Robust peak-to-average ratio reduction in OFDM with adaptive clipping control

Despite their many advantages, Orthogonal Frequency Division Multiplexing (OFDM) systems have been limited by nonlinear devices such as power amplifiers and DACs due to OFDM's inherently high Peak-to-Average power Ratio (PAR). This high PAR limits the use of high efficiency amplification devices. To reduce the PAR in OFDM systems, some low complexity tone reservation (TR) algorithms have been proposed. However, we find the existing low complexity TR algorithms can not achieve the minimum PAR when the clipping level is set below the initially unknown optimum value. To overcome this problem, in this paper we propose a robust PAR reduction technique by combining low complexity TR and adaptive clipping control. Simulation results demonstrate the robustness of the proposed method to severely low clipping levels.