Nippon Telegraph and Telephone Corporation

Ntt Electronics Corporation

Hiroyuki Nouchi

Mitsuteru Yoshida

Katsuichi Oyama

Tomohiro Takamuku

Masanori Nakamura

Yoshiaki Kisaka

Masahito Tomizawa

Etsushi Yamazaki

Kazuhito Takei

Yasuharu Onuma

Tsutomu Takeya

Atsushi Suenaga

A known pattern comparison type phase difference detection unit () detects a phase difference between a known pattern extracted from a received signal and a true value of the known pattern as a first phase difference. M indicates the number of modulation phases in a phase modulation method of the received signal. An M-th power type phase difference detection unit () removes a modulation component by raising the received signal to M-th power, and detects phase variation from a modulation phase point used for mapping on a transmission side, as a second phase difference. A phase compensation unit () compensates phase variation of the received signal based on an addition result of the first phase difference and the second phase difference.

Phase variation compensation device, phase variation compensation method and communication device

An I component compensation unit calculates an I component in which a distortion has been compensated, by forming a first polynomial expressing the distortion of the I component based on an I component and a Q component of a quadrature modulation signal and multiplying each term of the first polynomial by a first coefficient. A Q component compensation unit calculates a Q component in which a distortion has been compensated, by forming a second polynomial expressing the distortion of the Q component based on the I component and the Q component of the quadrature modulation signal and multiplying each term of the second polynomial by a second coefficient. A coefficient calculation unit calculates the first and second coefficients by comparing outputs of the I component compensation unit and the Q component compensation unit and a known signal.

Optical transmission distortion compensation device, optical transmission distortion compensation method, and communication device

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Kanagawa, Japan

Hiroyuki Nouchi