Semi-Static HARQ-ACK Codebook for NR-U Feedback Overhead
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Solution Overview
Problem
Existing wireless communication systems face challenges in efficiently managing interference and congestion, particularly in shared spectrum environments, leading to increased signaling overhead and latency in HARQ-ACK feedback processes.
Innovation Solution
Implementing semi-static HARQ-ACK codebook enhancements that include coordinated resource partitioning and prioritized access to shared spectrum, allowing network operators to reserve specific time resources for exclusive or prioritized use, reducing the need for medium-sensing procedures and enhancing communication efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If medium-sensing procedures are implemented in shared spectrum environments, then interference detection capability is improved, but signaling overhead and latency increase
Solution Approach 1:
The patent applies preliminary action by performing medium sensing and acquiring channel occupancy time before actual data transmission. The LBT procedure is executed in advance to detect interference and secure transmission rights, with the sensing results and granted time resources being utilized for subsequent HARQ-ACK feedback transmission without requiring additional sensing during the feedback process itself
2Productivity
If coordinated resource partitioning is implemented with reserved time resources, then communication efficiency is improved, but device complexity increases
Solution Approach 1:
The patent applies segmentation by dividing the shared spectrum resources into specific reserved time resources for HARQ-ACK feedback transmission. This creates dedicated transmission opportunities separated from other uplink transmissions, allowing UEs to send feedback without competing for resources or performing complex medium sensing during feedback timing
Solution Approach 2:
The patent applies self-service by configuring UEs with predetermined resource allocations and transmission timing through RRC signaling. Once configured, UEs autonomously transmit HARQ-ACK feedback on their assigned resources without requiring complex real-time resource management or coordination with the base station during the actual feedback process
Data Source
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AI summary
Hybrid automatic repeat request (HARQ)-acknowledgement (ACK) feedback codebook enhancements are disclosed. A size of feedback codebook may be reduced explicitly or implicitly. For example, an indicator may be identified by a corresponding field of a downlink control message. In some aspects, the indicator may indicate that multiple Physical Downlink or Uplink Shared Channels (PDSCHs/PUSCHs) are actually scheduled during one or more slots of a window corresponding to the feedback codebook. Responsive to receiving the indicator, a device may refrain from reducing the size of the feedback codebook to exclude acknowledgement feedback for additional possible PDSCH/PUSCH occasions of the slots of the window. In some aspects, a device identifies possible PDSCH/PUSCH occasions that occur outside of one or more Channel Occupancy Times (COTs) of a window. The device may generate a reduced size feedback codebook by excluding the possible PDSCH/PUSCH occasions that occur outside of the COTs of the window.