fir_gaussps (MathScript RT Module Function)
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.
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).
Examples
x = fir_gaussps(0.13, 3, 5);