Variable bandwidth FIR filter
The VariableBandwidthFIRFilter
object filters
each channel of the input using FIR filter implementations. It does
so while having the capability of tuning the bandwidth. This filter
supports double and single precision inputs.
To filter each channel of the input:
Define and set up your variable bandwidth FIR filter. See Construction.
Call step
to filter
each channel of the input according to the properties of dsp.VariableBandwidthFIRFilter
.
The behavior of step
is specific to each object in
the toolbox.
Starting in R2016b, instead of using the step
method
to perform the operation defined by the System
object™, you can
call the object with arguments, as if it were a function. For example, y
= step(obj,x)
and y = obj(x)
perform
equivalent operations.
vbw = dsp.VariableBandwidthFIRFilter
returns
a System
object, vbw
, which independently filters
each channel of the input over successive calls to the step
method.
This System
object uses a specified FIR filter implementation.
The filter’s cutoff frequency may be tuned during the filtering
operation. The variable bandwidth FIR filter is designed using the
window method.
vbw = dsp.VariableBandwidthFIRFilter('
returns a variable bandwidth FIR filter System
object, PropertyName
',PropertyValue
,
...)vbw
,
with each property set to the specified value. You can specify additional
namevalue pair arguments in any order as (Name1,Value1,...,NameN,ValueN
).

Input sample rate Specify the sampling rate of the input in Hertz as a finite numeric scalar. The default is 44.1 kHz. This property is nontunable. 

Filter type Specify the type of the filter as one of 

FIR filter order Specify the order of the FIR filter as a positive integer scalar. The default is 30. This property is nontunable. 

Window function Specify the window function used to design the FIR filter as
one of 

Kaiser window parameter Specify the Kaiser window parameter as a real scalar. This property
applies when you set the window property to 

Filter cutoff frequency Specify the filter cutoff frequency in Hz as a real, positive
scalar, smaller than the 

Filter center frequency Specify the filter center frequency in Hz as a real, positive
scalar, smaller than 

Filter bandwidth Specify the filter bandwidth in Hertz as a real, positive scalar,
smaller than 

Chebyshev window sidelobe attenuation Specify the Chebyshev window attenuation as a real, positive
scalar in decibels (dB). This property applies if you set the 
reset  Reset internal states of variable bandwidth FIR filter 
step  Filter signal using variable bandwidth algorithm 
More Analysis Methods for Filter System Objects.
Common to All System Objects  

clone  Create System object with same property values 
getNumInputs  Expected number of inputs to a System object 
getNumOutputs  Expected number of outputs of a System object 
isLocked  Check locked states of a System object (logical) 
release  Allow System object property value changes 
[1] Jarske, P.,Y. Neuvo, and S. K. Mitra, "A simple approach to the design of linear phase FIR digital filters with variable characteristics." Signal Processing. Vol. 14, Issue 4, June 1988, pp. 313326.
Variable Bandwidth FIR Filter  Variable Bandwidth IIR Filter  dsp.AllpoleFilter
 dsp.BiquadFilter
 dsp.FIRFilter
 dsp.IIRFilter
 dsp.VariableBandwidthIIRFilter