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Spectrum Analysis of Signals in Simulink

This example shows you how to use Simulink® to undertake spectral analysis of signals. You can tune the radio to a band where a signal is present by changing the center frequency. You can then use the spectrum analyzer to view and make measurements on the received spectrum. You can either use recorded data from a file, or receive over-the-air signals in real time using an RTL-SDR radio, ADALM-PLUTO radio, or USRP™ radio.

The Spectrum Analysis of Signals example provides a MATLAB® implementation of this example.

Required Hardware and Software

By default, this example runs using recorded data from a file. Optionally, you can receive signals over-the-air. For this, you also need one of the following:


The spectralAnalysis model performs an FFT-based spectrum analysis at complex baseband, and provides:

  • 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

This figure shows the spectralAnalysis model:

Spectrum Analyzer

This figure shows the output of the Spectrum Analyzer for a data signal recorded in the file. The spectrum shows data captured over the FM radio band, specifically over the 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.