Multicast HARQ-ACK Feedback via Group-RNTI PDCCH Monitoring
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Solution Overview
Problem
Current wireless communication systems face inefficiencies in performing wireless signal transmission and reception procedures, particularly in efficiently managing multicast services and reducing latency and overhead in hybrid automatic repeat request (HARQ) acknowledgments.
Innovation Solution
A method and apparatus for a user equipment (UE) to monitor a physical downlink control channel (PDCCH) for a specific multicast service, receive downlink control information (DCI) scrambled with a group-RNTI, repeatedly receive transport blocks (TB) in a multicast frequency part, and transmit hybrid automatic repeat request acknowledgement (HARQ-ACK) on a physical uplink control channel (PUCCH) resource indicated by the DCI, allowing for efficient multicast service delivery and reduced latency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If transport blocks are repeatedly transmitted for multicast services, then reliability is improved, but latency increases
Solution Approach 1:
The system performs preliminary actions by pre-configuring the UE with multicast service parameters, search space configurations, and PUCCH resource allocations before actual data transmission. This preparation enables faster response and reduced latency when multicast data needs to be transmitted, while still maintaining the necessary repetition for reliability.
2Reliability
If HARQ-ACK is transmitted after every TB repetition, then reliability is improved, but PUCCH overhead increases
Solution Approach 1:
The invention extracts the HARQ-ACK feedback transmission from occurring after every single TB repetition and instead consolidates it to be transmitted only after the final repetition. This removes unnecessary feedback transmissions while maintaining the reliability benefits of repeated transmissions, thereby reducing PUCCH overhead significantly.
3Productivity
If search space is located in multicast frequency part, then multicast service efficiency is improved, but interference with active frequency part increases
Solution Approach 1:
The system segments the frequency resources by maintaining distinct active frequency parts and multicast frequency parts. The search space for multicast services is configured in the multicast frequency part, allowing multicast operations to proceed efficiently without interfering with ongoing unicast transmissions in the active frequency part. This spatial segmentation resolves the interference issue while preserving multicast service efficiency.
Data Source
AI summary
A terminal according to an embodiment of the present disclosure may: monitor a PDCCH in a search space for a specific multicast service to be received so as to receive downlink control information (DCI) in which a CRC is scrambled by a specific RNTI; repeatedly receive a TB related to the specific multicast service on a multicast frequency part on the basis of the DCI; and transmit, after repetition of the TB, an HARQ-ACK indicating a result of decoding of the TB through a PUCCH resource indicated by the DCI, wherein the specific RNTI is a group-RNTI (G-RNTI) associated with the specific multicast service that the terminal is to receive.