HARQ-ACK Reporting for Inter-Band Carrier Aggregation
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Solution Overview
Problem
Current wireless communication systems face limitations in flexibility and efficiency, particularly in handling Hybrid Automatic Repeat Request (HARQ) information for carrier aggregation, especially with different Time-Division Duplexing (TDD) configurations across various bands, which affects communication capacity and speed.
Innovation Solution
The systems and methods described enable efficient HARQ information sending and receiving by determining appropriate HARQ-ACK reporting subframes based on PCell and SCell configurations, using existing timing tables without adding new HARQ-ACK timings, and allowing different TDD UL-DL configurations on different bands, ensuring compatibility with current Radio Layer 1 agreements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If different TDD UL-DL configurations are allowed on different bands for carrier aggregation, then communication flexibility and efficiency are improved, but system complexity increases
Solution Approach 1:
The patent divides the carrier aggregation system into primary cell (PCell) and secondary cell (SCell) components, each with independent TDD UL-DL configurations. This segmentation allows different bands to operate with different configurations while maintaining overall system coordination through defined relationships between PCell and SCell timing structures.
Solution Approach 2:
The patent introduces a new dimension of configuration independence by allowing different TDD UL-DL configurations across different bands/carriers. Previously, carrier aggregation required identical TDD configurations; this invention adds the dimension of configuration diversity while maintaining synchronization through the K set mechanism that maps SCell downlink subframes to PCell uplink subframes.
2Productivity
If HARQ-ACK reporting is supported for different TDD configurations, then communication efficiency is improved, but the number of timing entries required increases
Solution Approach 1:
The patent creates a universal timing mechanism where a single set of K values can serve multiple TDD UL-DL configuration combinations. The K set defines downlink-to-uplink timing relationships that work across different configuration scenarios, eliminating the need for separate timing tables for each configuration combination and enabling multi-functionality with reduced overhead.
Solution Approach 2:
The patent changes the approach from fixed configuration-specific timing entries to dynamic parameter selection where the appropriate K value is chosen based on the actual PCell and SCell configuration. This allows the system to adapt timing parameters to different scenarios without requiring separate entries for each possible configuration combination.
3Device complexity
If existing timing tables are used without adding new HARQ-ACK timings, then device complexity is reduced, but support for different band configurations is limited
Solution Approach 1:
The patent introduces dynamic configuration selection where the system can adapt to different TDD UL-DL configurations on different bands by selecting appropriate K values from the timing table based on the actual PCell and SCell configurations. This dynamic approach enables support for various band combinations without requiring static pre-definition of all possible timing scenarios.
Solution Approach 2:
The patent uses the K set as an intermediary layer between the physical timing requirements and the configuration diversity needs. The K values act as mediators that translate different PCell-SCell configuration combinations into concrete HARQ-ACK timing relationships, enabling configuration support while reusing existing timing table structures.
Data Source
AI summary
A User Equipment (UE) for sending Hybrid Automatic Repeat Request (HARQ) information is described. The UE includes a processor and instructions stored in memory that is in electronic communication with the processor. The UE determines a primary cell (PCell) configuration. The UE also determines a secondary cell (SCell) configuration. The UE further determines whether the PCell configuration specifies uplink (UL) and the SCell configuration specifies downlink (DL) for a subframe or whether the PCell configuration specifies DL and the SCell configuration specifies DL for the subframe. The UE additionally determines a HARQ Acknowledgement (HARQ-ACK) reporting subframe based on the PCell configuration if the PCell configuration specifies DL and the SCell configuration specifies DL for the subframe. The UE also sends SCell Physical Downlink Shared Channel (PDSCH) HARQ-ACK information in the HARQ-ACK reporting subframe.