Device-to-Device Synchronization Using Pulse-Coupled Oscillators
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Solution Overview
Problem
Device-to-device communication systems face challenges in synchronization, particularly when devices cannot access a synchronous eNB or GPS, leading to difficulties in establishing and maintaining synchronization, especially in areas with limited or no network coverage, which hinders efficient data exchange and traffic management.
Innovation Solution
The method employs oscillators with the same phase increase rate for synchronization, using a Pulse-Coupled Oscillator (PCO) algorithm to adjust synchronization phase values based on received signals, allowing devices to synchronize without relying on external references like GPS or eNB, and different synchronization algorithms for connected and unconnected states to minimize data exchange disruptions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If devices use GPS or synchronous eNB for synchronization, then synchronization accuracy is improved, but device accessibility and coverage area are reduced
Solution Approach 1:
The patent introduces a synchronization signal as an intermediary that enables devices to achieve synchronization without directly accessing GPS or synchronous eNB. The synchronization signal acts as a mediator that carries timing information between devices, allowing them to synchronize their oscillators indirectly through received signals rather than requiring direct access to external synchronization sources.
Solution Approach 2:
Devices perform self-synchronization by using their own local oscillators and adjusting them based on received synchronization signals from other devices. Each device independently adjusts its phase and frequency without requiring external control, enabling autonomous synchronization in areas where GPS or synchronous eNB are unavailable.
2Speed
If devices instantly adjust synchronization phase upon receiving signals, then synchronization speed is improved, but data exchange stability is reduced
Solution Approach 1:
The patent implements dynamic synchronization adjustment where devices adapt their synchronization behavior based on their operational state. In connected state, devices use gradual accumulative adjustment to maintain stability, while in unconnected state, they can perform faster adjustments. This dynamic approach allows the system to optimize between speed and stability depending on current conditions.
Solution Approach 2:
The patent applies partial adjustment rather than complete instantaneous adjustment. Devices accumulate phase adjustment values over time and apply them gradually, performing partial adjustments that balance the need for synchronization speed with the need to maintain data exchange stability during connected operations.
Data Source
AI summary
A method and an apparatus for synchronization for a device-to-device communication are disclosed. The method includes: instantly adjusting a synchronization phase value according to a time point when a synchronization signal is received, as soon as a device receives the synchronization signal from an adjacent device in an unconnected state; accumulatively storing at least one phase adjustment value according to a time point when at least one synchronization signal is received, whenever the device receives the at least one synchronization signal from at least one adjacent device in a connected state; and adjusting the synchronization phase value according to the stored at least one phase adjustment value when the device transitions from the connected state to the unconnected state.