LTE-Advanced and Next Generation Wireless Networks: Channel Modelling and Propagation

Chapter 2

Propagation and Channel Modeling Principles

Andreas F. Molisch

University of Southern California, USA

This chapter will explore the basic principles of wireless propagation. It describes the fundamental processes of how signals can get from the transmitter to the receiver and summarizes the description/modeling methods for characterizing the propagation. We will not analyze any specific environments or give quantitative parameterizations of the channel models—those aspects will be treated in the later aspects of the book. Rather, it is the fundamental methodology that is at the center of this chapter. The description partly draws on the presentations [1–5], and the interested reader is referred to those expositions and the references therein for further details.

2.1 Propagation Principles

In almost all wireless communications, analogue passband Radio Frequency (RF) signals are sent from a transmitter to a receiver. At the transmitter, the signal is generated by baseband processing and modulated to a passband, where it is converted to an electromagnetic wave by the transmit antenna. This wave propagates through the channel to the receive antenna, where (part of) it is converted to a (passband) signal that can be further downcoverted and processed by appropriate circuitry. From this description it is clear that both the antennas and the propagation medium have an impact on the characteristics of the signal arriving at the receiver. It is useful to distinguish between the ...