Multi-PCell URLLC Design Against Fading and Interference

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Solution Overview

Problem

Existing wireless communication systems face challenges in achieving ultra-reliable and low-latency communications (URLLC) due to the susceptibility of primary serving cells to fading and interference, which can lead to radio link failures, especially in multi-cell environments.

Innovation Solution

User equipment evaluates the signal strength of both the primary cell and secondary cells jointly before connecting, utilizing reference signals from multiple transmission points to enhance reliability in multi-cell communication scenarios.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the UE connects to a single PCell in a multi-cell environment, then the connection setup is simplified and RRC management is easier, but the reliability of communication deteriorates due to susceptibility to fading and interference

Engineering Contradiction:
Improveconnection setup simplicityVSAvoidcommunication reliability
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent combines multiple cells (PCell and SCells) into a unified multi-cell communication system where the UE simultaneously communicates with multiple transmission points. This merging of multiple communication paths resolves the contradiction by maintaining connection simplicity through unified RRC management while improving reliability through diverse signal paths that resist fading and interference on any single cell.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent segments the communication connection into multiple independent cell connections (PCell and multiple SCells). Each cell provides an independent communication path, so if one cell experiences fading or interference, other segments maintain the connection. This segmentation resolves the contradiction by distributing risk across multiple segments while keeping overall connection management coordinated.

Inventive Principle:
Principle #1Segmentation

2Reliability

If the UE uses reference signals from multiple cells for evaluation, then the reliability of connection selection improves, but the complexity of signal evaluation and measurement increases

Engineering Contradiction:
Improveconnection selection reliabilityVSAvoidsignal evaluation complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies universal reference signal structures and evaluation criteria across all cells (PCell and SCells). The same reference signal types and measurement procedures are used for all cells, allowing the UE to evaluate multiple cells using a unified framework. This universality resolves the contradiction by enabling multi-cell evaluation without proportionally increasing complexity, as the same tools and methods apply to each cell.

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

Solution Approach 2:

The patent performs preliminary evaluation of multiple cells using reference signals before the UE commits to a connection. The UE measures and compares reference signals from PCell and candidate SCells in advance, identifying suitable cells for multi-cell communication before actual data transmission begins. This preliminary action resolves the contradiction by establishing reliable connections through advance evaluation, reducing the need for complex real-time decision-making during operation.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP3804199B1Multi-pcell design for urllc reliability
Publication Date: 2025.09.03 QUALCOMM INC
  • EP3804199B1 patent drawingFigure 1
  • EP3804199B1 patent drawingFigure 2
  • EP3804199B1 patent drawingFigure 3

AI summary

Aspects of the present disclosure provide a mechanism for improving reliability in a wireless communication network supporting a multi-cell transmission environment including a primary cell (PCell) and one or more secondary cells (SCells). In some examples, a user equipment (UE) in a connected mode with a PCell for multi-cell communication with the PCell and one or more SCells may utilize link quality measurements on both the PCell and one or more SCells to manage the connection with the PCell. In other examples, one or more SCells may function as a PCell to transmit common control signaling to the UE and/or receive uplink control information from the UE. In other examples, a UE in an idle mode may evaluate the reference signals transmitted from the PCell and one or more potential SCells before deciding whether to connect to the PCell for multi-cell communication.