Windowed Integrator (Communications Blockset)

Integrate over a time window of fixed length

Library

Integrators, in Basic Comm Functions

Description

The Windowed Integrator block integrates the input signal in discrete time, over a sliding time window of fixed length. If the Integration window length parameter is T, then the output at time t is the result of integrating the input signal from t-T to t. The block assumes that the input signal is zero for all negative t.

You can choose one of three integration methods: Forward Euler, Backward Euler, and Trapezoidal.

The input can be either a scalar, a sample-based vector, or a frame-based row vector. The block processes each vector element independently. If the input signal is a vector, then the output is a vector of the same length. This length appears as the Input vector size parameter.

Dialog Box

Integration method: The integration method. Choices are Forward Euler, Backward Euler, and Trapezoidal.
Input vector size: The length of the input vector.
Integration window length (s): The length of the interval of integration, in seconds.
Sample time: The integration sample time. This must not exceed the Integration window length parameter.

Examples

Integrate a scalar constant signal whose value is 1, for 10 seconds, using these parameters:

Integration method = Forward Euler
Input vector size = 1
Integration window length = 4
Sample time = .5

You can use a Simulink Constant block for the input signal. The Simulink Scope block shows the output below.

Notice that the output from time 0 to time 4 is a discrete approximation of a ramp. During this period, the interval of integration increases with time. Also notice that the output after time 4 is a constant value of 4. This is the result of integrating the value 1 over the full integration window length of 4 seconds.

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