Transmission system using transmitter with phase modulator and frequency multiplier

摘要

A transmission system for transmitting digital symbols by modulation according to a phase constellation includes a transmitter having a phase modulator and a frequency multiplier in cascade for producing a modulated signal having a desired transmission frequency. To prevent degradation of the bit error rate of such signal, the phase constellation at the input of the phase modulator has at least one additional phase state relative to the phase constellation at the output of the frequency multiplier. Advantageously, the number of phase states of the constellation at the input of the phase modulator is N times the number of phase states of the constellation at the output of the frequency multiplier, where N is the frequency multiplication factor.