The principle of a novel orthogonal modulation format of differential 8-level phase-shift keying amplitude-shift keying (D8PSK/ASK) with differential bi-phase encoding (DBC) is introduced. Based on it, an optical labeling scheme, in which the payload is 100 Gbit/s D8PSK signal and the label is 10 Gbit/s DBC-ASK signal, is proposed and simulated. The results are compared with other current schemes, and the effects of transmission range, modulation extinction ratio (ER) and received power on system performance are analyzed, respectively. The results show that the spectrum efficiency and bit error rate (BER) are improved greatly, and when the modulation ER is increased to 11 dB, the balanced performance between the payload and label is achieved.