Using Wireless Waveform Generator App

The Wireless Waveform Generator app is an interactive tool for creating, impairing, visualizing, and exporting modulated waveforms.

Start the app. On the Apps tab in the MATLAB® toolstrip, under Signal Processing and Communications, click the app icon. You can also start the app by entering wirelessWaveformGenerator at the MATLAB command prompt.

These are the typical workflows when using the Wireless Waveform Generator app.

  • Generate a waveform.

    • Select the desired waveform type from the options available in the Waveform Type section. Adjust the configuration parameters in the Waveform pane. For more information, see Waveform Type.

    • Select Impairments in the Generation section to open the Impairments pane. Adjust the configuration parameters in the Impairments pane. For more information, see Add Impairments.

    • To perform signal generation, click Generate. After generation, the waveform is displayed. You can adjust the waveform, filtering, and impairment configurations and then regenerate the waveform.

    • The default visualization plots vary based on the waveform type selected. Additional Visualization Options can be opened by selecting them from Visualize in the Generation section.

  • After generating a waveform you can export it by selecting the desired options from Export in the Export section. For more information, see Export Waveform.

  • You can save the current session, open a previously saved session, or open a new session by selecting the desired option in the File section. For more information, see Waveform Generator Session.

Waveform Type

To generate the various available waveforms, the Wireless Waveform Generator app uses Communications Toolbox™features. The supported waveform types include:

  • OFDM — The app uses the comm.OFDMModulator System object™ to generate this type of waveform.

  • QAM — The app uses the qammod function to generate this type of waveform.

  • PSK — The app uses the pskmod function to generate this type of waveform.

  • Sinewave — The app uses the dsp.SineWave System object to generate this type of waveform.

  • Bluetooth® — You can download the Communications Toolbox Library for the Bluetooth Protocol Add-On and generate Bluetooth modulated waveforms using features described in Bluetooth.

  • WLAN — If you have the WLAN Toolbox™ you can also generate 802.11™ modulated waveforms using features in the WLAN Toolbox.

  • LTE — If you have the LTE Toolbox™ you can also generate LTE modulated waveforms using features in the LTE Toolbox.

By default, generated waveforms have no filtering applied. To apply filtering to the waveform, select the desired filter option from the Filtering parameter on the Waveform pane. The available filter options vary based on the waveform type you select.

Add Impairments

You can add these impairments to the waveform that you generate.

  • AWGN — The app uses the awgn function to impair the waveform.

  • Phase offset — The app impairs the waveform by applying the specified phase offset as y = xejφ, where φ is the phase offset in radians.

  • Frequency offset — The app uses the comm.PhaseFrequencyOffset System object to impair the waveform.

  • Phase noise — The app uses the comm.PhaseNoise System object to impair the waveform.

  • DC offset — The app impairs the waveform by applying the specified DC offset as y = x + dcOff, where dcOff is the complex DC offset in Volts.

  • IQ imbalance — The app uses the iqimbal function to impair the waveform..

  • Memoryless cubic nonlinearity — The app uses the comm.MemorylessNonlinearity System object to impair the waveform.

Visualization Options

You can use these plot types to visualize waveforms that you generate.

  • Spectrum Analyzer — The app plots the waveform in the frequency domain.

  • OFDM Grid — For OFDM waveforms, the app plots the resource allocation of data and control channels.

  • Time scope — The app plots the inphase and quadrature (IQ) waveform samples in the time domain.

  • Constellation diagram — The app plots the constellation points of the modulation symbols.

Export Waveform

You can export the waveform to a runnable MATLAB script, to your workspace, or to a signal file.

  • Waveforms exported to a runnable MATLAB script can be used to reproduce your waveform outside of the Wireless Waveform Generator app by running the script.

  • Waveforms exported to the workspace are saved as a structure containing these fields:

    • type — This field is a character vector indicating the waveform type.

    • config — This field is a structure or object containing fields that specify the configured waveform type.

    • Fs — This field is the signal sample rate in Hertz.

    • waveform — The field is the complex waveform samples output as an NS-by-1 column vector or an NS-by-NT matrix. NS is the number of time-domain samples, and NT is the number of transmit antennas.

  • Waveforms exported to a singal file can be saved as a .mat or .bb file.

Transmit Using Lab Test Instrument

Generate a waveform that you can transmit using a connected lab test instrument. The Wireless Waveform Generator app can transmit using instruments supported by the rfsiggen function.

Use of the transmit feature in the Wireless Waveform Generator app requires Instrument Control Toolbox.

Waveform Generator Session

You can save the current session, open a previously saved session, or open a new session by selecting the desired option in the FILE section. When you save a waveform generator session, the session configuration is saved as a .mat file. For more information, see MAT-File Versions (MATLAB).

See Also