Carrier Aggregation TDD Configuration Sets and Especial Cell Design
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Solution Overview
Problem
The existing LTE-A system struggles to support user equipment configured with multiple cells using different Time Division Duplex (TDD) UL/DL configurations, leading to issues such as inaccurate pathloss reference, resource waste, and complex PUCCH design due to the inability to adapt to varying TDD configurations across aggregated cells.
Innovation Solution
Introducing the concept of TDD UL/DL configuration sets and designating an Especial Cell (Ecell) within each set to possess primary cell functions, allowing the eNB to configure and notify user equipment of these settings through RRC signaling, ensuring proper operation across different TDD configurations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple cells with different TDD UL/DL configurations are aggregated for user equipment, then spectrum resource utilization and adaptability are improved, but pathloss reference accuracy deteriorates and system complexity increases
Solution Approach 1:
The patent segments the aggregated cells into multiple TDD UL/DL configuration sets, where each set contains cells with the same TDD configuration. This segmentation allows the system to support multiple different TDD configurations simultaneously while maintaining accurate pathloss references within each set, as cells in the same set share identical uplink-downlink timing relationships.
Solution Approach 2:
The patent introduces Special Cells (SCells) as intermediary elements within each TDD UL/DL configuration set. These SCells are specifically designated to provide pathloss references for other cells in the same set, acting as mediators that enable accurate pathloss measurement across cells with different configurations while maintaining system coherence.
2Productivity
If multiple cells with different TDD UL/DL configurations are aggregated, then spectrum utilization is improved, but resource waste occurs due to cross-carrier scheduling limitations
Solution Approach 1:
By segmenting cells into TDD UL/DL configuration sets where cells within each set share the same configuration, the patent enables efficient cross-carrier scheduling within sets while avoiding the resource waste that would occur with cross-set scheduling, thus maintaining high spectrum utilization without unnecessary resource consumption.
Solution Approach 2:
The patent creates equipotential groups (TDD UL/DL configuration sets) where cells have identical uplink-downlink timing characteristics. This allows seamless cross-carrier scheduling within sets without timing conflicts, eliminating resource waste while still supporting diverse TDD configurations across different sets for optimal spectrum utilization.
3Adaptability or versatility
If multiple cells with different TDD UL/DL configurations are aggregated, then configuration flexibility is improved, but PUCCH design complexity increases
Solution Approach 1:
The patent segments the PUCCH design problem by associating each TDD UL/DL configuration set with a specific PUCCH configuration. This segmentation allows the UE to maintain separate PUCCH settings for each set, simplifying the overall design by breaking down the complex multi-configuration problem into manageable per-set configurations while still supporting high configuration flexibility.
Solution Approach 2:
The patent creates universal PUCCH handling mechanisms that work across all TDD UL/DL configuration sets. By defining a standardized approach for PUCCH transmission that adapts to each set's specific configuration, the system achieves both configuration flexibility and design simplicity, as the same fundamental PUCCH framework serves multiple different TDD configurations.
Data Source
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AI summary
The present invention discloses a method and device for data transmission based on carrier aggregation (CA) technology. The method and device are used for ensuring that user equipments can work normally, when the multiple cells aggregated from the user equipments supporting CA technology have different time division duplex (TDD) uplink/downlink (UL/DL) configurations. The method includes: a base station configures at least two time division duplex uplink/downlink carrier TDD UL/DL configuration collections for the user equipments, wherein each TDD UL/DL configuration collection includes at least one cell; the base station respectively configures one cell in each TDD UL/DL configuration collection to be an especial cell (Ecell).