Adaptive Conformal Arrays for Next-Generation Wireless Communications

University Of Arizona, Tucson AZ

Investigators

Abstract

0098547 Virga The rapid explosion in the number of wireless communications systems demands an ever increasing system performance capacity. It is imperative that innovative design paradigms that maximize system performance be pursued. Significant attention has been given to maximizing performance in the communications protocols, while less has been given to the system throughput available from "smart" array antenna design. Adaptive conformal antenna arrays are arrays with radiating elements that are placed in arbitrary locations and the elements may be directed in different directions. The interest in adaptive conformal antennas at the base station and on the mobile terminals is motivated by previous work reported on indoor wireless channels and on novel space-time coding techniques that suggests the use of conformal arrays improves the reliability of the communications over multi-path propagation effects and fading, and in general, improves the overall quality of service of the entire wireless network. This proposal addresses the development of simulation, design, and analysis approaches for adaptive conformal array antennas and provides an in-depth investigation to quantify the performance capabilities available from conformal arrays. The result will be a new class of array antennas and design tools for fourth generation wireless systems and beyond. This work will be focused in two main areas. The first area involves developing novel simulation algorithms to understand how the particular array weights for several conformal array configurations influences the spatial distribution of the transmitted or received signal. This work will include the development efficient tools to determine the optimal set array weights necessary to obtain a specified spatial response. The research will use the results of previous antenna modeling efforts to factor in the effects of realistic designs of typical antenna elements, (element patterns, gain and phase imbalance, and mutual coupling etc.) and real-time processing resources. The second area involves developing processing methods to determine space-time characteristics for conformal arrays. This will allow the determination of the angle-of-arrival of an incoming signal and will allow the PI's to adapt the array weights in order to maximize signal to noise ratio and quality of the wireless channel. The intellectual and creative aspects of the proposed activities include advancing the state-of-the-art for general conformal array antennas for wireless communications, implementing evolutionary programming methods that take into account multi-design criteria for conformal antenna arrays, quantifying fundamental characteristic design formulas to understand the capabilities and limitations of conformal array antennas, and utilizing directional elements in the design of conformal arrays and quantifying the performance enhancements obtained from the use of directional elements in conformal arrays. Other activities include investigating the mutual coupling between radiators in conformal arrays, and developing novel adaptive processing methods specifically for conformal arrays for angle-of-arrival and time-of-arrival estimation. The PIs plan to interface with research activities in this proposal with work in a wireless networking project when applicable. This will have broader impact beyond the research described in the present proposal.