Re: How to efficiently implement dechannelization (combine multiple narrowband signals into a single broadband spectrum)

Is this the same baseband signals copied at several place ?

It is yes.

What you can do is :

 * First modulate the signal to a narrow sample-rate (just enough for
the modulation)

 * Upsample that signal to 1 Msps.
   - Depending on the ration between the narrow rate and wide rate, it might be
     beneficial to do that in several steps.
   - So for instance you would go from 10 kHz to 100 kHz first with a
filter that's relatively sharp
   - Then you would go from 100 kHz to 1 MHz with a second filter than
can be much more relaxed (i.e. larger transition bandwidth and so much
less CPU usage)

 * Then use several rotators to position it at the various places you
need it in the 1MHz bandwidth

 * And finally add the output of all the rotators.

Thanks for the suggestion. I'll give that a go.

There is also the so called Polyphase Filter Banks, but that only

works if you need carriers that are all equally spaced. And is also
only a benefic if you really fill a significant number of them.

In my case the output channels are arbitrary, so your first suggestion sounds like the one I need to implement.

Thanks for taking the time to respond.