TDD UL/DL Configuration Indication for Carrier Aggregation
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Solution Overview
Problem
Current LTE TDD systems face challenges in efficiently managing uplink and downlink traffic variations and interference, particularly with carrier aggregation, where existing DCI formats are insufficient to support multiple carriers, leading to limitations in UL/DL configuration indication and potential timing complications during reconfiguration.
Innovation Solution
The method involves configuring a time division duplex (TDD) uplink/downlink configuration indication pattern using DCI format 1C, which supports up to five carriers by establishing a mapping relationship between TDD configurations and carrier indices, and utilizing RRC signaling to dynamically adjust UL/DL configurations, ensuring backward compatibility and improved link performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If existing DCI formats are used to indicate UL/DL configuration, then backward compatibility is maintained, but the ability to support multiple carriers in carrier aggregation is insufficient
Solution Approach 1:
The patent segments the UL/DL configuration indication by introducing a configuration indication pattern that maps different downlink subframes to different carriers. Each downlink subframe carries configuration information for specific carriers, enabling multi-carrier support while using the existing DCI format 1C structure.
Solution Approach 2:
The patent adds a temporal dimension to the configuration indication by utilizing multiple downlink subframes (subframe #0, #1, #5, or #6) to carry configuration information for different carriers. This transforms a single-subframe limitation into a multi-subframe solution, effectively supporting up to five carriers.
2Productivity
If DCI format 1C is used to indicate multiple TDD configurations, then signaling efficiency is improved, but the complexity of mapping relationships between configurations and carriers increases
Solution Approach 1:
The patent applies local quality by creating specific mapping relationships between downlink subframes and carrier indices. Each downlink subframe is assigned to indicate configurations for specific carriers, making the mapping rule-based and predictable rather than requiring complex dynamic signaling.
Solution Approach 2:
The patent changes the parameter of using multiple downlink subframe indices (0, 1, 5, 6) to carry configuration information, transforming a single-indicator system into a multi-indicator system that can represent up to five different carrier configurations efficiently.
3Adaptability or versatility
If dynamic reconfiguration of UL/DL configurations is implemented, then traffic adaptation capability is improved, but timing synchronization and reconfiguration coordination become more difficult
Solution Approach 1:
The patent uses preliminary action by configuring the configuration indication pattern and mapping relationships in advance through RRC signaling. This pre-configuration establishes the rules for how downlink subframes map to carriers, so that when dynamic reconfiguration occurs, the timing and coordination are already predetermined, reducing synchronization complexity.
Data Source
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AI summary
Systems, methods, apparatuses, and computer program products for time division duplex (TDD) uplink/downlink (UL/DL) configuration indication for TDD interference management and traffic adaptation (eIMTA) are provided. One method includes providing, by a network node, a time division duplex (TDD) uplink/downlink (UL/DL) configuration indication pattern. The TDD UL/DL configuration indication pattern may be used to indicate multiple TDD UL/DL configurations in DCI format C associated with the certain configured carriers andthe concrete fixed downlink subframe index.