Software Defined Radio Platform for Cognitive Radio: Design and Hierarchical Management

Cognitive Radio (CR) Mitola (2000) is a promising technology to improve spectrum utilization of wireless communication systems. Current investigations in CR have been focused on the physical layer functionality. The cognitive radio, built on a software-defined radio, assumes that there is an underlying system hardware and software infrastructure that is capable of supporting the flexibility needed by the cognitive algorithms. As already foreseen by Mitola Mitola & Maguire (1999), a Cognitive Radio is the final point of Software Defined Radio (SDR) platform evolution: a fully reconfigurable radio that changes its communication functions depending on network and/or user demands. Mitola’s definition on reconfigurability is very broad and we only focus here on the reconfigurability of the hardware platform for Cognitive Radio. SDR basically refers to a set of techniques that permit the reconfiguration of a communication system without the need to change any hardware system element. As explained in the schematic of figure 1, this relies on a cognitive circle. Figure 1 (a) is from Mitola (2000) and figure 1 (b) is a simplified view of the cycle summarized in three main steps: