HARQ ACK/NACK Mapping for CBG and TB PDSCH Transmission
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Solution Overview
Problem
Existing wireless communication systems face inefficiencies in the transmission and reception of wireless signals, particularly in managing hybrid automatic repeat request (HARQ) processes and acknowledgement/negative acknowledgement (A/N) information for code block groups (CBGs) and transport blocks (TBs).
Innovation Solution
The method and apparatus enable efficient transmission and reception of control information by configuring acknowledgement/negative acknowledgement (A/N) information at the TB level based on HARQ process IDs, even when code block group (CBG) level transmission is configured, using mechanisms such as slot index, downlink assignment index (DAI), and radio resource control (RRC) signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If CBG level transmission is configured for the carrier, then transmission granularity and retransmission efficiency are improved, but control information complexity and processing overhead increase
Solution Approach 1:
The patent segments the A/N information structure by introducing separate field configurations for different HARQ process types. CBG-based HARQ processes use CBG-level A/N fields while TB-based HARQ processes use TB-level A/N fields, allowing fine-grained control without uniformly increasing complexity across all processes. This segmentation enables efficient CBG retransmission where applicable while maintaining simpler TB-level control where appropriate.
Solution Approach 2:
The patent implements dynamic configuration of A/N information fields based on the HARQ process type. The gNB can dynamically indicate whether a PDSCH is transmitted using CBG-based or TB-based HARQ through DCI signaling, allowing the system to adapt the control information structure to the specific transmission requirements of each scheduling instance, thereby optimizing between efficiency and complexity on a per-transmission basis.
2Device complexity
If TB level A/N information is used for all HARQ process IDs, then device complexity is reduced, but transmission efficiency for partial CBG retransmission deteriorates
Solution Approach 1:
The patent segments the HARQ process management into two distinct types: CBG-based HARQ processes that use CBG-level A/N information for fine-grained retransmission control, and TB-based HARQ processes that use TB-level A/N information for simpler overall retransmission. This segmentation allows the system to achieve partial retransmission efficiency where needed while maintaining overall structural simplicity through the dual-mode approach.
Solution Approach 2:
The patent changes the granularity parameter of A/N information based on the HARQ process type. For CBG-based processes, the A/N information operates at CBG granularity (finer), enabling partial retransmission. For TB-based processes, the A/N information operates at TB granularity (coarser), maintaining simplicity. This parameter change approach allows the system to optimize retransmission efficiency without permanently increasing overall complexity.
3Measurement precision
If separate A/N fields are configured for each HARQ process ID, then retransmission control precision is improved, but signaling overhead and processing time increase
Solution Approach 1:
The patent segments the A/N field configuration to match the HARQ process type rather than uniformly applying fine-grained CBG-level fields to all processes. By configuring CBG-level A/N fields only for CBG-based HARQ processes and TB-level A/N fields for TB-based processes, the system achieves precise retransmission control where needed while reducing processing time and signaling overhead for processes where coarse-grained control suffices.
Data Source
AI summary
The present invention relates to a wireless communication system, and specifically, to a method including the steps of: receiving at least one PDSCH on a carrier in which a CBG-level transmission is configured; and transmitting control information including A/N information about the at least one PDSCH, wherein the at least one PDSCH includes CBGs respectively corresponding to TBs and is associated with one among all of HARQ process IDs of the carrier, and the A/N information about each of the HARQ process IDs of the carrier is configured of TB-level A/N information on the basis of the control information being configured on an HARQ process ID-basis with respect to all of the HARQ process IDs of the carrier, even though the CBG-level transmission has been configured with respect to the carrier. The present invention also relates to a device for said method.