Dynamic Codebook Timespan Adjustment for Uplink HARQ
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Solution Overview
Problem
Current wireless communication systems face challenges in efficiently managing uplink transmissions, particularly in adjusting codebook timespans to accommodate hybrid automatic repeat request (HARQ) acknowledgments and negative acknowledgments, leading to collisions with downlink symbols and difficulties in multiplexing physical uplink control channel (PUCCH) and physical uplink shared channel (PUSCH) transmissions.
Innovation Solution
The implementation of a method where user equipment (UE) and network entities adjust codebook timespans to align with HARQ timings, allowing for deferred or canceled PUCCH transmissions based on adjustments indicated by the network, enabling efficient multiplexing of HARQ acknowledgments and negative acknowledgments with PUSCH retransmissions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If codebook timespan is adjusted to accommodate HARQ acknowledgments, then HARQ reliability is improved, but collision with downlink symbols increases
Solution Approach 1:
The codebook timespan is made dynamic rather than fixed, allowing the network entity to adjust its duration based on current transmission conditions. When HARQ acknowledgments need to be accommodated, the timespan is extended; when downlink symbols are present, the timespan is adjusted to avoid collisions. This dynamic adjustment resolves the contradiction between ensuring HARQ reliability and avoiding harmful collisions with downlink symbols.
2Object-affected harmful factors
If PUCCH transmission is deferred to subsequent slot, then collision with downlink symbols is avoided, but transmission delay increases
Solution Approach 1:
The network entity performs preliminary assessment of the downlink slot configuration before determining PUCCH transmission timing. By examining the slot format indicator and downlink symbol allocation in advance, the network can proactively schedule PUCCH transmissions in slots that will not collide with downlink symbols, rather than deferring transmissions reactively. This preliminary action reduces unnecessary transmission delays while still avoiding collisions.
3Reliability
If codebook timespan is extended to include more slots, then HARQ acknowledgment coverage is improved, but multiplexing complexity with PUSCH increases
Solution Approach 1:
The codebook timespan is segmented into multiple independent codebook instances, each associated with specific downlink slots. Instead of creating one large codebook spanning many slots, the system divides the timespan into smaller codebook units that can be independently managed and multiplexed with PUSCH transmissions. This segmentation reduces the complexity of handling large codebooks while maintaining comprehensive HARQ acknowledgment coverage across the extended timespan.
Data Source
AI summary
Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may receive, from a network entity, a physical downlink shared channel (PDSCH) transmission in a first slot, wherein the PDSCH transmission is associated with a codebook timespan. The UE may perform, to the network entity, a physical uplink control channel (PUCCH) transmission in a subsequent slot based at least in part on an adjustment to the codebook timespan, wherein the PUCCH transmission indicates a hybrid automatic repeat request (HARQ) associated with the PDSCH transmission. Numerous other aspects are described.