FIR Narrowband Filter (Not in Base Package)

Filters the input sequence X using the IFIR filter specified by IFIR Coefficients as designed by the FIR Narrowband Coefficients VI. Details

X is the input signal to be filtered.
IFIR Coefficients is a cluster that contains IFIR coefficients.
filter type is the filter type that you use to determine how to filter the data.

0Lowpass
1Highpass
2Bandpass
3Bandstop
4Wideband-Lowpass (cutoff frequencies near Nyquist)
5Wideband-Highpass (cutoff frequencies near zero)
interpolation is the interpolation factor M. The model filter is stretched by interpolation times.
Model Filter contains the coefficients of the model filter.
Image Suppressor contains the coefficients of the filter image suppressor.
Filtered X is the output array of filtered samples.
error returns any error or warning from the VI. Refer to Signal Processing Error Codes for more information about these conditions.

FIR Narrowband Filter Details

The overall filter is a linear-phase FIR filter. The delay for this filter is

,

where

is the number of elements in the array Model Filter.

is the number of elements in the array Image Suppressor.

M is the value of interpolation in the cluster IFIR Coefficients.

You can design narrowband FIR filters using the FIR Narrowband Coefficients VI, and then implement the filtering using the FIR Narrowband Filter VI. The design and implementation are separate operations because many narrowband filters require long design times, whereas the actual filtering is very fast and efficient. Keep this in mind when creating your narrowband filtering diagrams.