Simulation Analysis of Low PAPR FFT-based OFDM Through Nakagami Channel

Abstract

In response to the inefficiency of power amplifier in conventional Orthogonal Frequency Division Multiplexing (OFDM) system, a low Peak-to-Average Power Ratio (PAPR) scenario can be obtained by implementing several PAPR reduction techniques. Partial Transmit Sequence (PTS) is a well-known instance to provide zero distortion for the system, while clipping is one of the simplest methods but it is sacrificing the error rate performance. In this work, Authors focused on analyzing the implementation of PTS and Palm Date Leaf clipping technique on OFDM system with 16-, 64-, 256-, and 1024-QAM under various Nakagami channel. In addition, the High-Power Amplifier (HPA) was also considered by using Solid State Power Amplifier (SSPA) model. It was found that linear HPA serves as the lower boundary for non-linear HPA, and system under high saturation level performs similarly. In physical properties, high saturation level is equivalent to higher power consumption in amplifier. Thus, optimal level was obtained by considering taking the one with moderate BER performance. After the system’s PAPR was reduced, the optimum saturation level of HPA was found to be 5 dB, 8 dB, 9 dB, and 11 dB for each Quadrature Amplitude Modulation (QAM) under Nakagami channel with m value of 1.5. However, this value was found to be ample for lower m value such as 1 or 0.7. In this case, the system required lower saturation level on the HPA for Nakagami channel with lower m value.