Full-filling algorithm for power allocation in OFDM-based cognitive radio systems

In this paper, we propose a sub-optimal technique to solve problem of power allocation in cognitive radio (CR) OFDM-based system. This technique called full-filling based on windowing the CR user´s signal and maximizing the power allocation at good sub-carrier positions of CR user. Thank to the interference reduction of windowing technique, the complexity of power allocation optimization problem with burden of computation can be reduced by using full-filling power allocation. The simulation results show that full-filling method outperforms the previous methods such as uniform allocation and interference inversion allocation. In the high tolerable interference range to primary user, full-filling method can achieve the optimal capacity performance.