FDM modulation on top of OFDM

Hi guys, I'm currently generating OFDM signal and send it to DAC and then upconvert them to 1 GHz carrier signal.

I want to multiplex several of them, like say I upconvert them to 1 GHz, 800 MHz, 1.2 GHz, which represents 3 different signals, then multiplex them together using FDM, is it possible or is there any other better way to do this?

If I guess your question right, you can use combiner to do so.

Hi tony, thanks for the reply, but how does combiner work? How do I demodulate at them at the receiver? Thanks!

In Mini-Circuits, there are some combiners. Use one for TX, and the other one for RX, for each branch of RX using filter to get only one carrier.

http://www.mini-circuits.com/pdfs/ZA3PD-1.5.pdf