Transmitter
Description
Transmitter defines a transmitter object belonging to a satellite scenario.
For an illustration of the signal power of a high power amplifier (HPA) and the system loss encountered at a transmitter, see Algorithms.
Creation
You can create Transmitter objects using the transmitter
function of satellite
, platform
, groundStation
, or
gimbal
.
Properties
Name
— Transmitter name
"Transmitter idx"
(default) | string scalar | string vector | character vector | cell array of character vectors
You can set this property only when calling the transmitter
function. After you call the transmitter
function, this property is
read-only.
Transmitter name, specified as a name-value argument consisting of
'Name'
and a string scalar, string vector, character vector, or a
cell array of character vectors.
If you are adding only one transmitter, specify
Name
as a string scalar or a character vector.If you are adding multiple transmitters, specify
Name
as a string scalar, character vector, string vector, or a cell array of character vectors. All transmitters that you add as a string scalar or a character vector are assigned the same specified name. The number of elements in the string vector or cell array of character vectors must equal the number of transmitters that you are adding. Each transmitter is assigned the corresponding name from the vector or cell array.
In the default value, idx is the ID assigned by the satellite scenario.
Data Types: char
| string
ID
— Transmitter ID assigned by simulator
real positive scalar
This property is set internally by the simulator and is read-only.
Transmitter ID assigned by the simulator, specified as a positive scalar.
MountingLocation
— Mounting location with respect to parent
[0; 0; 0]
(default) | three-element vector | matrix
Mounting location with respect to the parent object in meters, specified as a
three-element vector or a matrix. The position vector is specified in the body frame of
the input parent
.
If you are adding one transmitter,
MountingLocation
is a three-element vector. The elements specify the x, y, and z components of the Cartesian coordinates in the body frame of transmitter.If you are adding multiple transmitters,
MountingLocation
can be a three-element vector or a matrix. When specified as a vector, the same set of mounting locations are assigned to all specified transmitters. When specified as a matrix,MountingLocation
must contain three rows and the same number of columns as the transmitters. The columns correspond to the mounting location of each specified transmitter and the rows correspond to the mounting location coordinates in the parent body frame.
When the AutoSimulate
property of the satellite scenario is
false
, you can modify the MountingLocation
property only when SimulationStatus
is NotStarted
. You can use the
restart
function to
reset SimulationStatus
to NotStarted
, but doing
so erases the simulation data.
Data Types: double
MountingAngles
— Mounting orientation with respect to parent object
[0; 0; 0]
(default) | three-element row vector of positive numbers | matrix
Mounting orientation with respect to parent object in degrees, specified as a three-element row vector of positive numbers. The elements of the vector correspond to yaw, pitch, and roll, in that order. Yaw, pitch, and roll are positive rotations about the z-axis, intermediate y-axis, and intermediate x-axis of the parent.
If you are adding one transmitter, the
MountingAngles
property is a three-element vector.If you are adding multiple transmitters the
MountingAngles
property can be a three-element vector or a matrix. When specified as a vector, the same set of mounting angles are assigned to all specified transmitters. When specified as a matrix,MountingAngles
must contain three rows and the same number of columns as the transmitters. The columns correspond to the mounting angles of each specified transmitter and the rows correspond to the yaw, pitch, and roll angles in the parent body frame.
When the AutoSimulate
property of the satellite scenario is
false
, you can modify the MountingAngles
property only when SimulationStatus
is NotStarted
. You can use the
restart
function to
reset SimulationStatus
to NotStarted
, but doing
so erases the simulation data.
Example: [0; 30; 60]
Data Types: double
Antenna
— Antenna object associated with transmitter
scalar | vector
Antenna
object associated with the transmitter, specified as
either a scalar or a vector. This object can be the default
gaussianAntenna
object, or one from the Antenna Toolbox or Phased
Array System Toolbox. The default Gaussian antenna has a dish diameter of 1 meter and an
aperture efficiency of 0.65.
Antenna can be specified in transmitter as a name-value argument consisting of
'Antenna'
and a scalar, antenna or phased array objects.
If you are adding only one transmitter,
Antenna
must be a scalar.If you are adding multiple transmitters,
Antenna
is a vector. The same antenna is assigned to all transmitters.
SystemLoss
— Total system loss in the transmitter
5
(default) | scalar | vector
Total system loss in the transmitter in dB, specified as a scalar or a vector.
System loss can be specified in transmitter as a name-value argument consisting of
'SystemLoss'
and a scalar, or vector.
If you are adding only one transmitter, specify
SystemLoss
as a scalar.If you are adding multiple transmitters are added, specify
SystemLoss
as a scalar or a vector. WhenSystemLoss
is a scalar, the sameSystemLoss
is assigned to all transmitters. WhenSystemLoss
is a vector, its length must equal the number of transmitter and each element ofSystemLoss
is assigned to the corresponding transmitter in the parent.
