Direct Control Resource Synchronization for D2D Communication

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Solution Overview

Problem

In device-to-device communication, multiple unsynchronized transmissions of control signaling lead to increased power consumption, complexity, and interference due to the need for multiple reception windows and overlapping signals, making it difficult to receive weak messages amidst strong ones.

Innovation Solution

The method involves synchronizing Direct Control resources, allowing multiple DC messages to be received within the same reception window by assigning and negotiating resources between radio nodes, which reduces the need for multiple reception windows and simplifies receiver implementation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If multiple unsynchronized reception windows are used to receive control signaling from multiple devices, then the probability of receiving all messages is improved, but device power consumption increases and receiver complexity increases

Engineering Contradiction:
Improvemessage reception reliabilityVSAvoiddevice power consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The system performs preliminary synchronization of transmission timing among multiple transmitting devices before actual data transmission. By pre-aligning the transmission schedules and using synchronization signals, all devices transmit in coordinated time slots, allowing the receiver to use a single reception window instead of multiple windows, thereby reducing power consumption while maintaining reliable reception

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system employs feedback mechanisms where transmitting devices receive synchronization information from reference signals or network coordination, and adjust their transmission timing accordingly. This feedback loop ensures all transmitters align their timing with the receiver's expected reception window, enabling single-window reception and reducing the need for frequent wake-ups

Inventive Principle:
Principle #23Feedback

2Reliability

If multiple unsynchronized reception windows are used to receive control signaling, then message reception reliability is improved, but receiver complexity increases due to multiple FFT processes

Engineering Contradiction:
Improvemessage reception reliabilityVSAvoidreceiver complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

Transmitting devices perform preliminary timing synchronization using reference signals or network-provided synchronization information before data transmission. This pre-alignment ensures all control signaling messages arrive within a single expected reception window, eliminating the need for multiple parallel FFT processes and reducing receiver complexity to a single FFT operation

Inventive Principle:
Principle #10Preliminary action

3Use of energy by moving object

If Discontinuous Reception (DRX) is used to reduce power consumption, then energy efficiency is improved, but message reception reliability deteriorates when transmissions are unsynchronized

Engineering Contradiction:
Improveenergy efficiencyVSAvoidmessage reception reliability
Core Design Contradiction:
Use of energy by moving objectVSReliability

Solution Approach 1:

The system establishes preliminary transmission timing synchronization among all devices before DRX operation begins. By pre-coordinating transmission schedules and using synchronization signals, all control signaling messages are guaranteed to arrive within known time windows, allowing devices to confidently enter sleep mode between windows and wake only when needed, thus maintaining both low power consumption and high reception reliability

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

Synchronization feedback mechanisms provide transmitting devices with timing information from reference signals or network coordination, ensuring all transmissions are aligned to the receiver's DRX wake-up schedule. This feedback ensures no messages are missed during DRX sleep periods while maintaining energy efficiency

Inventive Principle:
Principle #23Feedback

4Productivity

If spectrum is shared between cellular and device-to-device services, then spectrum efficiency is improved, but interference increases

Engineering Contradiction:
Improvespectrum efficiencyVSAvoidinterference
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

The system segments the shared spectrum resources by allocating specific time slots, frequency resources, or spatial beams for device-to-device communication versus cellular communication. Through synchronization and resource coordination, D2D transmissions occur in dedicated segments that avoid conflicting with cellular uplink or downlink transmissions, reducing interference while maintaining high overall spectrum utilization

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system dynamically coordinates resource allocation between cellular and D2D services based on real-time traffic conditions. When cellular traffic is low, more resources are allocated to D2D communications, and vice versa. This dynamic resource management allows flexible sharing of spectrum while maintaining acceptable interference levels through coordinated scheduling

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP3200539B1A method and wireless device for providing device-to-device communication
Publication Date: 2020.09.23 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
  • EP3200539B1 patent drawingFigure 1~3
  • EP3200539B1 patent drawingFigure 4~5a
  • EP3200539B1 patent drawingFigure 5b~5c

AI summary

The present disclosure relates to methods and to a wireless device, 10, 20, for enabling device-to-device communication. In particular the present disclosure relates to a method, performed in a radio node, of assigning resources for direct control signalling. The method comprises receiving, S1, from at least one further radio node, 160, sets of resources for direct control signalling in a respective cell or cluster. The method further comprises assigning, S2, resources for direct control signalling transmission within an area controlled by the radio node based at least on the received sets of resources, and transmitting, S3, to wireless devices controlled by the radio node, a message indicating resources assigned for direct control signalling. The disclosure also relates to the corresponding method in a wireless device and to a radio and to a wireless device implementing the methods, as well as to corresponding computer programs.