sinr

Display or compute signal-to-interference-plus-noise (SINR) ratio

Since R2019b

Syntax

sinr(txs)

sinr(txs,propmodel)

sinr(___,Name,Value)

pd = sinr(txs,___)

r = sinr(rxs,txs,___)

Description

sinr(txs) displays the signal-to-interference-plus-noise ratio (SINR) for transmitter sites txs in the current Site Viewer. The map contours are generated using SINR values computed for receiver site locations on the map. For each location, the signal source is the transmitter site in TXS with the greatest signal strength. The remaining transmitter sites in txs with the same transmitter frequency act as sources of interference. If txs is scalar or there are no sources of interference the resultant map displays signal-to-noise ratio (SNR).

This function only supports plotting for antenna sites with a CoordinateSystem property value of "geographic".

sinr(txs,propmodel) displays the SINR map with the propagation model set to the value in propmodel.

sinr(___,Name,Value) sets properties using one or more name-value pairs, in addition to the input arguments in previous syntaxes. For example, sinr(txs,"MaxRange",8000) sets the range from the site location at 8000 meters to include in the SINR map region.

pd = sinr(txs,___) returns computed SINR data in the propagation data object, pd. No plot is displayed and any graphical only name-value pairs are ignored.

r = sinr(rxs,txs,___) returns the sinr in dB computed at the receiver sites due to the transmitter sites.

Examples

SINR Map for Multiple Transmitters

Define names and location of sites in Boston.

names = ["Fenway Park","Faneuil Hall","Bunker Hill Monument"];
lats = [42.3467,42.3598,42.3763];
lons = [-71.0972,-71.0545,-71.0611];

Create a transmitter site array.

txs = txsite("Name", names,...
       "Latitude",lats,...
       "Longitude",lons, ...
       "TransmitterFrequency",2.5e9);

Display the SINR map, where signal source for each location is selected as the transmitter site with the strongest signal.

sinr(txs)

Input Arguments

txs — Transmitter sites

txsite object | array of txsite objects

Transmitter site, specified as a txsite object. Use array inputs to specify multiple sites.

This function only supports plotting antenna sites when CoordinateSystem property is set to "geographic".

rxs — Receiver sites

rxsite object | array of rxsite objects

Receiver site, specified as a rxsite object. Use array inputs to specify multiple sites.

This function only supports plotting antenna sites when CoordinateSystem property is set to "geographic".

propmodel — Propagation model to use for path loss calculations

"longley-rice" (default) | "freespace" | "close-in" | "rain" | "gas" | "fog" | "raytracing" | propagation model created using propagationModel

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

• "freespace" — Free space propagation model

• "rain" — Rain propagation model

• "gas" — Gas propagation model

• "fog" — Fog propagation model

• "close-in" — Close-in propagation model

• "longley-rice" — Longley-Rice propagation model

• "tirem" — TIREM™ propagation model

• "raytracing" — Ray tracing propagation model that uses the shooting and bouncing rays (SBR) method. When you specify a ray tracing model as input, the function incorporates multipath interference by using a phasor sum.

• A propagation model created using the propagationModel function. For example, you can create a ray tracing propagation model that uses the image method by specifying propagationModel("raytracing","Method","image").

The default value depends on the coordinate system used by the input sites.

Coordinate System	Default propagation model value
"geographic"	"longley-rice" when you use a terrain. "freespace" when you do not use a terrain.
"cartesian"	"freespace" when Map is set to none. "raytracing" when Map is set to the name of a glTF™ file, the name of an STL file, or a triangulation object. The default ray tracing model uses the shooting and bouncing rays (SBR) method.

Terrain propagation models, including "longley-rice" and "tirem", are only supported for sites with a CoordinateSystem value of "geographic".

You can also specify the propagation model by using the PropagationModel name-value pair argument.

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: "MaxRange",8000

General

SignalSource — Signal source of interest

"strongest" (default) | transmitter site object

Signal source of interest, specified as the comma-separated pair consisting of SignalSource and "strongest" or as a transmitter site object. When the signal source of interest is "strongest", the transmitter with the greatest signal strength is chosen as the signal source of interest for that location. When computing sinr, SignalSource can be a txsite array with equal number of elements rxs where each transmitter site element defines the signal source for the corresponding receiver site.

