Main Content

propagationModel

Create RF propagation model

Syntax

``pm = propagationModel(modelname)``
``pm = propagationModel(___,Name,Value)``

Description

````pm = propagationModel(modelname)` creates an RF propagation model for the specified model.```

example

````pm = propagationModel(___,Name,Value)` specifies options using name-value arguments. For example, ```pm = propagationModel("rain","RainRate",96)``` creates a rain propagation model with a rain rate of 96 mm/h.```

Examples

collapse all

Specify transmitter and receiver sites.

```tx = txsite('Name','MathWorks Apple Hill',... 'Latitude',42.3001, ... 'Longitude',-71.3504, ... 'TransmitterFrequency', 2.5e9); rx = rxsite('Name','Fenway Park',... 'Latitude',42.3467, ... 'Longitude',-71.0972);```

Create the propagation model for a heavy rainfall rate.

`pm = propagationModel('rain','RainRate',50)`
```pm = Rain with properties: RainRate: 50 Tilt: 0 ```

Calculate the signal strength at the receiver using the rain propagation model.

`ss = sigstrength(rx,tx,pm)`
```ss = -87.1559 ```

Create a default transmitter site.

`tx = txsite;`

Create a Longley-Rice propagation model by using the `propagationModel` function.

`pm = propagationModel("longley-rice","TimeVariabilityTolerance",0.7)`
```pm = LongleyRice with properties: AntennaPolarization: 'horizontal' GroundConductivity: 0.0050 GroundPermittivity: 15 AtmosphericRefractivity: 301 ClimateZone: 'continental-temperate' TimeVariabilityTolerance: 0.7000 SituationVariabilityTolerance: 0.5000 ```

Find the coverage of the transmitter site by using the defined propagation model.

`coverage(tx,"PropagationModel",pm)`

Input Arguments

collapse all

Name of propagation model, specified as one of these options. Each option creates a different type of object.

OptionDescriptionObject
`"freespace"`

Free space propagation model.

`FreeSpace`
`"rain"`

Rain propagation model. For more information, see [3].

`Rain`
`"gas"`

Gas propagation model. For more information, see [6].

`Gas`
`"fog"`

Fog propagation model. For more information, see [2].

`Fog`
`"close-in"`

Close-in propagation model typically used in urban macro-cell scenarios. For more information, see [1].

Note

The close-in model implements a statistical path loss model and can be configured for different scenarios. The default values correspond to an urban macro-cell scenario in a non-line-of-sight (NLOS) environment.

`CloseIn`
`"longley-rice"`

Longley-Rice propagation model. This model is also known as Irregular Terrain Model (ITM). You can use this model to calculate point-to-point path loss between sites over an irregular terrain, including buildings. Path loss is calculated from free-space loss, terrain diffraction, ground reflection, refraction through atmosphere, tropospheric scatter, and atmospheric absorption. For more information and list of limitations, see [4].

Note

The Longley-Rice model implements the point-to-point mode of the model, which uses terrain data to predict the loss between two points.

`LongleyRice`
`"tirem"`

Terrain Integrated Rough Earth Model™ (TIREM™). You can use this model to calculate point-to-point path loss between sites over an irregular terrain, including buildings.

Path loss is calculated from free-space loss, terrain diffraction, ground reflection, refraction through atmosphere, tropospheric scatter, and atmospheric absorption.

This model needs access to an external TIREM library. The actual model is valid from 1 MHZ to 1000 GHz, but with Antenna Toolbox™ elements and arrays, the frequency range is limited to 200 GHz.

`TIREM`
`"raytracing"`

A multipath propagation model that uses ray tracing analysis to compute propagation paths and corresponding path losses. Path loss is calculated from free-space loss, reflection and diffraction loss due to interactions with materials, and antenna polarization loss.

You can perform ray tracing analysis using the shooting and bouncing rays (SBR) method or the image method. Specify a method using the `Method` name-value argument.

• The SBR method includes effects from surface reflections and edge diffractions but does not include effects from corner diffraction, refraction, or rough-surface diffuse scattering.

