Optimized PTS-SLM Techniques for Reducing Signal Power Fluctuations in OFDM Systems Using BPSK and QPSK Modulation under AWGN and Fading Channels

Orthogonal Frequency Division Multiplexing (OFDM) has emerged as a prominent modulation scheme for wireless communications due to its efficiency in combating multipath fading and supporting high data rates. A major drawback of OFDM is the high variation between peak and average signal power, which leads to nonlinear distortion when passed through power amplifiers. This paper presents improved Partial Transmit Sequence (PTS) and Selected Mapping (SLM) techniques aimed at reducing signal power fluctuations while minimizing computational complexity. The proposed method achieves effective suppression of signal peaks without compromising system efficiency. Simulations conducted in MATLAB R2012 under various modulation schemes (BPSK, QPSK) and channel models (AWGN, fading) demonstrate that the proposed PTS technique offers superior performance in terms of peak power control compared to conventional SLM approaches, as verified by Complementary Cumulative Distribution Function (CCDF) analysis.