raytrace
Plot propagation paths between sites
Description
raytrace(
plots the propagation paths from the transmitter site (tx,rx)tx) to the
receiver site (rx). The propagation paths are found using ray
tracing with surface geometry defined by the Map property. Each
propagation path is color-coded according to the received power (dBm) or path loss
(dB) along the path, assuming unpolarized rays.
Note
The ray tracing analysis includes surface reflections but does not include effects from refraction, diffraction, or scattering.
Operational frequency for this function is from 100 MHz to 100 GHz.
raytrace(
plots the propagation paths from the transmitter site (tx,rx,propmodel)tx) to the
receiver site (rx) based on the specified propagation model. To
input building and terrain materials to calculate path loss, please use the
'raytracing-image-method' propagation model and set the
properties to specify building materials.
raytrace(___,
plots propagation paths with additional options specified by one or more name-value
pairs.Name,Value)
rays = raytrace(___)rays.
Examples
Signal Strength Using Ray Tracing Image Method Propagation Model
Launch Site Viewer with buildings in Chicago. For more information about the osm file, see [1].
viewer = siteviewer("Buildings","chicago.osm");
Create transmitter site on a building.
tx = txsite('Latitude',41.8800, ... 'Longitude',-87.6295, ... 'TransmitterFrequency',2.5e9);
Create receiver site near another building.
rx = rxsite('Latitude',41.881352, ... 'Longitude',-87.629771, ... 'AntennaHeight',30);
Compute signal strength using ray tracing propagation model and default single-reflection analysis.
pm = propagationModel("raytracing-image-method");
ssOneReflection = sigstrength(rx,tx,pm)ssOneReflection = -54.0915
Compute signal strength with analysis up to two reflections, where total received power is the cumulative power of all propagation paths
pm.MaxNumReflections = 2; ssTwoReflections = sigstrength(rx,tx,pm)
ssTwoReflections = -52.3890
Observe effect of material by replacing default concrete material with perfect reflector.
pm.BuildingsMaterial = 'perfect-reflector';
ssPerfect = sigstrength(rx,tx,pm)ssPerfect = -41.9927
Plot propagation paths.
raytrace(tx, rx, pm)
Appendix
[1] The osm 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/.
Path Loss Due to Material Reflection and Atmosphere
Launch Site Viewer with buildings in Hong Kong. For more information about the osm file, see [1].
viewer = siteviewer("Buildings","hongkong.osm");
Define transmitter and receiver sites to model a small cell scenario in a dense urban environment.
tx = txsite("Name","Small cell transmitter", ... "Latitude",22.2789, ... "Longitude",114.1625, ... "AntennaHeight",10, ... "TransmitterPower",5, ... "TransmitterFrequency",28e9); rx = rxsite("Name","Small cell receiver", ... "Latitude",22.2799, ... "Longitude",114.1617, ... "AntennaHeight",1);
Create ray tracing propagation model for perfect reflection.
pm = propagationModel("raytracing-image-method", ... "BuildingsMaterial","perfect-reflector", ... "TerrainMaterial","perfect-reflector");
Visualize propagation paths and compute corresponding path losses.
raytrace(tx,rx,pm,"Type","pathloss") raysPerfect = raytrace(tx,rx,pm,"Type","pathloss"); plPerfect = [raysPerfect{1}.PathLoss]
plPerfect = 1×3
104.2656 104.2745 112.0095
Re-compute with material reflection loss by setting material type on the propagation model. The first value is unchanged because it corresponds to the line-of-sight propagation path.
pm.BuildingsMaterial = "glass"; pm.TerrainMaterial = "concrete"; raytrace(tx,rx,pm,"Type","pathloss") raysMtrls = raytrace(tx,rx,pm,"Type","pathloss"); plMtrls = [raysMtrls{1}.PathLoss]
plMtrls = 1×3
104.2656 106.2545 119.3577
Appendix
[1] The osm 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/.
Ray Tracing In Conference Room
Define a 3-D map for a conference room with one table and four chairs.
mapFileName = "conferenceroom.stl";Visualize the 3-D map.
figure; view(3); trisurf(stlread(mapFileName), 'FaceAlpha', 0.3, 'EdgeColor', 'none'); hold on; axis equal; grid off; xlabel('x'); ylabel('y'); zlabel('z');
Define a transmitter site close to the wall and a receiver site under the table.
tx = txsite("cartesian", "AntennaPosition", [-1.45; -1.45; 1.5],"TransmitterFrequency", 2.8e9); rx = rxsite("cartesian","AntennaPosition", [.3; .2; .5]);
Plot the transmitter site in red and receiver site in blue.
scatter3(tx.AntennaPosition(1,:), tx.AntennaPosition(2,:), tx.AntennaPosition(3,:), 'sr', 'filled'); scatter3(rx.AntennaPosition(1,:), rx.AntennaPosition(2,:),rx.AntennaPosition(3,:), 'sb', 'filled');
Create a ray tracing propagation model for Cartesian coordinates and set the surface material to wood.
pm = propagationModel("raytracing-image-method", "CoordinateSystem", "cartesian", ... "SurfaceMaterial", "wood", "MaxNumReflections", 2);
Perform ray tracing and save the computed rays using comm.Ray object
rays = raytrace(tx, rx, pm, 'Map', mapFileName);
rays = rays{1};Visualize rays in the 3D map.
for i = 1:length(rays) if rays(i).LineOfSight propPath = [rays(i).TransmitterLocation, ... rays(i).ReceiverLocation]; else propPath = [rays(i).TransmitterLocation, ... rays(i).ReflectionLocations, ... rays(i).ReceiverLocation]; end line(propPath(1,:), propPath(2,:), propPath(3,:), 'Color', 'cyan'); end
