Patent ID: 9225433
Filing Date: 2015-12-29
Classification: H04B

Abstract:
1. A receiver for processing a signal received over an optical communication channel, the signal comprising first and second polarization components and the optical communication channel introducing polarization mode dispersion effects into the signal, the receiver comprising: an analog front end to sample the signal based on a sampling clock to generate a digital vector representing the first and second polarization components of the signal; a matrix transformation block to apply a transformation matrix to the digital vector representing the first and second polarization components to generate a transformed digital vector having an increased timing tone energy relative to the digital vector, wherein the timing tone energy of the transformed digital vector is based on a memoryless nonlinearity of one of a first and second polarization component of the transformed digital vector; a timing recovery block to detect a symbol rate of the transformed digital vector and generate the sampling clock based on the detected symbol rate; an equalizer to equalize the transformed digital vector using equalizer coefficients that are updated based on estimated channel characteristics; a parameter estimator to apply a gradient optimization algorithm to determine updated rotation and phase parameters for the transformation matrix that optimize the timing tone energy based on the equalization parameters of the equalizer; and a matrix parameter updater to update the transformation matrix based on the updated rotation and phase parameters.