HARQ Codebook Structure for Mixed-Numerology ACK Bundling
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Solution Overview
Problem
Existing HARQ codebooks in 5G networks are inflexible and result in high signaling overhead due to fixed configurations, which is not compatible with the varying numerologies used in different communication directions.
Innovation Solution
Adopting a HARQ codebook structure that adapts to different numerologies in both transmission and acknowledgement directions, allowing for flexible slot durations and reduced signaling overhead by bundling acknowledgement information based on logical operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a fixed HARQ codebook configuration is used, then the codebook structure is simple and reliable, but the signaling overhead increases and flexibility is lost when different numerologies are used in different communication directions
Solution Approach 1:
The HARQ codebook configuration is made dynamic by introducing a flag that can be set to different values (e.g., 0 or 1) to adapt the codebook structure to different numerology combinations. This allows the same codebook framework to serve multiple scenarios without requiring separate fixed configurations for each numerology pair, thereby reducing signaling overhead while maintaining flexibility.
Solution Approach 2:
The invention changes the parameter of codebook configuration by using a flag-based mechanism that can take on different values to represent different numerology combinations. This parameter change approach allows the system to switch between different codebook structures (e.g., first HARQ codebook for first numerology, second HARQ codebook for second numerology) without explicit reconfiguration signaling, thus reducing overhead while adapting to varying numerologies.
2Productivity
If different numerologies are used for different communication directions, then communication efficiency is improved, but the HARQ codebook becomes complex and requires additional control signaling
Solution Approach 1:
The HARQ codebook is segmented into different parts or configurations based on the numerology being used. Instead of a single monolithic codebook, the system divides the codebook into first HARQ codebook for first numerology and second HARQ codebook for second numerology. This segmentation allows each codebook to be optimized for its specific numerology while using a unified flag-based selection mechanism to manage complexity.
Solution Approach 2:
A flag acts as an intermediary element that mediates between the different numerology configurations and the HARQ codebook selection process. The flag serves as a simple indicator that tells the system which codebook to use (first or second), thereby managing the complexity of supporting multiple numerologies without requiring complex control signaling or multiple separate codebook management systems.
3Device complexity
If a fixed HARQ codebook is used with varying numerologies, then the codebook configuration remains simple, but the slot duration mismatches cause processing delays
Solution Approach 1:
The system dynamically selects the appropriate HARQ codebook based on the numerology being used by setting a flag to the corresponding value. This dynamic selection ensures that the correct codebook (with appropriate slot duration expectations) is used for each numerology, preventing processing delays caused by mismatches between fixed codebook assumptions and actual varying slot durations.
Data Source
AI summary
This disclosure pertains to a method of operating a user equipment in a radio access network. The method includes transmitting acknowledgement information reporting on subject transmissions associated to one or more subject transmission slots based on a HARQ codebook. The HARQ codebook indicates a bit pattern of the acknowledgement information. Moreover, the HARQ codebook is based on a first numerology, the first numerology being used for the subject transmissions in a first communication direction, and a second numerology, the second numerology being used for transmitting the acknowledgement information in a second communication direction, wherein a first slot duration associated with the first numerology is different from a second slot duration associated with the second numerology. There are also disclosed related methods and devices.