Terminal Device QCL Reference Signal Switching

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Solution Overview

Problem

In telecommunications, during cross-component carrier (CC) or bandwidth part (BWP) switching, terminal devices face challenges in obtaining large-scale properties from the indicated transmission configuration indicator (TCI) state when the CC ID or BWP ID is absent, leading to difficulties in using reference signals as quasi co-location (QCL) references for downlink transmissions.

Innovation Solution

The method involves determining a time duration for using a first reference signal as a QCL reference, measuring a second reference signal in a new frequency part, and subsequently using the second signal for communication, allowing the terminal device enough time to obtain new properties and stabilize measurements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the terminal device uses the first reference signal from the first frequency part as QCL reference signal immediately after switching, then communication can continue without interruption, but the measurement precision and reliability of the QCL properties will be insufficient

Engineering Contradiction:

Improvereliability of QCL reference signalVSAvoidtime duration for measurement

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The terminal device performs measurements on the second reference signal in the second frequency part before actually switching to use it as the QCL reference signal. This preliminary measurement action allows the device to prepare the necessary channel properties in advance, ensuring reliable communication after switching without interrupting the ongoing communication using the first reference signal.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent introduces a dynamic switching mechanism where the terminal device transitions from using the first reference signal to the second reference signal as QCL reference over a determined time duration. This dynamic approach allows the system to adapt to frequency part switching while maintaining communication reliability by gradually transitioning the reference signal source based on measurement completeness.

Inventive Principle:

Principle #15Dynamics

2Speed

If the terminal device switches to the second frequency part immediately, then frequency part switching speed is improved, but the terminal device cannot obtain accurate large scale properties from the TCI state

Engineering Contradiction:

Improveswitching speedVSAvoidmeasurement precision of reference signal

Core Design Contradiction:

SpeedVSMeasurement precision

Solution Approach 1:

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent allows the terminal device to quickly switch frequency parts by determining a time duration for using the first reference signal, during which the device can rapidly transition while measurements are being performed in the background. This enables fast switching without waiting for complete measurements, as the device can rush through the switching process with a determined time duration.

Inventive Principle:

Principle #21Skipping (Rushing through)

3Loss of information

If the TCI state configuration does not include CC ID or BWP ID, then signaling overhead is reduced, but the terminal device cannot correctly identify the QCL reference signal source

Engineering Contradiction:

Improvesignaling overheadVSAvoidease of identifying QCL reference signal

Core Design Contradiction:

Loss of informationVSEase of operation

Solution Approach 1:

The terminal device autonomously determines the time duration for using the first reference signal as QCL reference and independently performs measurements on the second reference signal. This self-service mechanism allows the device to handle the frequency part switching and QCL reference signal identification without requiring additional network signaling, thereby reducing signaling overhead while maintaining operational capability.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The patent introduces an intermediary time duration mechanism that mediates between the old and new reference signals during frequency part switching. This time duration acts as an intermediary period where the terminal device can transition from using the first reference signal to the second reference signal, allowing correct identification of the QCL reference signal source without requiring explicit CC ID or BWP ID signaling.

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS20250007598A1Method, device and computer readable medium for communications

Publication Date: 2025.01.02 NEC CORP

AI summary

Embodiments of the present disclosure relate to methods, devices and computer readable media for communications. A method implemented at a terminal device comprises in response to switching to a second frequency part, determining a time duration for the terminal device to use a first reference signal received from a network device in a first frequency part as a Quasi Co-location (QCL) reference signal. The terminal device performs communication with the network device before the time duration ends based on a first set of properties obtained by measuring at least the first reference signal. The method also comprises obtaining, within the time duration, a second set of properties by measuring at least a second reference signal received from the network device in the second frequency part, the second reference signal and the first reference signal having a first identification. The method also comprises performing, after the time duration, communication in the second frequency part with the network device based on the second set of properties by using the second reference signal as the QCL reference signal.