Dynamic HARQ Codebook for Wireless Feedback
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing wireless communication systems face challenges in efficiently transmitting hybrid automatic repeat request (HARQ) feedback due to imbalanced downlink and uplink link budgets, which limits downlink throughput and increases latency.
Innovation Solution
The method involves receiving an indication of a codebook type for transmitting HARQ feedback, which can be a static HARQ feedback codebook associated with a fixed codebook size, and transmitting the HARQ feedback based on the decoding result of a downlink shared message in accordance with the codebook type.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If dynamic HARQ codebook is used to adapt to varying downlink traffic, then feedback accuracy improves, but uplink control channel resources and complexity increase
Solution Approach 1:
The patent implements dynamic HARQ codebook where the codebook size and content adapt to the actual downlink traffic conditions. The UE constructs the HARQ codebook dynamically based on received DCI formats and downlink assignment index (DAI) counters, allowing the feedback structure to change according to traffic patterns while maintaining manageable complexity through standardized construction rules
Solution Approach 2:
The patent changes the parameter of codebook size from fixed to variable based on traffic conditions. The DAI counter values and DCI format interpretations are adjusted dynamically to reflect actual downlink scheduling status, enabling the feedback mechanism to scale with traffic demand without proportionally increasing complexity
2Reliability
If larger HARQ codebook size is used to provide more detailed feedback, then communication reliability improves, but uplink control channel overhead increases
Solution Approach 1:
The patent employs dynamic codebook sizing where the HARQ feedback payload adapts to the actual number of downlink transmissions. When downlink traffic is light, the codebook remains small; when traffic increases, the codebook expands to provide comprehensive feedback, ensuring reliability scales with need rather than always occupying maximum uplink resources
Solution Approach 2:
The patent uses DAI counters to indicate only the necessary portion of HARQ feedback required for current traffic conditions. Rather than always transmitting complete feedback for all possible downlink transmissions, the system transmits partial feedback proportional to actual scheduling, reducing overhead while maintaining reliability for scheduled transmissions
3Productivity
If static HARQ codebook is used to reduce feedback overhead, then uplink resource efficiency improves, but adaptability to traffic variations deteriorates
Solution Approach 1:
The patent transitions from static to dynamic codebook construction where the feedback structure automatically adapts to traffic patterns. The UE monitors DAI counters in DCI formats and adjusts the HARQ codebook accordingly, providing both the resource efficiency of compact feedback and the adaptability to varying traffic conditions through standardized dynamic construction rules
Data Source
AI summary
Methods, systems, and devices for wireless communications are described. A user equipment (UE) may receive an indication of a codebook type for transmitting hybrid automatic repeat request (HARQ) feedback by the UE to a second device (e.g., a network device, a satellite, or a base station). The indication of the codebook type may indicate a HARQ feedback transmission configuration, such as a static HARQ feedback transmission configuration. The HARQ transmission configuration may be associated with a one bit or two bit HARQ codebook. The UE may receive a scheduled downlink shared channel transmission, and attempt to decode the received downlink shared channel transmission. The UE may transmit (or refrain from transmitting) the HARQ feedback based on the decoding of the scheduled downlink shared channel transmission and in accordance with the feedback mode.