A Novel Hybrid Technique for PAPR Reduction of Rayleigh Fading Channel Based OFDM System

The major disadvantage of Orthogonal frequency division multiplexing (OFDM) is a high peak-to-average power ratio (PAPR) which leads to reduce the efficiency of high-power amplifier (HPA) and also degrades system performance. Therefore, a hybrid technique is proposed to minimize high PAPR of OFDM system in this paper. The hybrid technique is based on the combination of discrete Fourier transform (DFT) precoder and new error function (NERF) companding. The DFT precoder distorts signal phase to minimize PAPR. Moreover, the NERF companding technique is also employed to DFT precoded OFDM signals for further reduction of PAPR. Consequently, proposed technique (DFT precoder with NERF companding) does not only reduces PAPR but also minimizes degradation of bitt error rate (BER) performance unlike other suggested techniques. The obtained results signify that at complementary cumulative distribution function (CCDF) = 10³, our proposed hybrid technique suppresses PAPR up to 3.53 dB and 3.83 dB for quadrature phase shift keying (QPSK) and 16-quadrature amplitude modulation (16-QAM) respectively. The PAPR performance of the proposed technique outperforms other techniques such as discrete Hartley transform (DHT) precoder, DFT precoder, iterative clipping and filtering (ICF), DHT-ICF, DFT-ICF, NERF companding, Si-Yu Zhang Method and time-domain kernel matrix (TKM)-ICF. Further, BER, as well as power spectral density (PSD) performance of the proposed hybrid technique, provides better than ICF, DHT + ICF, DFT-ICF and NERF companding technique over Rayleigh fading channel.