Semi-Static HARQ-ACK Codebook Sizing for PDSCH Repetitions
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Solution Overview
Problem
The 5G NR system faces issues with redundant information in semi-static HARQ-ACK codebooks, leading to poor transmission performance due to the inclusion of downlink transmissions with associated HARQ-ACK feedback in a slot.
Innovation Solution
Determine the size of the semi-static HARQ-ACK codebook based on the number of repetition transmissions of the PDSCH, reducing redundant information and improving HARQ-ACK feedback performance by focusing on the last transmission of the PDSCH with repetition transmissions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the semi-static HARQ-ACK codebook includes all downlink transmissions with associated HARQ-ACK feedback in a slot, then the codebook size increases to ensure complete feedback coverage, but redundant information is introduced leading to poor transmission performance
Solution Approach 1:
The patent extracts and removes redundant HARQ-ACK feedback information from the semi-static codebook by identifying and excluding downlink transmissions that do not require separate feedback bits. Specifically, when a downlink transmission is a repetition of a previous transmission and the HARQ process ID indicates it's part of a repetition sequence, the patent excludes creating duplicate feedback entries, thereby eliminating redundancy while preserving necessary feedback coverage.
Solution Approach 2:
The patent introduces dynamic adjustment to the semi-static HARQ-ACK codebook construction by using the HARQ process ID and transmission counter to dynamically determine whether a downlink transmission requires a separate feedback bit. The codebook size and content are dynamically adapted based on the actual transmission patterns and repetition configurations, allowing the system to optimize between complete coverage and redundancy elimination.
2Reliability
If the codebook size is determined by the quantity of downlink transmissions with associated HARQ-ACK feedback in a slot, then all transmissions are accounted for, but transmission performance deteriorates due to redundant feedback information
Solution Approach 1:
The patent extracts redundant feedback entries from the HARQ-ACK codebook by identifying downlink transmissions that are repetitions and should not generate separate feedback bits. The determination unit checks the HARQ process ID and transmission counter to identify repetitions, and the codebook generation unit excludes these from the feedback sequence, thereby improving transmission performance by removing redundancy while maintaining feedback completeness for unique transmissions.
Solution Approach 2:
The patent changes the parameters used for codebook size determination by introducing the transmission counter and HARQ process ID as key parameters. Instead of simply counting all downlink transmissions, the system uses these parameters to differentiate between unique transmissions and repetitions, dynamically adjusting the codebook size based on the actual number of transmissions requiring feedback rather than the total number of transmissions including repetitions.
3Productivity
If multiple downlink transmissions are multiplexed in the same slot, then resource utilization increases, but the codebook contains more redundant information reducing feedback efficiency
Solution Approach 1:
The patent extracts and removes redundant feedback information that arises from multiplexed downlink transmissions by using the HARQ process ID and transmission counter to identify which transmissions are repetitions. When multiple transmissions are multiplexed in the same slot, the system selectively excludes repetition transmissions from the HARQ-ACK feedback sequence, thereby reducing redundant feedback bits while maintaining efficient resource utilization for actual unique transmissions.
Data Source
AI summary
A data transmission method, a terminal device and a network device are provided. The method includes: receiving PDSCH; determining a size of a semi-static HARQ-ACK codebook according to a number of repetition transmissions of the PDSCH; and performing a corresponding HARQ-ACK feedback for the PDSCH with repetition transmissions according to the determined size of the semi-static HARQ-ACK codebook.