Optimized baseband Nyquist pulse-based PAPR reduction method for SEFDM systems

The optimized Nyquist pulse is used as a baseband signal of spectrally efficient frequency division multiplexing (SEFDM) system, where subcarriers use cyclic forms of the Nyquist pulse to reduce their mutual correlation, the probability of in-phase occurrence between them, and reduce the probability of the SEFDM signal peak. To reduce the subcarrier correlation and to establish a generic model based on fast roll-off characteristics, the ratio of the energy of the main lobe interval of the main function of the Nyquist pulse to the overall energy is set as a limiting condition. Based on the Fourier series, numerical methods are used to solve the limited long-pulse function. This function is multiplied by the sinc function to construct the Nyquist pulse that is suitable for reducing the peak-to-average power ratio of the SEFDM system. Simulation results have verified that under different symbol mapping types, the proposed optimized Nyquist pulse can achieve a significantly better PAPR reduction effect than the raised cosine Nyquist pulse and some of the commonly used Nyquist pulses in the SEFDM systems under different roll-off factors.