Electrical Dispersion Compensation for Multichip DPSK Detection Utilizing MISO DFE

Multichip differential phase-shift keying (MC-DPSK) is a promising method to improve the performance of DPSK signal. It has been proposed that a joint maximum likelihood sequence estimation (MLSE) equalizer can be utilized after MC-DPSK detection to further improve the chromatic dispersion (CD) and polarization-mode dispersion (PMD) tolerance in optical fiber transmission system. In this letter, we investigate electrical CD and PMD compensation for MC-DPSK detection with different chip numbers utilizing multiple-input-single-output (MISO) decision-feedback equalizers, which has less computation complexity than joint MLSE equalizers. Moreover, we propose the MISO equalization scheme after separate-photodiode MC-DPSK detection, which will further improve the distortion tolerance.