Fast self-adaptive dispersion compensation method in 40Gbps DWDM (dense wavelength division multiplexing) system

Abstract

The invention relates to a fast self-adaptive dispersion compensation method in a 40Gbps DWDM (dense wavelength division multiplexing) system. The fast self-adaptive dispersion compensation method specifically comprises the following steps: step A) delaying coarse regulation of an interferometer DLI (delay line interferometer) by an OTU (optical transport unit) receiver; step B) performing dispersion coarse regulation through a dichotomic method; step C) performing fine regulation through a TDC (time-to-digital converter); step D): optimizing the DLI through the receiver; and step E) monitoring through the TDC, judging whether dispersion changes or not by FEC (forward error control) error correction counting or warning and entering step B) or C) if the dispersion changes. According to the method disclosed by the invention, a coarse regulation point is fast found by using the dichotomic method, the optimal dispersion is found by adopting a mid-point method after entering the fine regulation step, the dispersion compensation time is effectively reduced, the efficiency is improved, and the defects of local optimization can be simultaneously avoided.

Description

technical field [0001] The invention relates to a 40Gbit / s DWDM long-distance transmission system, in particular to a fast adaptive dispersion compensation method in the 40Gbps DWDM system. In particular, it refers to the fast adaptive dispersion compensation method for a single channel in a 40Gbps DWDM system. Background technique [0002] At present, with the rapid development of broadband networks, the demand for massive data services has led to the development and research of various low-cost, high-speed optical fiber transmission systems. The optical fiber transmission network is experiencing from 10Gb / s system to With the leap from 40Gb / s system to 100Gb / s system, the transmission distance is also greatly increased. The impact of fiber dispersion on the transmission performance of DWDM (Dense Wavelength Division Multiplexing, Dense Wavelength Division Multiplexing) system is becoming more and more serious, which mainly limits The transmission distance of the system. ...

AI Technical Summary

Problems solved by technology

[0009] At present, the commonly used dispersion compensation methods are adjusted based on the step method. In a 40Gbit / s DWDM system, the dispersion of a single channel in the system needs to be compensated at about 800-1000ps / nm. The selected adjustable TDCM module (tunable Dispersion compensation module) compensation range will be wider, and the stepping method-based dispersion compensation method has the disadvantage of traversing all dispersion points with a certain step size to find the best residual dispersion point, which takes a long time and is inefficient

And most adjustments will use the point with the smallest bit error rate as the best point for dispersion adjustment. Since the bit errors are mostly sudden, this method is easy to fall into the trouble of local optimum, making the system unable to work at the best dispersion Point

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