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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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`ANDREA ELECTRONICS INC.,
`Patent Owner.
`
`Patent No. 6,049,607
`Issued: April 11, 2000
`Filed: Sept. 18, 1998
`
`Inventors: Joseph Marash, et al.
`Titles: INTERFERENCE CANCELING METHOD AND APPARATUS
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`IPR2017-00628
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`DECLARATION OF BERTRAND HOCHWALD REGARDING
`U.S. PATENT NO. 6,049,607
`
`
`
`
`Petitioner Apple Inc.
`Exhibit 1003, cover
`
`

`

`IPR2017-00628
`
`Declaration of Dr. Bertrand Hochwald
`
`I.
`
`TABLE OF CONTENTS
`
`INTRODUCTION ......................................................................................... 1
`A.
`Engagement ........................................................................................... 1
`B.
`Background and Qualifications ............................................................. 1
`C.
`Compensation and Prior Testimony ...................................................... 4
`D.
`Information Considered ......................................................................... 4
`LEGAL STANDARDS FOR PATENTABILITY ...................................... 7
`II.
`A. Anticipation ........................................................................................... 8
`B.
`Obviousness ........................................................................................... 9
`III. BACKGROUND INFORMATION ABOUT THE ’607 PATENT......... 11
`A.
`Effective Filing Date of the ’607 Patent ............................................. 11
`B.
`The Prosecution History of The ’607 Patent ....................................... 11
`C.
`Technical Field .................................................................................... 11
`D.
`Level of Ordinary Skill in the Art ....................................................... 11
`IV. TECHNICAL BACKGROUND ................................................................. 12
`A.
`Echo Cancellation ................................................................................ 12
`B.
`Discrete Fourier Transform ................................................................. 16
`C. Microphone Arrays and Beams ........................................................... 16
`V. ANALYSIS OF THE ’607 PATENT ......................................................... 17
`A. Overview of the ’607 Patent ................................................................ 17
`B.
`Claims .................................................................................................. 19
`VI.
`IDENTIFICATION OF THE PRIOR ART ............................................. 20
`VII. ANALYSIS OF THE PRIOR ART AND ’607 CLAIMS ........................ 21
`Chu ...................................................................................................... 21
`A.
`1. Overview of Chu ........................................................................... 21
`
`The Meaning of Certain Terms Used in the ’607 Patent’s
`
`Petitioner Apple Inc.
`Exhibit 1003, p. i
`
`

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`IPR2017-00628
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`B.
`
`Declaration of Dr. Bertrand Hochwald
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`2. Conventional Echo Cancellation: Comparison of Chu to the
`Independent Claims of the ’607 Patent ......................................... 23
`Kellermann .......................................................................................... 28
`1. Overview of Kellermann ............................................................... 28
`2. A Person of Ordinary Skill Would Have Considered Chu
`and Kellermann Together .............................................................. 31
`3. Conventional Echo Cancellation: Comparison of Chu and
`Kellermann to the Independent Claims of the ’607 Patent ........... 35
`
`Petitioner Apple Inc.
`Exhibit 1003, p. ii
`
`

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`IPR2017-00628
`
`Declaration of Dr. Bertrand Hochwald
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`I.
`
`INTRODUCTION
`A. Engagement
`1.
`I have been retained by counsel for Apple Inc. as an expert witness in
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`the above-captioned proceeding. I have been asked to provide an opinion
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`regarding the patentability of certain claims in U.S. Patent No. 6,049,607
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`(“the ’607 patent”). I have been asked to provide a discussion of the meaning of
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`certain words and phrases in the claims of the ’607 patent, to provide a description
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`of state of the art of the technology described in the ’607 patent, and to analyze
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`various references that I understand are prior art to this patent.
`
`B.
`2.
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`Background and Qualifications
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`In 1995 I received a Ph.D. in Electrical Engineering from Yale
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`University. My PhD work involved the analysis and processing of electromagnetic
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`and audio signals for the estimation of the location of electromagnetic and audio
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`sources. In 1993 I received an M.A. in Statistics from Yale University. My
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`primary area of study was Statistical Signal Processing. I received an M.S. in
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`Electrical Engineering from Duke University in 1986, and a B.S. in Engineering
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`from Swarthmore College in 1984.
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`3.
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`I have twenty years of combined industry and academic experience in
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`the research and design of systems for signal processing, and wireless and wireline
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`communications.
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`Petitioner Apple Inc.
`Exhibit 1003, p. 1
`
`

