propagationData

Create RF propagation data from measurements

Description

Use a propagationData object to import and visualize geolocated propagation data. The measurement data can be path loss data, signal strength measurements, signal-to-noise-ratio (SNR) data, or cellular information.

Creation

Syntax

pd = propagationData(filename)

pd = propagationData(table)

pd = propagationData(lat,lon,varname,varvalue)

pd = propagationData(___,Name=Value)

Description

pd = propagationData(filename) creates a propagation data object by reading data from the specified file.

pd = propagationData(table) creates a propagation data object from the specified table.

pd = propagationData(lat,lon,varname,varvalue) creates a propagation data object from the specified geographic coordinates and the specified measurement data.

pd = propagationData(___,Name=Value) sets properties using one or more name-value arguments.

Input Arguments

filename — Name of file containing propagation data

character vector | string scalar

Name of the file containing the propagation data, specified as a character vector or a string scalar. The file must be in the current directory, in a directory on the MATLAB^® path, or be specified using a full or relative path.

The file must be compatible with the readtable function. If customized parameters are required to import the file, then read the data into a table by using the readtable function, then pass the table to the propagationData function.

Propagation data in the file must have one variable corresponding to the latitude values, one variable corresponding to longitude values, and at least one variable containing numeric data.

Data Types: string | char

table — Table containing propagation data

table

Table containing propagation data. The table must have one variable corresponding to latitude values, one variable corresponding to longitude values, and at least one variable containing numeric data.

Data Types: table

lat — Latitude coordinates in degrees

vector with elements in range [–90, 90]

Latitude coordinate in degrees, specified as a vector with elements in the range [–90, 90]. The function assumes that the coordinates are referenced to the WGS84 reference ellipsoid.

Data Types: double

lon — Longitude coordinates in degrees

vector

Longitude coordinates in degrees, specified as a vector. The function assumes that the coordinates are referenced to the WGS84 reference ellipsoid.

Data Types: double

varname — Variable name

character vector | string scalar

Variable name, specified as a character vector or string scalar. This variable name must correspond to a variable with numeric data (other than latitude or longitude). The variable name and the corresponding values are stored as a variable in the table stored in Data.

Data Types: string | char

varvalue — Variable values

numeric vector

Variable values, specified as a numeric vector. The size of varvalue must match the sizes of lat and lon. The variable name and the corresponding values are stored as a variable in the table stored in Data.

Data Types: double

Properties

Name — Name of propagation data

'Propagation Data' (default) | character vector | string scalar

Name of propagation data, specified as a character vector or string scalar.

Data Types: char | string

Data — Propagation data table

Read-only: table

This property is read-only.

Propagation data table, specified as a table that contains a variable corresponding to latitude coordinates, a variable corresponding to longitude coordinates, and one or more variables corresponding to the associated propagation data.

Data Types: table

DataVariableName — Name of data variable to plot

character vector | string scalar

Name of the data variable to plot, specified as a character vector or string scalar corresponding to a variable name in the Data table used to create the propagation data object. The variable name must correspond to a variable with numeric data and cannot correspond to the latitude or longitude variables. The default value for this property is the name of the first numeric data variable name in the Data table that is not a latitude or longitude variable.

Data Types: char | string

Object Functions

plot	Display RF propagation data in Site Viewer
contour	Display contour map of RF propagation data in Site Viewer
location	Coordinates of RF propagation data
getDataVariable	Get data variable values
interp	Interpolate RF propagation data

Examples

Compute Signal Strength Data in Urban Environment

Launch Site Viewer with basemaps and building files for Manhattan. For more information about the OpenStreetMap® file, see [1].

viewer = siteviewer("Basemap","streets_dark",...
        "Buildings","manhattan.osm");

Show a transmitter site on a building.

tx = txsite("Latitude",40.7107,...
        "Longitude",-74.0114,...
        "AntennaHeight",80);
show(tx)

Create receiver sites along nearby streets.

latitude = [linspace(40.7088, 40.71416, 50), ...
        linspace(40.71416, 40.715505, 25), ...
        linspace(40.715505, 40.7133, 25), ...
        linspace(40.7133, 40.7143, 25)]';
longitude = [linspace(-74.0108, -74.00627, 50), ...
        linspace(-74.00627 ,-74.0092, 25), ...
        linspace(-74.0092, -74.0110, 25), ...
        linspace(-74.0110, -74.0132, 25)]';
rxs = rxsite("Latitude", latitude, "Longitude", longitude);

Compute signal strength at each receiver location.

signalStrength = sigstrength(rxs, tx)';

Create a propagationData object to hold computed signal strength data.

tbl = table(latitude, longitude, signalStrength);
pd = propagationData(tbl);

Plot the signal strength data on a map as colored points.

legendTitle = "Signal" + newline + "Strength" + newline + "(dB)";
plot(pd, "LegendTitle", legendTitle, "Colormap", parula);

Appendix

[1] The OpenStreetMap file is downloaded from https://www.openstreetmap.org, which provides access to crowd-sourced map data all over the world. The data is licensed under the Open Data Commons Open Database License (ODbL), https://opendatacommons.org/licenses/odbl/.

Capacity Map Using SINR Data

Define names and locations of sites around Boston.

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

Create an array of transmitter sites.

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

Create a signal-to-interference-plus-noise-ratio (SINR) map, where signal source for each location is selected as the transmitter site with the strongest signal.

sv1 = siteviewer("Name","SINR map");
sinr(txs,"MaxRange",5000)

Return SINR propagation data.

pd = sinr(txs,"MaxRange",5000);
[sinrDb,lats,lons] = getDataVariable(pd,"SINR"); 

Compute capacity using the Shannon-Hartley theorem.

bw = 1e6; % Bandwidth is 1 MHz
sinrRatio = 10.^(sinrDb./10); % Convert from dB to power ratio
capacity = bw*log2(1+sinrRatio)/1e6; % Unit: Mbps

Create new propagation data for the capacity map and display the contour plot.

pdCapacity = propagationData(lats,lons,"Capacity",capacity);
sv2 = siteviewer("Name","Capacity map");
legendTitle = "Capacity" + newline + "(Mbps)";
contour(pdCapacity,"LegendTitle",legendTitle);

Version History

Introduced in R2020a