A Flexible PAPR Reduction Scheme for Multicarrier Cognitive Radio Systems

Owing to intelligent behaviors, cognitive radio (CR) has become a promising technology to improve spectrum utilization efficiently. One of techniques which adapt CR concept to reduce peak-to-average-power ratio (PAPR) is known as tone injection scheme. However, a conventional tone injection scheme might increase averaged transmit power attributed to expanding the size of constellation. While, in order to enforce transmit power as low as possible, PAPR would be insufficiently reduced due to the restriction of possible positions of tones to be injected in constellation. In this paper, based on a weighted-sum genetic algorithm (WGA) to resolve multi-objective optimization problem (MOOP), we show that the modified tone injection scheme exploits the agility of CR technology to fulfill PAPR reduction as well as mitigation of power increase optimally.