Smart antenna technologies for future wireless systems: Trends and challenges

The adoption of smart antenna techniques in future wireless systems is expected to have a significant impact on the efficient use of the spectrum, the minimization of the cost of establishing new wireless networks, the optimization of service quality, and realization of transparent operation across multitechnology wireless networks. Nevertheless, its success relies on two considerations that have been often overlooked when investigating smart antenna technologies: first, the smart antennas features need to be considered early in the design phase of future systems (top-down compatibility); second, a realistic performance evaluation of smart antenna techniques needs to, be performed according to the critical parameters associated with future systems requirements (bottom-up feasibility). In this article an overview of the benefits of and most recent advances in smart antenna transceiver architecture is given first. Then the most important trends in the adoption of smart antennas in future systems are presented, such as reconfigurability to varying channel propagation and network conditions, cross-layer optimization, and multi-user diversity, as well as challenges such as the design of a suitable simulation methodology and the accurate modeling of channel characteristics, interference, and implementation losses. Finally, market trends, future projections, and the expected financial impact of smart antenna systems deployment are discussed.