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`IPR2017-00628
`
`Declaration of Dr. Bertrand Hochwald
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`4. My most recent appointment, starting in 2011, is with the University
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`of Notre Dame, where I am currently a Freimann Chaired Professor of Electrical
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`Engineering. I teach both graduate and undergraduate classes in Communication
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`Systems and in Signals and Systems, where the emphasis is on the processing of
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`analog and digital signals. My primary areas of research include communication
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`systems, radio-frequency circuits, and signal design and processing. I advise
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`graduate students who are attaining Ph.D. degrees through research and
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`coursework.
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`5.
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`Prior to Notre Dame, I worked from 2005-2010 at Beceem
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`Communications, a cellular wireless communication chipset start-up company in
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`Santa Clara, California, where I was Chief Scientist and Vice President of Systems
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`Engineering. I was an integral part of the chipset development team. Beceem was
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`bought by Broadcom Corporation in 2010 and no longer exists as a separate
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`company.
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`6.
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`Prior to Beceem, I worked from 1996-2005 at Lucent Bell
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`Laboratories in New Jersey, where I was as a Distinguished Member of the
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`Technical Staff doing research into communications systems and multiple-antenna
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`systems. As a result of my research, I obtained many patents and wrote numerous
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`publications across a variety of areas in communication theory, information theory,
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`and circuit design.
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`Petitioner Apple Inc.
`Exhibit 1003, p. 2
`
`

`

`IPR2017-00628
`
`Declaration of Dr. Bertrand Hochwald
`
`7.
`
`Prior to Bell Laboratories, I was a Visiting Assistant Professor at the
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`University of Illinois in Urbana-Champaign during the 1995-1996 school year,
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`where I worked on a broad range of research topics related to signal processing and
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`communications.
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`8.
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`Prior to completing my Ph.D., during 1986-1989 I worked at the
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`Department of Defense as a system engineer for signal processing and wireless
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`communication systems. In this job I designed communication equipment for the
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`sampling, filtering and processing of audio signals.
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`9.
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`I have published approximately 95 articles in scholarly journals, many
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`of them within the journals of the Institute of Electrical and Electronic Engineers
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`(IEEE), one of the premier societies for electrical engineers. I have been an invited
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`and plenary speaker at several international conferences throughout the world and
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`have received awards and recognition for my research and publications.
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`10.
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`I have 45 granted patents in a variety of areas related to
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`communication and signal processing systems. I have had experience drafting and
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`successfully prosecuting my own patents, and have worked with other experts in
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`signal processing systems as a co-inventor and co-author.
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`11.
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`In addition to my academic and practical experience, I have worked as
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`an expert in the areas of communication and signal processing systems, as detailed
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`in Exhibit A attached hereto..
`
`Petitioner Apple Inc.
`Exhibit 1003, p. 3
`
`

`

`IPR2017-00628
`
`Declaration of Dr. Bertrand Hochwald
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`12. A copy of my C.V. has been attached hereto as Exhibit B.
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`C. Compensation and Prior Testimony
`13.
`I am being compensated for my time at the rate of $600 per hour for
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`my work in connection with this matter. I am being reimbursed for reasonable and
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`customary expenses associated with my work in this investigation. This
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`compensation is not dependent in any way on the contents of this Declaration, the
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`substance of any further opinions or testimony that I may provide or the ultimate
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`outcome of this matter.
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`14. Within the last five years, I have testified by deposition in: Airvana v.
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`Ericsson. I have also testified at Andrea v. Lenovo. I also submitted declarations
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`in IPR2016-00459, IPR2016-00461, and IPR2016-00474 on behalf of Waves
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`Audio.
`
`D.
`Information Considered
`15. My opinions are based on my years of education, research, and
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`experience, as well as my investigation and study of relevant materials. In forming
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`my opinions, I have considered the materials I identify in this report and those
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`listed in the Exhibit List included with the petition:
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`Exhibit # Description
`1001
`U.S. Patent No. 6,049,607, “Interference Canceling Method And
`Apparatus,” to Joseph Marash and Baruch Berdugo, issued on
`Apr. 11, 2000 (“the ’607 patent”)
`
`1002
`
`Prosecution History of U.S. Patent Application No. 09/157,035
`
`Petitioner Apple Inc.
`Exhibit 1003, p. 4
`
`

