دانلود کتاب ارتباطات موج میلی‌متری در 5G و به سوی 6G

The focus of this book is on explaining different facets of millimeter wave (mmWave) systems. These systems form one of the core components of Fifth Generation (5G) cellular networks today and will remain a central pillar of the emerging Sixth Generation (6G) systems and beyond. Strictly speaking, the mmWave regime stands for systems that operate at a frequency regime corresponding to millimeter wavelengths (30–300 GHz). In practice, at the Third Generation Partnership Project (3GPP) level, the mmWave regime is denoted as Frequency Range 2 (FR2) and stands for the 24.25–71 GHz regime. Extensions to FR2 include Frequency Range 4 (FR4) focusing on 71–114.25 GHz and Frequency Range 5 (FR5) focusing on beyond 114.25 GHz frequencies. Different design aspects of FR2 systems also impact the design of Frequency Range 3 (FR3) systems focusing on 7.125–24.25 GHz, which are also of broad importance as 6G evolves from an available spectrum perspective. FR2 spectrum and more broadly mmWave systems did not attract attention from practicing wireless engineers till the beginning of the 5G standardization process due to a number of reasons. Some of these reasons included: • Lack of licensed spectrum in FR2 for cellular operations • Device level design complexities of radio frequency (RF) components and their high cost, area and power consumption profiles as well as the thermal management associated with higher power consumption • Poor link budgets that implied a small cell operation corresponding to 200– 500 meter inter-site distances (ISDs) in contrast to the 1–3 km coverage for Third/Fourth Generation (3G/4G) systems • Increased capital expenses (Capex) and operational expenses (Opex) associated with the deployment of these small cells • Necessity of multi-antenna beamforming at the RF level to bridge the link budget, requiring advances in antenna array design, radio frequency integrated circuit (RFIC) chip design and packaging technologies • Lack of a systematic physical layer design that would take advantage of the unique features associated with these frequencies and combat their impairments. Over the last ten years, mmWave wireless systems have seen a massive revolution starting from white-papers and vision documents leading to experimental prototypes and pre-5G standardization efforts followed by the Fifth Generation-New Radio (5GNR) standardization process for Release 15 (Rel. 15) at 3GPP. This led to the design, development, and evolution of 5G-NR compliant modems such as the Snapdragon®1 X50, X55, X60, X65, X70 and X75 modem families from Qualcomm Technologies. These developments have in parallel led to the evolution of the 3GPP specifications in Rel. 16 and beyond. Given this background, this book addresses, explores and demystifies the fundamental issues behind mmWave technology. We will see that the evolution can be seen as a continuum that starts with the multiple-input multipleoutput (MIMO) revolution that forms the backbone of 3G and 4G systems, as well as the Institute of Electrical and Electronics Engineers (IEEE) 802.11 series of standards for WiFi systems. At this stage, there are a number of books [1, 2, 3, 4] that have been published which address topics such as 5G, massive MIMO and mmWave communications including details on the 5G-NR standardization specifications and agreements. This book differs from the above class of books in the following aspects. This book is written with the express goal of explaining how the mmWave research developed and evolved. It explains the fundamental principles beneath the signal processing and technology determinants and more precisely, the Why? behind the What? that make the 5G-NR specifications. It is also written by theoreticians firmly grounded in the wireless industry and with significant academic and industrial experience. The subject matter of this book concerns the tradeoffs between different possible mmWave MIMO precoding and beamforming schemes, and how they are uniquely impacted by device level constraints (at the RF and antenna levels) such as cost, complexity, area, energy consumption, channel structure, performance gains, etc. The aim of this book is to help the reader understand the scope and scale of complexities involved in form factor user equipment (UE) and customer premises equipment (CPE) design, how the standardization process tries to address these complexities, and the efficacy of the solutions addressed by the standardization efforts. Upon reading this book, one can understand how mmWave technology concepts are applied in mobile and fixed wireless access systems. Further, one can understand how they perform with a focus on practical deployment considerations.