Carrier Deactivation for OFDM Transceiver

Hi fellas,

I am actually trying to change the ofdm module in the gnuradio library
order to add some carrier deactivation capability to it. As a matter of
I need to feed carrier deactivation data dynamically as an array of
and ones from spectrum sensing module to the ofdm block right before the
ifft module in order to obstrcut data for some of the carriers. Should I
create a new gnuradio block and put it before ifft module for this? or
may be some other less painful ways to do this. I appreciate any of you
and I was wondering if anyone has already impelemented such a system and
some code is publicly available.

Rahman Doost