INCREASING THE EFFICIENCY OF THE FIBER-OPTIC TRANSMISSION SYSTEM WITH WAVELENGTH DIVISION MULTIPLEXING

Abstract

The most efficient transmission systems of transport network are currently the optical transport network OTN transmission systems offered by ITU-T Recommendation G.709, in which optical channels of a fiber-optic system with wavelength division multiplexing are transfered by structured hierarchical digital streams using forward error correction coding methods. When developing this network, we began to use the effective modulation method - MQAM. However, there is no indication in the literature of the degree of MQAM that determines the number of points in the signal constellation, which ensures the maximum total rate of the entire multichannel system, if there are no limitations in the width of the optical range used. This work removes this gap, pointing to the existence of the optimal MQAM, as well as the corresponding optimal number of optical channels, in which the maximum total rate of the entire multichannel transmission system is reached and an estimate of the magnitude of this extremum is given.