Patent ID: 9654228
Date: 2017-05-16
CPC Classifications: H04B,H04L

Claim:
1. A signal reception processing apparatus comprising: a digital signal processor that demodulates symbols of a received signal based on a constellation of the inputted received signal and calculates a first Q value that indicates a quality of the received signal based on distribution of the symbols of the demodulated signal and distance between the symbols of the demodulated signal; an error corrector comprising one or more processors configured to perform a forward error correction for the demodulated signal, output the corrected signal as a demodulation electric signal, and calculate a second Q value that indicates a quality of the received signal based on an error rate at the time of the forward error correction; and a controller that calculates a penalty that indicates a degradation quantity of signal quality caused by a nonlinear optical effect of an optical fiber based on the first Q value and the second Q value, wherein the controller calculates the penalty based on a difference between the first Q value and the second Q value.