`

`IPR2017-00628
`
`Declaration of Dr. Bertrand Hochwald
`
`Exhibit # Description
`which issued as U.S. Patent No. 6,049,607
`
`1005
`
`1007
`
`1008
`
`1009
`
`1010
`
`1011
`
`1012
`
`1013
`
`1014
`
`1015
`
`U.S. Patent No. 5,263,019, “Method And Apparatus For Estimating
`The Level of Acoustic Feedback Between A Loudspeaker And
`Microphone,” to Peter L. Chu, issued on Nov. 16, 1993 (“Chu”)
`
`Walter Kellermann “Strategies for Combining Acoustic Echo
`Cancellation and Adaptive Beamforming Microphone Arrays”
`(1997) (“Kellermann”)
`
`S.C. Douglas, “A Family of Normallized LMS algorithms,” IEEE
`Signal Processing Letters, pp. 49-51 (1994) (“Douglas”)
`
`R. E. Crochiere et al., “Multirate Digital Signal Processing,”
`Prentice Hall, Englewood Cliffs, N.J. (1983) (“Crochiere”)
`
`P.P. Vaidyanathan, “Multirate Digitals Filters, Filter Banks,
`Polyphase Networks, and Applications A Tutorial,” Proceedings of
`the IEEE, Vol. 78, No. 1, January 1990 (“Vaidyanathan”)
`
`In the Matter of Certain Audio Processing Hardware and Software
`and Products Containing the Same, Inv. No. 337-TA-949, Claim
`Construction Order (U.S.I.T.C. Jan. 27, 2016) (“949 CC Order”)
`
`In the Matter of Certain Audio Processing Hardware and Software
`and Products Containing the Same, Inv. No. 337-TA-949,
`Complainant Andrea Electronics Corp.’s Initial Claim Construction
`Brief (U.S.I.T.C. Oct. 19, 2015) (“Andrea CC Br.”)
`
`In the Matter of Certain Audio Processing Hardware and Software
`and Products Containing the Same, Inv. No. 337-TA-949,
`Claimant Andrea Electronics Corp.’s Reply Claim Construction
`Brief (U.S.I.T.C. Nov. 2, 2015) (“Andrea Reply CC Br.”)
`
`U.S. Copyright Office, “Copyright Basics”
`
`U.S. Copyright Office, Copyright Record for “1997 IEEE
`International Conference On Acoustics, Speech, and Signal
`Processing” (Apr. 21, 1997)
`
`Petitioner Apple Inc.
`Exhibit 1003, p. 5
`
`

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`IPR2017-00628
`
`Declaration of Dr. Bertrand Hochwald
`
`Exhibit # Description
`1016
`B. Widrow, et al., “Adaptive Antenna Systems,” Proceedings of the
`IEEE, Vol. 55, No. 12, pp. 2143-59 (Dec. 1967)
`
`Schobben et al., “Transparent communication,” IEEE Benelux
`Signal Processing Chapter Symposium, pp. 171-74 (1998)
`
`Weiss et al., “On the optimality of subband adaptive filters,”
`Applications of Signal Processing to Audio and Acoustics, 1999
`IEEE Workshop, pp. 59-62 (1999)
`
`bin Abdul Rahman, Abdul Wahab, “Speech Enhancement IN
`Vehicular Environment,” Ph.D. Dissertation, school of Applied
`Science, Nanyang Technological University, Singapore (1997)
`
`1017
`
`1018
`
`1019
`
`
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`In addition to the exhibits above, I also reviewed my prior declarations/testimony
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`from IPR2016-00461, IPR2016-00474, and 337-TA-949.
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`16.
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`I may rely upon these materials and/or additional materials to respond
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`to arguments raised by the Patent Owner. I may also consider additional
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`documents and information in forming any necessary opinions—including
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`documents that may not yet have been provided to me.
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`17. My analysis of the materials produced in this investigation is ongoing,
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`and I will continue to review any new material as it is provided. This report
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`represents only those opinions I have formed to date. I reserve the right to revise,
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`supplement, and/or amend my opinions stated herein based on new information
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`and on my continuing analysis of the materials already provided.
`
`Petitioner Apple Inc.
`Exhibit 1003, p. 6
`
`

