File:Rayleigh fading.png
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Summary
| Description |
English: Developed according to [1] |
| Date | |
| Source | Own work |
| Author | Kirlf |
| PNG development |  This plot was created with Matplotlib. |
| Source code | Python codeimport numpy as np
from scipy import signal
import matplotlib.pyplot as plt
fs=2*np.pi*120 / 512 # sampling frequency (rad/s / samples)
ts = 1 / 120 # sampling period
""" Filter order """
N, Wn = signal.buttord(wp=0.1,
ws=0.3,
gpass=3,
gstop=40,
analog=False,
fs=fs)
""" Filter """
b, a = signal.butter(N, Wn, 'low',
analog=False)
""" Frequencies """
w, h = signal.freqz(b, a,
worN=512,
whole=True,
fs=fs)
""" Rayleigh series"""
sigma = 0.12 # variance
leng = 10000 # number of samples
""" I and Q components """
ii = np.random.randn(leng, 1) * sigma
qq = np.random.randn(leng, 1) * sigma
rayleigh = ii + 1j * qq
rayleigh = [i[0] for i in rayleigh]
""" Filtering """
ryfaux = signal.filtfilt(b, a, list(rayleigh))
ry_mod = abs(ryfaux)
t_axis = np.array([i for i in range(leng)])*ts
""" Plotting """
plt.subplots(figsize=(12, 7))
ax1 = plt.subplot(212)
ax1.margins(2, 2)
ax1.plot(t_axis, 20*np.log10(ry_mod))
ax1.axis([10, 12, -50, -10])
ax1.set_xlabel('Time (s)')
ax1.set_ylabel('Relative signal level (dB)')
ax1.set_title('Rayleigh fading series (filtered)')
ax1.grid(which='both', axis='both')
ax2 = plt.subplot(221)
ax2.plot(w * 512 / (2*np.pi), 20*np.log10(abs(h)))
ax2.axis([0, 31, -71, 0])
ax2.margins(.05)
ax2.set_title('Doppler filter responce (Butterworth lowpass digital filter)')
ax2.set_xlabel('Frequence (Hz)')
ax2.set_ylabel('Magnitude of frequency response (dB)')
ax2.grid(which='both', axis='both')
ax3 = plt.subplot(222)
ax3.margins(x=0, y=-0.25)
ax3.plot(t_axis, 20*np.log10(abs(np.array(rayleigh))))
ax3.axis([10, 12, -50, -10])
ax3.set_xlabel('Time (s)')
ax3.set_ylabel('Relative signal level (dB)')
ax3.set_title('Rayleigh fading series')
ax3.grid(which='both', axis='both')
plt.savefig("rayleigh_fading.png")
|
Licensing
I, the copyright holder of this work, hereby publish it under the following license:
This file is licensed under the Creative Commons Attribution-Share Alike 4.0 International license.
- You are free:
- to share – to copy, distribute and transmit the work
- to remix – to adapt the work
- Under the following conditions:
- attribution – You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use.
- share alike – If you remix, transform, or build upon the material, you must distribute your contributions under the same or compatible license as the original.
- ↑ Fontæn, F.P. and Espiæeira, P.M., 2008. Modelling the wireless propagation channel: a simulation approach with Matlab (Vol. 5). John Wiley & Sons. - p. 123 - 129
File history
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| Date/Time | Thumbnail | Dimensions | User | Comment | |
|---|---|---|---|---|---|
| current | 20:12, 19 October 2021 | | 864 × 504 (82 KB) | Kirlf | Uploaded own work with UploadWizard |
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