Adaptive antennas for wireless information networks

Currently, high-speed access to the Internet's wealth of information requires wired connections which are somewhat less than ubiquitous. All other things being equal, wireless access is certainly preferred; however, all other things are not equal. Competing with copper through wireless media is not a trivial task. Consumers have come to expect high-quality service at a low cost with great reliability. Living up to these lofty expectations is not a simple task for wireless information networks (WINs). Spectrum is a finite resource, and with their inherent ability to make much more efficient use of this resource, adaptive antennas are proving to be an effective technological tool in the ongoing battle for increasing information carrying capacity at decreasing cost. By appropriately processing signals from multiple antenna elements, adaptive array systems can continuously optimize their performance, providing dramatic increases in signal quality, spectral efficiency and coverage compared to conventional systems. The benefits of adaptive array or "smart antenna" technology accrue through the spatially selective reception and transmission of RF energy. Fully adaptive, full-duplex approaches are the only ones that have the potential to achieve the performance required of next generation wireless telecommunication systems. Herein, the basic factors that should be considered in designing adaptive array systems for WINs are discussed. The advantage of adaptive array technology is described and a new approach is presented along with selected results from field trials.