Fig. 1. Block diagrams of transmitter-side subcarrier multiplexing and receiver-side subcarrier de-multiplexing in electrical domain. (a) Block diagram of transmitter-side subcarrier multiplexing in electrical domain; (b) block diagram of receiver-side subcarrier de-multiplexing in electrical domain

Fig. 2. Signal power spectra of single carrier and dual-subcarrier. (a) Signal power spectrum of single carrier; (b) signal power spectrum of dual-subcarrier

Fig. 3. Block diagram of PS signal generation

Fig. 4. Illustration of simulation setup for transoceanic fiber transmission system

Fig. 5. Relationship between bit error rate and transmission distance

Fig. 6. Relationship between bit error rate and transmission distance under optimum launch power

Fig. 7. Relationship between bit error rate and launch power when optical fiber transmission distance is 18000 km

Fig. 8. Relationship between experimental bit error rate and transmission distance when launch power is 1 dBm