NR-U SSB Position Signaling for Accurate Shared-Spectrum Measurement

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Solution Overview

Problem

In the NR-U system, the uncertainty of channel usage rights on unlicensed spectrum leads to incorrect SSB measurement results due to unpredictable SSB positions caused by LBT failures, which affects frame synchronization and QCL relationships among SSBs.

Innovation Solution

A method where a network device sends position indication information to a terminal device, using a bitmap or bit representation to specify SSB position indexes within a measurement window, ensuring accurate SSB measurement by indicating quasi-co-located SSBs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the network device sends SSB on candidate positions based on LBT results, then the system can adapt to unlicensed spectrum channel availability, but the terminal device cannot correctly determine SSB positions leading to measurement errors

Engineering Contradiction:

Improvechannel usage adaptabilityVSAvoidSSB measurement accuracy

Core Design Contradiction:

Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The network device pre-configures multiple candidate SSB positions and sends position indication information in advance to tell the terminal which candidate position will actually be used. This preliminary action allows the terminal to prepare for measurement at the correct position without knowing the LBT result beforehand, resolving the contradiction between adapting to channel availability and enabling accurate measurement.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

Position indication information acts as an intermediary between the network device's LBT decision and the terminal device's measurement action. The position indication information carries the actual SSB position index, bridging the gap between the network's channel access decision and the terminal's measurement timing, ensuring the terminal can accurately locate and measure the SSB regardless of LBT outcomes.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Measurement precision

If the network device uses bitmap to indicate SSB positions, then the position indication is precise, but the signaling overhead increases

Engineering Contradiction:

Improveposition indication accuracyVSAvoidsignaling overhead

Core Design Contradiction:

Measurement precisionVSLoss of information

Solution Approach 1:

Instead of using a full bitmap to indicate all possible SSB positions, the network device uses a compressed representation that only indicates the necessary position information. The position indication information contains just enough data to identify the actual SSB position among candidates, providing precise location information while avoiding the overhead of a complete bitmap for all possible positions.

Inventive Principle:

Principle #16Partial or excessive action

Data Source

PatentUS12389447B2Information processing method for shared spectrum, terminal device, and network device

Publication Date: 2025.08.12 GUANGDONG OPPO MOBILE TELECOMMUNICATIONS CORP LTD

AI summary

Disclosed is an information processing method, comprising: a terminal device receives position indication information sent from a network device, at least one bit of the position indication information indicating a first set comprising at least one synchronization signal block (SSB) position index, and the position indication information indicating the position where SSB measurement needs to be performed in a measurement window. Also disclosed are an information processing method, a terminal device, a network device, and a storage medium.