Getting Started

Discrete Signals and Sample Times

The Sine Wave block in the DSP Blockset generates a discrete signal. This means that it updates the signal at integer multiples of a fixed time interval, called the sample time. You can set the length of this time interval in the Sample time parameter in the block's mask. In the example shown in the figure Sine Wave Model, the Sample time has the default value of 1/1000. All the sources in the Communications Blockset and the DSP Blockset generate discrete signals exclusively. These sources are primarily designed for modeling digital communication systems.

To learn more about sample times, see Building a Frequency-Shift Keying Model.

Continuous Signals

The Simulink libraries also contain blocks that generate continuous signals. This means that they update the signal at variable time intervals, whose length is determined by the numerical solver the simulation uses. For example, the Sine Wave block in the Simulink Sources library can generate a continuous sine wave.

Note    Many blocks in the Communications Blockset accept only discrete signals. To find out whether a block accepts continuous signals, consult the reference page for the block.

Frames and Frame-Based Processing

Building a Channel Noise Model