Signal processing method and apparatus, and communication system

A signal processing method, comprising:

• receiving a first pulse amplitude modulation (PAM)-N signal transmitted by a first device;
• determining a distortion parameter of an eye pattern of the first PAM-N signal;
• and
• sending the distortion parameter to the first device, so that the first device processes a to-be-transmitted signal based on the distortion parameter.

A communication device, wherein the communication device comprises a transmitting unit and a processing unit, wherein

• the transmitting unit is configured to transmit a first pulse amplitude modulation (PAM)-N signal, and N≥2;
• the processing unit is configured to:
• determine a distortion parameter of an eye pattern of the first PAM-N signal, wherein the distortion parameter is for reflecting a tilt status of the eye pattern;
• set coefficients of an equalizer based on the distortion parameter, wherein the equalizer is configured to perform anti-distortion preprocessing on a single-time sampled signal;
• perform, using the equalizer, anti-distortion preprocessing on a second PAM-N signal to be transmitted by the transmitting unit, to obtain a third PAM-N signal;
• and
• control the transmitting unit to transmit the third PAM-N signal;
• and
• the transmitting unit is further configured to transmit the third PAM-N signal.