Raising Performance of Optical Fiber and Optical Wireless Long-Haul Communication Systems

This study has described various hybrid modulation methods for optical fiber and wireless communication channels in the same network. To ascertain which hybrid modulation technique would be most appropriate for the system and yield the largest amount of electrical received power, while maintaining a reasonable optical signal-to-noise ratio, which is the most common problem in telecommunications, we tested (Frequency Shift Keying-Frequency Modulation), (Frequency Modulation-Phase Modulation), and (Differential Phase Shift Keying- Phase Modulation) strategies. Based on the results, this study developed a long-haul high-speed communication system to maintain each optical fiber with a length of up to 500 km and optical wireless communication in the most advantageous state possible using hybrid modulation and hybrid optical amplification techniques, as the signal is attenuated by the link length, air particles, or weather disturbances, during transit. The designed system uses a bit rate of 250 G bits/second, a symbol rate of 250 G symbols/second, and an input frequency of 193.414 THz, this frequency is used because attenuation in fiber is the lowest at this frequency, and an input power of 2 Watts, because large input powers cause greater attenuation to the transmitted signal and leads to weak signal at the receiver end that makes hard to get to know the information. This research got enhanced results by using a hybrid frequency shift keying-frequency modulation technique along with hybrid optical amplification in both the optical fiber and wireless communication for both received power which at 50 Km long fiber and the wireless channels were 8.683W and 1036 W respectively and optical signal to noise ratio were 25.27 dB, and 100.38 dB individually.