Study of new modulation data-transmission formats for dispersion-controlled high-bit-rate fibreoptic communication lines

The results of simulation of the propagation of optical signals in a multichannel high-bit-rate fibreoptic communication line with a combined scheme for amplifying optical signals based on new modulation data-transmission formats are presented. A comparative characteristic of formats with the amplitude and phase modulations of the electromagnetic-wave carrier is presented. The results of numerical simulation show that phase-modulation formats have a considerable advantage over amplitude formats. The use of phase-modulation formats leads to an increase in the maximum range of high-quality communications by a factor of three on average compared to amplitude-modulation formats. It is shown that optimal propagation regimes both in the case of amplitude-modulation and phase-modulation formats are realised for the normal (negative) group-velocity dispersion. However, the dispersion value for amplitude-modulation formats proves to be considerably greater than for phase-modulation formats.