Kryszkiewicz, Pawel; Kliks, Adrian; Bogucka, Hanna (Poznan University of Technology, Chair of Wireless Communications, 60-965 Poznan, Poland)
Cognitive ratio has attracted a lot of research interest already for more than ten years, since it creates great possibilities for efficient spectrum utilization. However, the cognitive transmission assumes that the signal of the licensed users will be protected. In this work the dynamic protection methods ofthe primary usen is considered, in particular the application of the cancellation carriers method combined with the windowing process is investigated in a non-contiguous multicarrier transmission. The novelty of this work is the derivation of the optimal number of subcarriers that have to be deactivated by the secondary user in order to keep the interference introduced to the primary user under the allowed threshold while providing the highest possible data rate to the cognitive radio.