Analysis and Development of Algorithms for Antenna Array Based Communications Systems

点击翻译按钮获取中文摘要

Communication systems employing antenna arrays are required in situations where multiple co-channel signals are present simultaneously. The spatial discrimination provided by multiple antenna elements allows spectrally overlapping signals to be individually extracted. While such systems have typically been proposed in the context of military applications, a number of important commercial applications have recently gained attention. In particular, it has been proposed that antenna arrays be used in land-based mobile radio systems to provide enhanced spatial discrimination and hence increased capacity. Such arrays could potentially provide frequency reuse in adjacent cells, or within a communication cell itself. This research is examining signal copy, interference cancellation, and source localization using antenna arrays, with particular emphasis on scenarios that might be encountered in mobile radio communications (e.g., multipath fading environments, certain signal formats such as analog FM IS-3 AMPS, GSM, IS-54 offset QPSK, IS-95 CDMA, etc.). A focus of this research is the development and analysis of algorithms that exploit all available temporal and spatial information. Conventional techniques for direction finding (DF) and signal copy (SC) rely on either spatial or temporal structure in the data, but typically not both. In situations where both array response data and information about the signal structure is available, it is obviously suboptimal to ignore either. Consequently, several different techniques that exploit both spatial and temporal signal structure for improved DF/SC will be studies: iterative blindleast-squares; decision directed algorithms array-based equalization of multipath channels; and optimal joint DF/SC with parametric array uncertainty. Finally, special emphasis will be placed in this research on the use f real mobile cellular radio data to test the effectiveness of the algorithms developed.