An adaptive equalizer and method for realizing adaptive equalization processing

Abstract

Provided are an adaptive equalizer and adaptive equalization method thereof. The method includes obtaining an X-polarization error signal based on a first distance between a tap center and a barycenter of coefficients for mapping H and V onto X and a Y-polarization error signal based on a second distance between a tap center and a barycenter of coefficient for mapping H and V onto Y, performing an interpolation for the X-polarization data with the X-polarization error signal and an interpolation for the Y-polarization data with the Y-polarization error signal in a clock synchronization. Since X-polarization and Y-polarization are considered separately when errors are calculated, and are adjusted separately, an X-polarization coefficient and a Y-polarization coefficient are flexibly and effectively controlled to approach a tap center.

Description

technical field [0001] The invention relates to high-speed optical transmission technology, in particular to an adaptive equalizer and a method for realizing adaptive equalization processing thereof. Background technique [0002] In high-speed optical transmission systems, coherent receivers need to compensate for various impairments in the optical channel, such as polarization film dispersion (PMD, Polarization Mode Dispersion), chromatic dispersion (CD, Chromatic Dispersion) and polarization-dependent loss (PDL, Polarization Dependent Loss) and so on. The adaptive equalizer uses a digital signal processing (DSP, Digital Signal Processing) technology to adaptively track channel characteristics, so as to achieve the function of compensating various impairments in the channel. [0003] figure 1 It is a schematic diagram of the composition function of the existing coherent receiver, such as figure 1 As shown, the input signal of the receiver is the polarization state horizo...

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Problems solved by technology

[0006] Judging from the above related technologies for monitoring and intervening in the working process of the adaptive equalizer, the system needs the convergence of the second adaptive equalizer. In this way, not only the process is complicated and the time to enter the system stability is affected, but also depends on the initial convergence Post-frame positioning feedback skew value between polarization states

In addition, since the error signal is obtained by calculating the two polarization states together, the fine-tuning of the coefficients and the movement of integer multiples of the sample point are carried out in one direction for the polarization state coefficients, which is not flexible enough to cover all channel scenarios

Moreover, after moving the coefficients to an integer multiple of samples, the method of directly padding the filter output with zeros will cause large bit errors due to the lack of consideration of the energy of the shifted coefficients, which will affect the performance of the back-end module.

[0007] That is to say, the existing technology cannot effectively solve the problems of adjusting the coefficients to the center of the coefficient taps and not having a large impact on system errors after the coefficients are adjusted.

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