Practical Signals Theory with MATLAB Applications

Classification of Signals

LEARNING OBJECTIVES

By the end of this chapter, the reader will be able to:

• List the different signal types in the time domain
• Recognize odd and even signals and their properties
• Identify common periodic signals by their appearance
• Explain the difference between power and energy signals
• Calculate the energy and power and V_rms of signals
• Describe new signals graphically in terms of common signals
• Use MATLAB to define and to plot common signals
• Compute the phase and magnitude of a complex signal
• Explain the properties defining a random signal
• Define a discrete time signal from a continuous time signal

A signal s(t) may be classified by identifying certain characteristics that serve to predict its behavior or appearance, to verify computational results and in many cases, to greatly simplify the mathematics involved in signal analysis. This chapter defines several important categories of signals, each of which describes some significant characteristic, which, in turn, may dictate the mathematical approach one might take in signals analysis. Related computations and practical MATLAB examples are presented for each signal type.

2.1 Introduction

The list of categories shown below summarizes the kind of characteristics that could be identified for a signal s(t). These classifications are not all mutually exclusive, and it is expected that every signal s