Flexible Response Indication for HARQ Code Block Groups

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Solution Overview

Problem

In communications systems using code block groups (CBGs) for data transmission, the existing response indication methods lack flexibility, leading to a poor balance between indication precision and resource efficiency, particularly in hybrid automatic repeat request (HARQ) processes.

Innovation Solution

The proposed solution involves using different indication manners for responses sent at different times to indicate the transmission results of target data, allowing for flexible adjustment of response indications to ensure precision while reducing transmission resources, by varying the number and arrangement of indication bits and data blocks indicated by each bit.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a single response indication manner is used for all transmissions, then the system is simple to implement, but the flexibility and adaptability of the response indication method is poor

Engineering Contradiction:
Improveflexibility of response indication mannerVSAvoidcomplexity of response indication method
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent implements dynamic response indication by allowing the receiving device to select from multiple indication manners (full indication, partial indication, or no indication) based on the actual transmission scenario and channel conditions. This dynamic selection mechanism enables the system to adapt flexibly to different situations without requiring a completely fixed complex structure for all possible scenarios.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent applies local quality by allowing different indication manners to be used for different code block groups (CBGs) within the same transmission. Specifically, the receiving device can selectively indicate which CBGs were received correctly and which require retransmission, rather than applying a uniform indication method to all CBGs. This localized differentiation improves overall system flexibility.

Inventive Principle:
Principle #3Local quality

2Measurement precision

If more indication bits are used in the response payload, then the indication precision is improved, but the transmission resources of the response increase

Engineering Contradiction:
Improveindication precision of the responseVSAvoidtransmission resources of the response
Core Design Contradiction:
Measurement precisionVSQuantity of substance

Solution Approach 1:

The patent implements partial indication by allowing the receiving device to send only the necessary portion of feedback information based on actual needs. When full retransmission is required, minimal indication is sent; when only specific CBGs need retransmission, selective indication is sent. This partial action approach provides sufficient indication precision for each scenario while minimizing the total transmission resources consumed by responses.

Inventive Principle:
Principle #16Partial or excessive action

Solution Approach 2:

The patent changes the parameter of indication bit quantity dynamically based on the transmission scenario. The receiving device adjusts the number of indication bits in the response payload according to factors such as channel conditions, transmission importance, and which specific CBGs were received correctly. This parameter adjustment enables the system to maintain adequate indication precision while reducing unnecessary transmission overhead.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If the entire TB is retransmitted when a small part is received incorrectly, then the transmission reliability is maintained, but the transmission resources are wasted

Engineering Contradiction:
Improvetransmission reliabilityVSAvoidtransmission resources
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The patent divides the transport block (TB) into multiple code block groups (CBGs) and implements independent indication and retransmission for each CBG. When only certain CBGs are received incorrectly, the receiving device sends selective indication for those specific CBGs, and the sending device retransmits only the indicated CBGs rather than the entire TB. This segmentation approach maintains transmission reliability for affected segments while significantly reducing retransmission resource consumption.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP3691167B1Communication method and device
Publication Date: 2022.07.20 HUAWEI TECH CO LTD
  • EP3691167B1 patent drawingFigure 1~2
  • EP3691167B1 patent drawingFigure 3A
  • EP3691167B1 patent drawingFigure 3B

AI summary

A communication method and a communications device are disclosed. In this solution, a first device in a communications system separately sends, to a second device, responses used to indicate a transmission result of target data: a first response and a second response, wherein an indication manner of the first response is different from an indication manner of the second response. This solution can improve flexibility of a response indication manner. Therefore, the communications system can flexibly adjust indication manners of responses sent at different times to ensure indication precision of the responses while reducing transmission resources of the responses.