PAPR reduction of OFDM signals using CI coded companding transform

Orthogonal frequency division multiplexing (OFDM) suffers with the major drawback of high peak-to-average power ratio (PAPR). In this paper we propose using linear non-symmetrical companding transform along with carrier interferometry (CI) spreading codes to reduce PAPR. CI spread out each information symbol onto all of the N subcarriers and the resultant superposition of the coded is shaped accordingly using companding transform to reduce PAPR. It can be inferred by simulations that the proposed CI coded companding transform improves the bit error rate (BER) performance of OFDM by reducing the PAPR significantly.