An SLM-based Real-time PAPR Reduction Method Using Dummy Sequence Insertion in the OFDM Communication

Abstract

OFDM (orthogonal frequency division multiplexing) communication is very attractive for high data rate transmission especially in the frequency selective fading channel. However, OFDM signal may be distorted by the nonlinear HPA (high power amplifier) since it has very high PAPR (peak-toaverage power ratio). The proposed method is basically similar to the conventional SLM (selective mapping) method. However, the selected dummy sequences instead of the phase rotation sequence are inserted to reduce the PAPR in the OFDM communication system. So, we propose a modified SLM method in which complementary sequence or other kind of dummy sequence produced by flipping method can be inserted at the predefined sub-carriers. After IFFT (inverse fast Fourier transform), the OFDM data signal with the lowest PAPR is selected for transmission like the SLM method. Unlike the conventional PTS (partial transmit sequence) and SLM, it is needless to transmit and recover the side information about the phase rotation. Also, it can be free from the computational burden caused by finding the phase rotation factor for peak value optimization and time delay problem can be additionally solved.