resamp

Resamp is an abbreviation for resampling, the process of changing the sampling rate of a discrete-time signal. It is a fundamental operation in digital signal processing used to adapt data to different systems, synchronize streams, or manage data rates for storage and transmission.

Resampling can be performed by upsampling (increasing the sampling rate) and downsampling (decreasing the sampling rate). In upsampling, new samples are inserted and then a low-pass filter is applied to remove spectral images. In downsampling, the signal is typically preceded by an anti-aliasing filter to prevent aliasing.

For non-integer resampling factors, interpolation-based methods or polyphase implementations are used. Common approaches include finite impulse response (FIR) or infinite impulse response (IIR) filters, fractional-delay/interpolator designs, and FFT-based resampling techniques. Polyphase filter banks enable efficient computation for arbitrary resampling ratios.

Applications include audio and video processing, telecommunications, data acquisition, and sensor networks. Resampling is also used in image processing when resizing arrays, though that domain emphasizes two-dimensional interpolation.

Key considerations include preserving signal integrity, avoiding aliasing and phase distortion, and balancing accuracy against computational cost. Proper resampling relies on appropriate filtering and knowledge of the original signal bandwidth.

See also: sampling theorem, interpolation, decimation, upsampling, anti-aliasing filter, polyphase filter.