Statistical modeling for land mobile satellite communications

The Land Mobile Satellite System (LMSS) to be available in the 1990 time frame will provide connection between mobile vehicles and the conventional terrestrial communication network. The design is dependent on the propagation characteristics of the land mobile satellite signal. Unlike fixed satellite links, there is blockage in the line of sight path, mainly in the form of vegetative shadowing. The focus of this study is to develop models for the fading of the received satellite signal. A brief review of the physics and statistics associated with mobile propagation is presented. This is followed by a review of current literature and experiments. The modeling of the cumulative distribution function for a totally vegetatively shadowed mobile (VS distribution) is presented. The VS distribution is then used in a model for the cumulative distribution function of a partially shadowed mobile. The complete model for partially shadowed routes permits calculations for arbitrary combinations of open and forested terrain. Comparisons are made to data reported for partially shadowed routes. The deterministic path model (DPM) developed in an earlier effort is a geometrically based tool for determining the signal path length through a stand of trees. It is expanded to give approximate expressions for the statistical parameters describing the fading of the line-of-sight component of the received signal. New expressions for the secondary statistics of a totally vegetatively shadowed mobile are derived. These new expressions are then used in models for the level crossing rate and average fade duration of a partially shadowed mobile. Comparisons are made to data reported for partially shadowed routes.

Name thesis:degree_name

M.S.

Level thesis:degree_level

masters

Discipline thesis:degree_discipline

Electrical Engineering

Department dc:contributor.department

Electrical Engineering

Grantor dc:publisher

Virginia Polytechnic Institute and State University

Year dc:date.issued

1986

Author dc:creator

• Smith, William Travis

Statement dc:rights

• In Copyright

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Language dc:language.iso

en_US

Handle dc:identifier.uri

http://hdl.handle.net/10919/91072

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/91072