Instantaneous Bandwidth

摘要

We consider the issue of local values for deterministic and random signals. By local values we mean physical quantities that are functions of time such as instantaneous frequency. We discuss how to define instantaneous bandwidth and show that it always consists of two parts which have different physical meanings. One is due to the instantaneous amplitude modulation and the other to instantaneous frequency modulation. The issue of the proper definitions for the random case is considered and a number of examples are given.