Fundamentals of Wireless Communication Engineering Technologies

Chapter 5

Propagation

All electromagnetic phenomena can be described by Maxwell's equations, so it might be argued that Maxwell's equations are all we need to study these phenomena. Nevertheless, it has been found that certain phenomena occur frequently, and it helps to study and classify them appropriately. Then, physical models and/or mathematical/geometrical/statistical models can be created. Such models are useful for:

• Studying and analyzing the phenomena.
• Predicting electromagnetic wave behavior.
• Creating analytical and simulation models for performance evaluation of wireless systems.
• Design techniques and technologies for communications over wireless channels.

In this chapter, therefore, we examine such models that describe common effects frequently observed. We begin in Section 5.1 with effects such as reflection, refraction, and diffraction that occur by virtue of the wave nature of electromagnetic waves. These effects are not specific to radio waves. We then consider the more specialized case of the cellular system propagation environment. We divide that discussion into two parts: The large-scale effects and related models are examined in Section 5.2, and the small-scale effects and related models are examined in Section 5.3. What we mean by large scale and small scale will become clear when we get to those sections. Finally, we examine briefly how propagation effects may be incorporated into the link budget for radio link design.

5.1 Electromagnetic Wave Propagation: ...