Análisis de la PAPR en las técnicas NOMA-OFDM y SEFDM : análisis de la PAPR en la técnica NOMA-OFDM.

Abstract

This project covers the study and analysis of the PAPR (Peak-to-Average Power Ratio) in a NOMA-OFDM system (Non-Orthogonal Multiple Access - Orthogonal Frequency Division Multiplexing) composed of two users. The PAPR is a phenomenon that can generate problems in the transmission of information since it can cause distortions in the amplification of the signal. Chapter 1 explains the concepts and characteristics of the NOMA-OFDM system, presenting the structures of the transmitter and receiver. It explores the effects of a high PAPR on transmission, specifically on the HPA (High Power Amplifiers), and exposes emerging reduction techniques found in the literature. Chapter 2 describes the design of the NOMA-OFDM system through block diagrams, which includes the PAPR reduction techniques to be implemented: SAP (Simple Amplitude Predistortion) and Clipping. The SAP technique divides the signal into smaller segments and then applies a precoding to reduce the peak amplitudes of each segment. On the other hand, Clipping limits the signal amplitudes to a certain threshold to avoid extreme spikes. In addition, the implementation in Matlab is detailed. Chapter 3 shows the results obtained and their respective analysis, where the performance of the SAP and Clipping techniques is evaluated through different metrics: CCDF (Complementary Cumulative Distribution Function), PSD (Power Spectral Density) and the BER (Bit Error Rate) vs Eb/N0 (Energy per-Bit to Noise Density) curve. Finally, the conclusions and recommendations obtained throughout the development of this work are presented.