[Baypiggies] Fwd: array in python
harshal jadhav
jadhav.harshal at gmail.com
Thu Oct 8 04:42:40 CEST 2009
Hi JC,
I am trying to implement space time coding on gnu radio.
I have a signal source generating sinusoidal wave.
The output of this signal source is the sampled version of sinusoidal wave.
I want to capture these samples in an array, so that i can group certain
number of samples and mark them as symbol S1 and similarly have symbol S2
gropu of other samples.
I have pyhton code which generates two sinusoidal signals and routes them
over two USRP boards which bears the antenna. one signal is routed through
daughterboard1 and other is routed through daughterboard2.
I want to trap the samples of the source signal before they enter the usrp
board.
*code :*
Transmit 2 signals, one out each daughterboard.
Outputs SSB (USB) signals on side A and side B at frequencies
specified on command line.
Side A is 600 Hz tone.
Side B is 350 + 440 Hz tones.
"""
from gnuradio import gr
from gnuradio.eng_notation import num_to_str, str_to_num
from gnuradio import usrp
from gnuradio import audio
from gnuradio import blks2
from gnuradio.eng_option import eng_option
from optparse import OptionParser
from usrpm import usrp_dbid
import math
import sys
class example_signal_0(gr.hier_block2):
"""
Sinusoid at 600 Hz.
"""
def __init__(self, sample_rate):
gr.hier_block2.__init__(self, "example_signal_0",
gr.io_signature(0, 0, 0),
# Input signature
gr.io_signature(1, 1, gr.sizeof_gr_complex))
# Output signature
src = gr.sig_source_c (sample_rate, # sample rate
gr.GR_SIN_WAVE, # waveform type
600, # frequency
1.0, # amplitude
0) # DC Offset
self.connect(src, self)
class example_signal_1(gr.hier_block2):
"""
North American dial tone (350 + 440 Hz).
"""
def __init__(self, sample_rate):
gr.hier_block2.__init__(self, "example_signal_1",
gr.io_signature(0, 0, 0),
# Input signature
gr.io_signature(1, 1, gr.sizeof_gr_complex))
# Output signature
src0 = gr.sig_source_c (sample_rate, # sample rate
gr.GR_SIN_WAVE, # waveform type
350, # frequency
1.0, # amplitude
0) # DC Offset
src1 = gr.sig_source_c (sample_rate, # sample rate
gr.GR_SIN_WAVE, # waveform type
440, # frequency
1.0, # amplitude
0) # DC Offset
sum = gr.add_cc()
self.connect(src0, (sum, 0))
self.connect(src1, (sum, 1))
self.connect(sum, self)
class my_top_block(gr.top_block):
def __init__(self):
gr.top_block.__init__(self)
usage="%prog: [options] side-A-tx-freq side-B-tx-freq"
parser = OptionParser (option_class=eng_option, usage=usage)
(options, args) = parser.parse_args ()
if len(args) != 2:
parser.print_help()
raise SystemExit
else:
freq0 = str_to_num(args[0])
freq1 = str_to_num(args[1])
# ----------------------------------------------------------------
# Set up USRP to transmit on both daughterboards
self.u = usrp.sink_c(nchan=2) # say we want two channels
self.dac_rate = self.u.dac_rate() # 128 MS/s
self.usrp_interp = 400
self.u.set_interp_rate(self.usrp_interp)
self.usrp_rate = self.dac_rate / self.usrp_interp # 320 kS/s
# we're using both daughterboard slots, thus subdev is a 2-tuple
self.subdev = (self.u.db[0][0], self.u.db[1][0])
print "Using TX d'board %s" % (self.subdev[0].side_and_name(),)
print "Using TX d'board %s" % (self.subdev[1].side_and_name(),)
# set up the Tx mux so that
# channel 0 goes to Slot A I&Q and channel 1 to Slot B I&Q
self.u.set_mux(0xba98)
self.subdev[0].set_gain(self.subdev[0].gain_range()[1]) # set max
Tx gain
self.subdev[1].set_gain(self.subdev[1].gain_range()[1]) # set max
Tx gain
self.set_freq(0, freq0)
self.set_freq(1, freq1)
self.subdev[0].set_enable(True) # enable transmitter
self.subdev[1].set_enable(True) # enable transmitter
# ----------------------------------------------------------------
# build two signal sources, interleave them, amplify and connect
them to usrp
sig0 = example_signal_0(self.usrp_rate)
sig1 = example_signal_1(self.usrp_rate)
intl = gr.interleave(gr.sizeof_gr_complex)
self.connect(sig0, (intl, 0))
self.connect(sig1, (intl, 1))
# apply some gain
if_gain = 10000
ifamp = gr.multiply_const_cc(if_gain)
# and wire them up
self.connect(intl, ifamp, self.u)
def set_freq(self, side, target_freq):
"""
Set the center frequency we're interested in.
@param side: 0 = side A, 1 = side B
@param target_freq: frequency in Hz
@rtype: bool
Tuning is a two step process. First we ask the front-end to
tune as close to the desired frequency as it can. Then we use
the result of that operation and our target_frequency to
determine the value for the digital up converter.
"""
print "Tuning side %s to %sHz" % (("A", "B")[side],
num_to_str(target_freq))
r = self.u.tune(self.subdev[side]._which, self.subdev[side],
target_freq)
if r:
print " r.baseband_freq =", num_to_str(r.baseband_freq)
print " r.dxc_freq =", num_to_str(r.dxc_freq)
print " r.residual_freq =", num_to_str(r.residual_freq)
print " r.inverted =", r.inverted
print " OK"
return True
else:
print " Failed!"
return False
if __name__ == '__main__':
try:
my_top_block().run()
except KeyboardInterrupt:
pass
Regards,
Harshal
On Wed, Oct 7, 2009 at 7:32 PM, JC Lawrence <claw at kanga.nu> wrote:
> Why don't we start at the other end and look at what the data actually is
> and what you need to be able to do with it? The combination of the data's
> natural structure plus your access requirements will drive the choice of
> data-structure (and thus Python Modules etc). What are you trying to deal
> with here, and what sorts of operations do you need to be able to do
> efficiently with it?
>
> -- JCL
>
>
> On 7 Oct 2009, at 19:23 , harshal jadhav wrote:
>
> I am having the data in complex form...
>>
>> Regards,
>> Harshal
>>
>> On Wed, Oct 7, 2009 at 7:15 PM, Stephen McInerney <
>> spmcinerney at hotmail.com> wrote:
>>
>> Yes, NumPy is good for large datasets.
>>
>> Harshav - is the problem importing the data format, or what?
>> What formnat do you currently have it in?
>>
>>
>> > Date: Wed, 7 Oct 2009 19:05:25 -0700
>> > From: keith at dartworks.biz
>> > To: baypiggies at python.org
>> > Subject: Re: [Baypiggies] Fwd: array in python
>> >
>> > === On Wed, 10/07, harshal jadhav wrote: ===
>>
>> > > I am using python language for GNU Radio. For this i have a sampled
>> > > signal. The signal is a sine wave. I have to trap each sample of this
>> > > sine wave in an array.Is it possible to capture the samples of the
>> > > sine wave in an array in python?
>> > ===
>> >
>> > Yes. You might also want to take a look at the numpy extension.
>> >
>> >
>> > -- Keith Dart
>> >
>> > --
>> > -- --------------------
>> > Keith Dart
>> > <keith at dartworks.biz>
>> > =======================
>> > _______________________________________________
>> > Baypiggies mailing list
>> > Baypiggies at python.org
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