Peak-To–Average Power Ratio Reduction of Ofdm Siganls

Abstract

Orthogonal frequency division multiplexing (OFDM) is a form of multicarrier modulation technique with high spectral efficiency and immunity to interference. Despite of many advantages the main disadvantage of OFDM is that the time domain of OFDM signal which is a sum of subcarrier sinusoids leads to high Peak-to-Average power ratio (PAPR). A simple technique used to reduce the PAPR of OFDM signals is to clip the signal to a maximum allowed value, at the cost of bit error rate(BER) degradation and out-ofband radiation. The other method is Selective mapping method(SLM) technique which is a probabilistic technique for PAPR reduction with aim of reducing the occurrence of peaks in a signal. In this project partial transmit (PTS) scheme along with the threshold technique has been simulated using Matlab and the simulation results shows that the technique performs better. To compare the results SLM and clipping methods are also simulated.