Multiplexing CBG and TB Feedback to Reduce Redundant Retransmissions
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Solution Overview
Problem
Current wireless communication systems face inefficiencies in resource utilization due to redundant retransmissions of code block groups (CBGs) when some CBs within a transport block (TB) are successfully received while others are not, leading to wasteful ACK/NACK feedback.
Innovation Solution
The proposed solution involves multiplexing CBG-level and TB-level feedback, allowing for balanced utilization of communication resources by selecting appropriate feedback signaling arrangements based on available resources and network conditions, thereby reducing redundant retransmissions and optimizing resource use.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If TB-level feedback is used, then the feedback signaling is simple and resource overhead is low, but redundant retransmissions occur when some CBs are successfully received while others are not
Solution Approach 1:
The patent segments the feedback mechanism into two levels: TB-level feedback for overall transport block acknowledgment and CBG-level feedback for specific code block group acknowledgment status. This segmentation allows the system to send TB-level NACK only when necessary (when CBG-level feedback indicates partial failure), reducing redundant retransmissions while maintaining manageable signaling complexity through hierarchical structure.
Solution Approach 2:
The patent dynamically selects between TB-level and CBG-level feedback modes based on transmission conditions and channel state. When channel conditions are good and full TB transmission is successful, TB-level ACK is sent; when partial failures occur, CBG-level feedback is activated to provide granular acknowledgment, optimizing the balance between signaling overhead and retransmission efficiency.
2Productivity
If CBG-level feedback is used, then redundant retransmissions are reduced, but communication resources increase compared to TB-level feedback
Solution Approach 1:
The patent applies partial action by selectively using CBG-level feedback only for the specific CBGs that require acknowledgment, rather than sending full CBG-level feedback for all CBGs in every transmission. This partial feedback approach reduces communication resource consumption while still achieving the goal of minimizing redundant retransmissions by focusing feedback only where needed.
3Productivity
If a feedback signaling arrangement is selected to balance TB-level and CBG-level feedback, then resource utilization is optimized, but signaling complexity increases
Solution Approach 1:
The patent performs preliminary action by pre-configuring feedback signaling arrangements and determining the appropriate feedback mode (TB-level or CBG-level) before actual data transmission. This advance determination includes pre-establishing the mapping between CBGs and feedback resources, so that when feedback is needed, the system can quickly select the appropriate pre-determined arrangement without complex real-time decision-making, thus optimizing resource utilization while managing signaling complexity.
Data Source
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AI summary
Methods, systems, and devices for multiplexing code block group (CBG) level and transport block (TB) level feedback are described. An example method includes receiving a set of TBs, generating a bit sequence providing CBG-level feedback on a first subset of the TBs and TB-level feedback on at least a second subset of the TBs, and transmitting the bit sequence. Another example method includes transmitting a set of TBs, receiving a bit sequence providing CBG-level feedback on a first subset of the TBs and TB-level feedback on at least a second subset of the TBs, and retransmitting at least one CBG for each TB in the first subset of TBs and the second subset of TBs based at least in part on the bit sequence.