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`UNITED STATES PATENT AND TRADEMARK OFFICE
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`BEFORE THE PATENT TRIAL AND APPEAL BOARD
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`APPLE INC.
`Petitioner
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`v.
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`UNWIRED PLANET INTERNATIONAL LIMITED
`Patent Owner
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`Case IPR2020-00642
`Patent No. 9,001,774
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`
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`DECLARATION OF ZHI DING, PH.D. IN SUPPORT OF
`PETITION FOR INTER PARTES REVIEW OF
`U.S. PATENT NO. 9,001,774
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`APPLE 1002
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`TABLE OF CONTENTS
`Background ...................................................................................................... 1 
`I. 
`II.  Materials Considered ....................................................................................... 6 
`III.  Legal Principles ............................................................................................... 7 
`A. 
`Claim Construction ............................................................................... 7 
`
`B.  Anticipation ........................................................................................... 9 
`
`C.  Obviousness ......................................................................................... 10 
`
`IV.  Summary of Opinions .................................................................................... 12 
`V. 
`Technical Background to the ’774 Patent ..................................................... 13 
`A.  Multiple Antenna Systems .................................................................. 13 
`
`B.  Use of “Gains,” “Phase Rotations,” and “Time Delays” for Diversity
` ............................................................................................................. 15 
`
`VI.  The ’774 Patent .............................................................................................. 19 
`A. 
`Background to the ’774 Patent ............................................................ 19 
`
`B. 
`
`C. 
`
`D. 
`
`Summary of the ’774 Patent ................................................................ 20 
`
`The Prosecution History of the ’774 Patent ........................................ 21 
`
`Person of Ordinary Skill in the Art ..................................................... 26 
`
`VII.  Claim Construction—“at least one of a time delay, a phase rotation and a
`gain” ............................................................................................................... 26 
`VIII.  Overview of the Principal Prior Art References ............................................ 28 
`A.  Onggosanusi ........................................................................................ 28 
`
`B.  Kuchi ................................................................................................... 34 
`
`IX.  GROUND 1: Claims 6-10 Are Unpatentable as Obvious Over Onggosanusi
`(Ex. 1003) in View of Kuchi (Ex. 1004). ...................................................... 35 
`A. 
`[6. Preamble]—“A method, comprising:” .......................................... 35 
`
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`B. 
`
`C. 
`
`D. 
`
`E. 
`
`F. 
`
`G. 
`
`H. 
`
`[6.1]—“receiving a processing parameter for transmission of data on
`two antenna ports, the processing parameter including at least one of a
`time delay, a phase rotation and a gain determined based on a received
`uplink signal” ...................................................................................... 36 
`
`[6.2]—“receiving a first pilot, a second pilot, a first data symbol and a
`second data symbol transmitted on the two antenna ports” ................ 52 
`
`[6.3]—“demodulating the first data symbol and the second data
`symbol based on the processing parameter, the first pilot and the
`second pilot.” ....................................................................................... 54 
`
`[7]—“The method of claim 6, wherein the first pilot and the second
`pilot are generated independently of the symbol processing
`parameter” ........................................................................................... 58 
`
`[8]—“The method of claim 6, wherein the processing parameter is
`determined on a user-by-user basis” ................................................... 60 
`
`[9]—“The method of claim 6, wherein the time delay is in a time
`domain and the phase rotation is in a frequency domain” .................. 62 
`
`[10]—“The method of claim 6, wherein the demodulating further
`comprises: estimating a channel using the first pilot, the second pilot
`and the processing parameter; and demodulating the first and second
`data based on the estimated channel” .................................................. 65 
`
`X.  GROUND 2: Claims 6-10 Are Unpatentable as Obvious Over Onggosanusi
`(Ex. 1003) in View of Kuchi (Ex. 1004). ...................................................... 70 
`A. 
`[6. Preamble]—“A method, comprising:” .......................................... 71 
`
`B. 
`
`[6.1]—“receiving a processing parameter for transmission of data on
`two antenna ports, the processing parameter including at least one of a
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`ii
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`C. 
`
`D. 
`
`E. 
`
`F. 
