Main Content

Variable-Size Signal Support DSP System Objects

Several DSP System Toolbox™ System objects support variable-size input signals. In these System objects, you can change the frame size (number of rows) of the input matrix even when the object is locked. The number of channels (number of columns) of the input matrix must remain constant. The System object™ locks when you call the object to run its algorithm.

Variable-Size Signal Support Example

Open Live Script

Create a dsp.FIRHalfbandDecimator System object™. The input signal contains 10 channels, with 1000 samples in each channel.

FIRHalfband = dsp.FIRHalfbandDecimator;
input = randn(1000,10);

Lock the object by running the algorithm.

FIRHalfband(input);
isLocked(FIRHalfband)
ans = logical
   1

Change the frame size of the input to 800 without releasing the object.

input = randn(800,10);
FIRHalfband(input);

The System object runs without error.

DSP System Toolbox System Objects That Support Variable-Size Signals

Sources
dsp.UDPReceiver
Sinks
spectrumAnalyzer
dsp.UDPSender
Adaptive Filters
dsp.AdaptiveLatticeFilter
dsp.AffineProjectionFilter
dsp.FastTransversalFilter
dsp.FilteredXLMSFilter
dsp.FrequencyDomainAdaptiveFilter
dsp.LMSFilter
dsp.RLSFilter
Single-Rate Filters
dsp.AllpassFilter
dsp.AllpoleFilter
dsp.CoupledAllpassFilter
dsp.Differentiator
dsp.FIRFilter
dsp.IIRFilter
dsp.FourthOrderSectionFilter
dsp.HampelFilter
dsp.HighpassFilter
dsp.LowpassFilter
dsp.NotchPeakFilter
dsp.SOSFilter
dsp.VariableBandwidthFIRFilter
dsp.VariableBandwidthIIRFilter
Multirate and Multistage Filters
dsp.Channelizer
dsp.ChannelSynthesizer
dsp.CICCompensationDecimator
dsp.ComplexBandpassDecimator
dsp.FarrowRateConverter
dsp.FilterCascade (if the cascaded filters support variable-size signals)
dsp.FIRDecimator
dsp.FIRHalfbandDecimator
dsp.FIRHalfbandInterpolator
dsp.FIRInterpolator
dsp.FIRRateConverter
dsp.IIRHalfbandDecimator
dsp.IIRHalfbandInterpolator
dsp.SampleRateConverter
dsp.SubbandAnalysisFilter
Transforms
dsp.FFT
dsp.IFFT
dsp.ZoomFFT
Measurements and Statistics
dsp.MovingAverage
dsp.MovingMaximum
dsp.MovingMinimum
dsp.MovingRMS
dsp.MovingStandardDeviation
dsp.MovingVariance
dsp.MedianFilter
dsp.PeakToRMS
Signal Operations
dsp.DCBlocker
dsp.Delay
dsp.VariableFractionalDelay
dsp.PhaseExtractor
Signal Management
dsp.AsyncBuffer

For a list of DSP System Toolbox blocks that support variable-size signals, open the block data type support table from the MATLAB® command prompt: 

showsignalblockdatatypetable

See the blocks with an X in the Variable-Size Support column of the block data type support table.