Over-the-Air Dynamic TDD with Uplink-Multiplexed Channel Use Indicators

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Solution Overview

Problem

Existing wireless communication systems face interference issues due to uncoordinated access to shared radio frequency spectrum, leading to increased signaling overhead and latency, particularly in dynamic time division duplex (TDD) operations.

Innovation Solution

Implementing a dynamic TDD operation with channel use indicators multiplexed in uplink transmissions to manage UE-to-UE interference, eliminating the need for dedicated clear-to-send bursts and reducing overhead by integrating channel use indicators with scheduled uplink regions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If dedicated clear-to-send bursts are used for channel usage indication, then interference management between UEs is achieved, but signaling overhead and latency increase

Engineering Contradiction:
Improveinterference managementVSAvoidsignaling overhead and latency
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent combines the channel usage indication function with existing uplink transmission resources. Instead of using separate dedicated clear-to-send bursts, the channel use indicator is multiplexed with scheduled uplink regions, merging two functions into a single transmission resource, thereby reducing signaling overhead and latency while maintaining interference management capability

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The uplink transmission resources are designed to serve multiple purposes: they carry both data transmissions and channel use indicators simultaneously. This multi-functionality eliminates the need for dedicated resources solely for channel indication, reducing overall signaling overhead while maintaining the ability to manage UE-to-UE interference effectively

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

2Productivity

If dynamic TDD operations are implemented in shared spectrum, then network capacity and flexibility are improved, but UE-to-UE interference increases

Engineering Contradiction:
Improvenetwork capacity and flexibilityVSAvoidUE-to-UE interference
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

The patent implements a feedback mechanism where UEs transmit channel use indicators in uplink regions to inform other UEs about their transmission status. This feedback allows receiving UEs to adjust their operations and avoid causing or suffering from interference, enabling dynamic TDD to operate effectively in shared spectrum while managing UE-to-UE interference

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The channel use indicators are transmitted in advance within scheduled uplink regions before potential interference scenarios occur. This preliminary indication allows other UEs to prepare appropriate interference mitigation actions, enabling dynamic TDD operations to maintain high network capacity while preventing harmful interference through proactive coordination

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP3756412B1Over the air dynamic TDD with channel usage indicator-receive multiplexed in ul
Publication Date: 2025.10.01 QUALCOMM INC
  • EP3756412B1 patent drawingFigure 1
  • EP3756412B1 patent drawingFigure 2
  • EP3756412B1 patent drawingFigure 3

AI summary

Over-the-air (OTA) dynamic time division duplex (TDD) is disclosed with a channel use indicator (CUI) receiver (CUI-R) signal multiplexed in uplink transmissions. According to various aspects, a user equipment (UE) may receive a downlink grant from a serving base station, in which the downlink grant identifies downlink transmissions in one or more subsequent communication slots. The UE may identify a trigger for transmission of a channel usage signal associated with the grant that may be received by neighboring UEs that may potentially interfere. The UE transmits the channel usage signal in a next scheduled uplink region and then receives downlink data from the serving base station according to the downlink grant. If the neighboring UE receives a conditional uplink grant, then it may proceed with uplink transmissions when it fails to detect the channel usage signal from the UE.