Estimation of PeaktoAverage Power Ratio of Optimal FTN Signals The development of 5G and 6G networks is impossible without improving spectral efficiency. Faster than Nyquist (FTN) signaling allows increasing symbol rate of transmission and may be applied both to multicarrier and singlecarrier signals. However, it leads to uncontrollable intersymbol interference in the time domain. Optimal FTN signaling assumes application of optimal pulses obtained as a solution of an optimization problem and provides controllable intersymbol interference. In this paper, we propose to investigate peaktoaverage power ratio (PAPR) of singlecarrier optimal FTN signals obtained with the constraint on the minimum Euclidean distance. Comparison with FTN signals based on rootraisedcosine pulses shows that optimal FTN signals provide the gain in PAPR about 2 dB at the same bit rate.

Optimal SLM PAPR Reduction based on IQComplex Data Symbol Components To overcome the significant but unpredicted increase in the peaktoaverage power ratio (PAPR) in the presence of an OFDM system, in this paper, a new implementation of an SLM scheme is represented. The effects of the candidate phase vectors on both the real and imaginary parts of the complex data symbols are discussed. Hence, instead of modifying the generated complex data symbol as a single component, the real and imaginary parts are modified independently using a corresponding phase element among a commonly generated phase vector. After applying an inverse fast Fourier transform (IFFT) for the real, imaginary, and original baseband vectors, the (most) minimum peaktoaveragepower ratio (PAPR) for each part is observed. The phase vector that introduces the most minimal PAPR is considered to convert the original data block for transmission. This technique is called the optimal IQSLM scheme. According to the results obtained, the CCDF PAPR performance of the proposal acquires greater decibel reduction than a conventional SLM (conv.SLM) method at different subcarrier length N and candidate phase vectors U. In addition, at different levels of inputbackoff (IBO), the power spectral density (PSD) of the original and modified OFDM signals are represented, where the PSD of the proposal shows the best outofband characteristic against conv.SLM.