Coherent optical receiving method and receiver

Abstract

The present disclosure provides a coherent optical receiving method and receiver capable of detecting an optical signal transmitted at a high transmission rate while having low complexity and bit error rate, the coherent optical receiving method comprising the steps of: receiving a transmission optical signal that is transmitted by being offset QAM modulated so that an I signal and a Q signal from a transmitter have a delay time difference equal to an offset time as a reception optical signal; generating a local optical signal having a frequency difference within a bandwidth range from the transmission optical signal by a local oscillator; obtaining a beating optical signal by beating the reception optical signal and the local optical signal; receiving the beating optical signal by a balanced photo detector to obtain a reception signal; and restoring data transmitted by the transmitter from the reception signal.

Dependencies are inferred from the claim text.