• The image method considers only surface reflections.

Both ray tracing methods are reasonable for a frequency range of 100 MHz to 100 GHz. For information about differences between the image and SBR methods, see Choose a Propagation Model.

Use the `raytrace` function to compute and plot the propagation paths between the sites.

`RayTracing`

Data Types: `char` | `string`

Name-Value Arguments

Specify optional pairs of arguments as `Name1=Value1,...,NameN=ValueN`, where `Name` is the argument name and `Value` is the corresponding value. Name-value arguments must appear after other arguments, but the order of the pairs does not matter.

Before R2021a, use commas to separate each name and value, and enclose `Name` in quotes.

Example: `propagationModel("rain","RainRate",50)` sets the rate of rainfall in the rain propagation model to 50 millimeters per hour.

Each type of propagation model object supports a different set of properties. For a full list of the properties and their descriptions for a propagation model type, see the associated object page.

Type of Propagation ModelObject Page
`"freespace"``FreeSpace`
`"rain"``Rain`
`"gas"``Gas`
`"fog"``Fog`
`"close-in"``CloseIn`
`"longley-rice"``LongleyRice`
`"tirem"``TIREM`
`"raytracing"``RayTracing`

collapse all

References

[1] Sun, Shu, Theodore S. Rappaport, Timothy A. Thomas, Amitava Ghosh, Huan C. Nguyen, Istvan Z. Kovacs, Ignacio Rodriguez, Ozge Koymen, and Andrzej Partyka. “Investigation of Prediction Accuracy, Sensitivity, and Parameter Stability of Large-Scale Propagation Path Loss Models for 5G Wireless Communications.” IEEE Transactions on Vehicular Technology 65, no. 5 (May 2016): 2843–60. https://doi.org/10.1109/TVT.2016.2543139.

[2] International Telecommunications Union Radiocommunication Sector. Attenuation due to clouds and fog. Recommendation P.840-6. ITU-R, approved September 30, 2013. https://www.itu.int/rec/R-REC-P.840/en.

[3] International Telecommunications Union Radiocommunication Sector. Specific attenuation model for rain for use in prediction methods. Recommendation P.838-3. ITU-R, approved March 8, 2005. https://www.itu.int/rec/R-REC-P.838/en.

[4] Hufford, George A., Anita G. Longley, and William A.Kissick. A Guide to the Use of the ITS Irregular Terrain Model in the Area Prediction Mode. NTIA Report 82-100. National Telecommunications and Information Administration, April 1, 1982.

[5] Seybold, John S. Introduction to RF Propagation. Hoboken, N.J: Wiley, 2005.

[6] International Telecommunications Union Radiocommunication Sector. Attenuation by atmospheric gases. Recommendation P.676-11. ITU-R, approved September 30, 2016. https://www.itu.int/rec/R-REC-P.676/en.

[7] International Telecommunications Union Radiocommunication Sector. Effects of building materials and structures on radiowave propagation above about 100MHz. Recommendation P.2040-1. ITU-R, approved July 29, 2015. https://www.itu.int/rec/R-REC-P.2040/en.

[8] International Telecommunications Union Radiocommunication Sector. Electrical characteristics of the surface of the Earth. Recommendation P.527-5. ITU-R, approved August 14, 2019. https://www.itu.int/rec/R-REC-P.527/en.

[9] Yun, Zhengqing, and Magdy F. Iskander. “Ray Tracing for Radio Propagation Modeling: Principles and Applications.” IEEE Access 3 (2015): 1089–1100. https://doi.org/10.1109/ACCESS.2015.2453991.

[10] Schaubach, K.R., N.J. Davis, and T.S. Rappaport. “A Ray Tracing Method for Predicting Path Loss and Delay Spread in Microcellular Environments.” In [1992 Proceedings] Vehicular Technology Society 42nd VTS Conference - Frontiers of Technology, 932–35. Denver, CO, USA: IEEE, 1992. https://doi.org/10.1109/VETEC.1992.245274.

Version History

Introduced in R2017b

expand all