Re: [Discuss-gnuradio] USRP2 transmission issues

[Matt Ettus]

On 01/27/2011 03:44 AM, nyquist82 wrote:
> Hi!! I am trying to transmit a complex signal with the USRP2+WBX system.
> First I tried transmitting from file, an 8MHz band recorded with the USRP2,
> by connecting the "from file" block to the USRP2 transmitter, with and
> appropriate interpolation.
> When visualizing the output on a spectrum analyzer I can see that the USRP2
> is transmitting a very narrow bell-shaped signal band and on the sides what
> seem to be harmonics of the center signal.
> Changing the interpolation on the usrp2 seems to affect the bandwidth of the
> central signal (the smaller the interpolation the larger the bandwidth).
> Any ideas on where I'm going wrong?

Dear nyquist82,

You are not setting the proper sampling rate.  Changing the 
interpolation rate changes the sampling rate and thus the bandwidth. 
This relationship was first proved by your namesake many years ago.

Matt