HARQ-ACK Codebook Feedback for Multi-PDSCH Single-DCI Scheduling
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Solution Overview
Problem
In wireless communication systems, particularly in unlicensed carriers, transmitted messages are often lost or corrupted due to channel quality imperfections, leading to increased latency and reduced reliability, necessitating improved control mechanisms for detection and retransmission of lost or corrupted messages.
Innovation Solution
Implementing enhanced dynamic HARQ-ACK codebook and one-shot feedback schemes with multiple transmission opportunities, utilizing DCI format 1_1 to schedule multiple PDSCHs, and introducing bit fields for PDSCH group index, new feedback indication, and number of request PDSCH groups to enhance HARQ-ACK feedback.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multiple PDSCHs are scheduled by a single DCI to improve transmission efficiency, then productivity is improved, but device complexity increases due to enhanced HARQ-ACK codebook generation requirements
Solution Approach 1:
The patent segments the HARQ-ACK feedback mechanism by introducing separate bit fields for different PDSCH groups within a single DCI. Each PDSCH group can be independently acknowledged, allowing the UE to generate targeted HARQ-ACK codebooks for specific groups rather than processing all PDSCHs uniformly. This segmentation reduces the computational complexity of codebook generation while maintaining the productivity benefit of multi-PDSCH scheduling.
Solution Approach 2:
The patent implements dynamic HARQ-ACK codebook generation where the codebook structure adapts based on the actual PDSCH scheduling situation. The UE dynamically determines which PDSCH groups require acknowledgment and constructs the codebook accordingly, rather than using a fixed codebook structure. This dynamic approach optimizes the balance between transmission efficiency and processing complexity.
2Reliability
If enhanced dynamic HARQ-ACK codebook feedback mode is implemented to improve reliability, then reliability is improved, but device complexity increases due to additional bit fields and processing requirements
Solution Approach 1:
The patent enhances feedback reliability by introducing multiple feedback mechanisms including new feedback indication bit fields that provide explicit acknowledgment status for each PDSCH group. The UE generates detailed HARQ-ACK codebooks that feed back comprehensive reception status information to the gNB. This enhanced feedback loop improves reliability by ensuring accurate transmission status reporting, while the structured bit field design keeps processing complexity manageable.
3Loss of time
If one-shot HARQ-ACK feedback mode is used to reduce latency, then loss of time is reduced, but measurement precision may be affected due to condensed feedback timing
Solution Approach 1:
The patent implements one-shot HARQ-ACK feedback mode where the UE is pre-configured to send consolidated acknowledgment feedback at predetermined timing opportunities. Instead of sending individual acknowledgments for each PDSCH, the UE prepares and transmits a comprehensive HARQ-ACK codebook at the pre-arranged feedback timing. This preliminary action approach reduces feedback latency significantly while maintaining timing precision through pre-configured timing relationships defined in the specification.
Data Source
AI summary
The present disclosure describes methods, system, and devices for generating a hybrid automatic repeat request acknowledgement (HARQ-ACK) codebook feedback for at least one physical downlink shared channel (PDSCH) scheduled by a downlink control information (DCI). One method includes receiving, by a user equipment (UE), a radio resource control (RRC) parameter to configure an enhanced dynamic HARQ-ACK codebook feedback mode; receiving, by the UE, the DCI comprising a set of parameters to configure at least one PDSCH group comprising the at least one PDSCH; and transmitting, by the UE, a HARQ-ACK codebook feedback based on the set of parameters in the DCI and the at least one PDSCH group. Another method includes receiving, by the UE, the DCI comprising a bit field used for triggering a one-shot HARQ-ACK feedback mode; and transmitting, by the UE, a one-shot HARQ-ACK feedback based on a set of parameters in the DCI.