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Spectrum Analysis of Signals in Simulink

This example shows you how to use Simulink® and Communications Toolbox™ to perform spectrum analysis of the downstream 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 (Communications Toolbox) example provides a MATLAB® implementation of this example.

Overview

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 spectrum_capture.bb 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.