`
`G. 
`
`H. 
`
`time delay, a phase rotation and a gain determined based on a received
`uplink signal” ...................................................................................... 71 
`
`[6.2]—“receiving a first pilot, a second pilot, a first data symbol and a
`second data symbol transmitted on the two antenna ports” ................ 80 
`
`[6.3]—“demodulating the first data symbol and the second data
`symbol based on the processing parameter, the first pilot and the
`second pilot.” ....................................................................................... 80 
`
`[7]—“The method of claim 6, wherein the first pilot and the second
`pilot are generated independently of the symbol processing
`parameter” ........................................................................................... 82 
`
`[8]—“The method of claim 6, wherein the processing parameter is
`determined on a user-by-user basis” ................................................... 83 
`
`[9]—“The method of claim 6, wherein the time delay is in a time
`domain and the phase rotation is in a frequency domain” .................. 85 
`
`[10]—“The method of claim 6, wherein the demodulating further
`comprises: estimating a channel using the first pilot, the second pilot
`and the processing parameter; and demodulating the first and second
`data based on the estimated channel” .................................................. 85 
`
`XI.  Availability for Cross-Examination .............................................................. 87 
`XII.  Right to Supplement ...................................................................................... 87 
`XIII.  JURAT ........................................................................................................... 87 
`
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`iii
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`I, Zhi Ding, Ph.D, declare as follows:
`
`I.
`
`Background
`1.
`I presently serve as Professor in the Department of Electrical and
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`Computer Engineering at the University of California, Davis. I have held this
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`position since my appointment on July 1, 2000. I am also a private technical
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`consultant on various technologies related to information systems and wireless
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`systems. I have more than three decades of research experience on a wide range of
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`topics related to data communications and signal processing.
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`2.
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`I earned my Bachelor of Engineering degree in 1982, majoring in
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`wireless engineering from the Nanjing Institute of Technology (later renamed as
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`Southeast University) in Nanjing, China. I earned my Master of Applied Science
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`degree in 1987 in electrical engineering from the University of Toronto in Toronto,
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`Canada. I earned my Ph.D. in 1990 in electrical engineering from Cornell
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`University in Ithaca, New York.
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`3. My responsibilities as Professor at University of California, Davis
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`include classroom instruction on various topics of communication systems and
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`signal analysis, as well as mentoring undergraduate students and supervising
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`graduate students in their research and development efforts on various topics related
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`to communication systems, networking, and signal processing. I have directly
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`supervised research and development works ranging from signal transmission and
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`
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`1
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`data detection to wireless networking. As the chief academic advisor, I have also
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`directly supervised the completion of over 20 Masters theses and 27 Ph.D.
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`dissertations on various topics related to communications and networking. I have
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`served full time as a faculty member at three major research universities in the
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`United States over the past three decades, including Auburn University from 1990
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`to 1998, University of Iowa from 1999 to 2000, and University of California, Davis,
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`from 2000 to present.
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`4.
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`Since 1990, I have been selected as the principal investigator of
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`multiple highly competitive federal and local research grants, including sixteen
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`major research projects supported by the National Science Foundation and two
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`research projects funded by the U.S. Army Research Office. These competitive
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`research projects focused on developing more efficient and effective digital
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`communication transceivers, networks, and signal processing tools. I have also
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`participated in several large-scale projects supported by the Defense Advanced
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`Research Projects Agency (DARPA) with teams of researchers. I have applied for,
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`and received support from, other federal, state, and industry sponsors.
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`5.
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`I have published over 190 peer-reviewed research articles in premier
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`international journals, in addition to over 230 peer-reviewed technical articles at top
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`international conferences on communications and information technologies. I also
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`authored two books on communications technologies. My most recent book, co-
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`2
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`authored with B.P. Lathi, is entitled, Modern Digital and Analog Communication
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`Systems, 5th edition, and was published by the Oxford University Press in 2018.
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`The 4th edition of this book (published in 2009) had been widely adopted as an
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`introductory textbook to communication systems.
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`6.
