Flexible-Radio: A General Framework with PHY-layer algorithm-design insights

This is a tutorial paper on the concept of flexible/reconfigurable radio systems and, especially, on the elements of flexibility residing in the PHY sical layer (PHY). It reviews past research efforts towards flexible radios and introduces the various ways in which a reconfigurable transceiver can be used to provide multi-standard capabilities, link adaptation and user/service personalization. It overviews specific tools developed within two IST projects aiming at such flexible transceiver architectures and presents a specific example of a mode-selection algorithmic architecture which incorporates all the proposed tools. Thus, it serves to illustrate a baseband version of flexibility mechanisms.