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General QAM Modulator Baseband

Modulate using quadrature amplitude modulation


AM, in Digital Baseband sublibrary of Modulation

  • General QAM Modulator Baseband block


The General QAM Modulator Baseband block modulates using quadrature amplitude modulation. The output is a baseband representation of the modulated signal.

The Signal constellation parameter defines the constellation by listing its points in a length-M vector of complex numbers. The input signal values must be integers in the range [0, (M-1)]. The block maps an input integer m to the (m+1)st value in the Signal constellation vector.

This block accepts a scalar or column vector input signal. For information about the data types each block port supports, see the Supported Data Types table on this page.


Signal constellation

A real or complex vector that lists the constellation points.

View Constellation

Click View Constellation on the block mask to visualize a signal constellation for the specified block parameters. Before viewing a constellation, apply the parameter settings. For more information, see View Constellation of Modulator Block.

Output data type

Output data type, specified as double, single, fixdt(1,16), fixdt(1,16, 0), Inherit via back propagation, or <data type expression>.

Setting this parameter to

  • fixdt(1,16), fixdt(1,16.0), or <data type expression> enables parameters in which you can further specify details.

  • Inherit via back propagation sets the output data type and scaling to match the following block.

The Data Type Assistant helps you set data attributes. To use the Data Type Assistant, click Show data type assistant . For more information, see Specify Data Types Using Data Type Assistant (Simulink).

Supported Data Types

PortSupported Data Types


  • Double-precision floating point

  • Single-precision floating point

  • 8-, 16-, 32-bit signed integers

  • 8-, 16-, 32-bit unsigned integers

  • ufix(log2M)


  • Double-precision floating point

  • Single-precision floating point

  • Signed fixed-point

Extended Capabilities

C/C++ Code Generation
Generate C and C++ code using Simulink® Coder™.

Version History

Introduced before R2006a