Code Block Group Segmentation for Reducing Feedback Overhead
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Solution Overview
Problem
In LTE systems, especially in 5G, the existing hybrid automatic repeat request mechanism leads to significant resource waste due to the large number of code blocks in a transport block, resulting in high feedback overheads when retransmissions are required.
Innovation Solution
The method involves puncturing a resource mapped to a transport block, replacing part of the eMBB service data with URLLC service data, and transmitting original data of specific code blocks along with indication information to reduce feedback overheads by instructing not to transmit feedback for those blocks that meet certain conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the receive end feeds back each CB that fails to be received to the transmit end, then the data pass rate is improved, but the feedback overheads increase significantly
Solution Approach 1:
The patent segments the transport block into multiple code blocks and further groups them into CB groups. By operating at the CB group level rather than individual CB level, the feedback overhead is reduced while maintaining reliable transmission. The receive end feeds back only the indices of failed CB groups, not every individual failed CB.
Solution Approach 2:
The patent applies partial action by selectively retransmitting only the failed CB groups rather than the entire TB or all CBs. This partial retransmission approach reduces feedback overhead compared to feedback-based individual CB retransmission, while still achieving good data pass rate through targeted retransmission of only the necessary portions.
2Reliability
If the transmit end retransmits the entire TB when one CB fails, then the reliability is maintained, but resource waste increases
Solution Approach 1:
The patent segments the TB into multiple CB groups, enabling selective retransmission at the CB group level. This segmentation allows the system to retransmit only the specific failed CB groups rather than the entire TB, reducing resource waste while maintaining reliability through targeted retransmission.
Solution Approach 2:
The patent applies local quality by treating different CB groups differently based on their reception status. Successful CB groups are not retransmitted, while failed CB groups are selectively retransmitted. This localized approach to retransmission optimizes resource usage by avoiding unnecessary retransmission of already successfully received data.
3Productivity
If the quantity of CBs in a TB is increased to meet larger bandwidth requirements, then the transmission capacity is improved, but the feedback overheads and resource waste become more severe
Solution Approach 1:
The patent introduces CB group segmentation as an intermediate level between individual CBs and the entire TB. This additional segmentation layer reduces feedback overhead by operating at the group level rather than individual CB level, making the system scalable to larger bandwidths and more CBs without proportionally increasing feedback overhead.
Solution Approach 2:
The patent enables partial retransmission at the CB group level, which becomes increasingly beneficial as the number of CBs increases. With more CBs in a TB, the probability of having some failed but not all failed increases, making selective CB group retransmission more efficient than full TB retransmission, while the grouped feedback mechanism keeps overhead manageable.
Data Source
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AI summary
An information transmission method and a related apparatus are provided. The method includes: transmitting, by a first device, a TB to a second device; and transmitting, to the second device before a feedback time corresponding to the TB, original data of a first CB included in the TB, where the first CB is a CB that meets a condition necessary for system bits being occupied. In this case, a waiting time for the first device to transmit the first CB is effectively shortened, and feedback overheads are reduced. Alternatively, the first device may directly transmit first indication information to the second device, and in this case, according to the first indication information, the second device may not directly transmit feedback information of the first CB, thereby effectively reducing feedback overheads. Alternatively, the first device may transmit original data of the first CB and first indication information to the second device, so that the first device can transmit the first CB to the second device in time, thereby further ensuring that feedback overheads are effectively reduced.