Performance of retrieving the clipped OFDM signals

摘要

One of the biggest drawbacks of OFDM is its high peak to average power ratio (PAPR). High PAPR of OFDM makes it unusable in non-linear systems. So the clipping signals scheme is one useful and simple method to reduce the PAR. But because of the clipping process, the subcarrier's orthogonality is destroyed, the recovered signal is distorted at receiver, so the performances of bit-error-rate (BER) and channel capacity drop severely when clipping process is relatively severe. This paper presents a new receive algorithm for OFDM signals with limited dynamic range. The estimator is based on the distribution of the real and imaginary parts of the complex baseband OFDM signal. It recovers the original undistorted process by minimizing the mean-square estimation error. It is shown that the estimator significantly improves the error rate of OFDM systems impaired by clipping at the transmitter.