Cumulative symbol optimization–based partial transmit sequence technique for PAPR reduction in low complexity GFDM system

Abstract

The new waveform called generalized frequency division multiplexing (GFDM), which has been increasing its popularity among the fifth generation (5G) waveform candidates day by day, is suggested very recently to meet the requirements of the next-generation cellular systems. On the other hand, it is possible to generate and demodulate the GFDM signal with a less processing load by using low-complexity GFDM (LC-GFDM) system proposed shortly after the GFDM scheme. However, similar to the GFDM and the other multicarrier systems, high peak-to-average power ratio (PAPR) problem stands as one of the biggest obstacles, making difficulties for smooth communication in the LC-GFDM system. In this system, the GFDM symbols obtained by the multiplication of time domain GFDM data sequences with circularly shifted prototype filter impulse responses are added together to achieve the transmission signal. Due to the related symbol addition process, direct application of the conventional partial transmit sequence (C-PTS) technique, which was actually first developed for orthogonal frequency division multiplexing (OFDM), to the LC-GFDM system without any modification will be useless. For this reason, we developed a new technique called cumulative symbol optimization–based partial transmit sequence (CSO-PTS) for PAPR reduction in the LC-GFDM system. In the simulations, the CSO-PTS technique is compared to two different PAPR reduction methods called selective mapping and GreenOFDM. Simulation results evidently demonstrates that our novel proposal outperforms the other considered methods by ensuring quite efficient PAPR reduction, side lobe suppression, and bit error rate improvement in the LC-GFDM system.