Alexandros Pollakis

Technische Universität Dresden | TUD · Communications Laboratory

Self-organized synchronization occurs in a variety of natural and technical systems but has so far only attracted limited attention as an engineering principle. In distributed electronic systems, such as antenna arrays and multi-core processors, a common time reference is key to coordinate signal transmission and processing. Here we show how the se...

Experimental data file. S1_File.zip. (ZIP)

Components of electronic networks can be orchestrated using a common time reference. For instance, antenna arrays in massive multiple-input multiple-ouput (MIMO) applications require synchronous carrier frequencies for all antennas. We show that mutually coupled digital phase-locked loops (DPLLs) can self-organize to provide frequency-synchronous c...

For next-generation wireless networks, massive multiple-input multiple-output (MIMO) promises significant performance gains compared to today's wireless communication standards. In this paper, we address the challenge of how to synchronize the carrier signals of all antenna units in a large network. We show that mutually coupled digital phase-locke...

Electronic components that perform tasks in a concerted way rely on a common time reference. For instance, parallel computing demands synchronous clocking of multiple cores or processors to reliably carry out joint computations. Here, we show that mutually coupled phase-locked loops (PLLs) enable synchronous clocking in large-scale systems with tra...

Modern cellular communication systems facilitate fine-grained resource allocation that can opportunistically exploit the time variations and frequency selectivity of mobile channels by exploiting multi-user diversity. However, extracting such benefits requires the scheduler to have accurate channel state information (CSI). Channel estimation in the...