# fir_gaussps (MathScript RT Module Function)

LabVIEW 2012 MathScript RT Module Help

Edition Date: June 2012

Part Number: 373123C-01

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Owning Class: filter design

Requires: MathScript RT Module

## Syntax

x = fir_gaussps(bst)

x = fir_gaussps(bst, n)

x = fir_gaussps(bst, n, of)

Legacy Name: `gaussfir`

## Description

Creates an FIR Gaussian pulse-shaping filter.

Details

Examples

## Inputs

Name Description
bst Specifies the 3-dB bandwidth-symbol time product.
n Specifies the number of symbol periods between the start and the peak. The default is 3.
of Specifies the oversampling factor, or the number of samples per symbol. The default is 2.

## Outputs

Name Description
x Returns the coefficients of the Gaussian pulse-shaping filter. The length of x equals 2*n*of + 1.

## Details

The following equation represents the analog impulse response of the Gaussian pulse-shaping filter:

h(t) = sqrt(pi)*exp(-(pi*t / B)^2) / B

where B is the 3-dB bandwidth of the baseband Gaussian pulse-shaping filter, which LabVIEW uses the following equation to compute:

B = sqrt(log(2) / 2) / bst

After LabVIEW transforms the Gaussian pulse-shaping filter into a discrete signal, the following equation represents the signal:

h(k) = sqrt(pi)*exp(-(pi*k / B)^2) / B

where k ranges from -n*of to n*of.

You can use the Gaussian pulse-shaping filter to counter the effects of intersymbol interference (ISI).

The following table lists the support characteristics of this function.

 Supported in the LabVIEW Run-Time Engine Yes Supported on RT targets Yes Suitable for bounded execution times on RT Not characterized

## Examples

x = fir_gaussps(0.13, 3, 5);