ESTIMATION OF THE 3R REGENERATION SECTION LENGTH OF THE OPTICAL SYSTEM WITH POLARISATION MULTIPLEXING

Abstract

The development of a digital society is directly linked to the continuous improvement and expansion of telecommunications networks. The modern world is in the process of a significant transition to the digital paradigm, where information and communication have become the basis for further development. Today, fibre-optic transmission systems (FOTS) provide reliable real-time communication and are the core of transport and access networks. In modern optical transport systems, a combination of several methods is used to increase the spectral efficiency of the optical signal. This paper presents the results of studying the quality characteristics of the digital channel of an OTH FOCS with a transmission rate of 264 Gbps and QAM-16 modulation. It is known that in fiber-optic networks, the signal quality is affected not only by the additive noise of optical amplifiers, but also by linear (attenuation and dispersion) and nonlinear signal distortions in the optical fibre. Therefore, this paper also investigates the effect of signal power on the error probability in an optical channel. To obtain reliable results, a corresponding simulation model of the transmission system was developed in MatLab, On the basis of the mathematical model of the signal processing. In order to reduce the length of the test sequence of symbols and the requirements for the algorithm's computing resources, the value of the error vector magnitude EVM and the corresponding bit error probability BER were determined from the output sequence of KAM-16 symbols. It was shown that when a flexible decision decoder (SD-FEC) is used in the receiver, the length of the 3R regeneration section of the optical channel is about 1600 km.