A broadband RF converter empowering cognitive radio networks in the TV white space

Research in Cognitive Radio wireless networks has been experiencing increased interest in the last decade, as it could represent a considerable solution to today´s crowded spectrum and inefficient spectrum usage. However, testing and verifying algorithms and hardware for such systems over-the-air pose difficulties in the already licensed telecommunication bands. Meanwhile, digital TV broadcasting has left vacant and unlicensed bandwidth among the allocated spectrum, the so called TV white space, which blends itself for research in the fields of cognitive radio applications, possibly leading to opportunistically offloading LTE traffic to those unused bands. In this paper the system design and implementation of a Radio Frequency Converter Platform is presented that facilitates cognitive radio research to be extended to the air interface using the TV white space without causing interference to licensed telecommunication operators. The converter uses a high-IF architecture and not only fulfills LTE specifications but also legacy standards. It can interface with any experimental or commercially available Software Defined Radio front end and any LTE modem or transceiver, contributing to the BMBF founded kogLTE project. [1] [2] Embedded in the system, the converter enables dynamic and cognitive use of available frequencies in the TV white space. Our presented converter platform therefore enables research in decongesting networks, operation at high network loads, investigating new cognitive radio algorithms and repurposing unused network resources.