`

`IPR2017-00628
`
`Declaration of Dr. Bertrand Hochwald
`
`II. LEGAL STANDARDS FOR PATENTABILITY
`18. Certain basic legal principles have been explained to me by counsel
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`for Apple. Below, I have recorded these legal standards as they were explained to
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`me.
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`19.
`
`I understand that for an invention claimed in a patent to be found
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`patentable, it must be, among other things, new and not obvious from what was
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`known before the invention was made.
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`20.
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`I understand the information that is used to evaluate whether an
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`invention is new and not obvious is generally referred to as “prior art” and can
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`include patents and printed publications. I also understand that a patent will be
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`prior art if it was filed before the earliest effective filing date of the claimed
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`invention, while a printed publication will be prior art if it was publicly available
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`before that date. I understand that in this proceeding, the information that may be
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`evaluated to show unpatentability is limited to patents and printed publications.
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`21.
`
`I understand that in this proceeding Apple has the burden of proving
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`that the challenged claims are unpatentable over the prior art by a preponderance of
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`the evidence. I understand that “a preponderance of the evidence” is evidence
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`sufficient to show that a fact is more likely true than it is not.
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`22.
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`I understand that there are two ways in which prior art may render a
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`patent claim unpatentable. First, the prior art can be shown to “anticipate” the
`
`Petitioner Apple Inc.
`Exhibit 1003, p. 7
`
`

`

`IPR2017-00628
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`Declaration of Dr. Bertrand Hochwald
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`claim. Second, the prior art can be shown to have made the claim “obvious” to a
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`person of ordinary skill in the art.
`
`A. Anticipation
`23.
`I understand that, for a patent claim to be “anticipated” by the prior art,
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`each and every requirement of the claim must be found, expressly or inherently, in
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`a single prior art reference as recited in the claim.
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`24.
`
`I understand that claim limitations that are not expressly described in
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`a prior art reference may still be there if they are “inherent” to the thing or process
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`being described in the prior art.
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`25.
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`I understand that it can be acceptable to consider evidence other than
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`the information in a particular prior art document to determine if a feature is
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`necessarily present in or inherently described by that document.
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`26.
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`I understand that if a reference incorporates other documents by
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`reference, the incorporating reference and the incorporated reference(s) should be
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`treated as a single prior art reference for purposes of analyzing anticipation.
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`27.
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`I understand that to be anticipatory, a reference must not only
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`explicitly or inherently disclose every claimed feature, but those features must also
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`be “arranged as in the claim.” Differences between the prior art reference and a
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`claimed invention, however slight, invoke the question of obviousness, not
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`anticipation.
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`Petitioner Apple Inc.
`Exhibit 1003, p. 8
`
`

`

`IPR2017-00628
`
`Declaration of Dr. Bertrand Hochwald
`
`B. Obviousness
`28.
`I understand that a claimed invention is not patentable if it would have
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`been obvious to a person of ordinary skill in the field of the invention at the time
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`the invention was made. I understand that in determining whether a patent claim is
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`obvious, one must consider the following four factors: (i) the scope and content of
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`the prior art, (ii) the differences between the prior art and the claims at issue, (iii)
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`the knowledge of a person of ordinary skill in the pertinent art; and (iv) objective
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`factors indicating obviousness or non-obviousness, if present (such as commercial
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`success or industry praise).
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`29.
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`I understand the objective factors indicating obviousness or non-
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`obviousness may include: commercial success of products covered by the patent
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`claims; a long-felt need for the invention; failed attempts by others to make the
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`invention; copying of the invention by others in the field; unexpected results
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`achieved by the invention; praise of the invention by those in the field; the taking
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`of licenses under the patent by others; expressions of surprise by experts and those
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`skilled in the art at the making of the invention; and the patentee proceeded
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`contrary to the accepted wisdom of the prior art. I also understand that any of this
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`evidence must be specifically connected to the invention rather than being
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`associated with the prior art or with marketing or other efforts to promote an
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`invention. I am not presently aware of any evidence of “objective factors”
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`Petitioner Apple Inc.
`Exhibit 1003, p. 9
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`

