Fixed-Point Filters

Fixed-point filter design

Objects

Single-Rate Filters

`dsp.AllpoleFilter`	IIR Filter with no zeros
`dsp.BiquadFilter`	IIR filter using biquadratic structures
`dsp.Differentiator`	Direct form FIR fullband differentiator filter
`dsp.FIRFilter`	Static or time-varying FIR filter
`dsp.HDLFIRFilter`	Finite impulse response filter—optimized for HDL code generation
`dsp.HighpassFilter`	FIR or IIR highpass filter
`dsp.IIRFilter`	Infinite impulse response (IIR) filter
`dsp.LowpassFilter`	FIR or IIR lowpass filter

Multirate and Multistage Filters

`dsp.CICCompensationDecimator`	Compensate for CIC decimation filter using FIR decimator
`dsp.CICCompensationInterpolator`	Compensate for CIC interpolation filter using FIR interpolator
`dsp.CICDecimator`	Decimate signal using cascaded integrator-comb (CIC) filter
`dsp.CICInterpolator`	Interpolate signal using cascaded integrator-comb filter
`dsp.DigitalDownConverter`	Translate digital signal from intermediate frequency (IF) band to baseband and decimate it
`dsp.DigitalUpConverter`	Interpolate digital signal and translate it from baseband to IF band
`dsp.FarrowRateConverter`	Polynomial sample rate converter with arbitrary conversion factor
`dsp.FIRDecimator`	Polyphase FIR decimator
`dsp.FIRHalfbandDecimator`	Halfband decimator
`dsp.FIRHalfbandInterpolator`	Halfband interpolator
`dsp.FIRInterpolator`	Polyphase FIR interpolator
`dsp.FIRRateConverter`	Sample rate converter
`dsp.HDLFIRRateConverter`	Upsample, filter, and downsample—optimized for HDL code generation
`dsp.SubbandAnalysisFilter`	Decompose signal into high-frequency and low-frequency subbands
`dsp.SubbandSynthesisFilter`	Reconstruct signal from high-frequency and low-frequency subbands

Adaptive Filters

dsp.LMSFilter Compute output, error, and weights of LMS adaptive filter

Functions

`autoscale`	Automatic dynamic range scaling
`denormalize`	Undo filter coefficient and gain changes caused by normalize
`freqrespest`	Frequency response estimate via filtering
`freqrespopts`	Options for filter frequency response analysis
`freqz`	Frequency response of filter
`impz`	Impulse response of discrete-time filter System object
`isstable`	Determine whether filter is stable
`limitcycle`	Response of single-rate, fixed-point IIR filter
`noisepsd`	Power spectral density of filter output due to roundoff noise
`noisepsdopts`	Options for running filter output noise PSD
`normalize`	Normalize filter numerator or feed-forward coefficients
`reffilter`	Reference filter for fixed-point or single-precision filter
`reorder`	Rearrange sections in SOS filter
`scale`	Scale second-order sections of dsp.BiquadFilter System object
`set2int`	Configure filter for integer filtering
`specifyall`	Fully specify fixed-point filter System object settings
`zplane`	Z-plane zero-pole plot for discrete-time filter System object

Blocks

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Single-Rate Filters

Allpole Filter	Model allpole filters
Biquad Filter	Model biquadratic IIR (SOS) filters
Differentiator Filter	Direct form FIR fullband differentiator filter
Discrete Filter	Model Infinite Impulse Response (IIR) filters
Discrete FIR Filter	Model FIR filters
Discrete FIR Filter HDL Optimized	Finite impulse response filter—optimized for HDL code generation
Highpass Filter	Design FIR or IIR highpass filter
Lowpass Filter	Design FIR or IIR lowpass filter

Multirate and Multistage Filters

CIC Compensation Decimator	Compensate for CIC filter using FIR decimator
CIC Compensation Interpolator	Compensate for CIC filter using FIR interpolator
CIC Decimation	Decimate signal using cascaded integrator-comb filter
CIC Interpolation	Interpolate signal using cascaded integrator-comb filter
Digital Down-Converter	Translate digital signal from Intermediate Frequency (IF) band to baseband and decimate it
Digital Up-Converter	Interpolate digital signal and translate it from baseband to Intermediate Frequency (IF) band
Farrow Rate Converter	Polynomial sample-rate converter with arbitrary conversion factor
FIR Decimation	Filter and downsample input signals
FIR Halfband Decimator	Decimate signal using polyphase FIR halfband filter
FIR Halfband Interpolator	Interpolate signal using polyphase FIR half band filter
FIR Interpolation	Upsample and filter input signals
FIR Rate Conversion	Upsample, filter, and downsample input signals
FIR Rate Conversion HDL Optimized	Upsample, filter, and downsample input signals—optimized for HDL code generation
Two-Channel Analysis Subband Filter	Decompose signal into high-frequency and low-frequency subbands
Two-Channel Analysis Subband Filter	Decompose signal into high-frequency and low-frequency subbands

Adaptive Filters

LMS Filter

Compute output, error, and weights using LMS adaptive algorithm

Filter Realization

Filter Realization Wizard

Construct filter realizations using digital filter blocks or Sum, Gain, and Delay blocks

Topics

Fixed-Point Precision Rules for Avoiding Overflow in FIR Filters

Precision Rules for Avoiding Overflow in FIR Filters

Create an FIR Filter Using Integer Coefficients

Learn how to create an FIR filter using integer coefficients.

Use Filter Designer with DSP System Toolbox Software

Presents a detailed reference covering the fixed-point, multirate, and scaling pages of the Filter Designer App.

Featured Examples

Sigma-Delta A/D Conversion

Model analog-to-digital conversion using a sigma-delta algorithm implementation.

Open Model

Cochlear Implant Speech Processor

Simulate the design of a cochlear implant that can be placed in the inner ear of a profoundly deaf person to restore partial hearing. Signal processing is used in cochlear implant development to convert sound to electrical pulses. The pulses can bypass the damaged parts of a deaf person's ear and be transmitted to the brain to provide partial hearing.

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Design and Analysis of a Digital Down Converter

Use the digital down converter (DDC) System object to emulate the TI Graychip 4016 digital down converter in a simple manner. We base the example on a comparison with the GSM Digital Down Converter example. We show how the DDC System object can be used to design and analyze the decimation filters and to quickly explore different design options that meet various passband and stopband frequency and attenuation specifications. This example requires a Fixed-Point Designer™ license.

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