Cross-Carrier HARQ Feedback Reporting Across Mixed-Numerology Cells
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing wireless communication systems face challenges in efficiently managing hybrid automatic repeat request (HARQ) feedback reporting for cross-carrier scheduling, particularly in scenarios involving multiple cells with different numerologies, leading to difficulties in updating counter downlink assignment indices (DAIs) and generating accurate HARQ codebooks.
Innovation Solution
A method for cross-carrier scheduling that involves incrementing counter DAIs based on a combination of starting symbols, cell indices, and PDCCH monitoring occasions, allowing for dynamic HARQ codebook generation and accurate HARQ feedback reporting, even in scenarios with mixed numerology across cells.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If cross-carrier scheduling is implemented with multiple cells having different numerologies, then system flexibility and spectral efficiency are improved, but the complexity of managing HARQ feedback reporting and updating counter DAIs increases significantly
Solution Approach 1:
The patent segments the HARQ feedback management by introducing separate counter DAI mechanisms for different cells and scheduling occasions. Each cell's HARQ processes are independently tracked using cell-specific counter DAIs, which are updated based on the specific cell index and scheduling occasion. This segmentation allows the system to handle multiple numerologies independently without creating a monolithic complex management structure.
Solution Approach 2:
The patent adds dimensional parameters to the counter DAI structure by incorporating cell index and scheduling occasion as additional dimensions. The counter DAI is no longer a simple sequential counter but becomes a multi-dimensional identifier that includes cell-specific and occasion-specific components. This dimensional expansion enables precise tracking of HARQ processes across multiple cells with different numerologies while maintaining manageable complexity through structured parameterization.
2Measurement precision
If counter DAI is updated based on multiple parameters (starting symbol, cell index, monitoring occasion), then HARQ codebook generation accuracy is improved, but the computational overhead and processing complexity increases
Solution Approach 1:
The patent implements preliminary action by pre-defining the counter DAI update rules and HARQ codebook generation procedures before actual scheduling operations. The system establishes predetermined relationships between cell indices, monitoring occasions, and counter DAI values through configuration signaling. This allows the UE to efficiently generate HARQ codebooks by simply following pre-established rules rather than performing complex real-time calculations, thus achieving high accuracy with reduced processing complexity.
Solution Approach 2:
The patent utilizes parameter changes by dynamically adjusting counter DAI values based on specific combinations of cell index, starting symbol, and monitoring occasion parameters. Each parameter change triggers a predetermined counter DAI update rule, allowing the system to achieve precise HARQ codebook generation through structured parameter manipulation rather than complex algorithms. The base station signals these parameter changes through DCI formats, enabling efficient UE-side processing.
3Productivity
If multiple PDCCH communications are transmitted in the same monitoring occasion across different cells, then resource utilization efficiency is improved, but the difficulty of tracking and managing HARQ processes increases
Solution Approach 1:
The patent implements feedback mechanisms where the base station monitors HARQ acknowledgments from the UE and adjusts subsequent scheduling decisions accordingly. The counter DAI structure provides implicit feedback by encoding information about which HARQ processes have been acknowledged and which require retransmission. This feedback loop enables the system to efficiently manage multiple concurrent PDCCH communications across different cells, as the UE can independently track each process using cell-specific counter DAIs and report status through structured HARQ feedback.
Data Source
AI summary
Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a base station may transmit a plurality of physical downlink control channel (PDCCH) communications in a same PDCCH monitoring occasion in a first cell, and may transmit a plurality of physical downlink shared channel (PDSCH) communications in at least one of the first cell or a second cell. Each of the PDCCH communications schedules a respective PDSCH communication of the plurality of PDSCH communications. A PDCCH communication, of the plurality of PDCCH communications, includes an indication of a counter downlink assignment index that is based at least in part on a combination of a starting symbol and a cell in which an associated PDSCH communication is to be transmitted, a cell index of the cell in which the associated PDSCH communication is to be transmitted, and the PDCCH monitoring occasion. Numerous other aspects are provided.