 is an Associate Dean for Research in the College of Engineering and a Professor in the Department of Electrical and Computer Engineering at Utah State University, Logan, UT, USA. She is a Fellow of IEEE. Yi Qian, PhD, is an IEEE Fellow and is a Professor in the Department of Electrical and Computer Engineering at the University of Nebraska-Lincoln, Lincoln, NE, USA. He is a Fellow of IEEE. Preface Motivated by the increasing demands for connectivity, modern wireless technologies have experienced rapid developments. Efforts from academia, industry, and government have pushed wireless research at an unprecedented level. As a complex solution, wireless sys- tems comprise many components, from physical layer, to network and upper application layer. One of the most exciting innovations in the past decade is 5G physical layer, which includes new radio (NR), new spectrum, coding, etc. Inspired by recent physical layer research advances in 5G and beyond wireless systems, this book intends to present the state-of-art challenges and solutions for physical layer techniques that are already applied, or will be utilized in wireless systems. This book covers a variety of topics, primarily on the intersection of 5G and beyond system with NR, mobile edge computing, and machine learning, and spectrum sharing. Ultimately, we expect to deliver a more energy-, spectral-, and computation-efficient wireless technology. There are twelve chapters in this book. They can be categorized into three main topics. Chapters 1-6 focus on 5G new radio research, especially recent advancements and sys- tematic research on non-orthogonal multiple access (NOMA). Chapters 7-9 discuss the interactions of mobile edge computing and wireless technology. Chapters 10 and 11 focus on secure spectrum sharing in 5G and beyond era. Chapter 12 concludes this book and further discusses some future research directions. Below, we briefly summarize each chapter. Chapter 1 presents an overview of 5G and beyond wireless system. We start by intro- ducing system requir