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`In addition to the over 400 published technical papers that have been
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`cited over 12,000 times (as of January 2020) according to Google Scholar, I am also
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`co-inventor of three issued U.S. patents on communication technologies.
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`7. Many of my research works and publications are directly related to
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`the substantive improvement of wireless communication systems, including 2nd
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`generation (2G), 3rd generation (3G), 4th generation (4G), and the latest 5th
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`generation (5G) cellular networks. I have also led multiple research projects
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`regarding multiple-input-multiple-output (MIMO) wireless links. One of my major
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`areas of expertise is estimating channel state information (CSI) of wireless
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`channels, including MIMO channels.
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`8.
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`I am a member of the Institute of Electrical and Electronics Engineers
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`(IEEE) and was elevated to the grade of Fellow in January 2003 for contributions
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`made in signal processing for communication. The IEEE is the world’s largest
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`professional society of engineers, with over 400,000 members in more than 160
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`countries. The IEEE has led the development of many standards for modern digital
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`communications and networking, most notably, the IEEE 802 series of network
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`
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`3
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`standards. The IEEE Grade of Fellow is conferred by the Boards of Directors upon
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`a person with an extraordinary record of accomplishments in any of the IEEE fields
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`of interest. The total number selected in any one year does not exceed one-tenth of
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`one percent of the total voting Institute membership.
`
`9.
`
`I have served the IEEE in the following capacities:
`
`
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`Chief Information Officer of the IEEE Communications Society
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`from January 2018 to present.
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`
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`General Chair of the 2016 IEEE International Conference on
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`Acoustics, Speech, and Signal Processing, the flagship conference of
`
`the IEEE Signal Processing Society.
`
`
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`Chair of the Steering Committee for the IEEE Transactions on
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`Wireless Communications from 2008 to 2010.
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`
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`Distinguished Lecturer of the IEEE Communications Society
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`from January 2008 to December 2009.
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`
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`Technical Program Chair of the 2006 IEEE Globecom, one of
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`two flagship annual IEEE Communication Society conferences.
`
`
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`Distinguished Lecturer of the IEEE Circuits and Systems
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`Society from 2004 to 2005.
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`
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`Associate Editor of the IEEE Transactions on Signal Processing
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`from 1994 to 1997 and from 2001 to 2004.
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`
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`Member of the IEEE Statistical Signal and Array Processing for
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`Communications Technical Committee from 1993 to 1998.
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`
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`Member of the IEEE Signal Processing for Communications
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`Technical Committee from 1998 to 2004.
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`10.
`
`In 2012, I received the annual Wireless Communications Technical
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`Committee Recognition Award from the IEEE Communications Society, a peer
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`award given to a person with a high degree of visibility and contribution in the field
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`of “Wireless and Mobile Communications Theory, Systems, and Networks.”
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`11.
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`I have also served as a technical consultant for the telecommunication
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`industry. For example, in 1995 I consulted for Analog Devices, Inc. to develop the
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`first generation DOCSIS cable modem systems for broadband access. I have also
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`consulted for other companies, including Nortel Networks and NEC US
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`Laboratories. I worked as a visiting faculty research fellow at NASA Glenn
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`Research Center in 1992 and at U.S. Air Force Wright Laboratory in 1993. I have
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`served on multiple review panels of the National Science Foundation to evaluate
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`competitive research proposals in the field of communication. I have also reviewed
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`a large number of research proposals at the request of the National Science and
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`Engineering Research Council (NSERC) of Canada as an expert panelist from 2010
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`to 2013, and also at the request of the Research Grant Council (RGC) of Hong
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`Kong as an external reviewer.
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`12.
`
`I have served as an expert witness or consulting expert on a number of
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`matters related to intellectual property, mostly in the arena of telecommunications,
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`including cellular communications, Wi-Fi technologies, Bluetooth, and optical
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`communications.
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`13.
`
`Further experience and a complete list of my publications are
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`presented in my curriculum vitae, which is attached as Appendix A.
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`14.
`
`I have been retained by counsel for Apple Inc. (“Apple” or
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`“Petitioner”) as an independent expert witness for the above captioned Petition for
`
`Inter Partes Review of claims 6-10 of U.S. Patent No. 9,001,774 (“’774 patent”)
`
`(Ex. 1001).
