Advanced Physics-Based Propagation Models for Channel Characterization in a Wireless Network

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9979376SarabandiIn this proposal the basic science issues related to the development of a high fidelity propagation model, for application in wideband, high data rate wireless systems, are addressed. The emphasis is placed on the development of new methodologies for obtaining accurate and efficient field calculations needed for the propagation model. The electromagnetic wave between a transmitter and a receiver, through its interaction with its environment, experiences phenomena such as shadowing, reflection, diffraction, attenuation and multiple scattering. Development of advanced, high speed, innovative wireless systems requires accurate knowledge of the propagation channel and its effects on modulation and coding schemes, system bandwidth, transmitter power and antenna design. Current methods of prediction are either heuristic or overly simplistic (based on ray-tracing and simple diffraction models) and tend to neglect physical phenomena which have a significant effect on radio wave propagation. With this in mind development of a physics-based approach to propagation prediction, with emphasis in providing the basic understanding of the physical phenomena and developing advanced analytical and numerical electromagnetic (EM) models, is proposed. Specifically, a number of realistic canonical geometries and generic propagation blocks for a propagation model are considered and detailed plans for acquiring the diffracted fields and its statistics accurately and efficiently are provided. The propagation problem will be divided into three categories or environments, each of which has its own unique characteristics representing rural, urban, and atmospheric propagation. Within each environment EM scattering and diffraction phenomenon will be investigated and appropriate models, representing various environmental features and including stochastic variations, will be developed and integrated. Within each environment a layered approach will be taken with each layer representing the degree of approximation necessary for accurate prediction. These models will eventually be integrated with existing terrain data bases obtained from geographical information systems (GSI) or remote sensing technology to produce a highly accurate and general prediction tool. For a given environment and transmitter and receiver configurations the proposed propagation model will provide mean-field strength (path loss estimate), signal fading statistics, spatial decorrelation distance, frequency decorrelation bandwidth, Doppler spectrum for mobile platforms, and the time delay response of the channel.***