A flexible approach to combating chromatic dispersion in a centralized 5G network

This article proposes and examines a solution in which the base-station for the fifth generation radio access network is simplified by using a single millimeter-wave oscillator in the central-station and distributing its millimeter-wave signal to the base-stations. The system is designed in such a way that the low-phase-noise signal generated by an opto-electronic oscillator is transmitted from the central-station to multiple base-stations via a passive optical network infrastructure. A novel flexible approach with a single-loop opto-electronic oscillator at the transmitting end and a tunable dispersion-compensation module at the receiving end(s) is proposed to distribute a power-penalty-free millimeter-wave signal in the radio access network. Power-penalty-free signal transmission from 10 MHz up to 45 GHz with an optical length of 20 km is achieved by a combination of a tunable dispersion-compensation module and an optical delay line. In addition, measurements with a fixed modulation frequency of 39 GHz and discretely incrementing optical fiber lengths from 0.625 km to 20 km are shown. Finally, a preliminary idea for an automatically controlled feedback-loop tuning system is proposed as a further research entry point.

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1. The authors would like to express their gratitude to the company InLambda BDT d.o.o. for the research equipment and devices. The work presented in this article was carried out with the financial support of the Slovenian Research Agency (research core funding No. P2-0246) and the FiWiN5G Innovative Training Network, which has received funding from the European Union’s Horizon 2020 Research and Innovation Program 2014–2018 under the Marie Skłodowska-Curie grant agreement No. 642355.

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2. Opracowanie rekordu ze środków MNiSW, umowa Nr 461252 w ramach programu "Społeczna odpowiedzialność nauki" - moduł: Popularyzacja nauki i promocja sportu (2020).