`
`15.
`
`I am being compensated at my normal consulting rate of $690 per
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`hour. My compensation does not depend on the outcome of this matter, and in no
`
`way affects the substance of my statements in this Declaration. I also do not have
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`any financial interest in any of the parties to this case.
`
`II. Materials Considered
`16.
`I have reviewed the specification, claims, and file history of the ’774
`
`patent. I understand that the ’774 patent claims priority through a series of
`
`continuing applications to three U.S. provisional applications filed in 2005. I have
`
`reviewed these applications.
`
`17.
`
`I have also reviewed the following references, which I understand to
`
`
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`6
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`

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`be prior art to the ’774 patent:
`
` U.S. Patent Application Publication No. 2002/0114269 to
`
`Onggosanusi et al. (Ex. 1003) (“Onggosanusi”);
`
` U.S. Patent No. 6,542,556 to Kuchi et al. (Ex. 1004) (“Kuchi”).
`
`18.
`
`In addition to the documents listed above, I have also reviewed all the
`
`documents listed in Petitioner’s List of Exhibits in the accompanying petition and
`
`the other documents cited throughout this declaration.
`
`III. Legal Principles
`19.
`I am not an attorney. For the purposes of this declaration, I have been
`
`informed about certain aspects of the law that are relevant to my opinions. My
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`understanding of the law is as set forth below.
`
`A. Claim Construction
`20.
`I have been informed that claim construction is a matter of law and
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`that the final claim construction will ultimately be determined by the Board. For the
`
`purposes of my analysis in this proceeding and with respect to the prior art, I have
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`been informed that patents are currently reviewed in an inter partes review under
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`what is known as “the Phillips standard,” which I have summarized below.
`
`21.
`
`I have been informed and understand that the terms of a patent claim
`
`are generally given their ordinary and customary meaning. This is the meaning that
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`the term would have to a person of ordinary skill in the art at the time of the
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`7
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`claimed invention (the time at which the application for the patent was filed).
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`22.
`
`I have been informed and understand that although the parties may not
`
`agree on the priority date for the ’774 patent, the earliest alleged priority date for
`
`the patent is April 21, 2005.
`
`23.
`
`I have been informed and understand that a patent specification may
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`reveal a special definition given to a claim term by the patentee that differs from the
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`meaning it would otherwise possess. In such cases, the inventor’s “lexicography”
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`governs. In other cases, the specification may reveal an intentional disclaimer, or
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`clear disavowal, of claim scope by the inventor. In that instance as well, I have
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`been informed and understand that the inventor has dictated the correct claim scope,
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`and the inventor’s intention, as expressed in the specification, governs.
`
`24.
`
`I have been informed and understand that terms of a claim should be
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`understood in the context of the claim as a whole. I also understand that the
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`specification of the patent is relevant to the meaning of a claim term. I have been
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`informed and understand that the claims must be read in light of the specification.
`
`25.
`
`I have been informed and understand that the file history should also
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`be considered when interpreting the meaning of the claims of a patent. The file
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`history can contain evidence of how the U.S. Patent and Trademark Office (“PTO”)
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`and the applicant understood the patent and the meaning of the terms of the patent.
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`26.
`
`I have been informed and understand that the claim language,
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`8
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`specification, and prosecution history are referred to as “intrinsic evidence.” I also
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`have been informed and understand that proceedings before the PTO regarding the
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`issued patent such as inter partes reviews (IPRs) may also be considered intrinsic
`
`evidence.
`
`27.
`
`I have been informed and understand that evidence from literature in
`
`the field may also be relevant in the determination of how a person of ordinary skill
`
`in the art would understand the claims. I have been informed and understand that
`
`this evidence, which is referred to as a type of “extrinsic evidence,” must be
`
`considered in the context of the intrinsic evidence and cannot be used to change the
`
`meaning of a claim term to be inconsistent with the intrinsic evidence.
`
`B. Anticipation
`28.
