Filter Design Toolbox

Multirate Filter Constructors

Filter Design Toolbox includes functions that create multirate filtering objects, as shown in this table.

Multirate Filter Object	Filter Object Description
mfilt.cicdecim	Construct a cascaded integrator-comb decimation filter object
mfilt.cicdecimzerolat	Construct a cascaded integrator-comb decimation filter object that does not display latency
mfilt.cicinterp	Construct a cascaded integrator-comb interpolation filter object
mfilt.cicinterpzerolat	Construct a cascaded integrator-comb interpolation filter object that does not display latency
mfilt.fftfirinterp	Construct an overlap-add FIR polyphase interpolation filter object
mfilt.firdecim	Construct a direct-form FIR polyphase decimation filter object
mfilt.firfracdecim	Construct a direct-form FIR polyphase fractional decimation filter object
mfilt.firfracinterp	Construct a direct-form FIR polyphase fractional interpolation filter object
mfilt.firinterp	Construct a direct-form FIR polyphase interpolation filter object
mfilt.firsrc	Construct a direct-form FIR polyphase sample rate conversion filter object
mfilt.firtdecim	Construct a direct-form, transposed FIR polyphase decimation filter object
mfilt.holdinterp	Construct an FIR interpolation filter object that uses "hold" interpolation between input samples
mfilt.linearinterp	Construct an FIR linear interpolation filter object that applies linear interpolation between input samples

For more information about a multirate filter object, refer to the reference page for the object.

Methods Operating on Adaptive Filter and Multirate Filter Objects

The following methods support adaptive filter and multirate filter objects. In addition, existing filter analysis methods such as freqz work with the objects just as they do for qfilt and dfilt objects.

Method Name	Supported Objects	Description
block	Multirate (some)	Generate a DSP Blockset block that duplicates the filter object. Works only when DSP Blockset is installed. Some multirate objects cannot be modelled as blocks since the blockset does not provide blocks for all the multirate filters in the toolbox.
coefficients	Multirate	Return the multirate filter objects coefficients.
euclidfactors	Multirate	Use Euclid's theorem to determine the integer factors for an mfilt object.
msepred	Adaptive filter	Return the predicted mean-square error for the adaptfilt object.
msesim	Adaptive filter	Return the measured mean-square error for the adaptfilt object via simulation.
maxstep	Adaptive filter	Return the maximum step size for an adaptfilt object.
nstates	Multirate filter	Return the number of states in an mfilt object.
polyphase	Multirate filter	Return the polyphase matrix for an mfilt object.

To see the full listing of analysis methods that apply to the adaptfilt and mfilt objects, type help adaptfilt and help mfilt at the MATLAB prompt.

The Filter Visualization Tool (FVTool) supports these objects so you can use the full power of FVTool to analyze the objects you create.

Adaptive Filters Constructors

Functions Operating on Quantized Filters