Method for receiving and sending signal in optical communication, optical transceiver, and system

An optical transmitter, wherein the optical transmitter comprises a digital signal processor (DSP) and a modulator, and wherein:

• the DSP is configured to generate a plurality of first subcarriers based on a bit stream;
• the DSP is configured to perform state of polarization (SOP) rotation on at least one subcarrier in the plurality of first subcarriers to generate a plurality of second subcarriers, wherein the plurality of second subcarriers comprise a plurality of subcarriers each with a relative SOP rotation angle, and the relative SOP rotation angle is not zero and is not an integer multiple of 90 degrees;
• and
• the modulator is configured to:
• modulate the plurality of second subcarriers to an optical signal, and send the modulated optical signal.

An optical communication system, wherein the optical communication system comprises an optical transmitter and an optical receiver, wherein the optical transmitter comprises a digital signal processor (DSP) and a modulator, and wherein:

• the DSP is configured to generate a plurality of first subcarriers based on a bit stream;
• the DSP is configured to perform state of polarization (SOP) rotation on at least one subcarrier in the plurality of first subcarriers to generate a plurality of second subcarriers, wherein the plurality of second subcarriers comprise a plurality of subcarriers each with a relative SOP rotation angle, and the relative SOP rotation angle is not zero and is not an integer multiple of 90 degrees;
• and
• the modulator is configured to:
• modulate the plurality of second subcarriers to an optical signal, and send the modulated optical signal.