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Link

Link analysis object belonging to Transmitter

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    Description

    The Link object defines a link analysis object belonging to Transmitter.

    Creation

    You can create a Link object using the link object function of the Transmitter or Receiver objects.

    Properties

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    You can set this property only when calling Link. After you call Link, this property is read-only.

    Transmitter or receiver ID, specified as a vector of positive numbers.

    Visual width of link line in pixels, specified as a scalar in the range (0 10].

    The line width cannot be thinner than the width of a pixel. If you set the line width to a value that is less than the width of a pixel on your system, the line displays as one pixel wide.

    Color of the link line, specified as an RGB triplet, a hexadecimal color code, a color name, or a short name.

    For a custom color, specify an RGB triplet or a hexadecimal color code.

    • An RGB triplet is a three-element row vector whose elements specify the intensities of the red, green, and blue components of the color. The intensities must be in the range [0,1]; for example, [0.4 0.6 0.7].

    • A hexadecimal color code is a character vector or a string scalar that starts with a hash symbol (#) followed by three or six hexadecimal digits, which can range from 0 to F. The values are not case sensitive. Thus, the color codes '#FF8800', '#ff8800', '#F80', and '#f80' are equivalent.

    Alternatively, you can specify some common colors by name. This table lists the named color options, the equivalent RGB triplets, and hexadecimal color codes.

    Color NameShort NameRGB TripletHexadecimal Color CodeAppearance
    'red''r'[1 0 0]'#FF0000'

    Sample of the color red

    'green''g'[0 1 0]'#00FF00'

    Sample of the color green

    'blue''b'[0 0 1]'#0000FF'

    Sample of the color blue

    'cyan' 'c'[0 1 1]'#00FFFF'

    Sample of the color cyan

    'magenta''m'[1 0 1]'#FF00FF'

    Sample of the color magenta

    'yellow''y'[1 1 0]'#FFFF00'

    Sample of the color yellow

    'black''k'[0 0 0]'#000000'

    Sample of the color black

    'white''w'[1 1 1]'#FFFFFF'

    Sample of the color white

    'none'Not applicableNot applicableNot applicableNo color

    Here are the RGB triplets and hexadecimal color codes for the default colors MATLAB® uses in many types of plots.

    RGB TripletHexadecimal Color CodeAppearance
    [0 0.4470 0.7410]'#0072BD'

    Sample of RGB triplet [0 0.4470 0.7410], which appears as dark blue

    [0.8500 0.3250 0.0980]'#D95319'

    Sample of RGB triplet [0.8500 0.3250 0.0980], which appears as dark orange

    [0.9290 0.6940 0.1250]'#EDB120'

    Sample of RGB triplet [0.9290 0.6940 0.1250], which appears as dark yellow

    [0.4940 0.1840 0.5560]'#7E2F8E'

    Sample of RGB triplet [0.4940 0.1840 0.5560], which appears as dark purple

    [0.4660 0.6740 0.1880]'#77AC30'

    Sample of RGB triplet [0.4660 0.6740 0.1880], which appears as medium green

    [0.3010 0.7450 0.9330]'#4DBEEE'

    Sample of RGB triplet [0.3010 0.7450 0.9330], which appears as light blue

    [0.6350 0.0780 0.1840]'#A2142F'

    Sample of RGB triplet [0.6350 0.0780 0.1840], which appears as dark red

    Example: 'blue'

    Example: [0 0 1]

    Example: '#0000FF'

    Object Functions

    showShow object in satellite scenario viewer
    ebnoEb/No at final node of link
    linkPercentagePercentage of time when link between first and last node in link analysis is closed
    linkStatusStatus of link closure between first and last node
    linkIntervalsIntervals during which link is closed
    hideHides satellite scenario entity from viewer

    Examples

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    Open Live Script

    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
           Viewers: [0×0 matlabshared.satellitescenario.Viewer]
        Satellites: [1×0 matlabshared.satellitescenario.Satellite]
    GroundStations: [1×0 matlabshared.satellitescenario.GroundStation]
          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 a transmitter to the satellite.

    frequency = 27e9;                                                                             % Hz
power = 20;                                                                                   % dBW
bitRate = 20;                                                                                 % Mbps
systemLoss = 3;                                                                               % dB
txSat = transmitter(sat,"Name","Satellite Transmitter","Frequency",frequency,"power",power,...
        "BitRate",bitRate,"SystemLoss",systemLoss)
    txSat = 
  Transmitter with properties:

                Name:  Satellite Transmitter
                  ID:  2
    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]

    Add a receiver to the satellite.

    gainToNoiseTemperatureRatio = 5;                                                                              % dB/K
systemLoss = 3;                                                                                               % dB
rxSat = receiver(sat,"Name","Satellite Receiver","GainToNoiseTemperatureRatio",gainToNoiseTemperatureRatio,...
        "SystemLoss",systemLoss)
    rxSat = 
  Receiver with properties:

                           Name:  Satellite Receiver
                             ID:  3
               MountingLocation:  [0; 0; 0] meters
                 MountingAngles:  [0; 0; 0] degrees
                        Antenna:  [1x1 satcom.satellitescenario.GaussianAntenna]
                     SystemLoss:  3 decibels
    GainToNoiseTemperatureRatio:  5 decibels/Kelvin
                   RequiredEbNo:  10 decibels

    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");

    Add gimbals to the ground stations. These gimbals enable you to steer the ground station antennas to track the satellite.

    mountingLocation = [0; 0; -5];                                                              % meters
mountingAngles = [0; 180; 0];                                                               % degrees
gimbalGs1 = gimbal(gs1,"MountingLocation",mountingLocation,"MountingAngles",mountingAngles);
gimbalGs2 = gimbal(gs2,"MountingLocation",mountingLocation,"MountingAngles",mountingAngles);

    Track the satellite using the gimbals.

    pointAt(gimbalGs1,sat);
pointAt(gimbalGs2,sat);

    Add a transmitter to gimbal gimbalGs1.

    frequency = 30e9;                                                                             % Hz
power = 40;                                                                                   % dBW
bitRate = 20;                                                                                 % Mbps
txGs1 = transmitter(gimbalGs1,"Name","Ground Stationn 1 Transmitter","Frequency",frequency,...
        "Power",power,"BitRate",bitRate);

    Add a receiver to gimbal gimbalGs2.

    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);

    Add link analysis to transmitter txGs1.

    lnk = link(txGs1,rxSat,txSat,rxGs2)
    lnk = 
  Link with properties:

    Sequence:  [8 3 2 9]
    LineWidth:  1
    LineColor:  [0 1 0]

    Determine the times when ground station gs1 can send data to ground station gs2 via the satellite.

    linkIntervals(lnk)
    ans =

  0×8 empty table

    Visualize the link using the Satellite Scenario Viewer.

    play(sc);

    Version History

    Introduced in R2021a

    See Also

    Objects

    Functions

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