Paper Title
PAPR Reduction in OFDM-IM System

Abstract
OFDM is the multiple carrier modulation technique in which all the subcarriers are needed for the transmission. The high Peak to Average ratio in the OFDM leads the amplifier to work in the non-linear region, which degrade the performance of the amplifier. Orthogonal frequency division multiplexing (OFDM) has been effectively combined with Index Modulation by activating several subcarriers in a sub-block while de-activating the remaining ones. In OFDM-IM, for a given sub-block size, only a fixed number of active subcarriers are selected to carry constellation symbols, which does not make full use of the other possible numbers of active subcarriers. The main issue in the OFDM-IM is the high PAPR (Peak to Average Power Ratio).To overcome high PAPR, SLM (Selective Mapping) scheme is used for reductionBy implementing DCT-OFDM-IM spectral efficiency is improved and PAPR is reduced for lower modulation order scheme. For higher modulation scheme PAPR remains the same. Keywords - Orthogonal Frequency Division Multiplexing with Index Modulation(OFDM-IM), Selective Mapping Scheme(SLM), Peak to Average Power Ratio (PAPR), Discrete Cosine Transform Orthogonal Frequency Division Multiplexing(DCT-OFDM-IM).