High baud-rate and high order modulation formats, such as 64-giga-baud 64QAM per wavelength are being popularly researched to enlarge the transmission capacity of coherent optical system. In such multilevel modulations, the influence from electrical amplifier nonlinearity along with strong memory effect from imperfect device design in coherent optical transmitter and receiver becomes more and more significant and needs careful research. In this paper, nonlinear characteristic of a commercially-available electrical amplifier in coherent optical transmitter for tens of gigahertz signal amplification is investigated, measured and modelled by a novel gain-isolated Volterra model. Experiment had verified that the proposed gain-isolated Volterra model can model the impact of electrical amplifier nonlinearity under various gain conditions, and has high accuracy in estimating both distorted waveforms and bit-error-rate penalty in 64QAM coherent optical system.
|ジャーナル||Research Reports on Information Science and Electrical Engineering of Kyushu University|
|出版物ステータス||出版済み - 1 25 2019|
All Science Journal Classification (ASJC) codes
- Computer Science(all)
- Electrical and Electronic Engineering