Overlay Cognitive Radio Based on UFMC System

In this paper, we consider an overlay cognitive radio (CR) consisting of a primary macro-cell and cognitive small cells of cooperative secondary base stations (SBS). We suggest studying a CR where an orthogonal frequency division multiplexing (OFDM) is used for the primary users (PU) whereas the secondary users (SU) are based on universal filtered multicarrier (UFMC). We derive the interference expression due to SU at the PU receiver. Then, we propose to use zero forcing beamforming/block diagonalization (ZFBF/BD) technique to cancel the interference. At the end, a comparative study with CR based on OFDM systems for both the PU and the SU confirms the efficiency of the proposed scheme.