A Joint PAPR Suppression Scheme of DSSS-GFDM System using DFT Precoding and Clipping for Satellite Communications

With the development of emerging satellite communication constellations, it is of great significance to carry out research on the space-terrestrial information networks. The generalized frequency division multiplexing (GFDM) has been proposed in combination with direct sequence spread spectrum (DSSS) technology to improve the transmission performance of GFDM waveforms in low signal-to-noise ratio satellite communication scenarios. However, the high peak-to-average power ratio (PAPR) problem is still one of the critical issues in the implementation of GFDM based systems. The discrete Fourier transform (DFT) precoding has been applied to suppress the PAPR of DSSS-GFDM system while retaining the reliability performances over satellite channels. But the suppression effect needs to be improved. In order to further optimize the PAPR performance while maintaining the bit error rate (BER) performance of DFT-DSSS-GFDM system, we propose to utilize clipping technology after GFDM modulation. Three existing clipping functions and an new average noise-based clipping (ANC) function we proposed are applied in the joint scheme. Morever, their PAPR performances and BER performance under different clipping ratios over the additive white Gaussian noise and the international telecommunication union satellite channels are analyzed. The simulation results are provided to demonstrate that the proposed joint scheme can achieve a large-scale optimization of PAPR when using the traditional Clipping function, while maintaining a BER performance similar to that of the DFT-DSSS-GFDM scheme, and can achieve a further compromise between PAPR suppression, BER performance degradation and clipping function complexity than benchmark scheme when using ANC function.