UE-Specific Synchronization Signals for Direct D2D Discovery

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Solution Overview

Problem

Current user equipment lacks the ability to discover other user equipment for device-to-device communication without network mediation, especially in scenarios like emergency situations where network availability is compromised.

Innovation Solution

A method for device discovery in device-to-device communication is provided, where user equipment generate and transmit UE-specific synchronization signals, such as UE-specific primary and secondary synchronization signals, to indicate availability for D2D communication, allowing auto-correlation by receiving UE for timing estimation and channel quality assessment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If user equipment communicate via network-mediated paths, then communication reliability is maintained through network control, but communication efficiency and resource utilization deteriorate due to additional network elements in the path

Engineering Contradiction:
Improvecommunication reliabilityVSAvoidcommunication efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent extracts the communication path from the network-mediated route by enabling direct device-to-device communication. User equipment can establish direct wireless links for data transmission, separating the communication function from network infrastructure while maintaining network control for signaling and resource management.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The network acts as an intermediary for control and signaling functions rather than for data transmission. The network provides synchronization signals, resource allocation, and coordination, while actual data communication occurs directly between devices, reducing network load and improving efficiency.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If user equipment discover each other through network assistance, then discovery reliability is improved, but device complexity and signaling overhead increase

Engineering Contradiction:
Improvediscovery reliabilityVSAvoiddiscovery mechanism complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The network pre-configures user equipment with synchronization signal parameters, resource allocations, and discovery procedures before device discovery begins. This preliminary configuration simplifies the discovery process by providing ready-to-use templates and reducing real-time decision complexity.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

User equipment copies and transmits network synchronization signals for discovery purposes. Instead of creating entirely new discovery mechanisms, devices replicate existing network signals, simplifying the discovery process while maintaining reliability through proven signal structures.

Inventive Principle:
Principle #26Copying

3Measurement precision

If synchronization signals are generated using Zadoff-Chu sequences, then signal quality and auto-correlation properties are improved, but sequence selection and management complexity increases

Engineering Contradiction:
Improvetiming estimation precisionVSAvoidsequence management complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent manages Zadoff-Chu sequence complexity by parameterizing sequence selection based on device identity, cell ID, and synchronization signal index. These parameters dynamically determine which sequences to use, reducing the need for complex manual configuration while maintaining optimal auto-correlation properties for timing estimation.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP2891377B1Device discovery for device-to-device communication
Publication Date: 2019.04.10 ALCATEL LUCENT SA
  • EP2891377B1 patent drawingFigure 1
  • EP2891377B1 patent drawingFigure 2~3
  • EP2891377B1 patent drawingFigure 4

AI summary

Embodiments of the claimed subject matter provide a method and apparatus for device discovery in device-to-device (D2D) communication. One embodiment of the method includes generating first information indicative of a first synchronization signal in response to a request from a first user equipment to be authenticated for D2D communication with one or more second user equipment. The first information corresponds to a sequence used to generate a primary synchronization signal for transmission by a serving cell for the first user equipment. This embodiment of the method also includes providing the first information to the first user equipment so that the first user equipment can transmit the first synchronization signal.