Aperiodic Tracking Reference Signal Trigger Mechanism

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Solution Overview

Problem

Wireless communication systems face inefficiencies and synchronization issues due to the use of periodic reference signals, which are not always active, leading to partial desynchronization between user equipment (UE) and base stations, especially during UE mobility and time/frequency shifts.

Innovation Solution

The implementation of an aperiodic tracking reference signal (TRS) mechanism, where a trigger signal is used to activate the transmission of TRS based on triggering events, such as beam changes or DRX mode changes, allowing for dynamic resource allocation and synchronization without continuous resource occupancy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If periodic reference signals are used for synchronization tracking, then time/frequency tracking capability is maintained, but resource wastage increases and system throughput decreases

Engineering Contradiction:
Improvesynchronization tracking capabilityVSAvoidresource wastage
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The patent implements periodic reference signals that are transmitted only during configured periods rather than continuously. The network device configures the UE with specific periodicity for TRS transmission, allowing the system to maintain tracking capability during active periods while conserving resources during inactive periods. This resolves the contradiction by making the reference signal transmission periodic rather than continuous.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The patent introduces dynamic activation and deactivation of periodic reference signals based on network conditions and UE requirements. The network can activate periodic TRS when tracking is needed and deactivate it when not needed, making the system adaptive to changing conditions. This dynamic approach allows the system to maintain reliability when necessary while reducing resource wastage when not needed.

Inventive Principle:
Principle #15Dynamics

2Reliability

If always on reference signal configuration is used, then synchronization is maintained continuously, but channel occupancy time increases and system throughput is reduced

Engineering Contradiction:
Improvesynchronization maintenanceVSAvoidsystem throughput
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent replaces always-on reference signals with periodic reference signals that are transmitted only during configured periods. The UE is configured with specific periodicity parameters, allowing synchronization to be maintained at regular intervals rather than continuously. This frees up channel resources during inactive periods for other data transmissions, thereby increasing system throughput while maintaining adequate synchronization.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The patent extracts the reference signal transmission from a continuous always-on state and confines it to specific periodic intervals. By taking out the reference signal from continuous transmission and placing it in periodic bursts, the system maintains synchronization capability while reducing channel occupancy time and freeing resources for productive data transmissions.

Inventive Principle:
Principle #2Taking out (Extraction)

3Productivity

If periodic reference signals are not activated, then resource allocation is optimized, but UE and base station become partially out of synchronization

Engineering Contradiction:
Improveresource allocation efficiencyVSAvoidsynchronization alignment
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent configures the UE with periodic reference signal parameters in advance through RRC signaling, including periodicity, offset, and duration parameters. This preliminary configuration allows the UE to know when to expect reference signals and when to perform tracking, enabling efficient resource allocation while maintaining synchronization alignment. The network can activate or deactivate these pre-configured periodic signals based on actual needs.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent implements a feedback mechanism where the UE measures the periodic reference signals and reports channel state information back to the network. This feedback loop allows the network to assess synchronization quality and adjust the activation/deactivation of periodic reference signals accordingly, maintaining synchronization alignment while optimizing resource allocation based on actual channel conditions.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP3738253B1Aperiodic tracking reference signal
Publication Date: 2024.03.13 QUALCOMM INC
  • EP3738253B1 patent drawingFigure 1
  • EP3738253B1 patent drawingFigure 2
  • EP3738253B1 patent drawingFigure 3

AI summary

Methods, systems, and devices for wireless communications are described. A base station may determine that a triggering event associated with a user equipment (UE) has occurred. The UE may receive, based at least in part on an occurrence of a triggering event associated with the UE, a trigger signal that identifies resources to be used for transmission of an aperiodic tracking reference signal (TRS). The UE may receive the aperiodic TRS based at least in part on the trigger signal and the identified resources. The UE may perform at least one of a tracking function, or a synchronization function, or an alignment function, or a combination thereof, in response to the occurrence of the triggering event and based at least in part on the aperiodic TRS.