PAPR Performance of OFDM System Using Modified SLM Approach

In the era of modern wireless technology Multicarrier communication is one of the more suitable and reliable communication techniques. Orthogonal Frequency Division Multiplexing (OFDM) is used as modulation technique in multicarrier communication. OFDM has numerous advantages over single carrier communication but in spite of the advantages it suffers from one major drawback that is OFDM signal has high Peak Power – to – Average Power ratio (PAPR) . In this paper PAPR performance is simulated using conventional approach of Selective Mapping (SLM) technique and Modified SLM technique for different types of modulation techniques like QPSK, QAM and DPSK. The modified SLM technique is a probabilistic approach to reduce PAPR of OFDM system. This uses Linear Block Code (LBC) that is Extended Hamming Code where the different code having same information and by using selection criteria one of the codes having less PAPR is selected. Modified approach reduces system PAPR to a great extend as well as it reduces cost and complexity of the system. From simulated results it shows that the modified SLM approach is more suitable for practical implementation.