Modified Dummy Sequence Insertion Method for PAPR Reduction of OFDM Signal

One of the major drawbacks of the OFDM system is a large peak to average power ratio. This leads to performance degradation due to nonlinear distortion in the high power amplifier. In this paper, we propose a modified dummy sequence insertion (m-DSI) method whereby low complexity and high PAPR reduction can be realized in OFDM system. The m-DSI method designs the sequence that achieves low covariance value with other sequences. After IFFT operation, the m-DSI sequence with the lowest PAPR is selected for transmission. Also, in order to reduce the IFFT complexity, the N-point IFFT block is divided into two sub-IFFT blocks due to avoiding the repeated calculation of IFFT operation. Simulation results of the m-DSI method in comparison with the DSI method are presented. The results demonstrate that the m-DSI method yields superior PAPR performance and lower IFFT complexity than the DSI method with almost the same BER performance while utilizing the same number of dummy bits.