RF frequency converters for White Space devices

The spectrum scarcity caused by the exploding wireless data demand is seen to be combatable with the help of cognitive radio techniques. However, not only in the fields of algorithms and digital signal processing, research has to be done. To derive accurate channel models, to conduct field tests and to find realistic spectrum sensing scenarios, testing with air interfaces is inevitable for conducting cognitive radio research. As conventional software defined radios either do not possess the required wide frequency range, the required linearity or the out-of-band rejection to fulfill the specifications, alternative possibilities for air interfaces have to looked into. In this paper, two frequency converters for operation of commercial radio transceivers in the TV White Space are presented. While “whiteLAN” enables the use of standard wireless LAN equipment in the TV white space, “kogHF” enables cellular LTE devices to operate in the TV white space. Both converters are described and their performance is evaluated. The combination of the realized frequency converter and any software-defined radio or any standard transceiver then fulfills the corresponding specifications and spectrum masks while operating in the TV White Space.