Channel adaptive technologies and cross layer designs for wireless systems with multiple antennas [Book Review]

The book Channel Adaptive Technologies and Cross Layer Designs for Wireless Systems with Multiple Antennas, written by Vincent Lau and Yu Kwong Kwok, is a survey of multiple-antenna and channel-adaptive techniques for wireless systems proposed in recent years. In the first part of the book, the authors present the fundamentals of multiple-antenna systems based on the information theory. Then the channeladaptive and cross-layer techniques are discussed: the routing and medium access control (MAC) layer algorithms are optimized when the information about the radio channel is applied. This book is a summary of the research of the authors rather than a review of the particular area in electronics or communications. Generally, the whole book consists of three parts. In Part 1, “Theory,” the authors focus on multiple-input multiple-output (MIMO) systems. First, in Chapter 1, the fundamentals of wireless communications are presented. Simple models of frequency-flat and frequencyselective fading channels are introduced, as well as the concepts of channel spreading and coherence. Also, the notion of channel capacity and Shannon’s theorem are explained. In Chapter 2, the capacity of MIMO channels is considered. The channel state information (CSI) in MIMO systems is used for either detection at the receiver or adaptation purposes at the transmitter. Therefore, four basic cases are analyzed: CSI can be available at the receiver, at the transmitter, on both sides of the radio channel, or nowhere. The problems of imperfect CSI are addressed in Chapter 3. The focus is on the limited feedback in the MIMO channel and, as a consequence, imperfect CSI at the transmitter. The solutions for achieving high signal-to-noise ratio (SNR) and channel capacity are provided. In Chapter 4, the coding techniques for MIMO systems are discussed. The authors show the trade-off between diversity and multiplexing when multiple antennas are applied. Space-time block codes, suitable for achieving high diversity, as well as layered space-time codes (BLAST, T-LST) for exploiting multiplexing gain (high capacity) are described. Some receiver architectures, like zero-forcing and minimum mean square error, are also presented. In the next chapter, the issues of imperfect CSI are again developed. The problem mainly investigated is proper constellation design. Chapter 6 ends this part of the book. Multiuser systems with multiple antennas are covered. The concepts of multiuser diversity and orthogonal transmit beamforming are introduced. Simple cross-layer optimization is also illustrated: the decision to give access to the radio channel to a particular user is made on the basis of the CSI of all users. The second part of the book, “Design Examples and Applications,” deals with MAC layer protocols and scheduling algorithms. In Chapter 7, the protocols for access to the wireless channel are analyzed. The authors start with simple ALOHA and continue with more advanced channel-adaptive protocols. The SCAMA protocol, developed by the authors, is widely explained. Chapter 8 is devoted to the problem of fairness in sharing the wireless medium by multiple users. The notions of fairness as well as algorithms of fair queueing are considered. Numerical calculations comparing the performance of various protocols and algorithms are also provided in these two chapters. In Chapter 9, the examples of packet scheduling algorithms existing in Universal Mobile Telecommunications System (UMTS) are presented. First, some features of the UMTS architecture are discussed. Then packet scheduling mechanisms in the Rel 99 and Rel 5 UMTS standards are described. Additional subjects concerning crosslayer system optimization are covered in the third part of the book, “Advanced Topics. ” Wideband MIMO systems are investigated in Chapter 10. The techniques of multiple access to the wideband radio channel, direct sequence code-division multiple access (DSCDMA), and orthogonal frequencydivision multiple access (OFDMA) are introduced and compared. The scheduling based on CSI for both of them is discussed. Also, some implementation issues for OFDMA are described. In Chapter 11, the problem of appropriate scheduling is extended by the issue of source statistics of the user applications. Some users have priority data to send; at the same time, other users do not need access to the channel — this should be taken into account by the scheduling algorithm. Therefore, information theory is combined with queuing theory to meet this challenge. The authors present some scheduler designs adaptable to the buffer status of users and radio channel conditions as well. Finally, Chapter 12 is devoted to ad hoc routing protocols. After the overview of existing protocols, the authors elaborate on their own channel-adaptive ad hoc routing protocol. The comparison of all these protocols based on computer simulations ends this chapter and the whole book. Each chapter in the book begins with an overview and ends with a summary, which helps to get a general idea about its subject. Also, a list of exercises is provided, but without solutions. At the end of the book, a list of references (about 150 entries) and a topic index are included. However, the numbers of references in the text of the book, as well as the numbers of pages in the topic index are frequently incorrect. I cannot recommend this book as the basis for a university course. For this purpose, it is rather too mathematical, full of theorems and proofs. The topics of this book would be difficult for students to assimilate. There are no vivid, evocative explanations of the issues raised. The book is theoretic, and lacks examples of existing solutions and standards, which is due in part to the novelty of the topics discussed. The presented subjects do not fit together into a harmonious whole. Nevertheless, the book by Lau and Kwok can be found interesting for researchers and professionals working in the area of channel-adaptive and multiple-antenna wireless systems. The subject matter is very topical. A large majority of the references are papers and books written in the last six years. Many important and innovative algorithms and solutions are collected together and compared in numerical simulations. This book can be helpful in both research and future wireless standards planning.