First, I assume that you need 2 seperate computers to run 2 USRP boards
(1 to transmit and 1 to receive). I just wanted to make sure.
Second, for a simple transmit using the fm_tx4.py example, how do you
change the output gain for the transmitting signal. I assume it has to
do with the line:
gain = gr.multiply_const_cc (4000.0 / options.nchannels)
but I don’t know what the max gain can be set to.
Third, in the fm_tx4.py example, instead of opening a single file of
floats and doing an FM modulation, I simply want to open 2 seperate
files of floats and combine them into a single stream of complex data.
I have changed the following code as follows but I’m not sure about what
I have to change about the last line.
def init(self, fg, filename, lo_freq, audio_rate, if_rate):
src1 = gr.file_source (gr.sizeof_float, "file name and path
src2 = gr.file_source (gr.sizeof_float, “file name and path
# Local oscillator lo = gr.sig_source_c (if_rate, # sample rate gr.GR_SIN_WAVE, # waveform type lo_freq, #frequency 1.0, # amplitude 0) # DC Offset mixer = gr.multiply_cc () converter = gr.float_to_complex() fg.connect (src1, (converter, 0)) fg.connect (src2, (converter, 1)) fg.connect (converter, (mixer, 0)) fg.connect (lo, (mixer, 1)) gr.hier_block.__init__(self, fg, src, mixer)