Default Physical Cell Identification for Multi-TRP Processing

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Solution Overview

Problem

In wireless communication networks, determining the appropriate physical cell identification (PCI) for multiple transmission-reception points (TRPs) when communicating with user equipment (UE) is unclear, leading to inefficiencies in bit scrambling and signal processing.

Innovation Solution

The UE and base station employ layer 1 or layer 2 signaling to indicate a selected subset of PCIs associated with a subset of TRPs, establishing communication channels, and determining default PCIs for physical processing when explicit IDs are not signaled, using methods such as anchor cell, lowest/highest PCI rules, or targeted PCIs for bit scrambling, DMRS sequence determination, and time/frequency hopping patterns.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If multiple TRPs are used to communicate with the UE, then communication capacity and reliability are improved, but it becomes unclear which PCI to use for bit scrambling and signal processing

Engineering Contradiction:
Improvecommunication reliabilityVSAvoidPCI determination complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent introduces TCI states as an intermediary mechanism to resolve the PCI ambiguity. The base station configures multiple TCI states, each associated with one or more PCIs, and signals the UE which TCI state to use for physical processing. This intermediary structure allows multiple TRPs to be used while providing clear PCI guidance for scrambling and signal processing operations.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent segments the PCI configuration into multiple TCI states, where each TCI state can be associated with different PCIs. This segmentation allows the system to handle multiple TRPs by dividing the PCI space into distinct, manageable groups, each tied to specific beam directions or TRPs, thereby reducing the complexity of determining which PCI to use.

Inventive Principle:
Principle #1Segmentation

2Measurement precision

If explicit PCI configuration is provided for each TRP, then signal processing accuracy is improved, but signaling overhead and processing complexity increase

Engineering Contradiction:
Improvesignal processing accuracyVSAvoidsignaling overhead
Core Design Contradiction:
Measurement precisionVSQuantity of substance

Solution Approach 1:

The patent makes TCI states multi-functional by allowing a single TCI state configuration to serve multiple purposes: indicating the active TRP, specifying the PCI for bit scrambling, and providing beam direction information. This multi-functionality reduces the need for separate explicit PCI configuration signaling for each TRP, thereby reducing overhead while maintaining processing accuracy.

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

Solution Approach 2:

The patent merges the TRP identification function with the PCI configuration function into the TCI state structure. Instead of separately signaling which TRP is active and which PCI to use, the TCI state combines both pieces of information, reducing the total quantity of signaling elements required while maintaining the precision needed for accurate signal processing.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP4140247B1Determining physical cell identification
Publication Date: 2025.07.02 QUALCOMM INC
  • EP4140247B1 patent drawingFigure 1
  • EP4140247B1 patent drawingFigure 2
  • EP4140247B1 patent drawingFigure 3

AI summary

Aspects of the present disclosure include methods, apparatuses, and computer readable media for receiving a layer 1 signaling or a layer 2 signaling indicating a subset of a plurality of physical cell identifications (PCIs) associated with a plurality of serving cells in the network, establishing a plurality of communication channels with one or more of transmission-reception points (TRPs), wherein each TRP of the one or more TRPs comprises a corresponding PCI of the plurality of PCIs, and determining one or more PCIs of the plurality of PCIs used as one or more default input cell identifications (IDs) associated with a plurality of physical processings, when no explicit configured input ID is signaled to the UE associated with the plurality of physical processings.