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In this article, the editor introduces in detail "how to achieve the simulation two-path effect in Python". The content is detailed, the steps are clear, and the details are handled properly. I hope this article "how to achieve the simulation two-path effect in Python" can help you solve your doubts.

Multipath effect

Multipath effect (multipath effect): after the electromagnetic wave propagates through different paths, the arrival time of each component field to the receiver is different, which causes interference according to their respective phases, resulting in distortion or error of the original signal. For example, if the electromagnetic wave propagates along two different paths, and the length of the two paths is exactly half a wavelength apart, then the two signals cancel each other out when they reach the end point (the peaks and troughs coincide). Some approximate methods are usually used to describe the propagation characteristics of signals, and one of the most common approximate methods is ray tracing calculation. The ray tracing model approximates the wavefront to simple particles, and then determines the influence of reflection and refraction on the wavefront. The simplest ray tracking model is the two-path model, which means that there is only one direct path and one reflection path between the transmitter and the receiver. The reflected signal in the two-path model is generally reflected from the ground. For the signal propagation on highways, rural roads and water surface, the two-path model is a good approximation and can accurately reflect the propagation characteristics of the signal.

Two-diameter model

The two-path model is used in the case where a single ground reflection wave plays a leading role in the multipath effect, as shown in the following figure. The received signal consists of two parts: the direct component which reaches the receiver through the free space and the reflection component that reaches the receiver through the ground reflection.

Pt is the transmit power, Gt is the product of self-incident antenna gain, GaGb,Gr is the product of antenna gain, GcGd,l is the path of reflection, x0+x1 is the path of reflection, △ φ is the phase difference between reflection path and direct path, △ φ = 2 Pi (x0+x1-l) / λ, reflection coefficient R ≈ 0.9.

Model analysis

Suppose the communication frequency is 2000MHz, the height of the base station is 1m, and the height of the handheld terminal is 1m, then θ = actan (1/18x2) = 6.353 °, x0=x1=1/sin (6.353 °) = 9.0373m, △ φ = 360 °x (x0 + x1Mul) / λ = 179°. The phase difference between the incident wave and the reflected wave is close to 180 °and cancel each other out. At this time, the receiving power is minimized.

According to the above set value, draw the receiving power diagram of the 4m-150m:

Two-path model simulation program

Import numpy as npimport matplotlib.pyplot as pltdef Radiation (theta Kt=0.2): theta = theta+np.pi/2 pi = np.pi gmax_t = (np.cos (2 * pi * kt * np.cos (pi/2))-np.cos (2 * pi * kt)) / np.sin (pi/2) gain = (np.cos (2 * pi * kt * np.cos (theta))-np.cos (2 * pi * kt)) / np.sin (theta) / gmax_t return gain* * 2def multipath_effect (): Hagj = 1 for i in range c = 1 f = 2 lamda = 0.3 / f x = [] y = [] for i in range (20 1500): l = I / 10 x.append (l) lumbc = hagc / (hexamj + hexamc) * l lumbj = hexamj / (hexamj + hexamc) * l lx = (hallelc * * 2 + lumbc * * 2) * * 0.5 + (hexamj * 2 + lumbj * * 2) * Ly = (l * * 2 + (hexamc-hexamj) * * 2) * * 0.5lqd = lx-ly phase = Laudd / lamda * 2 * np.pi theta_z = np.arctan (abs (hexamj-hallelc) / l) theta_f = np.arctan (hexamj / hexamj) tmp = Radiation (theta_z) * Radiation (theta_z) / ly * 2 + Radiation (theta_f) * Radiation (theta_f) / lx * * 2 * np.sin (phase) y.append (20 * np.log10 (tmp)) plt.plot (x Y, 'rmuri') plt.show () multipath_effect () read here This article "how to achieve the two-path effect of Python" has been introduced. If you want to master the knowledge points of this article, you still need to practice and use it yourself. If you want to know more about related articles, welcome to follow the industry information channel.

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