What exactly are you looking to do? Basically anything custom is going to require some DSP tools, like Matlab or our VSG60 software.
For the VSG25 you’ll need to choose your I/Q sample rate and pattern length so the sequence can repeat perfectly, e.g. 4 MSPS, upsample by 32 for a 128 MHz sample clock. Use a repeating pattern of e.g. 32 symbols for 1024 sample pattern length. Then you can shift the center frequency in units of 128/1024 MHz, repeat for each QPSK signal, add and scale.
You can generate a sequence twice as long, then use the middle portion, to remove any edge artifacts.
Note that the VSG60 does not have the same limitations, and is generally the preferred tool for applications like this.
