AbstractThe growing use and demand for microwave communication systems has led to an increase in system density, particularly in urban areas. Consequently this rise has increased the risk of interference. Especially in urban areas the abundant presence of potential obstacles increase the risk of multipath propagation. Multipath propagation on radio links is associated with signal delays and signal level fades on which adversely influences the system performance.
For efficient frequency planning the knowledge of the multipath geometries involved is required. This knowledge can be obtained by resolving the experienced multipath field into its constituent components yielding their amplitudes and angles of arrivals at a receiver terminal.
Some previous investigations into the resolution of multipath generated height gain curves are documented in the literature. These generally however oncentrate on resolving the two predominant signal components. In an urban environment the number of expected constituent signal components exceed the number of two. Resolution of more than two components requires considerably more effort than this relatively simple case.
This thesis provides a component resolution procedure which determines the individual amplitudes and angles of arrival of constituent multipath components. The procedure is applied to the spatial amplitude envelope observed when displacing a receiver incrementally over a distance of a few wavelength through a multipath field. The presented solution can be applied with inexpensive easurement and computational means. For the resolution process it is only required to record the envelope pattern amplitude values without any phase information being required. The use of a single standard antenna as receiver is also sufficient. The procedure does not require data of an array of antenna elements. The performance of the resolution procedure has been tested and validated in an extensive experimental programme which was part of this research.
Preliminary results of this project are published in the report of the European COST 235 project.
|Date of Award||May 1998|