D2D Synchronization Using Peer Relays and Feedback Control
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Solution Overview
Problem
Device-to-device (D2D) communication networks face challenges in achieving reliable time and frequency synchronization without centralized infrastructure, particularly in decentralized environments where satellite-based synchronization may be unreliable and temperature-induced frequency drift affects local oscillators.
Innovation Solution
A tiered synchronization system where devices act as synchronization masters, relays, and slaves, using internal clocks and peer-based synchronization, and a control loop that corrects for measurement noise and temperature-based frequency drift, allowing for accurate frequency synchronization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If satellite-based synchronization is used in decentralized D2D networks, then time and frequency synchronization can be achieved, but reliability deteriorates in environments where satellite signals are unavailable or unreliable
Solution Approach 1:
The patent introduces peer devices as intermediary synchronization sources. When satellite-based synchronization is unavailable, devices select other D2D devices as temporary synchronization masters, allowing synchronization to continue through intermediate devices rather than directly from satellites. This mediator approach maintains reliability in decentralized environments where satellite signals are blocked or unreliable.
Solution Approach 2:
The patent implements self-service synchronization where devices autonomously select and switch between synchronization sources without centralized control. Devices monitor signal quality from multiple potential masters and independently switch to alternative masters when current masters become unreliable, enabling the system to maintain synchronization reliability through self-managed adaptation to environmental conditions.
2Device complexity
If internal clocks are used for synchronization in D2D devices, then device complexity is reduced, but frequency drift occurs due to temperature variations
Solution Approach 1:
The patent implements feedback-based frequency correction where devices continuously monitor frequency offsets from their selected synchronization master and adjust their internal clock frequencies accordingly. This closed-loop feedback mechanism compensates for temperature-induced drift by detecting frequency errors and applying corrective adjustments, maintaining synchronization accuracy despite using simple internal oscillators.
Solution Approach 2:
The patent dynamically adjusts operational parameters of the internal oscillator based on environmental conditions and measured frequency offsets. By changing the oscillator frequency parameter in response to temperature variations and drift measurements, the system maintains accurate synchronization without requiring complex hardware while adapting to changing physical conditions.
3Reliability
If a tiered synchronization system with multiple roles (masters, relays, slaves) is implemented, then synchronization reliability improves in decentralized networks, but device complexity increases
Solution Approach 1:
The patent implements dynamic role assignment where devices can transition between master, relay, and slave roles based on current network conditions and signal quality. Rather than fixed roles, devices adapt their synchronization function dynamically, selecting masters and becoming relays when appropriate. This dynamic behavior maintains reliability by optimizing the synchronization topology for current conditions while managing complexity through role flexibility rather than rigid structure.
Data Source
AI summary
A wireless device includes a radio transceiver, and a digital transmitter configured to transmit, via the radio transceiver, a first data symbol, and to transmit, via the radio transceiver, a repetition of the first data symbol immediately after the first data symbol, where the first data symbol forms a cyclic prefix for the repetition of the first data symbol.