In digital signal processing (DSP), a normalized frequency is a ratio of a variable frequency) and a constant frequency associated with a system (such as a sampling rate). Some software applications require normalized inputs and produce normalized outputs, which can be re-scaled to physical units when necessary. Mathematical derivations are usually done in normalized units, relevant to a wide range of applications.

Examples of normalization

A typical choice of characteristic frequency is the sampling rate has the unit cycle per sample is expressed in Hz (cycles per second is expressed in samples per second.

Some programs (such as MATLAB toolboxes) that design filters with real-valued coefficients prefer the Nyquist frequency cycle/sample half-cycle/sample. Therefore, the normalized frequency unit is important when converting normalized results into physical units.

(see ). The samples (sometimes called frequency bins with the unit th cycle/sample.

Angular frequency and with the unit radians per second the normalized Nyquist angular frequency is .

kHz samples/second (often denoted by 44.1 kHz), and 4 normalization conventions:

See also

• Prototype filter

References