Papr Reduction Using Modified Selective Mapping Technique and Turbo Coding

Multi-carrier modulation is an attractive technique for fourth generation wireless communication. Orthogonal Frequency Division Multiplexing (OFDM) is an efficient method of data transmission for high speed communication systems. However, the main drawback of OFDM system is that, it exhibits high Peak to Average Power Ratio (PAPR) of the transmitted signals. OFDM consist of large number of independent subcarriers, as a result of which, the amplitude of such a signal can have high peak values. The Selected Mapping (SLM) and turbo coding is one of the promising PAPR reduction techniques for OFDM. In this paper, the issue of PAPR in OFDM is discussed. Two new methods are proposed to reduce the PAPR. First method is carried out by selecting mapping, the input sequence properly using a Hamming code and second method is turbo code using interleavers encoder. These two methods provide better result.