[Discuss-gnuradio] User Generated Signals

[Jonathan Shan]

Hello,

I am trying to transmit and receive a signal that the user defines. I am 
following the directions written by Eric Blossom on independently 
generating signals and then transmitting them.
"
  u = usrp.sink_c(...)

  i = <generate I somehow>
  q = <generate Q somehow>
  f2c = gr.float_to_complex()
  fg.connect(i, (f2c, 0))
  fg.connect(q, (f2c, 1))
  fg.connect(f2c, u)
"

i = [1000, .... , 923]   // 16 values in this array, one period of cosine
q = [0, .....,  -383]   // calculated using hilbert transform, 16 values
isrc = gr.vector_source_f(i, 1)
qsrc = gr.vector_source_f(q, 1)
fg.connect(isrc .... ....)

The signal "i" is supposed to be a cosine wave.

When I connect f2c to gr.filesink, I see a cosine wave. However, the 
received signal looks like noise centered around 51.

Also: why is the waveform of gr.sig_source_c(SIN_WAVE, offset = 0) a 
cosine wave? I got this by using gr.file_sink, and looking at the odd=real 
values. file_sink output = "REAL IMAG REAL IMAG .... "

Any help would be appreciated.

Jonathan Shan