Re: [Discuss-gnuradio] GNURADIO 64 QAM 200 MHZ

[Eric Blossom]

On Tue, Jan 27, 2009 at 02:57:04AM -0800, didem colak wrote:
> Hi all,
> 
> I want to configure USRP with Basic TX and Basic RX daughter boards using GNU 
> Radio.
> 
> I am not sure their capabilities are convenient for VHF 200 MHz and 64 QAM 
> transmission.

The DACs run at 128MS/s, thus there's a "fold" at 64MHz.  There's an
image in the 4rd Nyquist zone that you might be able to use, but 200 MHz
is pretty close to 3fs/2 (192MHz).  If you're a bit above 200M you
this can probably be made to work.  You'd need a bandpass filter to
suppress the other images.  If you've got access to a spectrum
analyzer, just fire it up and see what you get.

> If they are suitable , which python or C++ programs can I use as examples for 
> writing new program?

There's python code in
gnuradio-core/src/python/gnuradio/blks2impl/qam*.py that's probably
usable for a transmitter.

Eric