Efficient Power Loading in MIMO-OFDM Based Cognitive Radio Networks
Due to their spectrum shaping capability and high adaptability, the multi-carrier systems are considered as prime candidates for use in the Cognitive Radio (CR) networks. In these structures, the deactivation of the Primary Users' (PUs) bands makes the Secondary Users (SUs) use a limited number of sub-carriers, so the total capacity of CR networks is reduced. However, multiple transmit antennas can be applied to OFDM- based CR to compensate for such a low capacity. The present paper investigates the problem of power allocation in MIMO-OFDM based CR Networks.