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`IPR2017-00628
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`Declaration of Dr. Bertrand Hochwald
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`suggesting the claimed methods are not obvious, and reserve my right to address
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`any such evidence if it is identified in the future.
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`30.
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`In addition, I understand that the obviousness inquiry should not be
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`done in hindsight, but must be done using the perspective of a person of ordinary
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`skill in the relevant art as of the effective filing date of the patent claim.
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`31.
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`I understand that the Supreme Court has rejected a rigid approach to
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`determining the question of obviousness, such as one that requires a challenger to
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`identify a “teaching, suggestion, or motivation to combine” known elements.
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`Instead, a challenger needs to articulate reasoning for combining known elements.
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`Such reasoning can be based on design considerations, market demands, looking to
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`solutions to related problems in related fields, and on the “ordinary innovation”
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`and creativity that would be applied by a person of ordinary skill in the art.
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`32.
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`I understand that an invention that might be considered an obvious
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`variation or modification of the prior art may be considered non-obvious if one or
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`more prior art references discourages or leads away from the line of inquiry
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`disclosed in the reference(s). A reference does not “teach away” from an invention
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`simply because the reference suggests that another embodiment of the invention is
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`better or preferred. My understanding of the doctrine of teaching away requires a
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`clear indication that the combination should not be attempted (e.g., because it
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`would not work or explicit statements saying the combination should not be made).
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`Petitioner Apple Inc.
`Exhibit 1003, p. 10
`
`

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`IPR2017-00628
`
`Declaration of Dr. Bertrand Hochwald
`
`III. BACKGROUND INFORMATION ABOUT THE ’607 PATENT
`A. Effective Filing Date of the ’607 Patent
`33. The ’607 patent issued from Application No. 09/157,035 filed on
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`September 18, 1998. It does not claim the benefit of priority to any other
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`application. Accordingly, it is my understanding that the effective filing date of
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`the ’607 patent claims is no earlier than September 18, 1998.
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`B.
`34.
`
`The Prosecution History of The ’607 Patent
`
`I understand that all claims of the ’607 patent were allowed with no
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`rejections. I understand that the Examiner stated in his/her reasons for allowance
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`that the prior art of record taken alone and in combination does not disclose the
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`“beam splitter” limitation recited in claim 1 (“a beam splitter for beam-splitting
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`said target signal . . . whereby for each band-limited target signal there is a
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`corresponding band-limited interference signal.”). [’607 patent, 10:17-24].
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`C. Technical Field
`35. The ’607 patent disclosure generally relates to digital signal
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`processing techniques that are used to cancel interference (echoes) present in an
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`audio speech signal. [’607 patent, Abstract].
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`D. Level of Ordinary Skill in the Art
`36.
`I understand that the claims of a patent are to be reviewed from the
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`point of view of a hypothetical person of ordinary skill in the art at the time of the
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`filing of the patent.
`
`Petitioner Apple Inc.
`Exhibit 1003, p. 11
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`

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`IPR2017-00628
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`Declaration of Dr. Bertrand Hochwald
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`37.
`
`I believe a person of ordinary skill in the art in the field of the ’607
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`patent would be a person with a good working knowledge of digital signal
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`processing techniques and their applications. The person would have gained this
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`knowledge through an undergraduate education in electrical engineering or a
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`comparable field, in combination with either a graduate degree (or two years of
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`graduate work) in electrical engineering or a comparable field, or through two
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`years of practical work experience, where such graduate education or work
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`experience focused on or involved the use of digital signal processing techniques.
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`38.
`
`In preparing this declaration, I have considered the issues from the
`
`perspective of a hypothetical person of ordinary skill in the art on or before Sept.
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`18, 1998. I believe the explanations and observations I provide in this declaration
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`are consistent with the beliefs and understandings of such a person of ordinary skill
`
`in the art on or before September 18, 1998.
`
`IV. TECHNICAL BACKGROUND
`A. Echo Cancellation
`39. Echo cancellation techniques for full-duplex communication (i.e.,
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`conference calls) were well developed by 1998. The below figure illustrates the
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`basic steps of standard echo cancellation techniques in 1998 as applied to a
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`speakerphone or teleconference system where the far-end signal is broadcast
`
`Petitioner Apple Inc.
`Exhibit 1003, p. 12
`
`

