PCell-Triggered Reference Signals for SCell Activation

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Solution Overview

Problem

Existing wireless communication systems face challenges in efficiently activating secondary serving cells (SCells) in multi-cell transmission environments, particularly in coordinating multi-TRP transmissions across different radio access technologies, which can impact user experience and throughput.

Innovation Solution

A mechanism is introduced where a primary serving cell (PCell) triggers the communication and processing of reference signals with a secondary serving cell (SCell) using a medium access control - control element (MAC-CE), enabling synchronization and activation of the SCell through beam sweeping and acknowledgement information, allowing for coordinated multi-point (CoMP) network configurations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a PCell triggers reference signal communication with an SCell using MAC-CE for SCell activation, then the activation process is enhanced and synchronization is improved, but the device complexity and coordination overhead increase due to multi-TRP coordination requirements

Engineering Contradiction:
Improvetransmission reliabilityVSAvoidcoordination complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent introduces a MAC-CE (Medium Access Control - Control Element) as an intermediary mechanism that enables the PCell to trigger reference signal communication with the SCell. This intermediary control structure facilitates coordinated multi-TRP transmissions by providing a standardized interface for activation commands, thereby improving transmission reliability while managing coordination complexity through protocol-level abstraction

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If beam sweeping and acknowledgement information are used for SCell activation, then synchronization accuracy is improved, but the activation time and processing delay increase

Engineering Contradiction:
Improvesynchronization accuracyVSAvoidactivation time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent implements preliminary beam sweeping operations before formal SCell activation. By performing beam management and synchronization procedures in advance through the MAC-CE triggered reference signal communication, the system prepares the SCell for rapid activation, thereby achieving high synchronization accuracy while minimizing the actual activation time when data transmission begins

Inventive Principle:
Principle #10Preliminary action

3Productivity

If multiple TRPs transmit different data to a UE simultaneously, then throughput is increased, but the coordination overhead and signal processing complexity increase

Engineering Contradiction:
ImprovethroughputVSAvoidsignal processing complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent segments the multi-TRP transmission by assigning different component carriers to different TRPs (PCell and SCell). This segmentation allows each TRP to transmit different data streams on dedicated carriers, increasing overall throughput while simplifying signal processing at the UE through carrier-specific processing rather than complex spatial multiplexing across all carriers

Inventive Principle:
Principle #1Segmentation

4Productivity

If carrier aggregation is performed across multiple component carriers for multi-TRP transmission, then data rate is improved, but the device complexity and resource management overhead increase

Engineering Contradiction:
Improvedata rateVSAvoidresource management complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent implements a universal MAC-CE control mechanism that functions across multiple component carriers and different RATs (Radio Access Technologies). This multi-functional control structure allows the same activation and coordination procedures to be applied universally across PCell and SCell regardless of carrier frequency or RAT type, thereby enabling carrier aggregation for higher data rates while reducing resource management complexity through standardized control procedures

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

Data Source

PatentEP4026268B1Triggering reference signals in wireless networks
Publication Date: 2025.08.27 QUALCOMM INC
  • EP4026268B1 patent drawingFigure 1
  • EP4026268B1 patent drawingFigure 2
  • EP4026268B1 patent drawingFigure 3

AI summary

Aspects provide a mechanism for activating a secondary serving cell (SCell) in a wireless communication network supporting a multi-cell transmission environment. In some examples, a scheduled entity (e.g., a UE) in a connected mode with a primary serving cell (PCell) may synchronize with the SCell to activate the SCell for multi-cell communication with the PCell and the SCell. To enable synchronization with the SCell, the PCell may trigger communication and processing of one or more reference signals between the scheduled entity and the SCell.