def build_graph (input, raw, snr, freq_offset, coeffs, mag):
# Initialize empty flow graph
fg = gr.top_block ()
# Set up file source
src = gr.file_source (1, input)
# Set up GMSK modulator, 2 samples per symbol
mod = gmsk_mod(2)
# Amplify the signal
tx_amp = 1
amp = gr.multiply_const_cc(1)
amp.set_k(tx_amp)
# Compute proper noise voltage based on SNR
SNR = 10.0**(snr/10.0)
power_in_signal = abs(tx_amp)**2
noise_power = power_in_signal/SNR
noise_voltage = math.sqrt(noise_power)
# Generate noise
rseed = int(time.time())
noise = gr.noise_source_c(gr.GR_GAUSSIAN, noise_voltage, rseed)
adder = gr.add_cc()
fg.connect(noise, (adder, 1))
# Create the frequency offset, 0 for now
offset = gr.sig_source_c(1, gr.GR_SIN_WAVE, freq_offset, 1.0, 0.0)
mixer = gr.multiply_cc()
fg.connect(offset, (mixer, 1))
# Pass the noisy data to the matched filter
dfile = open(coeffs, 'r')
data = []
for line in dfile:
data.append(complex(*map(float,line.strip().strip("()").split(" "))).conjugate())
dfile.close()
data.reverse()
mfilter = gr.fir_filter_ccc(1, data)
# Connect the flow graph
fg.connect(src, mod)
fg.connect(mod, (mixer, 0))
fg.connect(mixer, (adder, 0))
if mag:
raw_dst = gr.file_sink (gr.sizeof_float, raw)
magnitude = gr.complex_to_mag(1)
fg.connect(adder, mfilter, magnitude, raw_dst)
else:
raw_dst = gr.file_sink (gr.sizeof_gr_complex, raw)
fg.connect(adder, mfilter, raw_dst)
print "SNR(db): " + str(snr)
print "Frequency Offset: " + str(freq_offset)
return fg
def build_graph(outfile): # Initialize our top block fg = gr.top_block() # Input #input = [0xA4, 0xF2, 0xAC, 0xDD, 0xA4, 0xE2, 0xF2, 0x8C, 0x20, 0xFC, 0x00, 0x00, 0x00, 0x02] input = [0xAC, 0xDD, 0xA4, 0xE2, 0xF2, 0x8C, 0x20, 0xFC] # Unsigned char source to use the input src = gr.vector_source_b(input) # Set up GMSK modulator, 2 samples per symbol mod = gmsk_mod(2) # File sink fsink = gr.file_sink(gr.sizeof_gr_complex, outfile) fg.connect(src, mod, fsink) return fg
def build_graph (input, raw, amp):
# Initialize empty flow graph
fg = gr.top_block ()
# Set up file source
src = gr.file_source (1, input)
# Set up GMSK modulator, 2 samples per symbol
mod = gmsk_mod(2)
# Set up an amp
amp = gr.multiply_const_cc(amp)
# Connect the flow graph
raw_dst = gr.file_sink (gr.sizeof_gr_complex, raw)
fg.connect(src, mod)
fg.connect(mod, amp)
fg.connect(amp, raw_dst)
return fg
def test_with_phy(self):
sps = 4
mod = gmsk.gmsk_mod(
samples_per_symbol=sps,
bt=0.35,
verbose=False,
log=False,
)
demod = gmsk.gmsk_demod(
samples_per_symbol=sps,
gain_mu=0.175,
mu=0.5,
omega_relative_limit=0.005,
freq_error=0.0,
verbose=False,
log=False,
)
framer = gras.make('/grex/packet_framer',
samples_per_symbol = sps,
bits_per_symbol = 1,
)
burst_tagger = gras.make('/grex/burst_tagger', sps)
deframer = gras.make('/grex/packet_deframer')
src_data = tuple(numpy.random.randint(-1024, 1024, 11)) #40 bytes + padding
src = TestUtils.VectorSource(numpy.int32, src_data)
dst = TestUtils.VectorSink(numpy.int32)
s2d = gras.make('/grex/stream_to_datagram', numpy.dtype(numpy.int32).itemsize, 40) #mtu 40 bytes
d2s = gras.make('/grex/datagram_to_stream', numpy.dtype(numpy.int32).itemsize)
delay = gras.make('/grex/delay', numpy.dtype(numpy.complex64).itemsize)
delay.set_delay(73) #sample delay
#inject noise into the system
noise = gras.make('/grex/noise_source_fc32', -1)
noise.set_amplitude(0.05)
add = gras.make('/grex/add_fc32_fc32')
self.tb.connect(noise, (add, 1))
self.tb.connect(src, s2d, framer, mod, burst_tagger, delay, add, demod, deframer, d2s, dst)
#collect tags
tag_sink = TagSink()
self.tb.connect(add, tag_sink)
self.tb.start()
time.sleep(1.0)
self.tb.stop()
self.tb.wait()
self.tb.disconnect_all()
print "src_data", src_data
print "dst_data", dst.data()
print "tag_sink", tag_sink.data()
n = min(map(len, (src_data, dst.data())))
print n
self.assertTrue(n > 0)
self.assertEqual(src_data[:n], dst.data()[:n])
def test_with_phy(self):
sps = 4
mod = gmsk.gmsk_mod(
samples_per_symbol=sps,
bt=0.35,
verbose=False,
log=False,
)
demod = gmsk.gmsk_demod(
samples_per_symbol=sps,
gain_mu=0.175,
mu=0.5,
omega_relative_limit=0.005,
freq_error=0.0,
verbose=False,
log=False,
)
framer = gras.make(
'/grex/packet_framer',
samples_per_symbol=sps,
bits_per_symbol=1,
)
burst_tagger = gras.make('/grex/burst_tagger', sps)
deframer = gras.make('/grex/packet_deframer')
src_data = tuple(numpy.random.randint(-1024, 1024,
11)) #40 bytes + padding
src = TestUtils.VectorSource(numpy.int32, src_data)
dst = TestUtils.VectorSink(numpy.int32)
s2d = gras.make('/grex/stream_to_datagram',
numpy.dtype(numpy.int32).itemsize, 40) #mtu 40 bytes
d2s = gras.make('/grex/datagram_to_stream',
numpy.dtype(numpy.int32).itemsize)
delay = gras.make('/grex/delay', numpy.dtype(numpy.complex64).itemsize)
delay.set_delay(73) #sample delay
#inject noise into the system
noise = gras.make('/grex/noise_source_fc32', -1)
noise.set_amplitude(0.05)
add = gras.make('/grex/add_fc32_fc32')
self.tb.connect(noise, (add, 1))
self.tb.connect(src, s2d, framer, mod, burst_tagger, delay, add, demod,
deframer, d2s, dst)
#collect tags
tag_sink = TagSink()
self.tb.connect(add, tag_sink)
self.tb.start()
time.sleep(1.0)
self.tb.stop()
self.tb.wait()
self.tb.disconnect_all()
print "src_data", src_data
print "dst_data", dst.data()
print "tag_sink", tag_sink.data()
n = min(map(len, (src_data, dst.data())))
print n
self.assertTrue(n > 0)
self.assertEqual(src_data[:n], dst.data()[:n])
