Direct Reconstruction of Clipped Peaks in Bandlimited OFDM Signals
Kyong Hwan Jin, EPFL STI LIB

Meeting • 13 March 2018

Abstract
The high Peak-to-Average Power Ratio (PAPR) of transmitted signal is the challenging issue in Orthogonal Frequency Division Multiplexing (OFDM) system. It causes significant errors of transmitted bits due to the non-linearity of amplifiers and receivers. One approach to reduce PAPR is amplitude clipping of peaks. Clipping enables OFDM system to reduce PAPR, but causes band distortions leading to the information loss of transmission. Here, we propose a reconstruction algorithm for bandlimited OFDM signals after clipping without additional transmitted bits. We formulate a minimum-norm reconstruction with sinc-related basis to interpolate clipped peaks. The reconstruction consists of two steps: regression for reproducing coefficients of reproducing kernels and interpolation with them to obtain values of clipped peaks. Because the reconstruction is performed based on a matrix inversion and an interpolation, the proposed algorithm becomes non-iterative. Thus, the proposed method is free from tuning parameters and hardware friendly in the modern high-throughput digital communication receivers. Our experiment on realistic simulation shows that the reconstruction of clipped peaks can significantly reduce transmission errors.