الفهرس 
AcknowledgementOnly 14 pages are availabe for public view
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Abstract
Radio communication supported by reflection from ionized meteor trails has received a renewed interest recently. This interest is due to the fact that it is considered a stratigitic substitute for satellite communications. They provide ommunication when an expected breakdown to the conventional means occurs, at least temporarily, in the event of large scale nuclear warfare. There are many other important applications for MBC, for example remote monitoring applications, river level and rain fall monitoring, river quality, monitoring of air and water pollution, telemeasurements of meteorological conditions and controlling the motion of the vehicles during long routes in deserts. Meteor-burst communication, MBC, systems suffer from the time varying nature of the echoes from ionized meteor trails and usually necessitate the use of some advanced techniques, such as adaptive signaling rate and variable length coding, to achieve reliable communications. In this thesis, we are interested in developing new adaptive signaling techniques that are matched to the propagation and scattering parameters of ionized meteor trails. This is done with the aim of improving the performance of the MBC systems and increasing their reliability. At first, we develop models for the equivalent scattering from meteor trails by applying full-wave solutions and numerical techniques. In particular, two models are developed in which the actual meteor trail is mode led by either a
dielectric coated conductor cylinder or an equivalent conducting cylinder surrounded by free space.
Next, we present a novel technique for reliable MBe. This technique is
based on using FM carrier signals with matchedfrequency modulation law, in such a way that the scattering from the time varying meteor is equivalent to that from homogeneous ionized cylinder with constant volume ionization density. As a result the scattering parameters of overdense meteor trails become constant for a long period of reception. In addition, we present another new adaptive technique that is suitable for digital transmission across the time varying MBC channels. This technique utilizes adaptive matched punctured convolutional (PC) codes, for adaptive signaling. We
show that the use of adaptive punctured convolutional codes that are derived from 1/2 rate codes, provide considerable enhancement in the performance ofMBC channels. Also, an imperical formula for the optimum signaling data rate, that results in the maximum possible throughput, has been derived.
The results of the thesis are very promising and the computer simulations show that the new suggested techniques are very useful in improving the performance for future MBC systems.
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