Study Of Chromatic Dispersion Monitoring Method Of High-speed Optical Signal Based On Asynchronous Amplitude Sampling

In the next few years, with the emerging of wide bandwidth applications such as HDTV,3DTV,network video, internet of things and cloud computing, demands of wide bandwidth of single-userwill increase exponentially. The transmission bandwidth will grow continuously. Standard of100GE was made by IEEE802.3ba in2010, and later in2011the100G DWDM backbonetransmission solutions was launched by major communication equipment providers. For thedevelopment of100G DWDM network, there are still some technical challenges, such as networkmanagement and optical performance monitoring (OPM). The performance of optical transmissionsystems is impaired by optical signal-to-noise ratio, chromatic dispersion, polarization modedispersion and other impairments, so they must be taken seriously enough. The maximumtransmitting distance limited by chromatic dispersion is proportional to the square of reciprocal ofthe bit rate. With increasing of bit rate, the tolerance towards chromatic dispersion decreases rapidly.Therefore, in high-speed and long-haul transmitting system, the chromatic dispersion must bemonitored and compensated effectively. However, in DWDM system, the wavelength of eachwavelength channel is different, and the transmitting distance may be different for each wavelengthchannel. As a result, accumulated dispersion value of each channel may be different, so differentdispersion compensation value should be taken for different wavelength channel. Moreover, someother physical factors (such as temperature and humidity) will affect the fiber dispersion coefficient,so an effective dispersion monitoring technology should be employed to offer the function ofadaptive dispersion compensation.AAH-based monitoring method, having advantage of transparency for different modulationformats and different bit rates, is easy to be realized and cost-effective. However, due to a variety ofimpairments mixed together, the measuring range and accuracy of this monitoring method isreduced. On the basis of AAH method, the author found out the relationships among higher orderstatistical characteristics of signal samples (the original moments of first-order, second-order andthird-order), average noise power and average signal power. And then the author proposedparameter G, which was just only the function of dispersion, separating chromatic dispersion fromthe other impairments. Then in chapter3, the author builded up200Gbps DP-16QAM system basedon OptiSystem, calculated G according to the derived formulas. The author eventually achievedeffective dispersion monitoring result of high-speed transmission system. The result of simulation shows that, the monitoring method based on G parameter possesses the advantage of high accuracy,wide dispersion monitoring range and weak interference of noise.