Waveform generation for interplex modulation

摘要

A signal generator (26) develops baseband direct sequence spread spectrum digital bit streams (S1, S2, S3) from corresponding input data signals. The values of the digital bit steams are used to simultaneously control states (PI, PQ, GI, GQ) of phase modulators and variable attenuators which modulate the phase and amplitude of the in-phase and quadrature carrier components. This programmable waveform generator can be used to implement an interplex modulator producing a constant-envelope composite signal. <IMAGE>