PropagationModel — Propagation model to use for path loss calculations

"freespace" | "close-in" | "rain" | "gas" | "fog" | "longley-rice" | "raytracing" | propagation model created using propagationModel

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

• "freespace" — Free space propagation model

• "rain" — Rain propagation model

• "gas" — Gas propagation model

• "fog" — Fog propagation model

• "close-in" — Close-in propagation model

• "longley-rice" — Longley-Rice propagation model

• "tirem" — TIREM propagation model

• "raytracing" — Ray tracing propagation model that uses the shooting and bouncing rays (SBR) method. When you specify a ray tracing model as input, the function incorporates multipath interference by using a phasor sum.

• A propagation model created using the propagationModel function. For example, you can create a ray tracing propagation model that uses the image method by specifying propagationModel("raytracing","Method","image").

The default value depends on the coordinate system used by the input sites.

Coordinate System	Default propagation model value
"geographic"	"longley-rice" when you use a terrain. "freespace" when you do not use a terrain.
"cartesian"	"freespace" when Map is set to none. "raytracing" when Map is set to the name of a glTF file, the name of an STL file, or a triangulation object. The default ray tracing model uses the shooting and bouncing rays (SBR) method.

Terrain propagation models, including "longley-rice" and "tirem", are only supported for sites with a CoordinateSystem value of "geographic".

Data Types: char | string

ReceiverNoisePower — Total noise power at receiver

-107 (default) | scalar

Total noise power at receiver, specified as a scalar in dBm. The default value assumes that the receiver bandwidth is 1 MHz and receiver noise figure is 7 dB.

$$N=-174+10*\log (B)+F$$

where,

• N = Receiver noise in dBm

• B = Receiver bandwidth in Hz

• F = Noise figure in dB

ReceiverGain — Receiver gain

2.1 (default) | scalar

Mobile receiver gain, specified as a scalar in dB. The receiver gain values include the antenna gain and the system loss. If you call the function using an output argument, the default value is computed using rxs.

ReceiverAntennaHeight — Receiver antenna height

1 (default) | scalar

Receiver antenna height above the ground, specified as a scalar in meters. If you call the function using an output argument, the default value is computed using rxs.

Map — Map for visualization or surface data

siteviewer object | triangulation object | string scalar | character vector

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 System	Valid map values	Default 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

For Plotting SINR

Values — Values of SINR for display

[-5:20] (default) | numeric vector

Values of SINR for display, specified as a numeric vector. Each value is displayed as a different colored, filled on the contour map. The contour colors are derived using Colormap and ColorLimits.

MaxRange — Maximum range of coverage map from each transmitter site

numeric scalar

Maximum range of coverage map from each transmitter site, specified as a positive numeric scalar in meters representing great circle distance. MaxRange defines the region of interest on the map to plot. The default value is automatically computed based on the type of propagation model.

Type of Propagation Model	MaxRange
Atmospheric or empirical	30 km
Terrain	30 km or distance to the furthest building.
Ray tracing	500 m

For more information about the types of propagation models, see Choose a Propagation Model.

Data Types: double

Resolution — Resolution of receiver site locations used to compute SINR values

"auto" (default) | numeric scalar

Resolution of receiver site locations used to compute SINR values, specified as "auto" or a numeric scalar in meters. The resolution defines the maximum distance between the locations. If the resolution is "auto", sinr computes a value scaled to MaxRange. Decreasing the resolution increases the quality of the SINR map and the time required to create it.

Colormap — Colormap for coloring filled contours

"jet" (default) | M-by-3 array of RGB triplets

Colormap for coloring filled contours, specified as an M-by-3 array of RGB triplets, where M is the number of individual colors.

ColorLimits — Color limits for color maps

[-5 20] (default) | two-element vector

Color limits for color maps, specified as a two-element vector of the form [min max]. The color limits indicate the SINR values that map to the first and last colors in the colormap.

ShowLegend — Show signal strength color legend on map

"true" (default) | "false"

Show signal strength color legend on map, specified as "true" or "false".

