Signal source: 433 MHz ISM band, AM demodulated wave file


https://ibb.co/eYXPY8

Part of the signal zoomed with Pyplot zoom tool

https://ibb.co/cBQ6fo

from scipy.io import wavfile
from matplotlib import pyplot as plt
import numpy as np

x_offset_lo = 0.348
x_offset_hi = 0.82
y_offset_lo = 140
y_offset_hi = 200
y_lim = 150
y_val = 176

def printWaveInfo():
    print 'Len ' + str(data.shape[0])
    print 'Channels ' + str(data.shape[1])
    print 'Datatype ' + str(data.dtype)
    print 'Samplerate ' + str(sampleRate)

def setYvalues():
    x = 0
    while x < len(data):
        if data[x, 0] > y_lim:
            data[x, 0] = y_val
        x += 1
    
sampleRate, dataVal = wavfile.read('af433-926.wav')
data = np.copy(dataVal)

printWaveInfo()
setYvalues()

times = np.arange(len(data))/float(sampleRate)

plt.figure(figsize=(19, 10))
plt.suptitle('433.926 MHz')
plt.subplot(311)
plt.style.use('seaborn')
plt.xlim(times[0] + x_offset_lo, times[-1] - x_offset_hi)
plt.ylim(y_offset_lo, y_offset_hi)
plt.xlabel('Time (s)')
plt.ylabel('Amplitude')
plt.grid(True)
plt.plot(times, data[:,0], color = 'k')

plt.subplot(312)
plt.style.use('seaborn')
plt.xlim(times[0] + x_offset_lo, times[-1] - x_offset_hi)
plt.ylim(y_offset_lo, y_offset_hi)
plt.xlabel('Time (s)')
plt.ylabel('Amplitude')
plt.grid(True)
plt.plot(times, dataVal[:,0], color = 'b')

plt.subplot(313)
plt.style.use('seaborn')
plt.xlim(times[0], times[-1])
plt.xlabel('Time (s)')
plt.ylabel('Amplitude')
plt.grid(True)
plt.plot(times, dataVal[:,0], color = 'y')

plt.show()