An energy efficient PTS scheme for PAPR reduction in OFDM relay systems

OFDM (orthogonal frequency division multiplexing) suffers from an inherent drawback which is named the high peak-to-average power ratio (PAPR) and leads to nonlinear distortion of the output signals. Partial transmit sequences (PTS) is one of the effective and low-complexity methods for reducing PAPR in OFDM systems. In this paper, an OFDM relay system is investigated. We mainly employ the PTS technique to the OFDM relay system, and analyze the effect of the PTS on energy efficiency (EE) and spectral efficiency (SE) in the OFDM relay system, respectively. As a result, the EE and SE of the OFDM relay system could be significantly increased with a total transmit power constraint over additive white Gaussian noise (AWGN) channel. Simulation results show that the OFDM relay system with PTS scheme would achieve higher SE and EE than the system without PAPR reduction.