Clipping Noise Mitigation by Adaptive Nulling and Nondata-Aided Compensation in Coded OFDM

Signal clipping is one of the simplest, yet effective method used to reduce the high peak-to-average power ratio (PAPR) in orthogonal frequency division multiplexing (OFDM) systems. However, clipping generates nonlinear distortion that causes spectral broadening and deteriorates the bit-error-rate (BER) performance of the OFDM system. This paper proposes a technique that incorporates Reed Solomon encoding and a feedback-based puncturing procedure to adaptively mitigate the clipping distortion on the OFDM spectrum and remove the out-of-band broadening caused by the intentional clipping. The new technique also employs a classical decision-aided method to iteratively compensate the residual frequency-domain distortion on data subcarriers. The simulation results show the effectiveness of the new technique in improving the BER of an OFDM system with various block sizes and practical clipping constraints.