Dynamic Semi-Persistent Reference Signal Activation for 5G SCell

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Solution Overview

Problem

In 5G mobile communications, the activation delay of Secondary Cells (SCells) and reduced resource utilization occur due to the periodic nature of Tracking Reference Signals (TRS), leading to inefficiencies in time-frequency tracking and resource allocation.

Innovation Solution

Implementing a cell processing method that dynamically determines and sets the transmission time of Semi-persistent Reference Signals (SP RS) to enable timely activation of SCells, using MAC CE signaling to activate both the SCell and the SP RS, ensuring the terminal device receives the SP RS in a timely manner.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a periodic TRS is used for time-frequency tracking on SCell, then tracking accuracy is improved, but activation delay increases and resource utilization decreases

Engineering Contradiction:

Improvetracking accuracyVSAvoidactivation delay

Core Design Contradiction:

Measurement precisionVSLoss of time

Solution Approach 1:

The patent applies dynamics by transitioning from a static periodic TRS transmission pattern to a dynamic aperiodic TRS transmission pattern. The network device determines TRS transmission based on SCell activation states and terminal device requests, allowing the system to adapt transmission timing to actual needs rather than following a fixed periodic schedule.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent implements preliminary action by having the network device activate the downlink SP RS in advance based on MAC CE signaling before the terminal device actually needs to perform time-frequency tracking. This ensures the reference signal is already available when the SCell activation is triggered, eliminating waiting time.

Inventive Principle:

Principle #10Preliminary action

2Measurement precision

If a periodic TRS is used for time-frequency tracking on SCell, then tracking accuracy is improved, but resource utilization decreases

Engineering Contradiction:

Improvetracking accuracyVSAvoidresource utilization

Core Design Contradiction:

Measurement precisionVSProductivity

Solution Approach 1:

The patent selectively applies periodic action only when necessary - when the SCell is in active state and time-frequency tracking is needed. When the SCell is deactivated or tracking is not required, the periodic TRS transmission is suspended, thus avoiding waste of radio resources while maintaining tracking accuracy when needed.

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

The patent changes the transmission parameter of TRS from a fixed periodic pattern to a flexible aperiodic pattern controlled by MAC CE signaling and terminal requests. This allows the system to adjust TRS transmission parameters (timing, frequency, presence) dynamically based on SCell activation state and actual tracking requirements.

Inventive Principle:

Principle #35Parameter changes

3Measurement precision

If the UE waits for the next TRS period to perform time-frequency tracking, then tracking accuracy is maintained, but activation delay increases

Engineering Contradiction:

Improvetracking accuracyVSAvoidactivation delay

Core Design Contradiction:

Measurement precisionVSLoss of time

Solution Approach 1:

The patent introduces MAC CE signaling as an intermediary mechanism that bridges the gap between SCell activation and TRS availability. The MAC CE signaling triggers both SCell activation and downlink SP RS activation simultaneously, ensuring the reference signal becomes available immediately without waiting for the next periodic TRS occasion.

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS11337269B2Cell processing method, terminal device, and network device

Publication Date: 2022.05.17 VIVO MOBILE COMM CO LTD

AI summary

A cell processing method, a terminal device and a network device are provided. The cell processing method includes: sending MAC CE signaling to a terminal device, wherein the MAC CE signaling is used to activate an SCell; activating a downlink SP RS based on the MAC CE signaling; sending the downlink SP RS to the terminal device according to a transmission time of the downlink SP RS, wherein the downlink SP RS is used by the terminal device to activate the SCell.