Equalization method and equipment in extreme scenarios in coherent optical fiber polarization division multiplexing system

Abstract

The invention provides an equilibrium method and equipment under an extreme scene in a coherent optical fiber polarization-division multiplexing system. The method comprises the following steps: performing segmented construction on an optical fiber channel with rotation of state of polarization RSOP and polarization division multiplexing PMD joint effect to acquire a signal damage model with two segments of equivalent structures of the PMD before the RSOP; performing window-split interception on a damage signal symbol sequence passing through the optical fiber channel to acquire a window-splitsignal; performing the PMD compensation on the PMD damage of the window-split signal at the frequency domain by using the Kalman filter equilibrium algorithm, and performing the RSOP compensation onthe RSOP damage of the window-split window at the time domain. Under the situations that the speed of the RSOP reaches up to million radians per second and the differential group delay of the PMD is multiple times of the symbol period, the equilibrium compensation work of the signal is finished; the error vector amplitude is much less than the forward error correction tolerance, and performs wellalong the optical signal-to-noise ratio change.

Description

technical field [0001] Embodiments of the present invention relate to the technical field of communications, and more specifically, to an equalization method and equipment in extreme scenarios in a coherent optical fiber communication polarization division multiplexing system. Background technique [0002] Driven by the explosive growth of Internet services, optical communication systems and networks as the transmission backbone network have also developed rapidly. The emergence of technologies such as time division multiplexing (TDM), wavelength division multiplexing (WDM), polarization multiplexing (Polarization division multiplexing, PDM) and high-order modulation formats have greatly improved the capacity of optical communication systems and spectral efficiency. Polarization effects, such as polarization state change (also known as polarization rotation, Rotation of state of polarization, RSOP), polarization mode dispersion (Polarization mode dispersion, PMD), polarizat...

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Problems solved by technology

[0004] The CMA-based MIMO algorithm can solve the compensation of large DGD, but cannot solve the fast RSOP, and the change of fast PSP caused by fast RSOP

The recently proposed algorithm combined with the Kalman filter can solve the equalization problem of fast RSOP, but because DGD compensation is only performed in the time domain, it cannot compensate the PMD of large DGD (the optical signal damage caused by DGD comes from each frequency component in the frequency domain Cause different phase delays, in the time domain, only the phase delay at the carrier frequency can be compensated, and for other frequency components, it can only be partially compensated)

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