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Spectral Analysis of signals in Simulink®

This example shows how to use the captured signals, or receive signals in real time using RTL-SDR, ADALM-PLUTO or USRP™ radio, as a data source for downstream spectrum analysis with MATLAB® and Simulink®. You can change the radio's center frequency to tune the radio to a band where a signal is present. You can then use the spectrum analyzer to view and make measurements on the received spectrum.

This example is implemented in two versions:

The following text describes the Simulink version, but both versions have the same functionality.


The model performs an FFT-based spectrum analysis at complex baseband, and provides the following graphical information:

  • A view of the spur-free dynamic range of the receiver

  • A view of the qualitative SNR level of the received signal

Structure of the Example

The following figure shows the receiver model:

Spectrum Analyzer

The following figure shows the output of the Spectrum Analyzer on a frequency range of -88 MHz to 108 MHz.

Running the Example

When you run the example, you can measure signal characteristics such as peaks, occupied bandwidth, adjacent channel power ratio, harmonic and intermodulation levels, and spur-free dynamic range.