Reconfigurable MIMO Antennas for Cognitive Radios

Abstract

The concept of cognitive radio (CR) is a new paradigm that autonomously discover the demographics of radio spectrum to get information about its utilization and determine the services being offered. The prospect usage of CR architectures in future generations of wireless communications is very promising. CR basically integrates machine learning algorithms into wireless devices and networks. It is evolving from self awareness stage to cognitive learning autonomously about its environment which would be helpful to adapt to new wireless standards, access users environment and behavior. A fundamental part in a CR is its front-end antenna system. The function of such antennas are self-awareness by scanning the entire spectrum of interest along with provides serving by reconfigurable antennas over several bands. In the near future, CR platforms will be integrated to become a part of wireless communication standards. The front end of a CR consists of a sensing antenna for spectrum scanning and a reconfigurable antenna or reconfigurable multiple-input-multiple-output (MIMO) antenna system for communication over several frequency bands. Reconfigurable antennas in CR applications are used to vary its fundamental properties to efficiently utilize the available bandwidth while MIMO antenna system based reconfigurable antennas are to be used to meet the high data rate requirements of future wireless terminals. This chapter will shine some light on the most recent CR front-end antennas focusing on MIMO based integrated architecture.