Abstract
A novel differential-phase-shift-keying (DPSK)/pulse-position-modulation (PPM) orthogonal modulation is proposed for optical labeling applications, with PPM data as the high-speed payload and DPSK signal as the optical label. The systematic setup for the proposed scheme and research on bit-error rate is presented. The results show that at the bit-error rate of 10−9, the power penalties for 70 km fiber transmission are in the range of 1–3 dB to DPSK label and 5–6 dB to PPM payload in our simulation system. This is under the condition that the large extinction ratio of 18–19 dB is used for the intensity modulators of the PPM payload, with a well received DPSK label. Thus the feasibility of the proposed scheme for all optical transmission networks is clearly verified.