Evaluation of BER and PAPR by using Different Modulation Schemes in OFDM System

There are various issues related to OFDM such as dispersion (ICI), external interference (crosstalk) and nonlinearities (PAPR). OFDM suffers from a high Peak to Average Power Ratio (PAPR), caused by the addition of a large number of independently modulated sub-carriers in parallel at the transmitter. When subject to a non-linear power amplifier, these signals may undergo significant spectral distortion, leading to interference both in-band and out-of-band and an associated degradation in system performance. In this paper, the main focus is on the comparative performance evaluation of OFDM system in terms of PAPR and BER. Later in this paper, simulation result shows the PAPR and BER performance to observe the effect of IFFT size on PAPR without any reduction technique, with clipping technique and with companding technique for different modulation schemes such as BPSK, QPSK and 16PSK with 256 subcarriers.