Impulsive noise mitigation for μ-law companded OFDM-based communication system

Companding schemes were proposed to alleviate the high peak-to-average-power ratio (PAPR) of OFDM signals. The effect of companding on OFDM-link performance has been well studied yet limited to Gaussian channels. In this paper, an improved impulsive noise mitigation technique is proposed for μ-law companded OFDM system in the presence of impulsive and additive white Gaussian noise (AWGN) channels. The proposed system performance is evaluated over an extensive system-parameter range that involves bit-error rates and threshold optimization. Simulation results indicate that while impulsive noise causes degradation in the bit-error performance of companded OFDM, the degradation is moderate under mild impulsive-noise densities. Furthermore, the uniformity of the companded OFDM envelope makes it easier to identify and remove of noise impulses at the receiver via the nonlinear preprocessors such as blanking, clipping or their hybrid.