`I understand that in an Inter Partes Review proceeding, a patent is not
`
`presumed valid and the Patent Trial and Appeal Board will evaluate the validity of
`
`the challenged claims under a preponderance of evidence standard. A
`
`preponderance standard is met when, considering the evidence presented, it is more
`
`likely than not a challenged claim is invalid. I have been informed and understand
`
`that a patent claim is invalid if it is “anticipated” by prior art. For the claim to be
`
`invalid because it is anticipated, all of its requirements must have existed in a single
`
`device or method that predates the claimed invention, or must have been described
`
`in a single publication or patent that predates the claimed invention. A patent claim
`
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`9
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`

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`may be “anticipated” if each element of that claim is present either explicitly or
`
`inherently in a single prior art reference. I have also been informed that, to be an
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`inherent disclosure, the prior art reference must necessarily disclose the limitation,
`
`and the fact that the reference might possibly practice or contain a claimed
`
`limitation is insufficient to establish that the reference inherently teaches the
`
`limitation.
`
`C. Obviousness
`29.
`I have been informed and understand that a patent claim is invalid if
`
`the claimed invention would have been obvious to a person of ordinary skill in the
`
`art at the time the application was filed. This means that, even if all of the
`
`requirements of a claim are not found in a single prior art reference, the claim is not
`
`patentable if the differences between the subject matter in the prior art and the
`
`subject matter in the claim would have been obvious to a person of ordinary skill in
`
`the art at the time the application was filed.
`
`30.
`
`I have been informed and understand that a determination of whether
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`a claim would have been obvious should be based upon several factors, including,
`
`among others:
`
` the level of ordinary skill in the art at the time the application was
`
`filed;
`
` the scope and content of the prior art; and
`
`
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`10
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`

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` what differences, if any, existed between the claimed invention and
`
`the prior art.
`
`31.
`
`I have been informed and understand that the teachings of two or
`
`more references may be combined in the same way as disclosed in the claims, if
`
`such a combination would have been obvious to one having ordinary skill in the art.
`
`In determining whether a combination based on either a single reference or multiple
`
`references would have been obvious, it is appropriate to consider, among other
`
`factors:
`
` whether the teachings of the prior art references disclose known
`
`concepts combined in familiar ways, which, when combined, would
`
`yield predictable results;
`
` whether a person of ordinary skill in the art could implement a
`
`predictable variation, and would see the benefit of doing so;
`
` whether the claimed elements represent one of a limited number of
`
`known design choices, and would have a reasonable expectation of
`
`success by those skilled in the art;
`
` whether a person of ordinary skill would have recognized a reason to
`
`combine known elements in the manner described in the claim;
`
` whether there is some teaching or suggestion in the prior art to make
`
`the modification or combination of elements claimed in the patent;
`
`
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`11
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`and
`
` whether the innovation applies a known technique that had been used
`
`to improve a similar device or method in a similar way.
`
`32.
`
`I understand that one of ordinary skill in the art has ordinary
`
`creativity, and is not an automaton.
`
`33.
`
`I understand that in considering obviousness, it is important not to
`
`determine obviousness using the benefit of hindsight derived from the patent being
`
`considered.
`
`34.
`
`I have been informed and understand that a single reference can alone
`
`render a patent claim obvious, if any differences between that reference and the
`
`claims would have been obvious to a person of ordinary skill in the art at the time of
`
`the alleged invention—that is, if the person of ordinary skill would adapt the
`
`reference to meet the claims of the patent, by applying known concepts to achieve
`
`expected results in the adaptation of the reference.
`
`IV.
`
`Summary of Opinions
`35.
`It is my opinion that every limitation of claims 6-10 of the ’774 patent
`
`was not new and is disclosed by the prior art, and that claims 6-10 are rendered
`
`obvious by the prior art cited in this declaration. In particular, the following table
`
`summarizes my opinions.
