Multirate Signal Processing

Decimation, interpolation, downsampling, upsampling, antialiasing filter

Resample uniform or nonuniform data to a new fixed rate. Perform decimation and linear or higher-order interpolation without introducing aliasing.

Functions

decimateDecimation — decrease sample rate by integer factor
downsampleDecrease sample rate by integer factor
fillgapsFill gaps using autoregressive modeling
interpInterpolation — increase sample rate by integer factor
interp11-D data interpolation (table lookup)
intfiltInterpolation FIR filter design
pchipPiecewise Cubic Hermite Interpolating Polynomial (PCHIP)
resampleResample uniform or nonuniform data to new fixed rate
splineCubic spline data interpolation
upfirdnUpsample, apply FIR filter, and downsample
upsampleIncrease sample rate by integer factor

Apps

Signal AnalyzerVisualize and compare multiple signals and spectra

Topics

Downsampling — Aliasing

Aliasing is the distortion that occurs when copies of a signal's spectrum overlap. Downsampling can introduce aliasing.

Filtering Before Downsampling

Filter before downsampling to mitigate the distortion caused by aliasing.

Upsampling — Imaging Artifacts

Upsample a signal and see how upsampling can result in images.

Filtering After Upsampling — Interpolation

Upsample a signal and apply a lowpass interpolation filter to remove imaging artifacts.

Simulate a Sample-and-Hold System

Simulate the output of a sample-and-hold system by upsampling and filtering a signal.

Resampling

Decimate, interpolate, or change the sample rate of signals, with or without intermediate filtering.

Changing Signal Sample Rate

Change the sample rates of a sinusoid and a recorded speech sample.

Multirate Filter Bank Implementation

Implement filter banks using the upfirdn function.

Featured Examples