ACK/NACK Feedback Transmission Using Dynamic and Semi-Static Channel Resources

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Solution Overview

Problem

In LTE-A systems, the existing methods for transmitting ACK/NACK feedback information using PUCCH Format 1b with channel selection lead to increased retransmissions and reduced throughput due to ambiguity in ACK/NACK mapping tables, especially when dynamic channel resources are used, and excessive resource overhead when semi-static channel resources are used alone.

Innovation Solution

A method where user equipment determines and transmits response information using a combination of dynamic and semi-static channel resources, optimizing the allocation of M candidate channel resources to improve system performance and throughput by selecting identification information to characterize the response information on both types of resources.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of substance

If dynamic channel resources are used for ACK/NACK transmission, then resource overhead is reduced, but mapping ambiguity increases leading to retransmissions

Engineering Contradiction:
Improveresource overheadVSAvoidmapping accuracy
Core Design Contradiction:
Loss of substanceVSReliability

Solution Approach 1:

The patent segments the channel resources into two distinct types: dynamic channel resources and semi-static channel resources. This segmentation allows the system to use dynamic resources for their intended purpose while introducing semi-static resources specifically for resolving mapping ambiguities, thereby maintaining low overall overhead while improving reliability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The semi-static channel resources act as an intermediary mechanism between the dynamic channel resources and the ACK/NACK mapping process. By providing predetermined, stable reference resources, they mediate the ambiguity issue without requiring changes to the existing dynamic resource allocation framework.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If semi-static channel resources are used for ACK/NACK transmission, then mapping accuracy is improved, but resource overhead increases

Engineering Contradiction:
Improvemapping accuracyVSAvoidresource overhead
Core Design Contradiction:
ReliabilityVSLoss of substance

Solution Approach 1:

The patent applies partial action by using semi-static channel resources only when necessary for resolving mapping ambiguities, rather than replacing all dynamic resources. This selective approach improves mapping accuracy where needed while avoiding the excessive resource overhead that would result from universal semi-static resource allocation.

Inventive Principle:
Principle #16Partial or excessive action

3Adaptability or versatility

If dynamic channel resources are used, then resource flexibility is maintained, but system throughput decreases due to retransmissions

Engineering Contradiction:
Improveresource flexibilityVSAvoidsystem throughput
Core Design Contradiction:
Adaptability or versatilityVSProductivity

Solution Approach 1:

By segmenting resources into dynamic and semi-static categories, the system maintains the flexibility benefits of dynamic resources while adding the reliability benefits of semi-static resources. This segmentation enables the system to adapt to varying conditions without suffering from mapping-induced retransmissions that would reduce throughput.

Inventive Principle:
Principle #1Segmentation

4Device complexity

If a unified ACK/NACK mapping table is used for both across-carrier and non-across-carrier scenarios, then standard complexity is reduced, but channel resource requirements increase

Engineering Contradiction:
Improvestandard complexityVSAvoidchannel resources
Core Design Contradiction:
Device complexityVSQuantity of substance

Solution Approach 1:

The patent implements a universal ACK/NACK mapping table that functions across both across-carrier and non-across-carrier scheduling scenarios. This multi-functional approach reduces standard complexity by eliminating the need for separate mapping tables, while the introduction of semi-static channel resources compensates for any additional resource requirements.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentEP2568647B1Response message transmission method, base station, and user equipment
Publication Date: 2015.06.03 CHINA ACAD OF TELECOMM TECH
  • EP2568647B1 patent drawingFigure 1~2
  • EP2568647B1 patent drawingFigure 3~4
  • EP2568647B1 patent drawingFigure 5A~6A

AI summary

Disclosed are a response message transmission method, a base station, and a user equipment (UE), to achieve an improved system performance while taking into account the system resource overhead. The method comprises: the UE confirming K bit of response message awaiting feedback; the UE confirming M number of channel resources awaiting selection, the M number of channel resources awaiting selection comprising J number of dynamic channel resources and N number of semi-static channel resources, wherein M=(J+N), 0=N=M, (M-N)=L=M, and M, L, and N are integers; the UE selecting at least one channel resource from the M number of channel resources, and selecting a piece of identification information for use in characterizing the response message awaiting feedback; on each of the selected channel resources, the UE transmitting the selected identification information for use in characterizing the response message awaiting feedback. Employment of the technical solution of the present invention allows to a certain degree an improved system performance and system throughput, while at the same time taking into account the system resource overhead.