PAPR Reduction Using Particle Swarm Optimisation Algorithm in OFDM-IM Systems

Index modulated orthogonal frequency division multiplexing (OFDM-IM) is a transmission method that expands the spatial modulation principle to OFDM subcarriers. In OFDM-IM, bits are transmitted using index modulation (IM); this provides better error performance and is more effective in the high signal-to-noise ratio (SNR) region. However, the high peak-to-average power ratio (PAPR) poses a significant challenge in OFDM-IM systems. The high PAPR can degrade system performance by introducing signal distortion, particularly when power amplifiers operate in a nonlinear regime. In this paper, we propose the combination of particle swarm optimisation (PSO) algorithm with partial transmit sequence (PTS) method, which is the one of the PAPR reduction method, to obtain an efficient PAPR reduction method. This paper includes a simulation study of this approach, in which graphical results are obtained in 10000 iterations. The computer simulation results demonstrate that the PSO-PTS used in the OFDM-IM system significantly reduces the PAPR value compared to the original system and the conventional PTS method. Simulation results obtained for different subcarrier numbers (N) and modulation index parameters (M) show the variation between the PAPR threshold $\mathrm{(PAPR}_{0})$ and complementary cumulative distribution function (CCDF).