Efficient clipping for broadband power line systems in impulsive noise environment

Abstract

For broadband power line communication systems, which may be incorporated with Orthogonal Frequency Division Multiplexing (OFDM) technique, the detrimental effect arising from strong and frequently occurred impulses is paramount as signaling on each sub-carrier is simultaneously corrupted thanks to frequency-domain transformation on a per-OFDM symbol basis at the front-end receiver. In this perspective, channel coding epoch on the basis of per-OFDM symbol cannot effect the coding gain. Recently, clipping operation on received samples has been addressed as an effective approach to mitigate this incurring performance loss subject to impulsive noise, given the knowledge of the probability density function (PDF) of impulsive noise at receiver. In this paper, we forgo the a-priori knowledge of the PDF of impulsive noise but devise the threshold to clipping, only relying on the probability of occurrence of impulses. To attest our method, we conduct computer simulations in compliance with the IEEE 1901 standard over commonly adopted memoryless impulsive noise models. Promisingly, the proposed scheme is on par with its counterpart, where the threshold of a limiter is realized by assuming the PDF of impulsive channels perfectly known to receiver. In addition, the devised clipping scheme is shown to be robust against impulses of frequent occurrence characterized by excessively high energy in the signal-to-noise ratio range of interest, regardless of the impulsive noise model assumed.