Propagation Models

Propagation models are used for inputting the information gather to predict the radio proapation. The models can be theoretical and empirical depending on the usecases.

• Theoretical Models
• Empirical Models

Thoretical Models

Theoretical model is a class which contains the functions for calculating propagation based on the theoretical radio propagation models.

• Initialization
• calculate_free_space_loss
• calculate_reflection_coefficient
• calculate_single_reflection_loss

Initialization

input

• result: Object, a result object with contain the ray tracing information such as line of sight, tx and rx positions.

Example

The result from the ray tracer can be calculated by the propagation models in radio_gyms.models. In this example, TheoreticalOutdoorModel can compute the traced results to predict the signal strength and delay between the receiver and transmitter based on the theoretical radio propagation models.

from radio_gyms.models import TheoreticalOutdoorModel
result = {
    'direct': False, 
    'reflections': {'single': [ [-28.94988531, 4.22886929, 62.39469675],
                                [-70.80339945, 7.04682531, 15.22840999]],
                    'double': []},
    'roof_edges': [[-19.24403786, 8.5621709 , 28.8660568 ]],
    'tx_pos': [ 0, 15, 0],
    'rx_pos': [-30., 1.5, 45. ],
}
model = TheoreticalOutdoorModel(result, tx_power_dbm=20)
maximum_received_power = model.calculate_max_received_power(frequency=5.4e9) 
# -72.51 dBm
impulses = model.calculate_signal_impulses(freq=5.4e9)
# [{'strength': -85.94590320344925, 'delay': 1.8653420787826134e-07},
# {'strength': -74.3214622218488, 'delay': 2.910702009034143e-07}, 
# {'strength': -77.80902883055407, 'delay': 4.125241781539828e-07}]

calculate_free_space_loss(tx_pos, rx_pos, frequency, wave_speed)

input

• tx_pos: List, transmitting position.
• rx_pos: List, receiving position.
• frequency: float, frequency of radio wave.
• wave_speed: float, speed of propagating wave.

output

• free_space_loss: float, free space loss in dB.

calculate_reflection_coefficient(tx_pos, rx_pos, ref_pos, tx_medium_permittivity,ref_medium_permittivity, polar)

input

• tx_pos: List, trasnmitting position.
• rx_pos: List, receiving position.
• ref_pos: List, reflecting position.
• tx_medium_permittivity: float, medium permitivity of the incident wave.
• ref_medium_permittivity: float, medium permitivity of the reflected wave.
• polar: str ('TM' or 'TE'), wave polarization at reflecting point.

output

• reflection_coefficient: float, reflection coefficient.

calculate_single_reflection_loss(tx_pos, rx_pos, ref_pos, frequency, tx_medium_permittivity, ref_medium_permittivity,polar,wave_speed)

input

• tx_pos: List, trasnmitting position.
• rx_pos: List, receiving position.
• ref_pos: List, reflecting position.
• frequency: float, frequency of radio wave.
• tx_medium_permittivity: float, medium permitivity of the incident wave.
• ref_medium_permittivity: float, medium permitivity of the reflected wave.
• polar: str ('TM' or 'TE'), wave polarization at reflecting point.
• wave_speed: float, speed of propagating wave.

output

• reflection_loss: float, reflection loss in dB.

calculate_double_reflection_loss(tx_pos, rx_pos, ref1_pos, ref2_pos, frequency, tx_medium_permittivity, ref_medium_permittivity, polar, wave_speed)

input

• tx_pos: List, trasnmitting position.
• rx_pos: List, receiving position.
• ref1_pos: List, first reflecting position.
• ref2_pos: List, second reflecting position.
• frequency: float, frequency of radio wave.
• tx_medium_permittivity: float, medium permitivity of the incident wave.
• ref_medium_permittivity: float, medium permitivity of the reflected wave.
• polar: str ('TM' or 'TE'), wave polarization at reflecting point.
• wave_speed: float, speed of propagating wave.

output

• reflection_loss: float, reflection loss in dB.

calculate_knife_edge_diffraction(tx_pos, rx_pos, frequency, edges, wave_speed)

input

• tx_pos: List, trasnmitting position.
• rx_pos: List, receiving position.
• frequency: float, frequency of radio wave.
• edges: List[List], List of edge positions.
• wave_speed: float, speed of propagating wave.

output

• diffraction_loss: float, diffraction loss in dB.

calculate_max_received_power(self, frequency: float = 2.4e9, wave_speed)

input

• frequency: float, frequency of radio wave.
• wave_speed: float, speed of propagating wave.

output

• max_receiving_power: float, expected maximum of receiving power in dBm

calculate_signal_delay(tx_pos, rx_pos, points, wave_speed)

input

• tx_pos: List, trasnmitting position.
• rx_pos: List, receiving position.
• points: List[List], list of radio traveling positions.
• wave_speed: float, speed of propagating wave.

output

• delay: float, signal delay in second

Empirical Models

Hata Model

WINNER CHANNEL II Model