Optical communication method and communication apparatus

A method comprising:

• receiving, through an optical fiber link, an optical signal sent by a sending device, wherein the optical signal is generated by the sending device based on PAM-N, an optical power distribution of the optical signal comprises N optical power values, the N optical power values correspond to N−1 optical power differences, the N−1 optical power differences comprise an ith optical power difference and a pth optical power difference, the ith optical power difference is a difference between an (i+1)th optical power value and an ith optical power value in the N optical power values, the pth optical power difference is a difference between a (p+1)th optical power value and a pth optical power value in the N optical power values, both i and p are positive integers less than or equal to N−1, i is less than p, N is a positive integer greater than 2, and the ith optical power difference is less than the pth optical power difference;
• and
• processing the optical signal.

A communication apparatus comprising:

• a processing unit configured to generate a first signal based on pulse amplitude modulation (PAM-N), wherein strength distribution of the first signal comprises N strength values, the N strength values correspond to N−1 strength differences, the N−1 strength differences comprise an ith strength difference and a pth strength difference, the ith strength difference is a difference between an (i+1)th strength value and an ith strength value in the N strength values, the pth strength difference is a difference between a (p+1)th strength value and a pth strength value in the N strength values, both i and p are positive integers less than or equal to N−1 , i is less than p, N is a positive integer greater than 2, and the ith strength difference is less than the pth strength difference;
• and
• a transceiver unit configured to transmit the first signal.