Patent attributes
A signal processing device that processes a digital signal formed by sampling an electric signal using a clock signal, the electric signal being obtained by converting an optical signal inputted from a transmission line, the signal processing device includes: a first chromatic dispersion compensator that compensates a waveform distortion caused by a chromatic dispersion with respect to the digital signal; a first nonlinear optical effect compensator that compensates a waveform distortion caused by a nonlinear optical effect with respect to one signal outputted from the first chromatic dispersion compensator; and a controller that detects a phase fluctuation of other signal outputted from the first chromatic dispersion compensator, and controls the clock signal based on the detected phase fluctuation.