On the PTS Optimization Using the Firefly Algorithm for PAPR Reduction in OFDM Systems

Orthogonal frequency division multiplexing (OFDM) is currently the most used technique for the high-data-rate transmission. However, OFDM systems have an inherent drawback in that the transmitted signals suffer from a high peak-to-average power ratio (PAPR). Partial transmit sequence (PTS) is generally applied to reduce the PAPR of an OFDM signal in wireless communication systems. Here, the search complexity for optimal phase vector increases exponentially with the number of phase vectors, since it involves an extensive random search over all the combinations of the allowed phase vectors. In this paper, a swarm intelligence algorithm for phase optimization based on the Firefly algorithm (FF) is applied to search the optimal combination of phase vectors. The proposed algorithm provides a superior trade-off between the improved PAPR performance and computational complexity when compared to the PTS scheme for a large number of sub-blocks. Simulation results show that the Firefly-algorithm-based PTS (FF-PTS) algorithm is an efficient method to achieve superior PAPR characteristics for OFDM signals when compared to conventional algorithms with very few parameters to adjust.