PAPR Reduction in LTE Uplink Communications by Airy Companding Transform

Abstract

Long Term Evolution uses Single Carrier Frequency Division Multiple Access (SC-FDMA) for uplink communications as it has low peak to average power ratio (PAPR). But PAPR is still an issue for higher order modulations in localized SC-FDMA systems. Companding is an attractive technique to reduce PAPR. $\boldsymbol{\mu}$ law companding is most widely used technique, but it increases the average signal power and introduces out-of-band radiation. This paper proposes a companding transform based on special airy function to limit PAPR without increasing the average signal power. The proposed method maintains the BER performance of SC-FDMA system without introducing out-of-band radiation, unlike $\boldsymbol{\mu}$ law companding.