sdaOCTWaveformGenerator
R2026bDescription
The sdaOCTWaveformGenerator
System object™ generates a Space Development Agency (SDA) Optical Communications Terminal (OCT)
waveform, as defined in the SDA OCT standard version 4.0.0 [1].
You can use the object to generate waveforms for data, management, or idle frames, as defined in the SDA OCT standard.
To generate an SDA OCT waveform:
Create the
sdaOCTWaveformGeneratorobject and set its properties.Call the object with arguments, as if it were a function.
To learn more about how System objects work, see What Are System Objects?
Creation
Syntax
Description
sdaOCTWaveObj = sdaOCTWaveformGeneratior
sdaOCTWaveObj = sdaOCTWaveformGeneratior(PropertyName=Value)sdaOCTWaveformGenerator(ARQMaxRetransmissions=3) sets the maximum
number of retransmissions to 3.
Properties
Usage
Description
waveform = sdaOCTWaveObj(fsn,numIdleFrames)fsn and the specified number of idle frames
numIdleFrames.
Note
This syntax is applicable when you set the FrameType property
to "idle".
Input Arguments
Output Arguments
Object Functions
To use an object function, specify the
System object as the first input argument. For
example, to release system resources of a System object named obj, use
this syntax:
release(obj)
Examples
Generate a time‑domain SDA OCT waveform using Manchester burst modulation with a 1/12 duty cycle. Also, specify the peak transmit power of the waveform.
SDAOCTObj = sdaOCTWaveformGenerator;
SDAOCTObj.ModulationFormat = "Manchester-BM12";
SDAOCTObj.PeakPower = 24;Generate random payload bits for two frames. Each frame requires 8416 bits, so set the payload length to an integer multiple of 8416.
frameLength = 8416;
numFrames = 2;
% Generate random payload bits for two frames
payload = randi([0 1],frameLength*numFrames,1);Specify the FSN as a scalar. For a multi-frame with scalar FSN, the object assigns consecutive FSNs for the frames in the payload.
Generate the waveform.
fsn = 1; % Resulting FSN are 1, 2 % Generate time-domain SDA OCT waveform SDADataWaveform = SDAOCTObj(fsn,payload);
Plot the waveform using different time scales to show its structure at both microsecond and nanosecond scales.
samplesPerSlot = 10; sampleRate = samplesPerSlot*SDAOCTObj.SignalingRate; samples = repelem(SDADataWaveform,samplesPerSlot); % Create time vector tsamp = 1/sampleRate; t = 0:tsamp:tsamp*(length(samples)-1); % Plot waveform at different time scales tl = tiledlayout(3,1); % Plot 1: Show a longer segment to visualize overall burst structure. ax(1) = nexttile; samplesToPlot = floor(length(samples)/10); plot(t(1:samplesToPlot)*1e6,samples(1:samplesToPlot)) % Plot 2: Zoom in further to examine finer transitions within the burst region. ax(2) = nexttile; samplesToPlot = floor(length(samples)/30); plot(t(1:samplesToPlot)*1e6,samples(1:samplesToPlot)) % Plot 3: Zoom in to the nanosecond scale to observe sample-level waveform detail. ax(3) = nexttile; samplesToPlot = floor(length(samples)/4e3); plot(t(1:samplesToPlot)*1e9,samples(1:samplesToPlot)) xlabel(ax(1:2),"Time (\musec)") xlabel(ax(3),"Time (nsec)") ylabel(ax,"Amplitude",FontSize=8) title(tl,"Plot for SDA OCT Waveform Modulated Using " + SDAOCTObj.ModulationFormat)
Generate data, idle, and management SDA OCT waveforms using Manchester modulation with an amplitude tracking tone.
SDAOCTObj = sdaOCTWaveformGenerator;
SDAOCTObj.ModulationFormat = "Manchester";
SDAOCTObj.SignalingRate = 625e6;
SDAOCTObj.ModulationIndex = 0.2;
SDAOCTObj.AMFrequency = 40e3;Set the number of frames for each frame type, and then generate random payload bits for data and management frames. Each frame uses 8416 payload bits.
