I am use to using RF Generators to simulate PCM FM modulation using serial bit streams. SOQPSK-TG is new to me. I understand a differential encoder and a pre-coder is required in front of the shaping filter. My question is - if I have a serial bit stream (say 5MB and a clock) can that be connected to the I/Q inputs to produce SOQPSK? The specs say the N5172B can produce SOQPSK, but is a bit slack on how to accomplish this.