Downlink Assignment Indicator Design for 5G Uplink Control Overhead Reduction

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Solution Overview

Problem

In 5G-NR systems, the current definition of Downlink Assignment Indicator (DAI) leads to increased uplink control overheads and misunderstandings between base stations and user equipment regarding the number of bits for feedback response information, affecting system performance.

Innovation Solution

A new DAI design is introduced, where the first indication information corresponds to a counter DAI and the second to a total DAI, indicating the accumulative and total number of downlink data channels with different data content, allowing for efficient feedback and reducing misunderstandings.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the current definition of DAI is used to dynamically determine the number of bits of feedback response information, then the terminal can adaptively adjust feedback based on downlink assignments, but uplink control overheads are significantly increased

Engineering Contradiction:
Improvedynamic feedback adjustmentVSAvoiduplink control overhead
Core Design Contradiction:
Adaptability or versatilityVSQuantity of substance

Solution Approach 1:

The patent segments the DAI information into two separate fields: counter DAI (indicating accumulative number of downlink data channels) and total DAI (indicating total number of downlink data channels). This segmentation allows the terminal to determine feedback bit length more efficiently by comparing these two values, avoiding the need to use excessive bits for dynamic adjustment while maintaining adaptability.

Inventive Principle:
Principle #1Segmentation

2Extent of automation

If the current definition of DAI is used, then dynamic HARQ-ACK multiplexing is enabled, but misunderstandings between base station and UE regarding the number of bits of feedback response information occur

Engineering Contradiction:
Improvedynamic HARQ-ACK multiplexingVSAvoidfeedback bit interpretation consistency
Core Design Contradiction:
Extent of automationVSReliability

Solution Approach 1:

The patent introduces a feedback mechanism where the terminal determines the number of feedback bits by comparing the counter DAI value with the total DAI value. This comparison-based approach provides a clear, unambiguous rule for both base station and terminal to interpret feedback bit length, eliminating misunderstandings while maintaining dynamic multiplexing capabilities.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent changes the parameters used for DAI representation from a single-field approach to a two-field approach (counter DAI and total DAI). This parameter change enables both the base station and terminal to consistently interpret the feedback bit length based on the relationship between these two parameters, ensuring reliability in dynamic multiplexing scenarios.

Inventive Principle:
Principle #35Parameter changes

3Quantity of substance

If the accumulative number and total number of downlink data channels are indicated separately, then uplink control overheads are saved, but the complexity of DAI design increases

Engineering Contradiction:
Improveuplink control overheadVSAvoidDAI design complexity
Core Design Contradiction:
Quantity of substanceVSDevice complexity

Solution Approach 1:

The patent makes the two DAI fields (counter DAI and total DAI) serve multiple functions: they not only indicate the accumulative and total numbers of downlink data channels but also jointly determine the feedback bit length through their relationship. This multi-functionality reduces the need for separate indication fields, thereby saving uplink control overhead while managing design complexity through unified field usage.

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

Data Source

PatentEP3648391B1Information transmission method and device
Publication Date: 2021.08.04 GUANGDONG OPPO MOBILE TELECOMMUNICATIONS CORP LTD
  • EP3648391B1 patent drawingFigure 1~2
  • EP3648391B1 patent drawingFigure 3~4
  • EP3648391B1 patent drawingFigure 5~6

AI summary

Embodiments of the present application provide an information transmission method, an apparatus, and a terminal. The method includes: a terminal receives first configuration information, and determining, based on the first configuration information, that multiple time units are used to transmit one downlink data channel in at least one carrier; and the terminal receives first downlink control information, where the first downlink control information carries first indication information and/or second indication information, where the first indication information is used to indicate an accumulative number of downlink data channels received by the terminal that have different data content and/or an accumulative number of DCI indicating downlink SPS resource release, and the second indication information is used to indicate a total number of downlink data channels received by the terminal that have different data content and/or a total number of DCI indicating downlink SPS release.