Amplitúdóshift

Amplitúdóshift is a term that appears in discussions of signal processing to describe a change in the amplitude of a waveform, either continuously or at discrete levels, without altering the signal’s timing or frequency content. It is distinct from time shifts or phase shifts, which modify when a signal occurs or its phase, rather than how tall its peaks are.

Mathematically, amplitúdóshift is modeled as a time-varying gain applied to a base signal. If x(t) is the original signal, the amplitude-shifted signal can be written as y(t) = a(t) x(t), where a(t) is a nonnegative function representing the instantaneous amplitude factor. In discrete-time systems, this becomes y[n] = a[n] x[n], with a[n] taking on one or more chosen levels in the case of digital modulation schemes.

There are two common interpretations of the term. One is continuous amplitude scaling, as used in gain control, compression, and envelope shaping. The other is discrete amplitude shift, as in amplitude-shift keying (ASK) used in digital communications, where different symbols correspond to distinct amplitude levels of a carrier.

Practical considerations include dynamic range, linearity of the system, and noise effects. Large or abrupt amplitude shifts can cause distortion, clipping, or spectral broadening, while carefully controlled shifts are essential in loudness normalization, modulation, and signal intelligibility.

See also: amplitude modulation, gain control, envelope detection, compression, amplitude-shift keying. Further reading in general signal processing and communication theory texts covers the mathematical treatment and practical implications of amplitude changes in signals.