Iterative Correction of Clipped OFDM Signals with Unknown Clipping Levels

Iterative correction can be employed to mitigate the distortion caused by nonlinear power amplifiers in OFDM systems. However, proposals found in the literature suppose that the receiver has perfect knowledge of the nonlinear conditions encountered in transmission. In this paper, we propose the use of the Extended Kalman Filter and the Unscented Kalman Filter to estimate the nonlinear characteristics of the amplifier before performing the iterative correction, and see that by using these filters, the amplifier clipping level can be correctly estimated even without a pilot signal.