`
`Ground
`1
`
`’774 Patent Claims Opinion
`6-10
`Obvious over Onggosanusi (Ex. 1003) in view
`
`
`
`12
`
`

`

`of Kuchi (Ex. 1004), using plaintiffs’
`construction of “at least one of a time delay, a
`phase rotation and a gain”
`Obvious over Onggosanusi (Ex. 1003) in view
`of Kuchi (Ex. 1004), using Apple’s
`construction of “at least one of a time delay, a
`phase rotation and a gain”
`
`2
`
`6-10
`
`
`
`36. This prior art1 is summarized below:
`
` Onggosanusi (Exhibit 1003) – U.S. Patent Application Publication
`
`No. 2002/0114269 to Onggosanusi, et al. (“Onggosanusi”) was filed
`
`on October 3, 2001 and published on August 22, 2002.
`
` Kuchi (Exhibit 1004) –U.S. Patent No. 6,542,556 to Kuchi et al.
`
`(“Kuchi”) was filed on March 31, 2000 and issued on April 1, 2003.
`
`V. Technical Background to the ’774 Patent
`A. Multiple Antenna Systems
`37. The ’774 patent is directed to a method that includes the reception of a
`
`“processing parameter” used to transmit data from two antenna ports, and use of the
`
`processing parameter and pilot signals to demodulate data symbols, where the
`
`processing parameter is determined based on a received uplink signal. Ex. 1001
`
`1 As described below, the prior art references relied on in this Petition predate the
`
`earliest possible priority date for the ’774 patent. For purposes of this Petition, I do
`
`not take a position as to whether the ’774 patent is entitled to the filing dates of the
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`priority applications.
`
`
`
`13
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`

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`(’774 patent) at Abstract, claim 6.
`
`38. Multiple transmit antenna systems existed in the prior art to the ’774
`
`patent in order to introduce diversity between signals received at a receiver. For
`
`example, the Kuchi reference, which existed in the prior art to the ’774 patent, sets
`
`forth a multiple antenna system (the antenna are shown in green, blue, purple, and
`
`orange in the figure below) at a transmitter.
`
`
`
`Ex. 1004 (Kuchi) at Fig. 1 (coloring added).
`
`39. The use of multiple transmit antennas in a wireless system can be used
`
`for multiple purposes, including improving the reliability of signal reception. In
`
`some transmitter systems, the same data can be sent from multiple transmit
`
`antennas. If the signal received at the receiver from a first transmit antenna is weak
`
`or experiences strong interference, the signal from a second transmit antenna may
`
`
`
`14
`
`

`

`be better, which increases the likelihood of successful signal reception at the
`
`receiver. The use of multiple transmit antennas can introduce spatial diversity in
`
`that the transmit antennas can be spaced apart—if even by a very small distance—to
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`form multiple channels of diverse characteristics from the transmitter to the
`
`receiver.
`
`40. A multiple transmit antenna system can introduce spatial diversity for
`
`signal quality enhancement in orthogonal frequency division multiplexing (OFDM),
`
`such as the OFDM network disclosed in the ’774 patent. Ex. 1001 (’774 patent) at
`
`Abstract (mentioning an OFDM network). OFDM is a method of transmitting data
`
`in a bank of orthogonal, frequency domain channels (known as subcarriers)
`
`simultaneously.
`
`B. Use of “Gains,” “Phase Rotations,” and “Time Delays” for
`Diversity
`In order to enhance signal diversity to improve reception quality, data
`
`41.
`
`signals can be transmitted from multiple transmit antennas against wireless fading
`
`channels using different processing parameters. Each wireless path from one
`
`transmit antenna to one receive antenna may have a time-varying and uncontrolled
`
`gain because of wireless channel fading. Signals transmitted from multiple
`
`antennas may cause the received signals at the receiver to interfere constructively or
`
`destructively. Constructive signal superposition can improve the signal strength or
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`reception signal-to-noise ratio, which strengthens the quality of signal reception. If
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`the unknown and time-varying wireless fading channels can be estimated, then the
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`transmitter can apply one or more parameters to the data signals in order to utilize
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`this multi-antenna transmit diversity (including spatial diversity) to effectively
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`achieve higher signal-to-noise ratio.
