HARQ Feedback Transmission via Downlink Shared Channel

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Solution Overview

Problem

In communication systems, especially in LTE and NR, terminal devices face challenges in distinguishing data reception status due to implicit feedback methods, leading to unnecessary protocol processing delays and competition failures when multiple devices transmit on the same uplink resource.

Innovation Solution

A method and terminal device that explicitly indicate uplink data feedback using a downlink data channel, combining feedback information for multiple terminal devices and carrying it through MAC Control Elements or Protocol Data Units, reducing overhead and enabling clear ACK/NACK indications.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of substance

If implicit feedback method using NDI in Uplink grant is used, then feedback channel overhead is reduced, but terminal device cannot distinguish data reception status clearly

Engineering Contradiction:

Improvecontrol channel overheadVSAvoidfeedback information clarity

Core Design Contradiction:

Loss of substanceVSLoss of information

Solution Approach 1:

The patent combines HARQ feedback information with downlink data transmission by embedding it in the Downlink Shared Channel (DL-SCH). This merging approach allows feedback information to be transmitted without requiring separate dedicated feedback channels, thereby reducing control channel overhead while maintaining feedback functionality.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The patent uses the Downlink Shared Channel (DL-SCH) as an intermediary to carry HARQ feedback information. Instead of using dedicated feedback channels or implicit methods, the DL-SCH serves as a mediator that can explicitly convey ACK/NACK information to terminal devices, resolving the ambiguity of implicit feedback methods.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Productivity

If multiple terminal devices transmit on the same uplink resource, then resource utilization is improved, but terminal devices cannot distinguish competition failure from demodulation failure

Engineering Contradiction:

Improveresource utilizationVSAvoiddata reception status distinction

Core Design Contradiction:

ProductivityVSLoss of information

Solution Approach 1:

The patent segments feedback information by terminal device, where each terminal device receives dedicated ACK/NACK feedback corresponding to its specific uplink transmission. This segmentation allows terminal devices to clearly distinguish their own data reception status even when multiple devices transmit on the same uplink resource, differentiating between competition failures and demodulation failures.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent introduces explicit feedback mechanisms where the network device sends ACK/NACK information back to terminal devices through the DL-SCH. This feedback enables terminal devices to determine whether their uplink transmission was successfully received, resolving the ambiguity caused by multiple devices sharing the same uplink resource.

Inventive Principle:

Principle #23Feedback

3Loss of information

If dedicated feedback channel PHICH is used, then feedback information clarity is improved, but control channel overhead increases

Engineering Contradiction:

Improvefeedback information clarityVSAvoidcontrol channel overhead

Core Design Contradiction:

Loss of informationVSLoss of substance

Solution Approach 1:

The patent merges feedback information transmission with downlink data transmission by carrying HARQ feedback in the DL-SCH. This combination eliminates the need for separate dedicated feedback channels like PHICH, thereby maintaining feedback information clarity while reducing control channel overhead.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The patent makes the Downlink Shared Channel (DL-SCH) multi-functional by using it both for downlink data transmission and for carrying HARQ feedback information. This universal usage of the DL-SCH eliminates the need for dedicated feedback channels, reducing overall control channel overhead while maintaining feedback functionality.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Data Source

PatentEP3499770B1Feedback information transmission method, network device and terminal device

Publication Date: 2022.02.02 GUANGDONG OPPO MOBILE TELECOMMUNICATIONS CORP LTD

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AI summary

Provided in the embodiments of the present application are a feedback information transmission method, a network device and a terminal device, which may explicitly indicate feedback information of uplink data for the terminal device, the method comprising: a network device generates hybrid automatic repeat request (HARQ) feedback information, the HARQ feedback information comprising feedback information of uplink data of at least one terminal device; and the network device transmits the HARQ feedback information to the at least one terminal device by means of a downlink data channel.