Discrete Impulse

Generate discrete impulse

  • Library:
  • DSP System Toolbox / Sources


The Discrete Impulse block generates an impulse (the value 1) at output sample D+1, where you specify D using the Delay parameter (D0). All output samples preceding and following sample D+1 are zero.

When D is a length-N vector, the block generates an M-by-N matrix output representing N distinct channels, where you specify frame size M using the Samples per frame parameter. The impulse for the ith channel appears at sample D(i)+1.

The Sample time parameter value, Ts, specifies the output signal sample period. The resulting frame period is MTs.



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Output signal containing a discrete impulse at output sample D(i)+1, where D is a scalar or vector specified by the Delay parameter. For more information, see Description.

Data Types: single | double | int8 | int16 | int32 | int64 | uint8 | uint16 | uint32 | uint64 | Boolean | fixed point


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The number of zero-valued output samples, D, preceding the impulse, specified as a scalar or vector of integer values, greater than or equal to zero. A length-N vector specifies an N-channel output.

The sample period, Ts, of the output signal specified as a positive finite scalar. The output frame period is MTs.

The number of samples, M, in each output frame, specified as a positive integer scalar.

Data Types

Specify the output data type for this block. You can select one of the following:

  • A rule that inherits a data type, for example, Inherit: Inherit via back propagation. When you select this option, the output data type and scaling matches that of the next downstream block.

  • A built-in data type, such as double

  • An expression that evaluates to a valid data type, for example, fixdt(1,16)

For help setting data type parameters, display the Data Type Assistant by clicking the Show data type assistant button .

See Control Signal Data Types (Simulink) for more information.

Block Characteristics

Data Types

Boolean | double | fixed point | integer | single

Direct Feedthrough


Multidimensional Signals


Variable-Size Signals


Zero-Crossing Detection


Extended Capabilities

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

Fixed-Point Conversion
Design and simulate fixed-point systems using Fixed-Point Designer™.

Introduced before R2006a