Method and device for dispersion compensation

Abstract

The invention discloses a method and a device for dispersion compensation. The method comprises the following steps: a sending end inserts pilot frequency information into Npilot OFDM (Orthogonal Frequency Division Multiplexing) symbols and loads the pilot frequency information onto subcarriers with same frequencies, wherein Npilot is more than 1; a receiving end acquires the pilot frequency information from the Npilot OFDM symbols, calculates the phase of the pilot frequency information and calculates the dispersion phase of the pilot frequency information according to the phase of the pilot frequency information; and according to the relation between the dispersion phase and the subcarriers, the dispersion phase of the pilot frequency information is utilized to calculate the dispersion phases on the subcarriers in the OFDM symbols and the dispersion phases are compensated. The method provided by the invention is used for efficiently realizing the dispersion compensation of a high-speed optical communication system and reducing the training cost of the dispersion compensation to be 1 / Nsc of the training cost of the traditional dispersion compensation disposing scheme, wherein the Nsc is the quantity of the subcarriers for carrying data in the OFDM symbols.

Description

technical field [0001] The invention relates to orthogonal frequency division multiplexing and optical communication technology, in particular to a method and device for performing dispersion compensation. Background technique [0002] Orthogonal frequency division multiplexing (OFDM) technology is a kind of multi-carrier modulation technology, which divides high-speed information data into N low-speed data streams, and modulates them to N mutually orthogonal sub-carriers for parallel transmission. , and its spectrum utilization can be nearly doubled compared with traditional single-carrier modulation techniques. At the same time, since the data is divided into N channels, the symbol period is N times larger than that of the original high-speed signal period, so that the OFDM system can reduce the impact of delay spread. [0003] When the OFDM system is applied to the optical transmission system, due to the characteristics of the optical fiber, the signal will be affected b...

AI Technical Summary

Problems solved by technology

At the same time, in order to estimate the dispersion phase impairment more accurately under the influence of the ASE noise introduced by the amplifier, it is necessary to insert multiple OFDM training sequence symbols (usually the number of OFDM training symbols > 5) at the initial stage of the transmitter, and one OFDM training sequence symbol The length of is equal to the number of subcarriers of an OFDM symbol, which makes the training sequence occupy a large system overhead in the process of dispersion estimation and compensation

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