Multicast Feedback via Shared Uplink Control Channel Resources
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current wireless communication systems face inefficiencies in multicast transmissions due to the lack of channel information for UEs receiving multicast data, leading to reduced reliability and efficiency, as they cannot adapt transmission parameters to individual UE conditions, and fail to support HARQ feedback reporting effectively.
Innovation Solution
Implementing shared uplink control channel resources for multicast-enabled UEs to transmit acknowledgment feedback based on measured channel state information, allowing the base station to determine channel conditions and adapt retransmissions accordingly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If shared uplink control channel resources are used for multicast feedback, then resource efficiency is improved, but measurement precision and feedback accuracy may deteriorate
Solution Approach 1:
The patent segments the uplink control channel resources into multiple subsets, where each subset is associated with specific channel state information types (e.g., CSI-RS resources, precoding matrix indices, channel quality indicators). This segmentation allows different UEs to transmit feedback on different subsets, preventing collisions while maintaining shared resource efficiency.
Solution Approach 2:
The patent introduces an intermediary mechanism where the base station provides indications of which uplink control channel resources should be used for feedback based on measured channel state information. This intermediary coordination allows UEs to select appropriate resources without direct conflict, maintaining both efficiency and accuracy.
2Device complexity
If multicast transmissions are performed without individual UE channel information, then transmission complexity is reduced, but reliability deteriorates
Solution Approach 1:
The patent implements feedback mechanisms where UEs transmit acknowledgment feedback messages indicating whether they successfully received multicast data. The base station uses this feedback information to determine which UEs require retransmission, enabling reliable communication while maintaining multicast simplicity.
Solution Approach 2:
The patent performs preliminary channel state information measurements by the base station before multicast transmissions. This preliminary action allows the base station to configure appropriate uplink control channel resources and anticipate channel conditions, improving reliability without increasing transmission complexity.
3Device complexity
If acknowledgment feedback is transmitted on shared resources, then device complexity is reduced, but information loss may increase
Solution Approach 1:
The patent segments feedback information into different types (acknowledgment feedback, channel state information) and assigns them to different uplink control channel resource subsets. This segmentation ensures that acknowledgment feedback is transmitted reliably without being lost in the shared resource pool, while keeping UE complexity low.
Solution Approach 2:
The base station acts as an intermediary that coordinates which UEs transmit on which resource subsets based on their channel state information. This intermediary coordination ensures complete feedback information delivery while requiring minimal complexity at the UE level.
Data Source
AI summary
Methods, systems, and devices for wireless communications are described. A set of uplink control channel resources that are configured for acknowledgment transmissions may be shared among user equipments (UEs) that are enabled to receive multicast communications. Each of the shared set of uplink control channel resources may be associated with set(s) of channel state information. UEs may measure a multicast channel to determine channel state information for the multicast channel. After failing to receive a multicast transmission, UEs may transmit an acknowledgment feedback message over one of the shared uplink control channel resources that is associated with the set of channel state information determined by the UE. A base station that receives the acknowledgment feedback message may transmit a multicast retransmission for the UEs using transmission parameters that are adapted for the set(s) of channel state information associated with the occupied uplink control channel resource.