A cognitive radio system applicable to UTRA as overlay radio system

摘要

Reconfigurability of transceivers for wireless communication systems such as UMTS/LTE, WiMAX, WLAN and GSM will become increasingly important. Therefore, a flexible and reliable software and hardware architecture based on the Software-Defined Radio (SDR) paradigm is a meaningful concept. Software-Defined Radios have paved the way towards Cognitive Radios, which are based on SDRs that additionally sense their environments, track changes, and react upon their findings. A Cognitive Radio is an autonomous unit in a communications environment that frequently exchanges information with the networks it is able to access as well as with other CRs. The artifical spectrum scarcity induced by strict regulations of available frequency spectrum resources leads to the fact that especially the frequency bands which are dedicated to cellular communications are used to full capacity while a wide part of the spectrum is nearly unused. Cognitive Radio is considered to be the enabling technology for a more efficient use of the available frequency spectrum. This contribution presents a Cognitive Radio hardware demonstration testbed in application to UTRA as overlay radio system.