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1、Introduction to MIMO CommunicationsThis accessible, self-contained guide contains everything you need to get up to speed onthe theory and implementation of MIMO techniques.In-depth coverage of topics such as RF propagation, space-time coding, spatial mul-tiplexing, OFDM in MIMO for broadband applica

2、tions, the theoretical MIMO capacityformula, and channel estimation, will give you a deep understanding of how the resultsare obtained, while detailed descriptions of how MIMO is implemented in commercialWiFi and LTE networks will help you apply the theory to practical wireless systems.Key concepts

3、in matrix mathematics and information theory are introduced and devel-oped as you need them, and key results are derived step by step, with no details omitted.Including numerous worked examples, and end-of-chapter exercises to reinforce andsolidify your understanding, this is the perfect introductio

4、n to MIMO for anyone new tothe field.Jerry R. Hampton is a research engineer with over 30 years experience in communi-cations systems engineering. He is a member of the principal professional staff in theApplied Physics Laboratory, and an Adjunct Professor in the Whiting School of Engi-neering, at T

5、he Johns Hopkins University, where he teaches a graduate course in MIMOwireless communications.“This is a well-organized comprehensive treatise on MIMO principles, methods, andapplications. While many concepts are introduced in intuitively pleasing ways; theintegration of detailed step-by-step mathe

6、matical developments of MIMO principles,propagation models, channel characterizations, and applications of MIMO in commer-cial systems adds tremendous depth and understanding to the concepts. After studyingthis text, if readers have interests in topics not covered, they will very likely be able toun

7、derstand or author for themselves advanced MIMO literature on such topics.”David Nicholson, Communications consultantIntroduction toMIMO CommunicationsJERRY R. HAMPTONThe Johns Hopkins UniversityUniversity Printing House, Cambridge CB2 8BS, United KingdomPublished in the United States of America by

8、Cambridge University Press, New YorkCambridge University Press is part of the University of Cambridge.It furthers the Universitys mission by disseminating knowledge in the pursuit ofeducation, learning, and research at the highest international levels of excellence.www.cambridge.orgInformation on th

9、is title: www.cambridge.org/9781107042834c ? Cambridge University Press 2014This publication is in copyright. Subject to statutory exceptionand to the provisions of relevant collective licensing agreements,no reproduction of any part may take place without the writtenpermission of Cambridge Universi

10、ty Press.First published 2014Printed in the United Kingdom by TJ International Ltd. Padstow CornwallA catalog record for this publication is available from the British LibraryISBN 978-1-107-04283-4 HardbackAdditional resources for this publication at www.cambridge.org/hamptonCambridge University Pre

11、ss has no responsibility for the persistence or accuracy ofURLs for external or third-party internet websites referred to in this publication,and does not guarantee that any content on such websites is, or will remain,accurate or appropriate.ContentsPrefacepage xi1Overview of MIMO communications11.1

12、What is MIMO?11.2History of MIMO31.3Smart antennas vs MIMO51.4Single-user and multi-user MIMO61.5Introduction to spatial diversity71.5.1The concept of diversity71.5.2Receive and transmit diversity91.5.3Common diversity performance metrics111.5.4Relationship between diversity order and diversity gain

13、121.6Introduction to spatial multiplexing151.6.1The concept of spatial multiplexing151.7Open- and closed-loop MIMO171.8The practical use of MIMO181.8.1Commercial MIMO implementations181.8.2Measured MIMO performance191.9Review of matrices211.9.1Basic definitions221.9.2Theorems and properties232The MI

14、MO capacity formula282.1What is information?282.2Entropy302.3Mutual information312.4Definition of SISO capacity332.5Definition of MIMO capacity342.5.1MIMO system model342.5.2Capacity352.6Evaluating H(z)362.7Evaluating H(r)372.8Final result382.8.1Real signals382.8.2Complex signals39viContents3Applica

15、tions of the MIMO capacity formula423.1MIMO capacity under the CSIR assumption423.2Eigen-channels and channel rank443.3Optimum distribution of channel eigenvalues463.4Eigenbeamforming473.5Optimal allocation of power in eigenbeamforming503.5.1The waterfilling algorithm503.5.2Discussion of the waterfi

16、lling algorithm513.6Single-mode eigenbeamforming533.7Performance comparison543.7.1Results for Nr Nt543.7.2Results for Nt Nr573.8Capacities of SIMO and MISO channels583.8.1SIMO capacity583.8.2MISO capacity593.9Capacity of random channels613.9.1Definition of Hw623.9.2Capacity of an Hwchannel for large

17、 N623.9.3Ergodic capacity633.9.4Outage capacity654RF propagation704.1Phenomenology of multipath channels704.2Power law propagation724.3Impulse response of a multipath channel744.4Intrinsic multipath channel parameters774.4.1Parameters related to 784.4.2Parameters related to t854.5Classes of multipat

