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Eye Diagram

Display eye diagram of time-domain signal

Since R2023b

  • Eye Diagram Scope block

Communications Toolbox / Comm Sinks
Communications Toolbox HDL Support / Comm Sinks
Mixed-Signal Blockset / Utilities
SerDes Toolbox / Utilities


The Eye Diagram block displays multiple traces of a modulated signal to produce an eye diagram. You can use the block to reveal the modulation characteristics of the signal, such as the effects of pulse shaping or channel distortions.

The Eye Diagram block has one input port. This block accepts a column vector or scalar input signal. The block accepts a signal with the following data types: double, single, base integer, and fixed point. All data types are cast as double before the block displays results.

To modify the eye diagram display, select SCOPE and click the Settings button () in CONFIGURATION.


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Display the eye diagram of a filtered QPSK signal using the Eye Diagram block.

Open the model EyeDiagramofQPSKSignal. Run the model and observe the eye diagram displayed.



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Input signal, specified as a scalar or column vector.

Data Types: double


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Display and Traces

Number of samples per symbol, specified as a positive integer. Use with Symbols per trace to determine the number of samples per trace.

Tunable: Yes

Sample offset, specified as a nonnegative integer smaller than the product of Samples per symbol and Symbols per trace. The offset provides the number of samples to omit before plotting the first point.

Tunable: Yes

Number of symbols plotted per trace, specified as a positive integer.

Tunable: Yes

Number of traces plotted, specified as a positive integer.

Tunable: Yes


Select this check box to fade the points in the display as the interval of time after they are first plotted increases.

Select this check box to display the imaginary plot of the eye diagram.

Axes and Labels

Text that the scope displays along the real axis.

Tunable: Yes

Label that appears above the eye diagram plot.

Tunable: Yes

Text that the scope displays along the imaginary axis.

Tunable: Yes

Lower and upper limit values of the y-axis.

Tunable: Yes

Select this radio button to show the grid on the scope window.


Use this tab to customize the style of the active display. You can change the color of the figure containing the displays, the background and foreground colors of display axes, and properties of lines in a display.

Select this radio button to preserve the colors when copying to a clipboard.

Specify the background color for the plot..

Specify the fill and line colors for the axes.

Specify the color of the labels on the axes.

Specify the line style for the displayed signal.

Specify the line thickness for the lines on displayed signal.

Data point marker for the selected signal, specified as one of the choices in this table data point markers. This parameter is similar to the Marker property for MATLAB® Handle Graphics® plot objects.

SpecifierMarker Type
noneNo marker (default)
Plus sign
Downward-pointing triangle
Upward-pointing triangle
Left-pointing triangle
Right-pointing triangle
Five-pointed star (pentagram)
Six-pointed star (hexagram)

Specify the color for the lines on displayed signal.

Block Characteristics

Data Types

Boolean | double | enumerated | fixed point | integer | single

Direct Feedthrough


Multidimensional Signals


Variable-Size Signals


Zero-Crossing Detection


More About

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Extended Capabilities

Version History

Introduced in R2023b