HARQ Timing Adaptation in Dynamic TDD Carrier Aggregation
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Solution Overview
Problem
In carrier aggregation configurations, dynamic adaptation of TDD DL/UL subframe configurations for evolved interference management (eIMTA) leads to timing complexities and potential interference, particularly in determining hybrid automatic repeat request (HARQ) timing and uplink control information (UCI) transmission.
Innovation Solution
A method and apparatus for wireless communication that allows user equipment (UE) to determine appropriate HARQ timing, including HARQ acknowledgement (ACK) and scheduling timing, based on dynamic changes in component carrier configurations, especially for eIMTA operation, to compensate for interference and ensure efficient communication.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If dynamic adaptation of TDD DL/UL subframe configurations is implemented for eIMTA, then traffic adaptation efficiency is improved, but HARQ timing complexity and interference increase
Solution Approach 1:
The patent implements dynamic adaptation of TDD DL/UL subframe configurations where the eNodeB can change the DL/UL configuration of a secondary cell carrier dynamically based on traffic conditions. This dynamic mechanism allows the system to adapt to varying traffic demands while managing HARQ timing through configured reference configurations that provide stable timing references even when the actual configuration changes.
Solution Approach 2:
The patent introduces a reference configuration as an intermediary element that mediates between the dynamic actual configuration and the HARQ timing requirements. The reference configuration provides a stable basis for determining HARQ timing while allowing the actual configuration to change dynamically. This intermediary approach resolves the complexity by separating the timing reference function from the dynamic traffic adaptation function.
2Adaptability or versatility
If dynamic adaptation of TDD DL/UL subframe configurations is implemented for eIMTA, then traffic adaptation efficiency is improved, but interference between carriers increases
Solution Approach 1:
The reference configuration acts as a mediator that ensures consistent HARQ timing across carriers even when actual configurations differ. By using the reference configuration to determine timing, the system prevents timing-related interference while allowing dynamic traffic adaptation on individual carriers without causing harmful interactions between carriers with different configurations.
Solution Approach 2:
The patent applies different DL/UL configurations to different carriers (primary and secondary cells) according to their specific traffic conditions, while using a common reference configuration for timing purposes. This allows local optimization of traffic adaptation on each carrier while maintaining global timing consistency to prevent interference.
3Productivity
If HARQ timing is determined based on dynamic configuration changes, then communication efficiency is improved, but timing determination complexity increases
Solution Approach 1:
The reference configuration serves as an intermediary that simplifies HARQ timing determination. Instead of calculating timing based on complex dynamic configuration changes, the system uses the reference configuration as a stable basis, significantly reducing the complexity of timing determination while maintaining communication efficiency through dynamic traffic adaptation.
Solution Approach 2:
The reference configuration is established in advance as a stable timing reference before dynamic changes occur. This preliminary action provides a known basis for HARQ timing calculation, eliminating the need to analyze complex dynamic changes in real-time and significantly reducing timing determination complexity.
Data Source
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AI summary
A user equipment (UE) communicating in a carrier aggregation (CA) or multi-connectivity operation using more than one component carrier (CC), where at least one of the CCs is enabled to use evolved interference management for traffic adaptation (elMTA), adapts the hybrid automatic repeat request (HARQ) timing of the UE communications based on changes in the elMTA and configurations. The HARQ timing includes HARQ acknowledgement (ACK) timing or HARQ scheduling timing.