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pathloss

Path loss of radio wave propagation

Since R2019b

Description

example

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

pl = pathloss(___,Name,Value) returns the path loss using additional options specified by Name,Value pairs.

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

Examples

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Specify the transmitter and the receiver sites.

tx = txsite('Name','bat365 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 heavy rainfall rate.

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

    RainRate: 50
        Tilt: 0

Calculate the pathloss at the receiver using the rain propagation model.

pl = pathloss(pm,rx,tx)
pl = 127.3208

Input Arguments

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Propagation model, specified as a FreeSpace, Rain, Gas, Fog, CloseIn, LongleyRice, TIREM (Antenna Toolbox), or RayTracing object.

Create propagation models by using the propagationModel function.

Receiver site, specified as a rxsite object. You can use array inputs to specify multiple sites.

Transmitter site, specified as a txsite object. You can use array inputs to specify multiple sites.

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: '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 bat365®.

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

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Path loss, returned as a scalar or M-by-N cell arrays containing a row vector of path loss values in decibels. M is the number of TX sites and N is the number of RX sites.

Path loss is computed along the shortest path through space connecting the transmitter and receiver antenna centers.

For terrain propagation models, path loss is computed using terrain elevation profile that is computed at sample locations on the great circle path between the transmitter and the receiver. If Map is a siteviewer object with buildings specified, the terrain elevation is adjusted to include the height of the buildings.

Information corresponding to each propagation path, returned as a M-by-N cell array containing vector of structures in each cell for ray tracing propagation models and M-by-N structure array for all other propagation models. The field and values for the structures are:

  • PropagationDistance — Total distance of propagation path returned as a double scalar in meters.

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

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

  • NumReflections — Number of reflections undergone by signal along propagation path, returned specified as 0, 1, or 2. This field and value is only for ray tracing propagation models.

Angle values in this structure are defined using the local East-North-Up coordinate system of the antenna when CoordinateSystem is set to geographic. Angle values in this structure are defined using global Cartesian coordinate system when CoordinateSystem is set to cartesian. Azimuth angle is measured either from east (when 'geographic') or from the global x-axis around the global z-axis (when 'cartesian'). Elevation angle is measured from the horizontal (or X-Y) plane to the x-axis of the antenna in the range -90 to 90.

Version History

Introduced in R2019b

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