1.4 Contributions of This Textbook
Today, active mmWave wireless device and product research programs exist at several major companies, such as Samsung [EAHAS+12] [KP11a] [PK11], Intel [CRR08], L3, Qualcomm, Huawei, Ericsson, Broadcom, and Nokia, and universities such as Georgia Tech [DSS+09], New York University [RSM+13][RRE14][PR07][RBDMQ12] [RQT+12] [AWW+13] [SWA+13] [RGAA09] [AAS+14] [ALS+14] [SR14] [Gho14] [SR14a] [MSR14], UC Berkeley [SB08][SB09a], UCLA [Raz08], UC San Diego [AJA+14] [BBKH06][DHG+13], UC Santa Barbara [RVM12][TSMR09], University of Florida [OKF+05], USC [BGK+06a], The University of Texas at Austin [GAPR09][GJRM10] [RGAA09][DH07][PR07][PHR09][DMRH10][BH13b][BH13c][BH14][EAHAS+12][AEAH12], and The University of Texas at Dallas [CO06][SMS+09]. Further, multiple textbooks and research books on the subject of mmWave devices and communications are available [Yng91][NH08][HW11]. Despite this research and progress, we have endeavored to create the first comprehensive text that brings communications and network-centric viewpoints to the intersection of antennas, propagation, semiconductors, and circuit design and fabrication for future wireless systems. Some existing texts on mmWave evolved from the circuits or packaging area but lack fundamental communications and network expertise. This book is distinct, since the ability to create future wireless communication systems requires a deep and fundamental understanding of multiple-user communications, antennas and propagation, and network theory, in addition to fundamental circuit design and microelectronics knowledge. It is rare that communications and network researchers work with circuit designers or semiconductor scientists in a university setting; this gap portends a huge void in the world’s wireless research capabilities. Innovation and leadership are enhanced through interdisciplinary approaches to the creation and fabrication of broadband mmWave wireless devices and networks. This book endeavors to guide engineering practitioners, researchers, and students to find new, interdisciplinary ways to create mmWave broadband wireless devices and the networks they will form.
In this text, we demonstrate the state of the art in the areas of antennas, propagation, semiconductors, analog and digital circuits, communications, networks, and standards, while identifying critical interdependencies that will impact the future of communications at the edge of the network. By combining previously separated research fields of semiconductor devices and circuit design with the fundamentals of antennas and propagation, communications, and networking research, this book illustrates the problems and provides the knowledge to create the next generation of devices that will operate at the spectral frontier of mmWave frequencies.
For communications engineers, this book provides key insights into circuits challenges and fundamental semiconductor physics, along with antenna and propagation fundamentals. This is important because the formation of design tradeoffs requires insights into multiple fields. For example, instead of using higher-order signaling constellations, the analog-to-digital converter can be simplified or even eliminated by using simple binary modulation, even something as simple as on-off keying or differential phase shift keying. Essentially, this becomes a tradeoff between low-cost communication efficiency and mixed-signal power efficiency. As semiconductor devices continue to scale toward higher frequencies, even into the terahertz (300 GHz and above) range by 2020 [SMS+09], communications researchers will be unable to produce working sensors, channel measurement systems, and other critical research tools that help to provide fundamental knowledge [RGAA09] unless they have core circuit design knowledge at the mmWave regime and above.
For analog, mixed-signal, and RF circuit designers, this book provides foundations in the operations of the higher layers, including radio channel aspects, digital signal processing, and network protocols. This will facilitate better technical interactions with communication engineers. While the wide majority of today’s wireless devices still use the standard superheterodyne and homodyne (direct conversion) architectures developed by Major Edwin Armstrong over a century ago, completely new receiver architectures, which fuse the detection and memory capabilities for pipelining received data, must be developed to handle such massive transmission bandwidths with low power consumption. New concepts in organizing memory cells at the chip level need to be integrated with communications coding techniques in order to implement the power efficient devices of the future, especially when considering that high-gain advanced antenna techniques, such as MIMO and phased arrays, will be implemented in such tiny physical sizes.
Coverage in the book is intentionally broad, but is also fundamental in nature, transferring key knowledge in mmWave communication, propagation, antennas, circuits, algorithms, design approaches, and standards. Such knowledge is crucial for understanding and balancing the demands for power, capacity, and delay in the era of wireless networks with unprecedented bandwidths.