selective mapping as PAPR reduction technique.

PAPR is a major disadvantage of OFDM systems,i introduce SLM as one of the reduction techniques.

we use (phase rotation)by multiplying all the subcarriers
in the sum by different phases to create a new data vector, not only that but also as we don't know the optimum phases to give the best PAR we create more than one vector and then select the optimum.