|Filter Design Toolbox Release Notes|
Incorporating functionality from the Quantized Filtering Toolbox, Filter Design Toolbox 2.0 is a new product for digital filter design, implementation, and analysis using fixed-point or arbitrary-precision floating-point arithmetic. This toolbox includes advanced FIR and IIR filter design methods and a new quantization tool for designing and analyzing quantized FIR and IIR filters. This section introduces the features and enhancements added in the Filter Design Toolbox 2.0 since the Quantized Filtering Toolbox 1.0 was released in Release 11.1.
|Note The Quantized Filtering Toolbox 1.1 has been integrated into the Filter Design Toolbox 2.0. The information below summarizes the changes to the Quantized Filtering Toolbox since Version 1.0 of that product. These changes are incorporated into the new Filter Design Toolbox 2.0.|
You must have the Signal Processing Toolbox installed to use Filter Design Toolbox.
New Quantization Tool for Advanced FIR and IIR Filter Design
Signal Processing Toolbox includes an interactive filter design tool called Filter Design and Analysis Tool (FDATool). You use this visual interface to design, convert, quantize, import, and export FIR and IIR filters. FDATool integrates filter design and analysis functions in a single tool, letting you do all your filter design tasks from within the tool instead of using the MATLAB command line. Filter Design Toolbox adds quantization analysis to FDATool.
When you install Filter Design Toolbox, FDATool operates in three modes:
To enable you to convert filters from one structure to another, for example, from direct form to coupled allpass, FDATool offers smart conversion tools. When you convert a filter, FDATool offers you a selection of conversion structures that depends on the current filter type.
To launch FDATool, enter
fdatool at the MATLAB command prompt or use the Launch Pad. For more information on the new tool, refer to "Filter Design and Analysis Tool" in the Signal Processing Toolbox User's Guide or use Help to review the online documentation.
The Filter Design Toolbox 2.0 includes these new objects:
quantizerfunction to construct a quantizer, and use the
quantizefunction to quantize the data according to your quantizer specifications. There are also many functions that calculate the characteristics associated with a given quantizer. For example,
epsdetermines the precision of the quantizer, and
realmaxdetermines the maximum number the quantizer can quantize without overflow.
qfftto construct a quantized FFT, and the function
fftto apply an FFT to data as specified by your quantized FFT.
New Filter Design Functions
The Filter Design Toolbox 2.0 includes these new filter design functions:
firlpnorm- Design a least P-norm FIR filter
gremez- Use generalized Remez techniques to design FIR filters
iirgrpdelay- IIR filter design with prescribed group delay value
iirlpnorm- Design a least P-norm IIR filter
iirlpnormc- Design a constrained least P-norm IIR filter
New Filter Conversion Functions
The Filter Design Toolbox 2.0 includes these new filter conversion functions:
ca2tf- Convert coupled allpass transfer function forms to transfer function forms
cl2tf- Convert coupled allpass lattice forms to transfer function forms
iirpowcomp- Compute a power-complementary IIR filter from a given IIR filter
sos: Convert the filter topology of a quantized filter to second-order sections with scaling
tf2ca- Convert transfer function forms to coupled allpass transfer function forms
tf2cl- Convert transfer function forms to coupled allpass lattice forms
New Filter Structures
Filter Design Toolbox 2.0 includes five new filter structures:
To learn more about these structures, refer to Filter Structures in the Filter Design Toolbox User's Guide.
New Analysis Methods
Filter Design Toolbox 2.0 includes two new analysis methods:
limitcycleuses Monte Carlo techniques to detect limit cycles in quantized filters.
nlmto use the noise loading method to calculate the frequency response of a quantized filter. Compare the response to the results from
freqz, which calculates the theoretical frequency response. To generate noise signals that contain complete frequency content across the spectrum,
nlmuses a series of Monte Carlo trials.
New Functions and Enhancements
Filter Design Toolbox 2.0 includes the following new functions and enhancements:
copyobjfunction for copying quantized filters, quantized FFTs, and quantizers. Copies are independent of the original items, but have the same property values as the original.
CoefficientFormatproperty to default to
Unitquantizerfor quantized filters, quantized FFTs, and quantizers.
NOperations, a new data-related read-only property for quantizers that counts the number of data points quantized by a quantizer.
NOperationsread-only values to the displayed information.
CoefficientFormatproperty for quantized filters and FFTs to
demofunction to access the new demos.
|Known Software and Documentation Problems||Upgrading from an Earlier Release|