Preamble Synchronization Signal for Unlicensed Band Reliability

Solution Overview

Problem

User equipment (UE) devices may not receive adequate synchronization information in unlicensed frequency bands, especially when Discovery Reference Signals (DRS) are interfered with or not received in time for data transmission, leading to synchronization issues in secondary cells (Scell) that are not aligned with primary cells (Pcell).

Innovation Solution

The evolved Node B (eNB) transmits a preamble signal with synchronization information based on the licensed frequency band's timing structure before data transmission in the unlicensed frequency band, using a sequence similar to the Primary Synchronization Signal (PSS) and Secondary Synchronization Signal (SSS) to align communication events and provide synchronization to UE devices.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the eNB uses Discovery Reference Signals (DRS) for synchronization in the unlicensed frequency band, then timing information is provided to UE devices, but the synchronization information may be interfered with or not received in time for data transmission

Engineering Contradiction:

Improvesynchronization information deliveryVSAvoidinterference to DRS

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The eNB transmits a preamble signal containing synchronization information before the actual data transmission in the unlicensed frequency band. This preliminary transmission of synchronization information ensures that UE devices have the necessary timing alignment before receiving data, even when DRS transmissions are interfered with or delayed.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent introduces a preamble signal as an intermediary element between the DRS and the data transmission. This preamble serves as a preliminary synchronization mechanism that bridges the gap when DRS fails to provide adequate synchronization, ensuring timing alignment is established before data reception.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Productivity

If the eNB transmits data in the unlicensed frequency band without ensuring adequate synchronization, then data transmission can proceed, but UE devices experience synchronization issues in secondary cells

Engineering Contradiction:

Improvedata transmission efficiencyVSAvoidtiming alignment between Pcell and Scell

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The eNB transmits a preamble signal containing synchronization information before the actual data transmission in the unlicensed frequency band. This preliminary transmission of synchronization information ensures that UE devices have the necessary timing alignment before receiving data, even when DRS transmissions are interfered with or delayed.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent modifies the timing structure by introducing a preamble signal with specific synchronization sequences (similar to PSS and SSS) that are transmitted before data. This changes the temporal parameters of the transmission, ensuring proper timing alignment is established prior to data reception in the secondary cell.

Inventive Principle:

Principle #35Parameter changes

3Reliability

If the eNB transmits a preamble signal with synchronization information before data transmission, then UE devices can obtain necessary synchronization information, but additional signaling overhead is introduced

Engineering Contradiction:

Improvesynchronization information deliveryVSAvoidsignal transmission overhead

Core Design Contradiction:

ReliabilityVSQuantity of substance

Solution Approach 1:

The patent transmits only the essential synchronization information in the preamble signal before data transmission, rather than transmitting complete synchronization data continuously. This partial transmission approach provides just enough synchronization information needed for reliable data reception without excessive overhead.

Inventive Principle:

Principle #16Partial or excessive action

Solution Approach 2:

The patent modifies the timing structure by introducing a preamble signal with specific synchronization sequences (similar to PSS and SSS) that are transmitted before data. This changes the temporal parameters of the transmission, ensuring proper timing alignment is established prior to data reception in the secondary cell.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS10362546B2Preamble synchronization signal in unlicensed frequency band

Publication Date: 2019.07.23 KYOCERA CORP

AI summary

An eNB transmits a preamble signal including synchronization information before transmitting data in an unlicensed band where the synchronization information is in accordance with a licensed frequency band communication standard used in a primary cell (Pcell) provided by the eNB. The preamble signal is transmitted in accordance with a timing structure used in the Pcell using the licensed frequency band. The eNB provides a secondary cell (Scell) that has a service area that at least partially overlaps with a service area of the Pcell. The preamble signal provides synchronization information to a user equipment (UE) device for the Scell.