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`42. A “gain,” a “phase rotation,” and/or a “time delay”—each of which
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`was known prior to the ’774 patent—can be used as a processing parameter applied
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`to the different transmit signals to enhance diversity and to better generate
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`constructive signal superposition at the receiver. The use of such parameters at the
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`transmitter can cause the signals received at the receiver from the different transmit
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`antenna to constructively enhance one another. Since the wireless path gain from
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`each pair of transmit and receive antenna may be different and may vary, this
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`channel state information (CSI) can be estimated, and the processing parameters at
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`the transmitter can be determined in response to the CSI estimates. Such transmit
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`processing may be known as precoding or transmit beamforming and is repeatedly
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`applied, generally using different parameters, respectively, on the multiple
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`subchannels (or subcarriers) in orthogonal frequency division multiplexing
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`(OFDM). This is, for example, a simplified explanation of how a multiple transmit
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`antenna wireless system can work to achieve spatial diversity for signal quality
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`enhancement in OFDM on every subchannel. Ex. 1001 (’774 patent) at Abstract
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`(mentioning an OFDM network).
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`43. The figure below2 is an example of the use of a “gain” applied to two
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`signals from two different transmit antennas (shown in red and blue triangles on the
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`left) in a very simplified example in a base station in a multiple transmit antenna
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`wireless system. The receiver is shown as a “UE,” or mobile device, on the right of
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`the figure. As shown in this figure, the red signal transmitted from the bottom
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`transmit antenna has a larger amplitude than the top (blue) signal, indicating that a
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`larger “gain” was applied to the signal from the red antenna. A person of ordinary
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`skill in the art would use numerous different terms for a “gain,” including a
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`“weight” or an “amplification factor.”
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`44. The next figure below shows an example of a “time delay” applied to
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`two signals from two different transmit antennas (shown in red and blue on the left)
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`2 The three figures below were taken from Apple’s technology tutorial in the
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`related litigation.
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`in the same wireless network as for the example above. Once again, this example
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`has been simplified. The signal from the top antenna (in blue) has been delayed by
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`a time D with respect to the signal transmitted from the bottom antenna (in red).
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`45. The third example below shows the use of a “phase rotation” applied
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`to two signals in the same wireless network as for the examples above. Once again,
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`this example has been simplified. The signal from the top antenna (in blue) has
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`been phase-shifted by 180 degrees with respect to the signal transmitted from the
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`bottom antenna (in red), since it is clear that the red signal is the exact opposite sign
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`of the blue signal.
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`46. The technology described above existed prior to the ’774 patent. The
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`’774 patent background acknowledges that it was known in the prior art (1) to use
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`multiple transmit antenna systems, (2) to use processing parameters including
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`“delay values” and “gain values” in these systems, and (3) to use a channel estimate
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`(or channel state information (CSI)) to determine the processing parameters. Ex.
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`1001 (’774 patent) at 1:48-66.
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`VI. The ’774 Patent
`A. Background to the ’774 Patent
`47. The ’774 patent background discloses the desirability of improving
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`reliability in a wireless system by transmitting multiple processed data signals,
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`carrying the same data, from different transmit antennas. Ex. 1001 (’774 patent) at
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`1:41-60. The ’774 patent background further sets forth the need for an improved
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`apparatus and method for performing channel estimation and then using this
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`information for selecting processing parameters to be applied to data symbols
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`transmitted from multiple antennas. Id. at 1:61-2:6.
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`B.
`Summary of the ’774 Patent
`48. The ’774 patent discloses receiving processing parameters and then
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`using those processing parameters and pilot signals to demodulate received data
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`signals. The processing parameter is based on a received uplink signal in a multi-
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`antenna system. Ex. 1001 (’774 patent) at claim 6. Figure 7 shows a message flow
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`diagram illustrating the transmission of data symbols from a base station 102 to a
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`subscriber station 116 according to one embodiment of the ’774 patent. Id. at 8:63-
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`66.
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`Id. at Fig. 7.
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`49. The transmitter processing parameter is determined in the base station
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`102, which has two antenna ports, ANT1 and ANT2. Id. at 8:66-9:1, Fig. 7.
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`Regarding these “processing parameters,” claim 6 recites, “the processing
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`parameter including at least one of a time delay, a phase rotation and a gain.” I