Transparency — Transparency of SINR map

0.4 (default) | numeric scalar

Transparency of SINR map, specified as a numeric scalar in the range [0, 1]. If the value is zero, the map is completely transparent. If the value is one, the map is completely opaque.

Output Arguments

r — Signal to interference plus noise ratio at the receiver

numeric vector (default)

Signal to interference plus noise ratio at the receiver due to the transmitter sites, returned as a numeric vector. The vector length is equal to the number of receiver sites.

Data Types: double

pd — SINR data

propagationData object

SINR data, returned as a propagationData object consisting of Latitude and Longitude, and a signal strength variable corresponding to the plot type. Name of the propagationData is "SINR Data".

Limitations

When you specify a RayTracing object as input to the sinr function, the value of the MaxNumDiffractions property must be 0 or 1.

Version History

Introduced in R2019b

R2023b: Perform ray tracing analysis with multiple materials in the same scene

The sinr function performs ray tracing analysis with multiple materials in the same scene when:

• You create the scene from a glTF file, and specify the propmodel input argument as "raytracing" or a RayTracing propagation model object with its SurfaceMaterial property set to "auto" (the default).

• You create the scene from an OpenStreetMap^® file or a geospatial table, and you specify the propmodel input argument as "raytracing" or a RayTracing propagation model object with its BuildingsMaterial property set to "auto" (the default).

The sinr function performs the ray tracing analysis using the materials stored in the file or table. If the file or table does not specify materials, or if the file or table specifies a material that the ray tracing analysis does not support, then the function uses concrete instead of the absent or unsupported material.

As a result, the sinr function can return different values in R2023b compared to previous releases. To avoid using the materials stored in the file or table, create a RayTracing object (by using the propagationModel function) and set its SurfaceMaterial property to "plasterboard" and its BuildingsMaterial property to "concrete". Then, use the object as input to the sinr function.

R2023b: Ray tracing analysis with SBR method shows improved performance in complex scenes

The sinr function shows improved performance with complex scenes when you specify a RayTracing propagation model object that uses the shooting and bouncing rays (SBR) method as input.

The time that MATLAB^® requires to perform ray tracing analysis depends on the scene and on the properties of the RayTracing object, such as the AngularSeparation, MaxNumDiffractions, MaxNumReflections, MaxAbsolutePathLoss, and MaxRelativePathLoss properties. In some cases, with moderate values of the MaxAbsolutePathLoss and MaxRelativePathLoss properties, the ray tracing analysis can be more than 2x faster in R2023b than in R2023a.

R2023a: Ray tracing models discard paths based on path loss

Ray tracing propagation models discard propagation paths based on path loss thresholds. By default, when you specify the propmodel input argument as "raytracing" or a RayTracing object, the propagation model discards paths that are more than 40 dB weaker than the strongest path.

As a result, the sinr function can return different values in R2023a compared to previous releases. To avoid discarding paths based on relative path loss thresholds, create a RayTracing object (by using the propagationModel function) and set its MaxRelativePathLoss property to Inf. Then, use the object as input to the sinr function.

R2022b: Ray tracing functions consider multipath interference

When calculating received power using ray tracing models, the sinr function now incorporates multipath interference by using a phasor sum. In previous releases, the function used a power sum. As a result, the calculations in R2022b are more accurate than in previous releases.

R2021b: "raytracing" propagation models use SBR method

Starting in R2021b, when you use the sinr function and specify the propmodel argument or PropagationModel name-value argument as "raytracing", the function uses the shooting and bouncing rays (SBR) method and calculates up to two reflections. In previous releases, the sinr function uses the image method and calculates up to one reflection.

To display or compute the SINR using the image method instead, create a propagation model by using the propagationModel function. Then, use the sinr function with the propagation model as input. This example shows how to update your code.

pm = propagationModel("raytracing","Method","image");
sinr(txs,pm)

For information about the SBR and image methods, see Choose a Propagation Model.

Starting in R2021b, all RF Propagation functions use the SBR method by default and calculate up to two reflections. For more information, see Default modeling method is shooting and bouncing rays method.