A satellite on-board processing scheme based on photon frequency conversion

A novel satellite on-board processing scheme based on photon frequency conversion is proposed for the purpose of realizing frequency conversion. For the received intermediate frequency signal, a Mach-Zehnder modulator is used to convert it into an optical signal. The modulated optical signal and an optical signal generated by a tunable laser enter the photodiode through a coupler to perform heterodyne beat frequency and generate an intermediate frequency signal of the target carrier frequency, thereby reducing the cost and power consumption of on-board processing. Simulation results show the spectrograms and constellation diagrams of frequency conversion from Q-band to V-band in 8PSK modulation format. The bit error rate(BER) obtained by simulation shows that in a satellite communication system, when the OSNR is higher than 5dB, the BER performance can meet the 2×10^-2 threshold when using 8PSK modulation format, which indicates that error-free transmission can be achieved when using 20% soft-decision FEC. The Q factor obtained by simulation shows that when the OSNR is higher than 5dB, the Q factor can reach more than 6.5 when using QPSK modulation format, which indicates that reliable transmission can be achieved. Compared with existing solutions, this scheme has the advantages of lower cost, lower power consumption and more flexible frequency selection, it can also solve the inflexibility and improve the performance of radio frequency conversion in traditional scheme.