Segmented Code Block Feedback for Efficient Retransmission
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Solution Overview
Problem
In current LTE systems, the lack of precise feedback on correctly and incorrectly decoded code blocks leads to inefficient retransmissions, where the access network device retransmits all code blocks even if most are correctly decoded, reducing transmission efficiency.
Innovation Solution
The terminal device sends separate feedback information for each part of the transport block, allowing the access network device to retransmit only the incorrectly decoded code blocks, thereby improving transmission efficiency by preventing the retransmission of correctly decoded blocks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the terminal device sends feedback on the entire transport block (TB), then the access network device can determine which TB to retransmit, but the access network device must retransmit all code blocks even if most are correctly decoded, reducing transmission efficiency
Solution Approach 1:
The patent segments the transport block feedback into individual code block feedback. Instead of providing a single feedback bit for the entire TB, the terminal device provides separate feedback bits for each code block (CB), indicating whether each CB was correctly decoded. This segmentation allows the access network device to identify and retransmit only the specific incorrectly decoded CBs rather than retransmitting the entire TB, thus resolving the contradiction between feedback accuracy and transmission efficiency.
2Reliability
If the access network device retransmits all code blocks in the transport block, then all code blocks are ensured to be received, but unnecessary data is retransmitted including correctly decoded blocks, wasting system resources
Solution Approach 1:
The patent extracts only the necessary retransmission data by identifying which specific code blocks require retransmission. Based on the segmented feedback from the terminal device, the access network device extracts and retransmits only the incorrectly decoded CBs, leaving out the correctly decoded CBs that do not need retransmission. This extraction approach ensures data reception completeness while eliminating unnecessary retransmissions and reducing system resource waste.
3Measurement precision
If the terminal device sends separate feedback information for each part of the transport block, then the feedback information size increases, but the retransmission data size decreases significantly
Solution Approach 1:
The patent changes the parameter of feedback granularity from block-level (entire TB) to code-block-level (individual CBs). By changing this parameter, the feedback precision is improved as each CB can be individually acknowledged. Although this increases the number of feedback bits, the increase is minimal (one bit per CB) compared to the significant reduction in retransmission data volume achieved by only retransmitting incorrectly decoded CBs rather than entire TBs.
Data Source
AI summary
A feedback Information sending method and a terminal are disclosed. In an embodiment a method includes receiving, by a terminal device within a first transmission time interval (TTI), a transport block (TB) sent by an access network device, wherein the TB comprises at least two code blocks (CBs), and wherein the at least two CBs comprise a first part of the CBs and a second part of the CBs and sending, by the terminal device, first feedback information and second feedback information to the access network device when the terminal device receives the second part of the CBs within a second TTI and does not receive the first part of the CBs, wherein the first feedback information indicates whether the terminal device correctly decodes the first part of the CBs, wherein the second feedback information indicates whether the terminal device correctly decodes the second part of the CBs, and wherein the second TTI is after the first TTI in a time sequence.