Exploring the Reconfigurability Options of Multi-Carrier CDMA in Cognitive Radio Systems

The ever increasing demands for access to frequency spectrum and more efficient methods of using this spectrum involving multi-carrier techniques are driving the development of reconfigurable and cognitive wireless devices. The potential for, and the need to accommodate the potentially time-varying entropy in these wireless systems presents several design and implementation challenges. However, significant opportunities for innovation extending from the wireless terminal implementation to the business and market models also exist. This paper focuses on the physical (PHY) and medium-access control (MAC) layer issues of these emerging systems, highlighting the following three main contributions: An introduction to reconfigurable multi-carrier code division multiple access (MC-CDMA), an exploration of the use of reconfigurable MC-CDMA and its impact on the design of the physical (PHY) and medium access control (MAC) layers in a cognitive radio context and overview of the practical design and development considerations of this novel system which is being implemented on a real cognitive radio development testbed.