Peak to average power ratio (PAPR) reduction techniques in OFDM for optic communications

In this study, benefits of orthogonal frequency division based on nonlinear amplify and forward relay system are examined. OFDM is a modulation technique that utilizes the optic communication band efficiently by dividing the high-speed information sequence into parallel arms and lifting the frequency selectivity of the multi-carrier channel at the same time and using vertically selected carriers at the same time. Also relay protocol preference is an important issue. Amplify and forward relay system is proper according to the other relay protocols because it only amplify the signal. Selected mapping is an accurate method for reducing peak to average power ratio from orthogonal frequency division multiplexing. A fundamental weakness of selected mapping is the high computational complexity. To reduce the complexity of the selected mapping, the real and imaginary part of the orthogonal frequency division multiplexing signals is treated separately. Numerical sequences and even real and imaginary elements are obtained using Fourier transform properties. More candidates are produced with a different combination of all the following sequences. The proposed scheme produces less computational complexity using the IFFT algorithm for M4 equations only. The simulation results show that the proposed design reduces the good performance of peak to average power ratio and also reduces computational complexity compared with the selected mapping design.