HARQ-ACK Codebook Feedback Segmentation for NR-U Signaling Overhead
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing downlink data scheduling methods in New Radio Unlicensed (NR-U) bands face challenges in reducing feedback delay and uplink control signaling overhead due to the uncertainty of Listen Before Talk (LBT) and limitations in processing time, where Downlink Control Information (DCI) can only indicate N consecutive groups for HARQ-ACK codebook feedback.
Innovation Solution
The proposed method involves determining whether a HARQ-ACK sub-codebook is detected by a user terminal, and if not, transmitting DCI to trigger retransmission with specific group number fields to instruct retransmission, allowing for specific downlink data scheduling group feedback rather than simultaneous feedback across N consecutive groups, thereby reducing uplink control signaling overhead.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of information
If DCI indicates N consecutive groups for HARQ-ACK codebook feedback, then feedback coverage is improved, but uplink control signaling overhead increases
Solution Approach 1:
The patent segments the HARQ-ACK codebook feedback into multiple groups, where each group corresponds to a specific downlink data scheduling group. Instead of requiring feedback for all N consecutive groups simultaneously, the system divides the feedback into separate groups that can be transmitted independently. This segmentation reduces the overhead of uplink control signaling while ensuring comprehensive feedback coverage across all scheduled groups.
2Loss of time
If HARQ-ACK codebook is fed back in same COT as downlink data, then feedback delay is reduced, but processing time requirements increase
Solution Approach 1:
The patent applies preliminary action by preparing and organizing the HARQ-ACK codebook feedback in advance within the same Contention Opportunity (COT) as the downlink data transmission. The system proactively groups and readies the feedback information before the actual transmission, allowing the feedback to be sent in the same COT without requiring additional LBT procedures. This preliminary preparation reduces feedback delay while managing processing time requirements through advance organization of feedback data.
Data Source
AI summary
Downlink data scheduling HARQ-ACK codebook feedback and generation methods and devices, and a medium are provided. The method comprises: determining whether a first HARQ-ACK codebook transmitted by a user terminal is detected; when the first HARQ-ACK codebook is not detected, delivering DCI for triggering retransmission of the first HARQ-ACK codebook to the user terminal, wherein the DCI for triggering retransmission of the first HARQ-ACK codebook comprises a first trigger group number field, the first trigger group number field is the same as a first scheduling group number field, the first trigger group number field is used for indicating a number of the first trigger group, and the first scheduling group number field is used for indicating a number of the first scheduling group; and receiving the first HARQ-ACK codebook retransmitted by the user terminal. The solution can indicate HARQ-ACK codebook feedback of a discontinuous downlink data scheduling group.