Feedback Window Segmentation for Early Multi-TTI Feedback

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Solution Overview

Problem

Conventional feedback techniques in wireless communications systems are deficient in providing early feedback for transmissions in multi-TTI grants and slot aggregation, leading to inefficient use of resources and increased retransmission latency.

Innovation Solution

Implementing a feedback window that allows for early feedback within a set of consecutive transmission time intervals, enabling the reallocation of resources and reducing retransmission latency by permitting earlier retransmissions when necessary.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of time

If conventional feedback techniques are used in multi-TTI grants and slot aggregation, then feedback is provided only after the last TTI, but this leads to increased retransmission latency and inefficient resource utilization

Engineering Contradiction:
Improveretransmission latencyVSAvoidfeedback mechanism complexity
Core Design Contradiction:
Loss of timeVSDevice complexity

Solution Approach 1:

The feedback mechanism is segmented into multiple feedback windows distributed across different TTIs within the multi-TTI grant. Instead of a single feedback window after the last TTI, feedback windows are created at intermediate points, allowing earlier feedback transmission and reducing retransmission latency without fundamentally changing the overall feedback mechanism structure

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Feedback windows are established in advance within the multi-TTI grant structure, allowing the receiver to transmit feedback earlier than conventional techniques. This preliminary action enables the transmitter to receive acknowledgment or negative acknowledgment before the multi-TTI grant period ends, reducing waiting time and enabling faster retransmission scheduling

Inventive Principle:
Principle #10Preliminary action

2Productivity

If feedback is provided only after the last TTI of a set of consecutive TTIs, then the feedback mechanism is simple, but resource allocation efficiency decreases and retransmission latency increases

Engineering Contradiction:
Improveresource allocation efficiencyVSAvoidfeedback delay
Core Design Contradiction:
ProductivityVSLoss of time

Solution Approach 1:

The feedback mechanism transitions from a static, single-point feedback window to a dynamic structure with multiple feedback windows at different time points within the multi-TTI grant. This allows the system to adapt feedback timing based on transmission needs, enabling earlier feedback when beneficial while maintaining the original simple structure when not needed

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

Multiple feedback windows are introduced within the multi-TTI grant, creating intermediate feedback opportunities. This allows the receiver to send feedback earlier in the transmission process, enabling the transmitter to make scheduling decisions sooner and improving overall resource allocation efficiency without requiring a complete redesign of the feedback mechanism

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP4246846B1Feedback window to provide early feedback for transmissions in a set of consecutive transmission time intervals
Publication Date: 2025.09.10 QUALCOMM INC
  • EP4246846B1 patent drawingFigure 1
  • EP4246846B1 patent drawingFigure 2
  • EP4246846B1 patent drawingFigure 3

AI summary

Methods, systems, and devices for wireless communications are described. A user equipment (UE) may receive an indicator of a feedback window that is offset relative to a beginning transmission time interval (TTI) of a set of consecutive TTIs. The consecutive TTIs may include a set of aggregated slots or may correspond to a multi-TTI grant. The feedback window may include multiple control channel occasions interspersed within a duration of the set of consecutive TTIs. The UE may receive a transport block within a first TTI of the set of consecutive TTIs and transmit, within a control channel, feedback to indicate whether the transport block was successfully received.