Dynamic HARQ Codebook Timing for 5G Subslot Acknowledgement
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Solution Overview
Problem
HARQ signaling in 5G networks faces inefficiencies due to semi-static codebook configurations that either require padding to accommodate varying transmission sizes, leading to resource wastage or result in significant control signaling overhead when transmission dynamics are considered.
Innovation Solution
Implement flexible HARQ signaling by using subslots and dynamic codebook size adjustments, allowing acknowledgement signaling to adapt to varying transmission scenarios with reduced overhead.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the HARQ codebook is configured to have a large size to cover maximum transmission cases, then reliability of HARQ signaling is improved, but resource wastage increases due to padding for smaller transmissions
Solution Approach 1:
The patent applies dynamics by enabling the HARQ codebook size to change adaptively based on the actual number of transmissions. Instead of using a fixed large codebook size for all cases, the system dynamically adjusts the codebook size to match the current transmission scenario, thereby avoiding padding for smaller transmissions while maintaining reliability when needed.
Solution Approach 2:
The patent changes the parameter of codebook size from a static configuration to a dynamic parameter that can be adjusted based on transmission conditions. By modifying the codebook size parameter according to the number of active HARQ processes, the system optimizes resource utilization while ensuring sufficient capacity for reliable acknowledgment signaling.
2Loss of energy
If the codebook size is reduced to match smaller transmission cases, then resource utilization is improved, but control signaling overhead increases due to frequent size changes
Solution Approach 1:
The patent segments the codebook size adjustment into discrete, manageable changes triggered by specific events (e.g., changes in the number of HARQ processes). Rather than continuous adjustment, the system divides the parameter space into distinct codebook size configurations that can be switched between based on transmission conditions, reducing the complexity of control signaling.
Solution Approach 2:
The system performs preliminary configuration of codebook sizes based on expected transmission patterns or pre-defined thresholds. By anticipating when codebook size changes will be needed and preparing accordingly, the system reduces the need for frequent reactive adjustments, thereby lowering control signaling overhead while maintaining resource utilization efficiency.
3Adaptability or versatility
If subslots are introduced for acknowledgement signaling, then flexibility in timing is improved, but the need for fixed codebook configuration increases leading to more padding
Solution Approach 1:
The patent combines the timing flexibility of subslots with dynamic codebook size adjustment. By making both the timing structure and codebook size adaptive rather than fixed, the system can utilize subslot-level timing granularity without being forced to maintain a large fixed codebook, thereby reducing padding overhead while preserving timing adaptability.
Data Source
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AI summary
There is disclosed a method of operating a wireless device (10) in a radio access network, the wireless device (10) being configured with a slot configuration according to which a slot has multiple subslots, the method comprising transmitting acknowledgement information reporting on subject transmission in a subslot based on a received timing indication indicating a subslot number for transmitting the acknowledgement information, and based on a subslot offset. There are also disclosed related methods and devices.