Calculation of descending communication line characteristics of the satellite repeater with the transistor power amplifier

Optimization of satellite repeater parameters with transistor power amplifiers is carried out as per the criterion of a minimum of an error of demodulation for a case of transmission through a communication line of the digital information great volume at the restricted strip of operating frequencies (4 %) relative frequencies of carrying frequency and when using Comtech CDM-700 modem on the Earth. The sender is installed on a HEO space vehicle. Dependences of probability of bit error rate for QPSK and 8PSK signals and various values of path attenuation are obtained.