Reconstruct signals from subbands
The DyadicSynthesisFilterBank
object reconstructs
signals from subbands with smaller bandwidths and lower sample rates.
The filter bank uses a series of highpass and lowpass FIR filters
to repeatedly reconstruct the signal.
To reconstruct signals from subbands with smaller bandwidths and lower sample rates:
Define and set up your synthesis filter bank. See Construction.
Call step
to reconstruct
the signal according to the properties of dsp.DyadicSynthesisFilterBank
.
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.
dydsyn = dsp.DyadicSynthesisFilterBank
returns
a synthesis filter bank, dydsyn
, that reconstructs
a signal from its subbands with smaller bandwidths and smaller sample
rates.
dydsyn = dsp.DyadicSynthesisFilterBank('
returns a synthesis filter bank, Propertyname
',PropertyValue
,...)dydsyn
, with each specified property
set to the specified value.

Type of filter used in filter bank Specify the type of filter used to determine the highpass and lowpass FIR filters in the
filter bank as one of
In order to automatically design waveletbased filters, install the Wavelet
Toolbox product. Otherwise, use the
 

Lowpass FIR filter coefficients Specify a vector of lowpass FIR filter coefficients, in descending powers of
z. Use a halfband filter that passes the frequency
band stopped by the filter specified in the
 

Highpass FIR filter coefficients Specify a vector of highpass FIR filter coefficients, in descending powers of
z. Use a halfband filter that passes the frequency
band stopped by the filter specified in the
 

Wavelet order Specify the order of the wavelet selected in the  

Wavelet order for synthesis filter stage Specify the order of the wavelet for the synthesis filter stage as:
This property applies only when you set the
 

Number of filter bank levels Specify the number of filter bank levels as a scalar integer.
An Nlevel asymmetric structure has N + 1 input subbands, and an Nlevel
symmetric structure has 2^{N} input
subbands. The default is rg  

Structure of filter bank Specify the structure of the filter bank as 
step  Reconstruct signal from high and lowfrequency subbands 
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 
This object implements the algorithm, inputs, and outputs described on the Dyadic Synthesis Filter Bank block reference page. The object properties correspond to the block parameters, except:
The object only receives data as a vector or matrix of concatenated
subbands, as specified using the step method. 