So I tested but I have another question. I read that the data through the USB cable (from computer to USRP) are in the format I/Q complex. (Dawei Shen tutorial)
My interpolation factor is 512, so the sample rate is 128M/512 = 250kSample/s I have a data list with 500e3 data. 250e3 are of 1000uV and 250e3 are of 0uV. I see with my spectrum analyzer during 1 second some power and during another second nothing. With a vector_source in complex, no problem. But if I specify a vector_source in short, during 0.5 second I see power and during another 0.5 second nothing. So there is a factor of 2 between the complex and short format. Therefore with a vector_list in short the sampling rate is doubled? Because in I/Q format there are 16bits * 2 (I & Q) and in short only 16bits? Is it true that when we have a source in short the sampling rate is double because we do not use the I/Q format? Thanks Julian De Lima -----Message d'origine----- De : Eric Blossom [mailto:[EMAIL PROTECTED] Envoyé : jeudi, 26. octobre 2006 15:36 À : De Lima Julian Cc : discuss-gnuradio@gnu.org Objet : Re: [Discuss-gnuradio] Sample rate for source_noise and source_vector On Thu, Oct 26, 2006 at 05:33:26PM +0200, De Lima Julian wrote: > Hello, > > When you specify a signal_source, you have to set up the sample rate. This is just for convenience and allows you to specify the output frequency in absolute instead of normalized terms. If you prefer, you can of course set the sample_rate to 1. > But with the noise and vector sources you do not have to specify this > parameter. > > What is the sample rate in the computer -> USB when we generate a noise > or generate data from a list/file? The sample rate across the USB is determined by the interpolation or decimation rate programmed into the usrp. On receive, USB sample rate = 64e6 / decimation_rate On transmit, USB sample rate = 128e6 / interpolation_rate Eric _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
