PUCCH Resource Configuration for Multicast HARQ-ACK Feedback
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Solution Overview
Problem
Current wireless communication systems face challenges in efficiently managing hybrid automatic repeat request (HARQ)-acknowledgement (ACK) feedback for multicast transmission, particularly due to timing constraints and the need for separate uplink timing, which complicates the reliable and efficient reporting of MBMS-related feedback.
Innovation Solution
The solution involves configuring a physical uplink control channel (PUCCH) resource set specifically for multicast transmission, where a PUCCH resource for HARQ-ACK is indicated through downlink control information (DCI) scrambled with a group-radio network temporary identifier (G-RNTI, allowing HARQ-ACK transmission only when the uplink timing is valid, and utilizing a separate PUCCH resource set for multicast compared to unicast channels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a separate PUCCH resource set is configured for multicast transmission, then HARQ-ACK feedback reliability is improved, but device complexity increases
Solution Approach 1:
The patent divides PUCCH resources into separate resource sets: one for unicast transmission and another for multicast transmission. This segmentation allows independent configuration and management of resources for different transmission types, ensuring that multicast HARQ-ACK feedback has dedicated resources that do not conflict with unicast resources, thereby improving reliability while maintaining manageable complexity through structured organization.
Solution Approach 2:
The patent introduces a PUCCH resource indicator (PRI) field in the DCI as an intermediary mechanism. This PRI field dynamically indicates which specific PUCCH resource from the multicast resource set should be used, allowing flexible resource allocation without requiring complex pre-configuration for all possible scenarios. The PRI acts as a mediator between the DCI and the actual PUCCH transmission, simplifying the overall system complexity.
2Adaptability or versatility
If PUCCH resources are dynamically indicated through DCI, then resource allocation flexibility is improved, but processing time and complexity increase
Solution Approach 1:
The patent utilizes the PUCCH resource indicator (PRI) field in DCI to dynamically change the parameter indicating which PUCCH resource should be used. By encoding resource selection information in this field, the system achieves flexible resource allocation without requiring complex processing. The terminal simply decodes the PRI field and maps it to the corresponding PUCCH resource from the pre-configured multicast resource set, balancing flexibility with processing efficiency.
3Stability of the object's composition
If HARQ-ACK transmission is restricted when uplink timing expires, then timing synchronization is improved, but feedback reliability deteriorates
Solution Approach 1:
The patent implements a mechanism where the terminal autonomously checks its uplink timing status before transmitting HARQ-ACK feedback. If the timing has expired, the terminal automatically performs timing alignment procedures (such as sending a random access preamble) to re-synchronize before transmitting the feedback. This self-service approach maintains timing synchronization stability while ensuring feedback reliability is not compromised, as the terminal proactively resolves timing issues before they affect feedback transmission.
Data Source
AI summary
Disclosed herein is a terminal configured to acquire a configuration for at least one PUCCH resource set associated with at least one downlink multicast channel, monitor a PDCCH in a search space for scheduling of a specific downlink multicast channel, and detect, as a result of the monitoring of the PDCCH, DCI having a CRC scrambled with a specific G-RNTI, wherein a specific PUCCH resource set associated with the specific downlink multicast channel may be mapped to a specific downlink frequency band having the search space for the monitoring of the PDCCH, wherein a PUCCH resource for transmission of HARQ-ACK for the specific downlink multicast channel among one or more PUCCH resources included in the specific PUCCH resource set may be indicated through the DCI.