A Cognitive Beamforming Scheme for Coexistence of Incumbent and Cognitive Radios

We propose a new cognitive beamforming scheme for coexistence of IR (incumbent radio) CR (cognitive radio). The proposed cognitive beamforming scheme does not cause any interference to the IRU (IR User), while the CRU (cognitive radio user) is served without additional radio resource consumption. Simulation results show that when using the proposed scheme the CRU does not interfere to the IRU and there is little bit error rate performance degradation of the CRU as compared to that of the ideal beamforming system which does not consider the IR priority.