دانلود رایگان مقاله هماهنگ سازی الگوریتم کرم شب تاب با برابرسازی نرخ فاز

Abstract

The convergence and precision of synchronization algorithms based on the theory of pulse-coupled oscillators is evaluated on programmable radios. Measurements in different wireless topologies show that such algorithms reach precisions in the low microsecond range. Based on the observation that phase rate deviation among radios is a limiting factor for the achievable precision, we propose a distributed algorithm for automatic phase rate equalization and show by experiments that an improved precision below one microsecond is possible in the given setups. It is also experimentally demonstrated that the stochastic nature of coupling is a key ingredient for convergence to synchrony. The proposed scheme can be applied in wireless systems for distributed synchronization of transmission slots, or sleep cycles.

8. Conclusions and outlook

Our experiments show that PCO algorithms can achieve convergence to synchrony with precisions below one microsecond in real-world settings. A key ingredient for stable convergence is stochastic coupling, which can be achieved by introducing the feature that synchronization packets are not always sent but only with a certain probability. A limiting factor for high precision is nonhomogeneous phase rates among radios. Hence, another key ingredient for high precision is phase rate equalization, for which a novel distributed algorithm has been proposed, integrated, demonstrated, and analyzed. These insights are important for the design and assessment of PCO algorithms. We can state that algorithms containing stochastic coupling and phase rate equalization along with an update function that combines excitatory and inhibitory coupling (as WD and IES do) are able to reach precisions that are sufficient for many applications, such as timing of sleep cycles and transmission slots, while they are still conceptually simple and completely distributed.