Simulation of a Multi-Frequency Satellite Communication Channel

The growing number of subscribers and the volume of transmitted information requires an increase in the capacity of satellite communication systems. This is possible through the use of high orders of signal constellations, spatial separation of channels, effective noise-resistant codes. In addition, the new standards require the effective use of nonlinear power amplifiers that must operate close to saturation. Of interest is the increase in the capacity of satellite communication systems due to the multi-frequency mode in the transponder channel. The article reveals the channel structure, gives a detailed description of the input and output multiplexers, a nonlinear amplifier, a mixer, and a local oscillator. The structure of the computer model of the transponder channel and the multi-frequency signal of the ground station is shown. The simulation results show that the multi-frequency mode introduces additional intermodulation distortion of the carriers of one channel. This requires the development of nonlinear predistortion systems at transmitting ground stations, as well as equalizers at receiving stations.