Nonlinear decision-feedback equalization for OFDM in a fast fading channel
ABSTRACT Orthogonal frequency division multiplexing (OFDM) has been adopted for several wireless network standards due to its robustness against multipath fading. Main drawback of OFDM is its high peak-to-average power ratio (PAPR) that causes a signal degradation in a peak-limiting (e.g., clipping) channel leading to a higher bit error rate (BER). At the receiver, the effect of peak-limitation can be removed to some extent to improve the system performance. In this paper, a combined decision-feedback equalization with clipping noise reduction technique is presented. An iterative equalization weight that minimizes the mean square error (MSE) with respect to residual clipping noise is derived. It is shown that the bit error rate (BER) performance of OFDM with proposed technique can be significantly improved in a peak-limited and frequency-selective fading channel.