Coherent light communication equalization method by using intersection mixed state

Abstract

The invention relates to the technical field of communications and particularly relates to a coherent light communication equalization method by using an intersection mixed state. The method is basedon an iterative least square method and comprises the following steps: mixing two paths of signals received by a receiving end of a filter into one path of signals by intersection; filtering the signals by the filter to obtain an output value; taking a point on a circle formed by rotating an ideal constellation point and nearest to the output value on a constellation diagram as a judgment value; taking a difference between the judgment value and the output value as an error coefficient to add to an update process of the iterative least square method; and enabling an updated system state to enter next iteration. According to the coherent light communication equalization method, effective equalization can be performed on signals affected by SOP effect in a coherent light communication transmission process; compared with a blind equalization algorithm, the coherent light communication equalization method can track a higher RSOP and has a quicker convergent speed; and meanwhile, compared with Kalman filtering, the coherent light communication equalization method has lower complexity and calculated amount, and the signals do not need to be decomposed into a real part and an imaginary part to input. Therefore, the coherent light communication equalization method is applied to each order of PSK and QAM PDM signals.

Description

technical field [0001] The present invention relates to the technical field of communication, and more specifically, relates to a coherent optical communication equalization method using a cross hybrid state. Background technique [0002] With the huge increase in demand for broadband networks and the high volume of data transmission, technologies based on advanced modulation methods, polarization-mode multiplexing (PDM), coherent detection and digital signal processing (DSP) have become an effective way to improve coherent optical communication systems. The scheme of the transmission rate. The polarization mode multiplexing system uses two mutually orthogonal polarization states (SOP) to transmit two channels of optical signals with the same wavelength. This method can double the transmission rate, so it has been extensively studied. The PDM system is more sensitive to the polarization effect of light than the ordinary optical path transmission mode. The main polarizatio...

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Problems solved by technology

[0005] In order to overcome at least one of the above-mentioned defects in the prior art, the present invention provides a coherent optical communication equalization method using a cross-mixed state, which has strong self-adaptability and can effectively solve various signal problems caused by polarization effects and distance transmission. distortion problem

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