated with the TAG is running. A corresponding method for the base station is provided.