ccsdsTCWaveform

Generate CCSDS TC waveform

Since R2021a

Syntax

waveform = ccsdsTCWaveform(bits,cfgFormat)

[waveform,encodedBits] = ccsdsTCWaveform(bits,cfgFormat)

Description

waveform = ccsdsTCWaveform(bits,cfgFormat) generates a Consultative Committee for Space Data Systems (CCSDS) Telecommand (TC) time-domain waveform, waveform, for the corresponding input bits, bits, and the given format configuration, cfgFormat.

[waveform,encodedBits] = ccsdsTCWaveform(bits,cfgFormat) also returns the bits obtained after TC synchronization and channel coding sublayer operations.

Examples

Create CCSDS TC Waveform for Multiple CLTUs

Create a Consultative Committee for Space Data Systems (CCSDS) Telecommand (TC) time-domain waveform for multiple communications link transmission units (CLTUs).

Create a default CCSDS TC configuration object.

cfg = ccsdsTCConfig;
disp(cfg)

  ccsdsTCConfig with properties:

             DataFormat: "CLTU"
          ChannelCoding: "BCH"
          HasRandomizer: 1
             Modulation: "PCM/PSK/PM"
              PCMFormat: "NRZ-L"
        ModulationIndex: 0.4000
    SubcarrierFrequency: 16000
             SymbolRate: 4000
       SamplesPerSymbol: 10

   Read-only properties:
     SubcarrierWaveform: "sine"

Specify the number of CLTUs and the transfer frame length.

numCLTUs = 10;
transferFramesLength = 8; % Number of octets in each transfer frame

Generate the CCSDS TC time-domain waveform for the transfer frames.

c = cell(1,numCLTUs); % Cell array to store the generated waveform for all CLTUs
for k=1:numCLTUs
    bits = randi([0 1],8*transferFramesLength,1); % Bits in the TC transfer frame
    waveform = ccsdsTCWaveform(bits,cfg);
    c{1,k} = waveform; % Waveform for each CLTU
end

Create a spectrum analyzer System object to display the frequency spectrum of the generated CCSDS TC time-domain waveform from the last CLTU.

scope = spectrumAnalyzer;
scope.SampleRate = cfg.SamplesPerSymbol*cfg.SymbolRate;
scope(waveform)  % Last CLTU spectrum display

Create CCSDS TC Waveform for Acquisition Sequence

Create a Consultative Committee for Space Data Systems (CCSDS) Telecommand (TC) time-domain waveform for a acquisition sequence with 20 octets.

Create a CCSDS TC configuration object, and then specify the object properties. Display the object properties.

cfg = ccsdsTCConfig;
cfg.DataFormat = "acquisition sequence";
cfg.Modulation = "PCM/PM/biphase-L";
cfg.ModulationIndex = 1.2;
disp(cfg)

  ccsdsTCConfig with properties:

          DataFormat: "acquisition sequence"
          Modulation: "PCM/PM/biphase-L"
     ModulationIndex: 1.2000
    SamplesPerSymbol: 10

Generate the CCSDS TC waveform.

bits = repmat([0;1],8*10,1); % Alternating 1s and 0s with 0s as a starting sequence bit
waveform = ccsdsTCWaveform(bits,cfg);

Input Arguments

bits — Information bits

binary-valued column vector

Information bits, specified as a binary-valued column vector.

• When you set the DataFormat property of the ccsdsTCConfig object to "CLTU", the length of this vector must be an integer multiple of 8.

• When you set the DataFormat property of the ccsdsTCConfig object to "acquisition sequence" or "idle sequence", this vector must be a sequence of alternating 1s and 0s, starting with either 1 or 0.

Data Types: double | int8 | logical

cfgFormat — Format configuration object

ccsdsTCConfig object

Format configuration object, specified as ccsdsTCConfig object. The properties of this object define the parameters required for CCSDS TC waveform generation.

Output Arguments

waveform — Generated time-domain CCSDS TC waveform

column vector

Generated time-domain CCSDS TC waveform, returned as a column vector. The waveform output is generated in the form of complex in-phase quadrature (IQ) samples.

Data Types: double
Complex Number Support: Yes

encodedBits — Output bits obtained after TC synchronization and channel coding sublayer operations

column vector

Output bits obtained after TC synchronization and channel coding sublayer operations, returned as a column vector.

Data Types: double

References

[1] CCSDS 231.0-B-3. Blue Book. Issue 3. "TC Synchronization and Channel Coding." Recommendation for Space Data System Standards. Washington, D.C.: CCSDS, September 2017.

[2] CCSDS 401.0-B-29. Blue Book. Issue 29. "Radio Frequency and Modulation Systems - Part 1". Earth Stations and Spacecraft. Washington, D.C.: CCSDS, September 2019.

Extended Capabilities

C/C++ Code Generation
Generate C and C++ code using MATLAB® Coder™.

Version History

Introduced in R2021a