Distributed D2D Synchronization Resource Allocation

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Solution Overview

Problem

In densely populated device-to-device (D2D) communication systems, synchronization channel resources are heavily reused, leading to interference and erroneous timing and frequency measurements, which reduces the ability of user equipment (UEs) to decode information effectively.

Innovation Solution

The proposed solution involves a distributed D2D synchronization protocol that allocates synchronization channel resources on a slower time scale and includes a beacon period, a paging period, and a timing information block (TIB) broadcast period, allowing UEs to transmit synchronization signals, request timing information, and indicate resource congestion or availability of better timing structures, thereby optimizing resource allocation and reducing interference.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If synchronization channel resources are heavily reused in densely populated D2D systems, then resource utilization efficiency is improved, but interference increases and measurement precision deteriorates

Engineering Contradiction:
Improveresource utilization efficiencyVSAvoidtiming and frequency measurement accuracy
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The synchronization protocol is segmented into distinct periods (beacon period, paging period, TIB broadcast period) with different resource allocation strategies. During the beacon period, resources are reused for synchronization signals, while during the TIB broadcast period, resources are protected from interference through selective transmission based on decoding success, thus segmenting the harmful reuse effect to specific periods where it is tolerable.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system implements periodic synchronization operations with a defined synchronization period containing multiple phases. UEs perform synchronization signal transmission and information decoding at specific periodic intervals. This periodic structure allows resource reuse during beacon periods while protecting measurement accuracy during TIB broadcast periods through conditional transmission mechanisms.

Inventive Principle:
Principle #19Periodic action

2Adaptability or versatility

If multiple UEs transmit in multiple broadcast resources simultaneously, then information exchange capability is improved, but interference increases and reliability deteriorates

Engineering Contradiction:
Improveinformation exchange capabilityVSAvoiddecoding reliability
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The system implements feedback-based transmission control where UEs monitor the synchronization channel for successfully decoded TIB messages from other UEs. If a UE detects that another UE has successfully decoded the TIB, it provides implicit feedback by not transmitting its own TIB in the same resources, thereby avoiding interference and ensuring reliable reception for other UEs in the group.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

Different UEs are assigned different transmission behaviors based on local conditions - specifically, whether they have successfully decoded the TIB message. UEs that successfully decode the TIB refrain from transmitting in the TIB broadcast period, while those that fail to decode transmit their TIB. This local quality differentiation ensures that at least one UE in each resource set can successfully receive the information without interference.

Inventive Principle:
Principle #3Local quality

3Use of energy by moving object

If synchronization resources are allocated on a slow time scale, then energy consumption is reduced, but adaptability to dynamic conditions deteriorates

Engineering Contradiction:
Improvebattery expenditureVSAvoidadaptability to dynamic conditions
Core Design Contradiction:
Use of energy by moving objectVSAdaptability or versatility

Solution Approach 1:

The system combines slow-time-scale resource allocation with dynamic transmission control. Resources are allocated periodically on a slow time scale to reduce overhead and energy consumption. However, within each synchronization period, UEs dynamically adjust their transmission behavior based on real-time decoding outcomes - successfully decoded UEs remain silent while failed UEs transmit, providing adaptability to dynamic channel conditions without requiring frequent resource reallocation.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP3097729B9Method and apparatus for resource allocation for distributed device to device synchronization
Publication Date: 2024.05.22 QUALCOMM INC
  • EP3097729B9 patent drawingFigure 1
  • EP3097729B9 patent drawingFigure 2
  • EP3097729B9 patent drawingFigure 3

AI summary

A method, an apparatus, and a computer program product for wireless communication are provided in connection with improving resource allocation for distributed D2D synchronization in densely populated communications systems. In an example, a communications device is equipped to transmit a synchronization signal during a beacon period of a synchronization channel. In an aspect, the synchronization channel may include the beacon period, a paging period, and a TIB period. The communications device may further be equipped to monitor at least one of the beacon period, the paging period, or the TIB period of the synchronization channel for one or more signals from one or more UEs in a D2D network, and determine whether to transmit information during at least one of the beacon period, the paging period, or the TIB period based at least in part on the monitoring.