Estimation and interpreting instantaneous frequency of signals in non-stationary measurement sensor systems: An overview

Abstract

The basic concepts and methods of joint time-frequency distributions are discussed. The primary purpose is to demonstrate how a signal's spectral composition alters over time as well as to modify the underlying physical and mathematical concepts of a time-varying spectrum. Main intent is to generate energy or intensity of signal distribution which was represented in both time and frequency. Over last 40 years, fundamental ideas have been developed steadily so that significant advances have occurred. The variety of ideas and motivations that have led to the development of the concepts are highlighted in this review, which is written with non-specialists in mind. An overview of several attempts to determine instantaneous frequency (IF) was given. Numerous characteristics, including the product of bandwidth time (BT), analytic signal as well as the link between time frequency distribution and IFs are explored. Finally, discussions of mono-component, multi-component, and instantaneous bandwidth signals are presented. It is shown that the context of the put forth theory adequately describes each of these ideas. These estimation and interpreting schemes find immediate applications like biomedical signal analysis, speech processing, health care sensor systems.

Keywords

• Bandwidth time
• Instantaneous frequency
• Non-stationary signals
• Parameter estimation
• Sensor systems
• Time frequency representation