I was hoping this was a Tayloe Mixer[1] based SDR. The Tayloe mixer has excellent image and harmonic rejection. <Oops... I missed the important detail about 10

I was hoping this was a Tayloe Mixer[1] based SDR. The Tayloe mixer has excellent image and harmonic rejection. <Oops... I missed the important detail about 100 different songs... sorry. I'd suggest putting the hit "Never gonna give you up" on loop for that version of the project> In hardware, it would be easier to feed a 200 khz square wave into a diode and pull off the first 10 mhz of harmonics, low pass filter it, and mix that with 99.1 Mhz fm audio to get 88.1 to 108.1 Mhz fm at 200 khz spacing. In software, you should be able to precompute a complete one cycle composite of -10 to +10 Mhz sine waves spaced 200 Khz apart. You could then loop this abitrary waveform and multiply it by an FM modulated source at 99.1 Mhz to get the same effect with a lot less processing power. This is the kind of thing GNU radio[2] is perfect for. <Correcting the above> Precompute the FM signal for each of the songs in it's channel from -10 to +10 mhz for the length of the song. Store them as 16 bit IQ samples. Each file will be different length. Loop though all of the songs, adding all of the components into a 32 bit I and Q sum. Round those to 16 bit values, or as appropriate for your SDR transmitter. You should have a very easy to compute 100 channel FM station with each channel separately timed. [1] https://www.norcalqrp.org/files/Tayloe_mixer_x3a.pdf https://www.norcalqrp.org/files/Tayloe_mixer_x3a.pdf [2] https://www.gnuradio.org/ https://www.gnuradio.org/