`

`IPR2017-00628
`
`Declaration of Dr. Bertrand Hochwald
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`throughout the room by a loudspeaker, and a microphone is used to pick up the
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`sound of people talking in the room.
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`40. One fundamental problem with speakerphone systems is that the
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`microphone picks up not only the sounds of people talking, but also the sounds
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`being emitted by the loudspeaker as they reverberate around the room. These
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`sounds of the far-end signal are then returned to the far-end as perceived echoes of
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`his/her own speech.
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`41. The goal of echo cancellation is to remove the echoes before sending
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`the speech signal to the far end. This permits a person at the far end of the
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`teleconference to avoid hearing annoying echoes of his or her own voice.
`
`
`
`Petitioner Apple Inc.
`Exhibit 1003, p. 13
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`

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`IPR2017-00628
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`Declaration of Dr. Bertrand Hochwald
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`42. A similar echo cancellation process is used at the far end so that a
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`person at the near end does not hear annoying echoes of his or her own voice.
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`43. The simplest method of removing the echoes might appear to be to
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`measure them directly, and then subtract them from the near-end signal. This is
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`impractical, however. Because the echoes are an unknown function of the size and
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`acoustical characteristics of the room and are mixed with near-end speech, it is
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`impractical to directly measure only the far-end echoes and then reliably subtract
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`them away. Furthermore, the environment of the room causing the echoes is not
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`fixed and may change as people move around the room.
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`44. However, since the teleconference system knows the signal being
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`emitted by the near-end speaker, this signal acts as a “reference signal” that can be
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`used to estimate the echoes entering the microphone. The echoes are versions of
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`the reference signal that are passed through the loudspeaker and then time-delayed
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`and scaled in amplitude by the room, apparatus, or environment.
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`45.
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`It was also well known in 1998 that most acoustical environments
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`reverberate different tones (frequencies) in different manners. For example, a large
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`conference room may have a perceptible cavernous echo for low frequencies and
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`none at high frequencies. Hence, by splitting a signal into frequency bands, a
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`room’s characteristics could be easily identified and adapted to.
`
`Petitioner Apple Inc.
`Exhibit 1003, p. 14
`
`

`

`IPR2017-00628
`
`Declaration of Dr. Bertrand Hochwald
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`46. Specifically, the far-end signal is split into frequency bands using a
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`DFT (Discrete Fourier Transform) or FFT (Fast Fourier Transform) filter bank
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`(GREEN). The near-end signal (which includes the echoes of the far-end signal) is
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`also split into the same number of frequency bands in the same way (RED).
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`47. The echo in each frequency band is assumed to be a function of the
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`far-end signal (i.e., the echo is assumed to be the far-end signal in each frequency
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`band times a coefficient). The coefficient values are allowed to adapt by applying
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`a cost function that minimizes the energy of the near-end signal energy minus the
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`estimated echo signal energy (i.e., the desired signal). A least mean-square or
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`normalized least mean-square cost function were the most common cost functions
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`used in the 1998 time frame. [’607 patent, 2:14-41]. The least-means square
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`technique for estimating and cancelling an echo was invented in the 1960’s by
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`Bernard Widrow, a Stanford Professor. [B. Widrow, et al., Proc. IEEE, vol. 55, No.
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`12 (Dec. 1967)]. The echo cancellation system then subtracts the estimated echo in
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`each frequency band from the near-end signal in each frequency band. The
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`coefficient adaption and subtraction steps are performed by an “echo canceller”
`
`(BLUE).
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`48. Finally, the echo-free speech signal is reconstructed from the
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`individual frequency bands by applying an inverse Fourier Transform, and this
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`echo-free speech signal is sent to the far end for broadcast.
`
`Petitioner Apple Inc.
`Exhibit 1003, p. 15
`
`

