—With the opening up of white spaces, efficient use of the fragmented spectrum - TV white space in particular - has become an extremely important focus of research. Apart from efficient spectrum usage, special care needs to be taken to maintain low out-of-band radiation to avoid harmful interference to incumbent services like TV signals and wireless microphones. For this reason, a flexible digital radio with multicarrier modulation scheme is the only solution. In this paper, we show the performance of two innovative multicarrier systems, Filter Bank Multi Carrier (FBMC) and Generalized Frequency Division Multiplexing (GFDM). A simple interference cancellation technique called serial inter-carrier interference cancellation scheme has been used to improve performance of the GFDM system. Channel equalization techniques have been implemented for FBMC. Keywords- cognitive radio, white space, PHY design, intercarrier interference, multicarrier modulation