A New PTS for PAPR Reduction by Local Search in GA

An orthogonal frequency division multiplexing (OFDM) system has the problem of the peak-to-average power ratio (PAPR) due to the inter symbol interference between the many sub-carriers. In general, in order to obtain optimal PAPR reduction using the partial transmitted sequence (PTS), the total search for the number of sub-blocks and the rotation factors must be accomplished. As the number of sub-blocks and rotation factors increases, PAPR reduction improves. The number of calculation increases as the number of sub-blocks increases, such that complexity increases exponentially and the process delay occurs simultaneously. In order to reduce the complexity in the system, in this paper a new method using GA is proposed to search for a rotation factor that reduces simultaneously both the PAPR and the amount of calculation, such that the complexity of calculation and the process time are reduced at the same time. Comparison is performed between the proposed method and the various techniques developed previously. The superiority of proposed method is presented by demonstrating the reduction of complexity and calculation time while a similar PAR reduction is obtained.