Abstract: An optical signal regeneration technique includes receiving optical symbols in a phase-modulation format. The received symbols are converted to symbols in a phase/amplitude-modulation format. A first amplitude regeneration, which involves reduction of amplitude noise, is applied to a first symbol pair. A modulation format conversion is performed on the optical signal in the phase/amplitude modulation format after the first amplitude regeneration. A second amplitude regeneration is applied to a second symbol pair, wherein the first and second symbol pairs differ from one another in respect of at least one different feature, which is selected from a group that includes a different nominal phase value assigned to the symbols of the symbol pair and a different temporal distance between the symbols of a symbol pair.