In this project thee performance of peak-to-average power ratio (PAPR) reduction scheme i.e. selected mapping (SLM) scheme is investigated. In the presence of nonlinearity, we analyze the impact of the selected mapping (SLM) technique on bit-error-rate (BER) performance of orthogonal frequency division multiplexing (OFDM) systems in an additive white Gaussian noise channel The SLM technique was first described by Bauml etal. Selective mapping scheme is a technique in which multiple phase rotations are applied to the constellation points, and the one that minimizes the time signal peak is used. Selective mapping involves generating a large set of data vectors all representing the same information. The data vector with the lowest resulting PAPR is selected. Information about the selected and transmitted data vectors is coded and these codes are by an additional sub carriers.