Evaluation of optimized PAPR of OFDM signal by using SLM technique

Orthogonal Frequency Division Multiplexing (OFDM) is a very effective field of research of wireless communication and also the high speed data transmission process in this system. The main drawback of OFDM system is high Peak to – Average Power Ratio (PAPR). Due to high PAPR there is inefficient use of high power amplifier and this could limit transmission efficiency. Selected mapping (SLM) is one efficient technique which reduces the PAPR in transmission channel. The PAPR problem is more important in the uplink since the efficiency of power amplifier is critical due to the limited battery power in a mobile terminal. The probabilistic technique is to scramble an input data block of the OFDM symbols and transmit one of them with the minimum PAPR so that the probability of high PAPR can be reduced. While it does not suffer from the out-of-band power, the spectral efficiency decreases and the complexity increase as the number of subcarriers increases.