The modulation and demodulation technology of 100Gbps satellite laser communication system

Starting from the current research status of the 100Gbps satellite laser communication system that has been realized, this paper expounds the research progress of the current typical 100Gbps satellite laser communication system, and analyzes the modulation and demodulation technology used in the 100Gbps satellite laser communication system. In this paper, we propose to use 100G-LR optical modules and the modulation method of PAM4 to realize high-speed satellite laser communication. At the transmitting end, the digital signal processing technology is used to realize the interleaving of 4*25Gbps electrical signals. The interleaved 100Gbps electrical signal is directly modulated onto the optical carrier, thereby realizing single-wavelength single-polarization 100Gbps communication. In this process, the optical system used is simple in structure, and there is no need to conduct research and design of special optical systems for wavelength multiplexing or polarization multiplexing. At the receiving end, digital signal processing technology is used to demodulate the 100Gbps signal into 4*25Gbps signals. Compared with the DP-QPSK modulation method, the sensitivity of the PAM4 modulation will be reduced to a certain extent.