HARQ-ACK Feedback Codebook DCI Type Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In LTE systems, the existing methods for transmitting HARQ-ACK feedback codebooks in HARQ-ACK multiplexing scenarios are inefficient, leading to increased overheads and reduced communication efficiency, particularly when only one or several code blocks fail, requiring the retransmission of entire transport blocks.
Innovation Solution
A method and apparatus for sending HARQ-ACK feedback codebooks, where the terminal detects downlink control information to determine whether to send CBG-level or TB-level HARQ-ACK information, adjusting the codebook size based on DCI types, allowing flexible feedback and improving decoding performance and system robustness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If CBG-level feedback is used to improve retransmission efficiency, then communication efficiency is improved, but feedback overheads are increased
Solution Approach 1:
The patent implements dynamic switching between TB-level and CBG-level feedback modes based on channel conditions and transmission requirements. The terminal device can flexibly select feedback granularity (TB-level or CBG-level) according to downlink control information, allowing the system to adapt feedback overhead to actual transmission needs while maintaining high retransmission efficiency when CBG-level feedback is applicable
Solution Approach 2:
The patent changes the feedback parameter granularity dynamically. When channel conditions are good and retransmission efficiency is critical, the system uses CBG-level feedback with finer granularity. When overhead needs to be reduced or channel conditions are poor, the system switches to TB-level feedback with coarser granularity, thus optimizing the balance between retransmission efficiency and feedback overhead
2Productivity
If CBG-level feedback is used to reduce retransmission overhead, then retransmission efficiency is improved, but system robustness is reduced due to DCI dependency
Solution Approach 1:
The patent prepares multiple feedback modes (TB-level and CBG-level) in advance as backup options. When DCI is lost or channel conditions deteriorate, the terminal can fall back to TB-level feedback mode, which is more robust and less dependent on precise DCI interpretation. This beforehand preparation of alternative modes cushions against the reliability risks of DCI dependency
Solution Approach 2:
The patent enables dynamic switching between feedback modes to adapt to changing channel conditions and DCI reception quality. When DCI reception is reliable, CBG-level feedback is used for high efficiency. When DCI reception becomes unreliable, the system dynamically switches to TB-level feedback, which maintains better robustness, thus balancing efficiency and reliability based on real-time conditions
3Quantity of substance
If TB-level feedback is used to reduce feedback overhead, then overheads are reduced, but communication efficiency decreases when only partial CBGs fail
Solution Approach 1:
The patent implements dynamic feedback granularity selection. When channel conditions are good and only partial CBGs fail, the system uses CBG-level feedback to provide fine-grained acknowledgment, improving communication efficiency by enabling selective retransmission. When overhead needs to be minimized or channel conditions are poor, the system switches to TB-level feedback, thus dynamically balancing overhead and efficiency based on actual transmission scenarios
Solution Approach 2:
The patent changes the feedback parameter granularity from fixed to variable. The terminal device can switch between TB-level (coarse granularity) and CBG-level (fine granularity) feedback based on transmission requirements. When partial CBG failures occur and efficiency is critical, CBG-level feedback with finer granularity is used. When overhead reduction is the priority, TB-level feedback with coarser granularity is selected, optimizing the trade-off between overhead and efficiency
Data Source
AI summary
This application provides methods and apparatuses for sending a HARQ-ACK feedback codebook. One example method includes detecting DCI in a plurality of time units corresponding to at least one carrier, where a type of the DCI is a first DCI type or a second DCI type, where the first DCI is used to indicate to feed back CBG-level HARQ-ACK information for data scheduled by the first DCI, and where the second DCI is used to indicate to feed back TB-level HARQ-ACK information for data scheduled by the second DCI. A HARQ-ACK feedback codebook is then sent to a network device, where the codebook includes HARQ-ACK information of at least one piece of data scheduled by the DCI, and the HARQ-ACK feedback codebook is determined according to the type of the DCI and a type of the HARQ-ACK feedback codebook.