[Discuss-gnuradio] Ofdm spectrum

[address@hidden]

Hello everyone,

I was trying to implement some OFDM transmission with a 
rfx2400 without using the ofdm code that comes with gnuradio but creating my 
own one.
I make a 256 bean Ifft transform after the windowing, and I've tried 
two different types of window the rectangular one (aka no window :) ) and the 
hamming one.
Transmitting I try to have a look at the spectrum of the signal 
with another USRP and a spectrum analyzer.
The first problem comes with the 
spectrum shape: it is not "flat" it has a "rised cosine" shape, with both 
windowing, I feel it's the transmission filter... am I correct?
The second is 
for the side lobe, zith the rect window they're pretty high... but zith the 
hamming one I don't know what kind of window I should use in Rx to recover, any 
hint?

Thank you a lot for your answer.