A nonlinear encoder, encoding method and optical transmission system

Abstract

A nonlinear encoder, an encoding method, and an optical transmission system, relating to the field of high-speed, long-distance optical transmission networks, the encoder includes: a non-negative conversion module, which is used to convert the real part or imaginary part signal of the input M-order QAM signal Convert to a non-negative number x with a minimum difference of 1 · (n), n is the serial number of time series, and n is a non-negative integer; Delay feedback module, it is used for x · (n) Delay, feedback, and sum to get y · (n), a linear transformation module, which is used to transform y · (n) obtains y(n) through linear transformation. Encode the M-order QAM signal into a 4M-order QAM signal with non-equal probability distribution to achieve spectrum compression. The ISI suffered by the compressed spectrum signal through the bandwidth-limited channel will be greatly reduced, which can effectively improve transmission performance and reduce The transmission performance loss caused by the limited bandwidth can improve the transmission quality.

Description

technical field [0001] The invention relates to the field of high-speed and long-distance optical transmission network, in particular to a nonlinear encoder, an encoding method and an optical transmission system. Background technique [0002] In order to achieve long-distance high-speed optical transmission with a single wavelength rate of 400Gb / s or more, the optical transmission system will use high baud rate signal transmission, which will reach more than 60Gbaud, and the digital-to-analog converter (Digital to analog converter, DAC), driver, The bandwidth of optical I / Q modulators, coherent receivers at the receiving end, analog to digital converters (Analog to digital converter, ADC) and other optoelectronic devices often cannot fully meet the requirements. Compared with the limited bandwidth of the signal baud rate, it will not be possible Avoid introducing intersymbol interference (Inter symbol interference, ISI), thereby affecting signal transmission quality. Conte...

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Problems solved by technology

[0002] In order to achieve long-distance high-speed optical transmission with a single wavelength rate of 400Gb / s or more, the optical transmission system will use high baud rate signal transmission, which will reach more than 60Gbaud, and the digital-to-analog converter (Digital to analog converter, DAC), driver, The bandwidth of optical I / Q modulators, coherent receivers at the receiving end, analog to digital converters (Analog to digital converter, ADC) and other optoelectronic devices often cannot fully meet the requirements. Compared with the limited bandwidth of the signal baud rate, it will not be possible Avoid introducing intersymbol interference (ISI), thus affecting the quality of signal transmission

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