Uplink Downlink Grant Acknowledgment Feedback Resource Determination

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

In wireless communication systems, the reliability of acknowledgment transmissions is hindered by the need for blind decoding of feedback resources, which consumes resources and increases time due to uncertainty in the location or amount of feedback, especially when both uplink and downlink grants are transmitted in the same time interval.

Innovation Solution

A method where a base station transmits both uplink and downlink grants in the same transmission time interval, with an indication of the downlink grant included in the uplink grant, allowing the user equipment to determine feedback resources and transmit acknowledgments using specific subsets of uplink resources, reducing the need for blind decoding by the base station.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the base station monitors multiple feedback resources to determine acknowledgment feedback, then the reliability of feedback reception is improved, but the base station requires more blind decoding operations which consume computational resources and time

Engineering Contradiction:
Improvefeedback reception reliabilityVSAvoidblind decoding complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies preliminary action by having the UE determine feedback resources before transmission based on pre-configured rules involving downlink grant indicators and uplink grant indicators. This allows the base station to know in advance where feedback will be transmitted, eliminating the need for blind decoding while maintaining reliable feedback reception

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent uses feedback mechanisms where the UE monitors downlink grants and generates acknowledgment feedback (ACK/NACK) based on successful reception. The feedback resource determination rules create a closed-loop system where the UE's feedback behavior is predictable and can be monitored efficiently by the base station without exhaustive searching

Inventive Principle:
Principle #23Feedback

2Quantity of substance

If the UE transmits feedback using resources in a shared channel, then the feedback capacity is increased, but the amount of blind decoding required to determine feedback location increases

Engineering Contradiction:
Improvefeedback capacityVSAvoidfeedback determination time
Core Design Contradiction:
Quantity of substanceVSLoss of time

Solution Approach 1:

The patent changes the parameter of feedback resource identification from unknown/variable to deterministic by introducing specific rules based on downlink grant indicators and uplink grant indicators. This allows the feedback location to be calculated rather than searched, maintaining high feedback capacity while eliminating time loss from blind decoding

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The UE performs preliminary determination of feedback resources before transmission by applying predetermined rules that consider downlink grant indicators and uplink grant indicators. This preliminary calculation establishes the feedback location in advance, allowing the base station to monitor specific resources without time-consuming blind decoding

Inventive Principle:
Principle #10Preliminary action

3Productivity

If both uplink and downlink grants are transmitted in the same time interval, then the system efficiency is improved, but the uncertainty in feedback location increases requiring more blind decoding

Engineering Contradiction:
Improvesystem efficiencyVSAvoidfeedback location uncertainty
Core Design Contradiction:
ProductivityVSDifficulty of detecting and measuring

Solution Approach 1:

The patent segments the feedback resource determination into distinct components: downlink grant indicators from downlink grants, uplink grant indicators from uplink grants, and predetermined rules that combine these indicators. This segmentation allows the base station to efficiently determine feedback locations even when multiple grants are transmitted in the same time interval, maintaining system efficiency while reducing detection difficulty

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces predetermined rules as an intermediary mechanism that translates downlink and uplink grant indicators into specific feedback resource locations. This intermediary eliminates the direct uncertainty between multiple simultaneous grants and feedback location determination, allowing efficient monitoring without increasing blind decoding requirements

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP3446424B1Techniques for acknowledgment of transmissions in a wireless communication system
Publication Date: 2022.08.17 QUALCOMM INC
  • EP3446424B1 patent drawingFigure 1
  • EP3446424B1 patent drawingFigure 2
  • EP3446424B1 patent drawingFigure 3A~3B

AI summary

A base station may provide both an uplink grant and a downlink grant in a same transmission time interval (TTI), and may provide an indication in the uplink grant that the TTI includes the downlink grant. A user equipment (UE) that receives the uplink grant may provide feedback using identified feedback resources in an uplink shared channel, and other uplink transmissions may be rate matched around the feedback resources in the uplink shared channel. A base station receiving the feedback may monitor the feedback resources to determine whether the downlink grant or one or more of the downlink transmissions were successfully received at the UE. A base station, in some examples, may monitor different sets of resources to determine whether certain of the uplink grant, downlink grant, downlink transmissions associated with the downlink grant, or any combinations thereof, have been successfully received at the UE.