The three-channel transmission of 42.8 Gbit/s nonreturn-to-zero differential phase-shift keying (NRZ-DPSK) signal is demonstrated.The 410 km transmission link consists of four spans using standard single-mode fiber (SSMF).The dispersion compensation fiber (DCF) and erbium-doped fiber amplifier/distributed raman amplifier (EDAF/DRA) hybrid amplification are used.Both optical power spectrum and eye diagrams of the DPSK signal are given in back-to-back configuration and after transmission (center channel).The curves of bit error rate (BER) of the center channel also is given,both in back-to-back configuration and after transmission,which is compared with the curve in single-channel transmission configuration.The BER of the DPSK signal of the center channel is 1.0E-3 after transmission using single-ended detection.张帆|fzhang@pku.edu.cn