[Discuss-gnuradio] Spectrum Sensing

[Shravan Rayanchu]

Hello everyone,

I was going through some gnuradio documentation (on comsec.org wiki)
which says "...16-bit I and 16-bit Q data (complex), resulting in 8M
complex samples/sec across the USB (32 Mbps max. data rate). This
provides a maximum effective total spectral bandwidth of about
6MHz...".

By Nyquist criteria, should not this be 4 Mhz? Also, I found this note
at some other place which said that we can sense spectrum upto +/-
15MHz from the carrier frequency. Which one of the above is correct?
And what is bottleneck for maximum amount of spectrum we can sense at
one time, is it limited by the usb bus speed?

Also, the in the program "usrp_spectrum_sense.py [options] min_freq
max_freq", is there a limit on (max_freq - min_freq)?

Thanks,
Shravan.
PS: My DSP background is zilch.