% Specify number of frames numDataFrames = 2; numIdleFrames = 2; numMgmtFrames = 2; % Specify payload size frameLength = 8416; % Generate random payload bits dataPayload = randi([0 1],frameLength*numDataFrames,1); mgmtPayload = randi([0 1],frameLength*numMgmtFrames,1);
Assign FSNs for data, idle, and management frames.
When you specify FSN as a vector, its length must be equal to the number of input frames.
% Specify starting FSN startFsn = 100; % Assign FSNs for each frame type dataFSN = startFsn:startFsn+numDataFrames-1; idleFSN = dataFSN(end)+1:dataFSN(end)+numIdleFrames; mgmtFSN = idleFSN(end)+1:idleFSN(end)+numMgmtFrames;
Generate the waveform for each frame type.
% Generate waveform for data frames SDAOCTObj.FrameType = "data"; dataSignal = SDAOCTObj(dataFSN,dataPayload); fprintf("Generated %d data frames\n",numDataFrames);
Generated 2 data frames
% Generate waveform for idle frames SDAOCTObj.FrameType = "idle"; idleSignal = SDAOCTObj(idleFSN,numIdleFrames); fprintf("Generated %d idle frames\n",numIdleFrames);
Generated 2 idle frames
% Generate waveform for management frames SDAOCTObj.FrameType = "management"; mgmtSignal = SDAOCTObj(mgmtFSN,mgmtPayload); fprintf("Generated %d management frames\n",numMgmtFrames)
Generated 2 management frames
Concatenate the waveform segments in order, and then plot the resulting waveform versus time.
% Concatenate data, idle, and management waveforms SDAWaveform = [dataSignal; idleSignal; mgmtSignal]; % Create time vector tsamp = 1/(2*SDAOCTObj.SignalingRate); t = 0:tsamp:tsamp*(length(SDAWaveform)-1); % Plot waveform plot(t,SDAWaveform) xlabel("Time (sec)") ylabel("Amplitude")
Generate a time-domain SDA OCT waveform for multiple data frames, and model ARQ retransmissions and acknowledgment signaling.
Create a three-frame random payload and specify the starting FSN.
% Specify number of frames and payload size numFrames = 3; frameLength = 8416; % Specify starting FSN fsn = 52; % Resulting FSN are 52, 53, and 54 % Generate random payload bits for three frames payload = randi([0 1],frameLength*numFrames,1);
Create the waveform generator, and enable ARQ by setting the maximum number of retransmissions.
SDAOCTObj = sdaOCTWaveformGenerator; % Generate data frames and enable ARQ retransmissions SDAOCTObj.FrameType = "data"; SDAOCTObj.ARQMaxRetransmissions = 5;
Configure the retransmission count and acknowledgment-related properties.
SDAOCTObj.RetransmissionCount = 1; % Indicate which frames carry acknowledgment information SDAOCTObj.HasAck = [1 1 0]; % Specify acknowledgment status and its span of applicability SDAOCTObj.AckStatus = [1 0 0]; SDAOCTObj.AckStartSequenceNum = [1 100 0]; SDAOCTObj.AckSpan = [2 1 0]; % Specify payload FEC encoding rate identifier per frame SDAOCTObj.PLRate = [1 2 3];
Set the modulation format to OOK-NRZ. Disable amplitude tone modulation by setting the modulation index to 0.
SDAOCTObj.ModulationFormat = "OOK-NRZ";
SDAOCTObj.ModulationIndex = 0;Generate the SDA OCT waveform for the specified frames.
SDAWaveform = SDAOCTObj(fsn,payload);
Plot the generated SDA OCT waveform sample versus time.
samplesPerSlot = 5; samplesToPlot = 60; samples = repelem(SDAWaveform(1:samplesToPlot),samplesPerSlot); % Create time vector tsamp = 1/(samplesPerSlot*SDAOCTObj.SignalingRate); t = 0:tsamp:tsamp*(length(samples)-1); % Plot waveform plot(t,samples) xlabel("Time (sec)") ylabel("Amplitude")
References
[1] Space Development Agency (SDA). Optical Communications Terminal (OCT) Standard Version 4.0.0. Washington DC: SDA United States Space Force, June 28, 2024.
Extended Capabilities
Version History
Introduced in R2026b
