On Tue, Jan 10, 2012 at 3:03 PM, Marcus D. Leech
<address@hidden> wrote:
On 01/10/2012 05:48 PM, UB wrote:
Here is my code for transmitting data from a file:
from gnuradio import gr
from gnuradio import uhd
symbolrate=0.5*10**5
samplerate=20*symbolrate # 1M
fg=gr.top_block()
src="">gr_complex*1,'data.txt',False)
snk=uhd.usrp_sink('serial=1R24X9U1',uhd.io_type.COMPLEX_FLOAT32,1)
snk.set_samp_rate(samplerate)
snk.set_center_freq(2.4*10**9)
fg.connect(src,snk)
fg.run()
And I run the uhd_fft.py on another USRP.. i constantly get a peak at centr
frequency for data being sent, why?
http://old.nabble.com/file/p33115067/data.txt data.txt
a) Plot your data with an FFT sink--rather than a usrp_sink. Is there a spectral peak at DC?
b) There will always be a small amount of DC offset in both directions (RX and TX) that will
cause an anomaly around DC. You can null this out to a certain extent using the calibrate
routines (assuming you have a USRP2/N2XX and either a WBX or SBX card).
c) You can always offset tune your TX, to take the DC offset anomaly away from your main
transmit bandwidth. Similarly in RX.
--
Marcus Leech
Principal Investigator
Shirleys Bay Radio Astronomy Consortium
http://www.sbrac.org