TABLE OF CONTENTS When a receiver is moving in a complicated, multipath environment, it is continuously receiving new contributions with changes in delay, amplitude and polarisation. The problem of exactly analysing the multipath problem is a formidable task, but is usually one without interest. What is important is to get a statistical description of the propagation parameters combined with a knowledge of their relevance, and to get an engineering understanding of the variety of multipath phenomena by reducing the problem as much as possible. In this section, the various propagation parameters are introduced for more detailed treatment in later sections.
In the general case, the transmitter, which may be either a base or mobile station, emits a field with a well defined polarisation. After a number of reflections from slanted and rough surfaces, or scatterers, the polarisation of the field is changed in a random way, so the incident field at the receiver, E R, has all three components and is dependent on both frequency, w , and position, r:
A time factor of exp(j w t) is assumed. Each component, such as Ex , is a complex scalar, and is also a function of frequency and position. In general, at each point in space, the polarisation is elliptical where the plane of the ellipse is skew (see Figure 2.1.1). At the same point in space there will also be three magnetic field components,...
