pathloss

Path loss of radio wave propagation

collapse all in page

Syntax

pl = pathloss(propmodel,rx,tx)
pl = pathloss(___,Name=Value)
[pl,info] = pathloss(___)

Description

pl = pathloss(propmodel,rx,tx) calculates the path loss of radio wave propagation at the receiver site from the transmitter site using the specified propagation model.

example

pl = pathloss(___,Name=Value) calculates the path loss using additional options specified by name-value arguments.

[pl,info] = pathloss(___) additionally returns information about the propagation paths.

Examples

collapse all

Open Live Script

Create a transmitter site and a receiver site.

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 a propagation model for heavy rain. Then, calculate the path loss at the receiver site using the propagation model.

pm = propagationModel("rain",RainRate=50);
pl = pathloss(pm,rx,tx)
pl = 127.3208

Input Arguments

collapse all

Propagation model to use for the path loss calculations, specified as one of these objects:

  • FreeSpace object — Free space propagation model

  • Rain object — Rain propagation model

  • Gas object — Gas propagation model

  • Fog object — Fog propagation model

  • CloseIn object — Close-in propagation model

  • LongleyRice object — Longley-Rice propagation model

  • TIREM object — TIREM™ propagation model

  • RayTracing object — Ray tracing propagation model

Create propagation models by using the propagationModel function.

When you specify propmodel as a propagation model that incorporates terrain, the function computes path loss by creating a terrain elevation profile with sample locations on the great circle path between rx and tx. The function uses the terrain specified by the Map argument. When Map is a Site Viewer object with buildings data, the function adjusts the elevation profile to include the buildings profile.

Receiver site, specified as an rxsite object or an array of rxsite objects.

Transmitter site, specified as a txsite object or an array txsite objects.

Name-Value Arguments

collapse all

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.

Example: pathloss(propmodel,rx,tx,Map="none")

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

Example: pathloss(propmodel,rx,tx,"Map","none")

Map for visualization or surface data, specified as a siteviewer object, a triangulation object, a string scalar, or a character vector. Valid and default values depend on the coordinate system.

Coordinate SystemValid map valuesDefault map value
"geographic"

  • A siteviewer objecta

  • A terrain name, if the function is called with an output argument. Valid terrain names are "none", "gmted2010", or the name of the custom terrain data added using addCustomTerrain.

  • The current siteviewer object or a new siteviewer object if none are open

  • "gmted2010", if the function is called with an output

"cartesian"

  • "none"

  • A siteviewer object

  • The name of a glTF™ file

  • The name of an STL file

  • A triangulation object

  • "none"

a Alignment of boundaries and region labels are a presentation of the feature provided by the data vendors and do not imply endorsement by MathWorks®.

In most cases, if you specify this argument as a value other than a siteviewer or "none", then you must also specify an output argument.

Data Types: char | string

Output Arguments

collapse all

Path loss, returned as a scalar or as an M-by-N cell array, where each cell contains a row vector of path losses in decibels. M is the number of transmitter sites and N is the number of receiver sites.

Supplementary information about the path loss, returned as an M-by-N structure array or an M-by-N cell array. M is the number of transmitter sites and N is the number of receiver sites.

The format of info depends on the value of propmodel.

Value of propmodelFormat of info

  • FreeSpace object

  • Rain object

  • Gas object

  • Fog object

  • CloseIn object

  • LongleyRice object

  • TIREM object

info is an M-by-N structure array with these fields:

  • PropagationDistance — Distance between the transmitter site and receiver site, returned as a double scalar in meters.

  • AngleOfDeparture — Angle of departure from the transmitter site, returned as a 2-by-1 double vector of azimuth and elevation angles in degrees.

  • AngleOfArrival — Angle of arrival to the receiver site, returned as a 2-by-1 double vector of azimuth and elevation angles in degrees.

The function calculates PropagationDistance, AngleOfDeparture, and AngleOfArrival using the Euclidean path between the sites.

  • RayTracing object

info is an M-by-N cell array. Each cell array contains a structure array that corresponds to a propagation path. The structure arrays have these fields:

  • PropagationDistance — Length of the propagation path, returned as a double scalar in meters.

  • AngleOfDeparture — Angle of the propagation path departing the transmitter, returned as a 2-by-1 double vector of azimuth and elevation angles in degrees.

  • AngleOfArrival — Angle of the propagation path arriving at the receiver, returned as a 2-by-1 double vector of azimuth and elevation angles in degrees.

  • NumReflections — Number of reflections along the propagation path, returned as a nonnegative integer.

  • NumDiffractions — Number of diffractions along the propagation path, returned as 0, 1, or 2.

For all propagation models, the interpretation of AngleOfDeparture and AngleOfArrival depends on the CoordinateSystem property of tx and rx.

  • When CoordinateSystem is "geographic", the angle values are defined using the local east-north-up coordinate system of the antenna. The azimuth angle is measured from east.

  • When CoordinateSystem is "cartesian", the angle values are defined using the global Cartesian coordinate system. The azimuth angle is measured from the global x-axis around the global z-axis.

The elevation angle is measured from the horizontal (or xy) plane to the x-axis of the antenna, in the range –90 to 90.

References

[1] International Telecommunications Union Radiocommunication Sector. Effects of Building Materials and Structures on Radiowave Propagation Above About 100MHz. Recommendation P.2040. ITU-R, approved August 23, 2023. https://www.itu.int/rec/R-REC-P.2040/en.

[2] International Telecommunications Union Radiocommunication Sector. Electrical Characteristics of the Surface of the Earth. Recommendation P.527. ITU-R, approved September 27, 2021. https://www.itu.int/rec/R-REC-P.527/en.

[3] Mohr, Peter J., Eite Tiesinga, David B. Newell, and Barry N. Taylor. “Codata Internationally Recommended 2022 Values of the Fundamental Physical Constants.” NIST, May 8, 2024. https://www.nist.gov/publications/codata-internationally-recommended-2022-values-fundamental-physical-constants.

Extended Capabilities

expand all

Version History

Introduced in R2017b

expand all

See Also

|

Topics