WAVELENGTH DISPERSION AMOUNT CALCULATION DEVICE, OPTICAL SIGNAL RECEPTION DEVICE, OPTICAL SIGNAL TRANSMISSION DEVICE, AND WAVELENGTH DISPERSION AMOUNT CALCULATION METHOD

摘要

A communication system with synchronous detection using an optical signal, by which estimation of a wavelength dispersion amount using a specific frequency band signal becomes possible, with the purpose of compensating the wavelength dispersion received at the time of optical fiber transmission. A wavelength dispersion amount calculation device is provided with a signal distribution circuit which distributes electric digital signals converted from reception signals into a plurality of signal sequences, wherein the reception signals are optical signals transmitted from the optical signal transmission device, and are formed by adding signals generated from a transmission data sequence and known signals having frequency components gathered to a plurality of specific frequencies; a plurality of frequency band passage filter circuits which separate only the plurality of specific frequency components containing the known signals from the signal sequences distributed by the signal distribution circuit, and allow the transmission of the separated frequency components; a plurality of power calculation circuits which are provided corresponding to the respective plurality of frequency band passage filter circuits for calculating power values of signals output from the corresponding frequency band passage filter circuits; a delay time calculation circuit which detects time at which the power has the maximum value or time at which the power exceeds a predetermined threshold value, from the respective signal sequences having the power values output from the plurality of power calculation circuits, and compares the detected times; and a wavelength dispersion amount calculation circuit which calculates a wavelength dispersion amount on the basis of the time comparison result by the delay time calculation circuit.