[Discuss-gnuradio] PSD Display from USRP Data

[Rahman Doost]

Hello Guys,

I am very new to GNU Radio. I am trying to develop a python program that graphically displays data from USRP which sweeps a user-defined frequency band from down-freq to up-freq. USRP is tuned to divide the input band to 3 MHz sub-bands and return the power spectral density. I am using usrp.source_c to connect to the board. I have two threads, one running GUI and shows the input of PSD; the second one stores the FFT components of each sub-band to a file. In the GUI, I use fftsink2.usrp_sink_c() to display the PSD for the currect scanning band. But what I can not display is the current sub-band whose FFT result are plotted by usrp_sink_c. That's because on the X-axis of the plot I have the center frequency 0 and freq ranging from -1.5 MHz to 1.5 MHz. What I need is either having the whole spectrum being plotted with history, not just the current scanned sub-band, or representing the currect frequency sub-band which is being scanned. I was wondering If someone can help me out on this.

Regards,
Rahman Doost