Modified selective mapping technique for PAPR reduction in OFDM systems

Orthogonal frequency division multiplexing (OFDM) is desirable technique of wireless communication. Subcarriers of OFDM signal are orthogonally used on the frequency spectrum, and can resist multipath effect characteristics. Recently, OFDM has been used widely in many kinds of communication standards. But the OFDM signal has a major disadvantage is high peak-to-average power ratio (PAPR), which can resulted in significant nonlinear distortion when the signal is operated through a nonlinear region of power amplifier, and induces the degradation of bit error rate (BER). The methods of PAPR reduction, selective mapping (SLM) is effective and uncomplicated. SLM is a linear operation, it doesn´t destroyed the signal itself. The received signal can be demodulated perfectly at receiver. But SLM has a problem of the high computational complexity, in this paper, introduce a modified SLM. The technique uses the concept of partition into subcarriers, called a partial-sequence SLM (P-SLM), which considerably reduces the computational complexity with the similar performance of PAPR reduction compared with the conventional SLM scheme. The simulation results show that it achieves better performance of reduces the computational complexity than the conventional SLM scheme.