> 1) noise_ave_pwr.jpg > * normalized average power over time > * is there any reason why the power would start high then go low?
The first samples could be corrupted because the pipeline may not be cleared. Drop the first samples > 2) noise_ave_psd.jpg > * average PSD of a chunk of the data > * why the very large energy at DC? It's less than 10 dB above the noise floor. Turn up the gain and you won't see it. > * why the spikes at +/- 1 MHz and -2 MHz? You are seeing synthesizer spurs or harmonics of the reference. You'll notice that they are only about 3 dB above the noise floor. > 1) wifi_psd.jpg > * fft of 0.5 sec. of data > * very pronounced DC component How many bins in the data? > > 2) wifi_psd_ave.jpg > * average PSD of entire data collection > * DC component not as pronounced > * I guess the half-band filter in the FPGA is causing attenuation at > the edges of the band? > > I have attached the script I am using to collect the data. It is just a > customized version of usrp_rx_file.py. I seem to see these affects > regardless of frequency, pga gain, or whether I write complex or short > samples to file. On a related note, besides space considerations, are > complex or short samples preferable one to another? What command line options are you using for the script? Matt _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
