Re: always a spike on the FFT at the center frequency (Matt Ettus)

GNU Radio
1

Hi,

I have exactly the same problem. A spike at the center of FFT (I am
using
USRP2 with BAsicRx).
Adding 0.5 to the signal I still have it (together with other spurious
signals that seems is not possible to eliminate them ).

2010/12/8 [email protected]

  1. Re: always a spike on the FFT at the center frequency (Matt

On Tue, Dec 07, 2010 at 11:36:19AM +0100, Anton Blad wrote:

of
over a second due to the large amounts of buffered data.
any
small change, that would allow an application developer to control the
could specify a limit of 512 bytes (or less for that matter), and the

scheduling policy disallows adding more samples to the flowgraph.
The policies I can think of being useful are:
acceptable performance.
CPU time (== user + sys).
Message: 2
Cyclone in the USRP1? Right now I’m hoping to do this to read P25

Content-Type: text/plain; charset=ISO-8859-1

produces no errors
That’s a very large number of samples per symbol. I know I tested up

On 12/05/2010 11:22 PM, adib_sairi wrote:

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getting called. I copied my code below. Could anyone tell me why is my

Generated: Mon Dec 6 01:19:50 2010

           grc_wxgui.top_block_gui.__init__(self, title="Tst Generate
           ##################################################
           self.usrp2_sink_xxxx_0.set_interp(p_interp)
   def set_p_eth(self, p_eth):
   def set_p_interp(self, p_interp):
   print "timer tick count is ", timer_tick_cnt
   parser.add_option("", "--p-freq-carrier", dest="p_freq_carrier",
           print "Error: failed to enable realtime scheduling."

Subject: Re: [Discuss-gnuradio] RuntimeError: bad lexical cast: source
Running uhd_find_devices I get the following outputs:
– UHD Device 0
Boost_103900; UHD_0001.20101204162446.a51fb2e
type: usrp2

Boost_103900; UHD_0001.20101204162446.a51fb2e

Done
linux; GNU C++ version 4.4.1 [gcc-4_4-branch revision 150839];
num_channels=2,
Tobias

cd …
make distclean
Is that right so far?
pythonpath.

when I get back to the office.

File
transmission

boost lexical cast doesnt have a very telling error does it…
-Josh

gnuradio isn’t able to run the generated code.
io_type=uhd.io_type_t.COMPLEX_FLOAT32,
self.uhd_multi_usrp_source_0.set_center_freq(2450000000, 0)

[email protected]

setup used just two USRPs: two antennas and two daughtercards – one

Adib

To: Tom R. [email protected], [email protected]
Ben

Ben

Content-Type: text/plain; charset=us-ascii

No idea if there is sufficient gate array capacity in the FPGA to implement

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2

Hi Luca

Remember you have to add 0.5 to both the real and the immaginary
parts of the signal.
self.gr_add_const_vxx_0 = gr.add_const_vcc((complex(.5, .5), ))

This line did the trick for me.

Charles