I have a query regarding flow graph in GRC.
I am trying to get spectrum from DBS_RX daughter board using GRC. I have
used three blocks as
USRP2 Source --> FFT Filter --> FFT Sink
They have following parameters,
USRP2 Source:
Decimation 1M
Frequency 1G
Gain (dB) 0
FFT Filter:
Decimation 1
Taps firdes.complex_band_pass(1.0, 3000, -0.05e3, 0.05e3, 5,
firdes.WIN_HAMMING, 0)
FFT Sink:
Sample Rate 2K
Baseband Frequency 1K
FFT Size 512
Refresh Rate 30
I need to display shows frequency spectrum centered at 1 GHz. Since I am
using decimation of 1M, the frequency is lowered down to 1K. I filter it
using FFT bandpass filter with 100 Hz bandwidth. The fft sink shows
spectrum at around 1 KHz. The problem is if I do not use decimation, the
GRC seems to be very slow (may be processing 1 GHz at GHz sample rate
is too much). I need to make a FFT plot showing spectrum at 1 GHz. How
Can I accomplish this?
Regards,
Umair N.
MSc Communication Engineering
Chalmers University ot Technology, Sweden.