When the AutoSimulate
property of the satellite scenario is
false
, you can modify the SystemLoss
value
while SimulationStatus
is NotStarted
or
InProgress
.
Frequency
— Transmitter frequency
14e9
(default) | scalar | vector
Transmitter frequency in Hz, specified as a name-value argument consisting of 'Frequency' and a scalar or a vector.
If you are adding only one transmitter, the
Frequency
must be a scalar.If you are adding multiple transmitters are added, the frequency value can be a scalar or a vector. All transmitters added as a scalar are assigned the same specified
Frequency
. The length of the vector must equal the number of transmitters added and each element ofFrequency
is assigned to the corresponding transmitter in the parent.
When the AutoSimulate
property of the satellite scenario is false, you can modify
the Frequency
value while SimulationStatus
is NotStarted
or
InProgress
.
BitRate
— Bit rate of transmitter
10
(default) | scalar | vector
Bit rate of the transmitter in Mbps, specified as a name-value pair consisting of 'BitRate' and a scalar or a vector.
If you are adding only one transmitter, the bit rate value must be a scalar.
If you are adding multiple transmitters, the bit rate value can be a scalar or a vector. All transmitters added as a scalar are assigned the same specified
BitRate
. The length of the vector must equal the number of transmitters added and each element ofBitRate
is assigned to the corresponding transmitter in the parent.
When the AutoSimulate
property of the satellite scenario is
false
, you can modify the BitRate
value
while SimulationStatus
is NotStarted
or
InProgress
.
Power
— Signal power at output of high power amplifier
12
(default) | scalar | vector
Signal power at the output of a high power amplifier in dbW, specified as a name-value pair consisting of 'Power' and a scalar or a vector.
If you are adding only one transmitter, the power value must be a scalar.
If you are adding multiple transmitters, the power value can be a scalar or a vector. All transmitters added as a scalar are assigned the same specified
Power
. The length of the vector must equal the number of transmitters added and each element ofPower
is assigned to the corresponding transmitter in the parent.
When the AutoSimulate
property of the satellite
scenario is false, you can modify the Power
value while
SimulationStatus
is
NotStarted
or
InProgress
.
CoordinateAxes
— Coordinate axes triad graphic object
CoordinateAxes
object (default)
You can set this property only when calling coordinateAxes
.
After you call coordinateAxes
,
this property is read-only.
Coordinate axes triad graphic object, specified as CoordinateAxes
object.
Links
— Link analysis objects
row vector of Link
objects
This property is read-only.
Link analysis objects, specified as a row vector Link
objects.
Object Functions
aer | Calculate azimuth angle, elevation angle, and range of another satellite or ground station in NED frame |
gaussianAntenna | Add Gaussian antennas |
link | Add link analysis objects to transmitter |
pattern | Plot 3-D radiation pattern of antenna |
pointAt | Point transmitter or receiver at target |
pointAt | Point satellite at target |
coordinateAxes | Visualize coordinate axes triad of satellite scenario assets |
dopplershift | Calculate Doppler shift at target asset in satellite scenario |
Examples
Determine Times of Availability for Satellite Link Between Two Ground Stations
Create a satellite scenario object.
startTime = datetime(2020,11,25,0,0,0);
stopTime = startTime + days(1);
sampleTime = 60; % seconds
sc = satelliteScenario(startTime,stopTime,sampleTime)
sc = satelliteScenario with properties: StartTime: 25-Nov-2020 StopTime: 26-Nov-2020 SampleTime: 60 AutoSimulate: 1 Satellites: [1×0 matlabshared.satellitescenario.Satellite] GroundStations: [1×0 matlabshared.satellitescenario.GroundStation] Platforms: [1×0 matlabshared.satellitescenario.Platform] Viewers: [0×0 matlabshared.satellitescenario.Viewer] AutoShow: 1
Add a satellite to the scenario.
semiMajorAxis = 10000000; % meters eccentricity = 0; inclination = 60; % degrees rightAscensionOfAscendingNode = 0; % degrees argumentOfPeriapsis = 0; % degrees trueAnomaly = 0; % degrees sat = satellite(sc,semiMajorAxis,eccentricity,inclination,rightAscensionOfAscendingNode, ... argumentOfPeriapsis,trueAnomaly,Name="Satellite");
Add gimbals to the satellite. These gimbals enable the satellite receiver antenna to steer to the first ground station, and its transmitter antenna to steer to the second ground station.
gimbalrxSat = gimbal(sat); gimbaltxSat = gimbal(sat);
Add a receiver to the first gimbal of the satellite.
