ESTIMATION OF QUALITY PARAMETERS OF OPTICAL TRANSMISSION SYSTEM WITH POLARIZATION MULTIPLEXING

Abstract

Rapid development of the Internet requires operators to constantly expand their networks and increase their bandwidth. On the segment of subscriber access networks, a gradual transition from networks based on a copper cable to an optical fiber is carried out. Therefore, the problem of increasing the speed of fiber-optic transmission systems, which is the basis of transport network networks, is always urgent. Achievement of the set goal in modern fiber systems is carried out by constructing them on a multi-channel principle. The transmission of optical signals in each channel is possible with any type of modulation. One of the simple methods for increasing the spectral efficiency is the polarization multiplexing of the channel signals. The influence of the optical signal parameters and the configuration of the linear path on the quality characteristics of the channel of the fiber transmission system (Q-factor) is studied in the article. A comparison is made between the two types of optical signal modulation that are common today: intensity and QPSK with polarization separation (DP-QPSK). For a system with intensity modulation, a comparison is made between the results of calculations for analytical expressions and simulation simulations. Comparison of the data obtained proved that a smaller quantity Q-factor corresponds to the simulation, as this takes into account the transition and transmission characteristics of the transmission system of functional units, and non-linear distortion of the signal in the optical fiber. Comparison of the simulation results with intensity modulation and DP-QPSK proved the advantages of the latter type of modulation, since it allows to increase the length of the linear path by about two times (from 5 to 10 sections).