18、h channels904.5.1Flat fading904.5.2Frequency-selective fading914.5.3Slow and fast fading934.6Statistics of small-scale fading934.6.1Rayleigh fading934.6.2Rician fading955MIMO channel models975.1MIMO channels in LOS geometry975.2General channel model with correlation995.3Kronecker channel model1015.4

19、Impact of antenna correlation on MIMO capacity1035.5Dependence of Rtand Rron antenna spacing and scattering angle1055.6Pinhole scattering1075.7Line-of-sight channel model110Contentsvii6Alamouti coding1146.1Maximal ratio receive combining (MRRC)1156.2Challenges with achieving transmit diversity1176.3

20、2 1 Alamouti coding1186.42 NrAlamouti coding1206.4.1The 2 2 case1206.4.2The 2 Nrcase1226.5Maximum likelihood demodulation in MRRC and Alamouti receivers1236.6Performance results1256.6.1Theoretical performance analysis1256.6.2Simulating Alamouti and MRRC systems1276.6.3Results1287Space-time coding131

21、7.1Space-time coding introduction1317.1.1Definition of STBC code rate1317.1.2Spectral efficiency of a STBC1337.1.3A taxonomy of space-time codes1347.2Space-time code design criteria1367.2.1General pairwise error probability expression1367.2.2Pairwise error probability in Rayleigh fading1407.2.3Pairw

22、ise error probability in Rician fading1427.2.4Summary of design criteria1427.3Orthogonal space-time block codes1467.3.1Real, square OSTBCs1467.3.2Real, non-square OSTBCs1477.3.3Complex OSTBCs1497.3.4Decoding OSTBCs1507.3.5Simulating OSTBC performance1537.3.6OSTBC performance results1537.4Space-time

23、trellis codes1557.4.1STTC encoding1567.4.2STTC performance results1578Spatial multiplexing1628.1Overview of spatial multiplexing1628.2BLAST encoding architectures1658.2.1Vertical-BLAST (V-BLAST)1658.2.2Horizontal-BLAST (H-BLAST)1668.2.3Diagonal-BLAST (D-BLAST)1668.3Demultiplexing methods for H-BLAST

24、 and V-BLAST1688.3.1Zero-forcing (ZF)1688.3.2Zero-forcing with interference cancellation (ZF-IC)1718.3.3Linear minimum mean square detection (LMMSE)175viiiContents8.3.4LMMSE with interference cancellation (LMMSE-IC)1798.3.5BLAST performance results1818.3.6Comparison of ZF and LMMSE at large SNR1868.

25、4Multi-group space-time coded modulation (MGSTC)1878.4.1The MGSTC encoder structure1878.4.2Nomenclature1888.4.3MGSTC decoding1898.4.4Group-dependent diversity1938.4.5MGSTC performance results1949Broadband MIMO1979.1Flat and frequency-selective fading1979.2Strategies for coping with frequency-selecti

26、ve fading1989.2.1Exploiting frequency-selective fading1999.2.2Combating frequency-selective fading2009.3Conventional OFDM2039.4MIMO OFDM2059.5OFDMA2109.6Space-frequency block coding (SFBC)21110Channel estimation21410.1Introduction21410.2Pilot allocation strategies21510.2.1Narrowband MIMO channels215

27、10.2.2Broadband MIMO channels21610.2.3Designing pilot spacing21710.2.4Spatial pilot allocation strategies21910.3Narrowband MIMO channel estimation22010.3.1Maximum likelihood channel estimation22110.3.2Least squares channel estimation22210.3.3Linear minimum mean square channel estimation22210.3.4Choo

28、sing pilot signals22410.3.5Narrowband CE performance22510.4Broadband MIMO channel estimation22710.4.1Frequency-domain channel estimation22810.4.2Time-frequency interpolation22911Practical MIMO examples23211.1WiFi23211.1.1Overview of IEEE 802.11n23211.1.2802.11n packet structure23511.1.3802.11n HT tr

29、ansmitter architecture23711.1.4Space-time block coding in 802.11n24211.1.5OFDM in 802.11n244Contentsix11.1.6Channel estimation24711.1.7Modulation and coding schemes in 802.11n25111.2LTE25211.2.1Overview and history25211.2.2LTE waveform structure25311.2.3LTE transmitter block diagrams25511.2.4DL tran

30、smit diversity25711.2.5Spatial multiplexing25911.2.6LTE data rates260Appendices264AMIMO system equation normalization264BProof of theorem 5.2266CDerivation of Eq. 7.9269DMaximum likelihood decoding rules for selected OSTBCs271EDerivation of Eq. 8.68274FParameters for the non-unequal HT modulation an

31、d codingschemes in IEEE 802.11n276References279Index285PrefaceThis book is an outgrowth of a graduate course I have taught for the past four years onMIMO Wireless Communications in the Engineering for Professionals (EP) Programwithin the Whiting School of Engineering at The Johns Hopkins University.

