SI (Spectrum Inversion)-based nonlinear fiber damage compensation method and device in OFDM system

Abstract

The invention relates to SI (Spectrum Inversion)-based nonlinear fiber damage compensation method and device in an O-OFDM (Optical-Orthogonal Frequency Division Multiplexing) system, belonging to the field of optical communication and applied to the O-OFDM system for nonlinear fiber damage compensation. The whole compensation module is arranged in front of a receiver of the O-OFDM system and comprises an SI unit and an HNLF (Highly Non-Linear Fiber) which has a certain length and is arranged behind the SI unit, wherein SI is realized by an SOA (Semiconductor Optical Amplifier) based on FWM (Four Wave Mixing) effect.

Description

technical field [0001] The design of the present invention relates to a compensation method and device for optical fiber nonlinear damage of an optical orthogonal frequency division multiplexing (Optical Orthogonal Frequency Division Multiplexing, O-OFDM) system based on spectrum inversion (Spectrum Inversion, SI), and belongs to the field of optical communication , applied to O-OFDM system for nonlinear compensation. Background technique [0002] With the continuous improvement of social informatization and the continuous maturity and development of some new data services in the network (such as: P2P in the network, IPTV, video on demand (VOD), etc.), the demand for information transmission bandwidth in human society is astonishing. With the rapid growth of speed, ultra-high speed and ultra-large capacity have become the main goals pursued by information transmission. Continuing to expand capacity through WDM technology will result in many limiting factors: First, continui...

AI Technical Summary

Problems solved by technology

First of all, because the frequency difference between the subcarriers of the optical OFDM system is very small, this makes the walk-off between subcarriers very weak, and it is easy to meet the conditions of nonlinear interaction of optical fibers and form crosstalk; the subcarrier spacing is generally tens of MHz , unlike WDM systems, the data correlation between subcarriers will also affect each other through cross-phase modulation (XPM) and four-wave mixing (FWM) nonlinear effects

Secondly, since the OFDM signal is overlapped by a series of sub-channel signals, it is easy to cause high PAPR

A high PAPR will not only increase the complexity of the signal DAC / ADC, reduce the efficiency of the RF power amplifier, increase the requirements for the linearity of the MZ modulator, increase the cost and power consumption of the transmitter power amplifier, and most importantly, high PAPR will make Optical OFDM systems are more sensitive to fiber nonlinear impairments and phase noise than other optical communication systems

Optical fiber nonlinear damage leads to system performance degradation and system nonlinear tolerance reduction

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