| 摘要 |
PROBLEM TO BE SOLVED: To compensate for waveform deterioration caused by wavelength dispersion or SPM. SOLUTION: A decoder 22 on the reception side decodes data signals by applying code error correction to electric signals being output from an optical receiver 21. Also, the decoder 22 compares the code error rate before the code error correction with the code error rate after the code error correction, to output error rate information generated on an optical fiber transmission line. An optical error rate information transmitter 24 converts an error rate information electric signal AM modulated by an error rate information modulator 23 to an optical signal to be forwarded to the transmission side. An optical transmitter 12 on the transmission side controls the bias voltage and signal amplitude to be fed to an EA modulation part according to error rate information S2 demodulated by an error rate information demodulator 14 so as to reduce the error rate to a minimum, and to optimize the chirp coefficient αin the EA modulation part. |