32、 When Ibegan to develop the course in the spring of 2006, I initially thought I would simplychoose a textbook from the collection of numerous books that had been written onMIMO communications at that time. As I began studying these books, however, I foundthat, although they were each excellent in va

33、rious ways, none of them was as accessibleto the average practicing communications engineer or early level electrical engineer-ing graduate student as I had hoped. Many of these books were written by experts inthe field, researchers who had made seminal contributions in the area of MIMO com-municati

34、ons, but the prerequisites needed to follow and understand the details in theirpresentations were often above the level of expertise of those being introduced to MIMOfor the first time.This book is my attempt to remedy this problem. In developing the course and in writ-ing this book, I have tried to

35、 make the concepts and techniques associated with MIMOcommunications accessible to an average communications engineer with an undergrad-uate degree in electrical engineering. I assume that readers are familiar with digitalcommunication techniques and that they have had a formal course (or its equiva

36、lent)in digital signal processing; however, I do not assume readers are familiar with infor-mation theory or are proficient in advanced matrix mathematics, areas of expertise thatare normally assumed in the MIMO literature and in many of the books that have beenpublished on this topic. When knowledg

37、e in these areas is required to understand MIMOconcepts, I have attempted to include the necessary information on those topics in thebook so that it is not necessary to consult external resources. In this sense, the book hasbeen designed to be as self-contained as possible.As its name suggests, this

38、 book is intended to provide an introduction to the fieldof MIMO communications, and is, therefore, by design not encyclopedic. My goal hasbeen to provide readers new to MIMO communications with an understanding of thebasic concepts and methods, thereby laying a foundation for further study and prov

39、idingthem with the ability to understand the vast literature on this subject.Although my goal has been to make the concepts of MIMO understandable to theaverage communications engineer, I have tried to remain rigorous at the same time. Oneof my initial frustrations when I began searching for a textb

40、ook was that there were oftenlarge steps or gaps in derivations that were not explained, so I have attempted to fill inxiiPrefacethe details of as many gaps as possible in my book, in some cases relegating the detailsto appendices to avoid interrupting the flow of the text.A third feature of this bo

41、ok that I hope will be useful to readers is that it containsdescriptions of how MIMO concepts are implemented in practical systems. MIMO tech-niques have now become as commonplace in wireless communications systems as mod-ulation and error correction coding, so there is no shortage of examples of sy

42、stems thatuse MIMO methods. In this book, I focus on WiFi (IEEE 802.11n) and LTE and explainhow these two popular wireless standards implement MIMO concepts in practice.Chapter 1 provides an overview of MIMO communication concepts and includesa section on key matrix properties and identities that ar

43、e used throughout the book.This initial chapter explains the different types of MIMO schemes, defines fundamen-tal concepts such as spatial diversity and spatial multiplexing, and presents measuredperformance results that demonstrate the performance benefits of MIMO.Chapter 2 is devoted to derivatio

44、n of the MIMO capacity formula, which predicts themaximum error-free data rate that can be supported by a MIMO communication sys-tem. This formula is used later in Chapter 3 to provide useful conceptual insights intohow multiple antennas enable increased spectral efficiency. Although the MIMO capac-

45、ity formula is derived using concepts from information theory, the chapter introducesconcepts as necessary to derive the final result and does not assume the reader has abackground in that subject.Chapter3explorestheimplicationsoftheMIMOcapacity formulaandusesittocom-pute the communications capaciti

46、es of MIMO systems under various assumptions. Theconcepts of eigenmodes and channel rank are examined, and the spatial multiplexingtechnique called eigenbeamforming is derived and explained in this chapter.Chapter 4 discusses RF propagation in general and develops the terminology andconcepts used in

47、 characterizing multipath propagation in particular.Chapter 5 presents several theoretical MIMO propagation models that have beendeveloped based on theory and empirical results. Expressions for the channel modelwhen both Rayleigh fading and line-of-sight propagation exist are also presented. Thesemo

48、dels are used to derive expressions for the dependence of the MIMO capacity onantenna correlation as well as on the amount of scattering in the channel.Chapter 6 describes Alamouti coding, which is an important practical MIMOtechnique used to achieve transmit diversity. This chapter begins by examin

49、ing theperformance of ideal maximal ratio receive combining and then shows how Alamouticoding achieves diversity gain equal to a maximal ratio receive combiner.Chapter 7 broadens the discussion begun in Chapter 6 to consider other types of cod-ing techniques, called space-time codes, that can be use

50、d to achieve transmit spatialdiversity. This chapter focuses on space-time block codes, but also introduces the readerto space-time trellis coding concepts. The chapter describes how to perform decoding,concluding with a presentation of representative performance results.Chapter 8 addresses spatial