Nonlinear effects and predictions in advanced antenna systems in 5G Distortion Effects in 5G

Abstract: In the next-generation wireless cellular communication systems known as 5G, radio equipment will be deployed in several frequency bands, among them is the millimeter wave bands (26 - 40 GHz). The use of these high frequencies can help to mitigate the limited spectrum problem and higher data rates can be achieved [2] . For 5G millimeter wave radios, due to a small area of cells, the number of distributed units will always be high. These technological advances have resulted in smaller and cheaper broadcast stations or radios, however, for these small cellular radios and Advanced Antenna System (AAS), the efficiency and performance of the Power Amplifier (PA) are of significant concern for designers and operators of the systems. The proposed solutions in this thesis work consist of the study of PA the used of the active load-pull modulation. As a result, signal components of each PA output are split into a MIMO (Multiple Input Multiple Output) configurations and then follow the development of an algorithm, to extract the transmitted and reflected signals from active load-pull modulation with different calibration procedures. The extracted data is used to develop a dual-input PA model to which is then applied later in the MIMO DPD (Digital Predistortion). The proposed analysis are tested in a lab and simulation environment. The load-pull measurement results could extract transmitted and reflected signals and they have been used to create the dual input PA model with NMSE of less than -42dB.