2 - Reviews

Abstract

This chapter presents the background on signal and systems, and the sampling theorem. In the traditional binary logics, all combinational logics can be represented by combinations of complement, intersection, and union of binary variables because all Boolean equations can be represented by either the sum of products or the product of sums. There are three fundamental operations in fuzzy logics and these operations represent the traditional complement, intersection, and union operations. Signals are usually used for describing physical phenomena. The most common signals employed for an analysis are impulse, step, and pure complex exponential signals. If both the input and output of a system are continuous time signals, then the system is called a continuous time system. If both the input and output of a system are discrete time signals, then the system is called a discrete time system. It is found that if the impulse response of a digital filter has finite support or finite length, then the digital filter is called a finite impulse response, otherwise it is called an infinite impulse response. If the transfer function of the digital filter is rational, then the digital filter is called rational. The relationships among continuous time signals, sampled signals, and discrete time signals in the frequency domain are also elaborated in the chapter.