PythonでAM変調、復調 その2

概要

PythonでAM変調、復調やってみた。
復調器は、GNURadio AM Demod。

写真

フローグラフ

サンプルコード

from gnuradio import analog
from gnuradio import audio
from gnuradio import blocks
from gnuradio import eng_notation
from gnuradio import filter
from gnuradio import gr
from gnuradio.eng_option import eng_option
from gnuradio.filter import firdes
from optparse import OptionParser
import sys
import scipy
import numpy as np
import scipy.signal as sg
import pylab

class radio(gr.top_block):
    def __init__(self, vam):
        gr.top_block.__init__(self)
        self.samp_rate = samp_rate = 32000
        self.blocks_vector_source_x_0 = blocks.vector_source_f(vam.tolist(), False, 1, [])
        self.hilbert_fc_0 = filter.hilbert_fc(65, firdes.WIN_HAMMING, 6.76)
        self.blocks_vector_sink_x_0 = blocks.vector_sink_f(1)
        self.analog_am_demod_cf_0 = analog.am_demod_cf(channel_rate=32000, audio_decim=1, audio_pass=8000, audio_stop=8100,)
        self.connect((self.hilbert_fc_0, 0), (self.analog_am_demod_cf_0, 0))
        self.connect((self.blocks_vector_source_x_0, 0), (self.hilbert_fc_0, 0))
        self.connect((self.analog_am_demod_cf_0, 0), (self.blocks_vector_sink_x_0, 0))
def main():
    sample_rate = 32000.
    nsamples = 320
    F_1 = 1000.
    A_1 = 1.0
    F_2 = 10000.
    A_2 = 0.5 
    t = np.arange(nsamples) / sample_rate
    vin = A_1 * np.sin(2 * np.pi * F_1 * t) 
    vam = (A_1 * np.sin(2 * np.pi * F_1 * t) + 1.0) * A_2 * np.sin(2 * np.pi * F_2 * t)
    put = radio(vam)
    put.run()
    data = scipy.array(put.blocks_vector_sink_x_0.data())
    f1 = pylab.figure(1, figsize = (12, 10), facecolor = 'w')
    s1 = f1.add_subplot(2, 2, 1)
    s1.plot(vin)
    s3 = f1.add_subplot(2, 2, 2)
    s3.plot(vam)
    s4 = f1.add_subplot(2, 2, 3)
    s4.plot(data)
    pylab.show()
if __name__ == "__main__":
    try:
        main()
    except KeyboardInterrupt:
        pass