gainToNoiseTemperatureRatio = 5; % dB/K systemLoss = 3; % dB rxSat = receiver(gimbalrxSat,Name="Satellite Receiver",GainToNoiseTemperatureRatio= ... gainToNoiseTemperatureRatio,SystemLoss=systemLoss)
rxSat = Receiver with properties: Name: Satellite Receiver ID: 4 MountingLocation: [0; 0; 0] meters MountingAngles: [0; 0; 0] degrees Antenna: [1x1 satcom.satellitescenario.GaussianAntenna] SystemLoss: 3 decibels PreReceiverLoss: 3 decibels GainToNoiseTemperatureRatio: 5 decibels/Kelvin RequiredEbNo: 10 decibels CoordinateAxes: [1x1 matlabshared.satellitescenario.CoordinateAxes]
Add a transmitter to the second gimbal of the satellite.
frequency = 27e9; % Hz power = 20; % dBW bitRate = 20; % Mbps systemLoss = 3; % dB txSat = transmitter(gimbaltxSat,Name="Satellite Transmitter",Frequency=frequency, ... power=power,BitRate=bitRate,SystemLoss=systemLoss)
txSat = Transmitter with properties: Name: Satellite Transmitter ID: 5 MountingLocation: [0; 0; 0] meters MountingAngles: [0; 0; 0] degrees Antenna: [1x1 satcom.satellitescenario.GaussianAntenna] SystemLoss: 3 decibels Frequency: 2.7e+10 Hertz BitRate: 20 Mbps Power: 20 decibel-watts Links: [1x0 satcom.satellitescenario.Link] CoordinateAxes: [1x1 matlabshared.satellitescenario.CoordinateAxes]
Specify the antenna specifications of the repeater.
dishDiameter = 0.5; % meters
apertureEfficiency = 0.5;
gaussianAntenna(txSat,DishDiameter=dishDiameter,ApertureEfficiency=apertureEfficiency);
gaussianAntenna(rxSat,DishDiameter=dishDiameter,ApertureEfficiency=apertureEfficiency);
Add two ground stations to the scenario.
gs1 = groundStation(sc,Name="Ground Station 1"); latitude = 52.2294963; % degrees longitude = 0.1487094; % degrees gs2 = groundStation(sc,latitude,longitude,Name="Ground Station 2");
Point gimbals of the satellite towards the two ground stations for the simulation duration.
pointAt(gimbaltxSat,gs2); pointAt(gimbalrxSat,gs1);
Add gimbals to the ground stations. These gimbals enable the ground station antennas to steer towards the satellite.
gimbalgs1 = gimbal(gs1); gimbalgs2 = gimbal(gs2);
Add a transmitter to ground station gs1
.
frequency = 30e9; % Hz power = 40; % dBW bitRate = 20; % Mbps txGs1 = transmitter(gimbalgs1,Name="Ground Station 1 Transmitter",Frequency=frequency, ... Power=power,BitRate=bitRate);
Add a receiver to ground station gs2
.
requiredEbNo = 14; % dB rxGs2 = receiver(gimbalgs2,Name="Ground Station 2 Receiver",RequiredEbNo=requiredEbNo);
Define the antenna specifications of the ground stations.
dishDiameter = 5; % meters
gaussianAntenna(txGs1,DishDiameter=dishDiameter);
gaussianAntenna(rxGs2,DishDiameter=dishDiameter);
Point gimbals of the ground stations towards the satellite for the simulation duration.
pointAt(gimbalgs1,sat); pointAt(gimbalgs2,sat);
Add link analysis to transmitter txGs1
.
lnk = link(txGs1,rxSat,txSat,rxGs2)
lnk = Link with properties: Sequence: [10 4 5 11] LineWidth: 2 LineColor: [0.3922 0.8314 0.0745]
Determine the times when ground station gs1
can send data to ground station gs2
via the satellite.
linkIntervals(lnk)
ans=4×8 table
Source Target IntervalNumber StartTime EndTime Duration StartOrbit EndOrbit
______________________________ ___________________________ ______________ ____________________ ____________________ ________ __________ ________
"Ground Station 1 Transmitter" "Ground Station 2 Receiver" 1 25-Nov-2020 00:20:00 25-Nov-2020 00:40:00 1200 NaN NaN
"Ground Station 1 Transmitter" "Ground Station 2 Receiver" 2 25-Nov-2020 03:19:00 25-Nov-2020 03:36:00 1020 NaN NaN
"Ground Station 1 Transmitter" "Ground Station 2 Receiver" 3 25-Nov-2020 06:15:00 25-Nov-2020 06:36:00 1260 NaN NaN
"Ground Station 1 Transmitter" "Ground Station 2 Receiver" 4 25-Nov-2020 22:20:00 25-Nov-2020 22:38:00 1080 NaN NaN
Visualize the link by using the Satellite Scenario Viewer.
play(sc);
Algorithms
This diagram shows the signal power of a HPA and the system loss experienced at the transmitting end.
Version History
Introduced in R2021a
See Also
Objects
Functions
play
|show
|hide
|groundStation
|access
|receiver
|transmitter
|pointAt
|platform
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