`

`IPR2017-00628
`
`Declaration of Dr. Bertrand Hochwald
`
`B. Discrete Fourier Transform
`49. Like other signals, an audio signal can be converted between the time
`
`and frequency domains using a Fourier transform. The audio signal is divided into
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`short frames, and then a Fast Fourier Transform (FFT) is applied to each frame.
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`The FFT segments the audio signal into its individual frequencies, measures the
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`magnitude of each, and the result is the frequency domain representation. The
`
`function has an inverse, allowing the frequency domain representation to be
`
`converted back into the time domain. [Crochiere, pp. 296-97 (“One of the most
`
`important classes of filter banks is the DFT (discrete Fourier transform) filter bank;
`
`thus a major portion of this chapter is devoted to this topic.”).
`
`C. Microphone Arrays and Beams
`50. A microphone array is a collection of several microphones spread out
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`over a device. Because each microphone is in a different place on the device, any
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`sounds generated in the room will reach each microphone at a different time and
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`amplitude. The time delay is a function of the direction of the source of the sound.
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`For example, the sound from a source that is directly facing the broadside of the
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`array arrives at all microphones at substantially the same time. On the other hand,
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`a source that is at an angle to the broadside creates a sound that reaches the nearest
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`microphone first and furthest last.
`
`Petitioner Apple Inc.
`Exhibit 1003, p. 16
`
`

`

`IPR2017-00628
`
`Declaration of Dr. Bertrand Hochwald
`
`51. By delaying the output of each microphone in a prescribed manner
`
`and summing the delayed outputs, the device can be made highly sensitive to
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`signals arriving from a prescribed particular direction. Thus, the device takes
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`advantage of time delays to amplify sounds coming from one area of the room
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`creating a “beam” from that area of the room.
`
`V. ANALYSIS OF THE ’607 PATENT
`A. Overview of the ’607 Patent
`52. The ’607 patent generally describes techniques for removing echoes
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`from an audio signal. Most of the specification describes echo cancellation
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`technique that use standard digital signal processing steps, such as splitting target
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`and reference signals into frequency bands, estimating an echo using an adaptive
`
`filter and a least mean square cost function, and subtracting the estimated echo
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`from the target signal [’607 patent, 5:36-50, 5:63-6:6, 6:63-7:13, 7:30-36].
`
`53. The echo cancellation process depicted in Figure 1 of the ’607 patent,
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`and corresponding passages of the specification, was a well known and
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`conventional approach to echo cancellation before 1998. As it shows, the system
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`estimates the echo signals picked up by the near-end microphone using the far-end
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`signal before the signal is broadcast from the near-end loudspeaker [’607 patent,
`
`Abstract, 5:63-6:6, 7:30-36]. The far-end signal is split into frequency bands using
`
`a DFT filter bank (GREEN) [Id. at 4:14-16]. The near-end signal captured by the
`
`Petitioner Apple Inc.
`Exhibit 1003, p. 17
`
`

`

`IPR2017-00628
`
`Declaration of Dr. Bertrand Hochwald
`
`near end microphone is also split into the same number of frequency bands in the
`
`same way (RED) [Id. at 5:36-40]. The echo in each frequency band is estimated
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`using an adaptive filter and a normalized least mean square cost function, and the
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`system then subtracts the estimated echo from the near-end signal using an “echo
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`canceller” (BLUE) [Id. at 5:67-6:1, 7:30-39].
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`[’607 patent, Fig. 1 (annotated)].
`
`54. The ’607 patent specification does not clearly state what advance the
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`patent claims over the prior art. The specification suggests that the patent provides
`
`an “efficient echo-canceling system” that “reduce[s] the echo drastically” and that
`
`
`
`Petitioner Apple Inc.
`Exhibit 1003, p. 18
`
`

`

`IPR2017-00628
`
`Declaration of Dr. Bertrand Hochwald
`
`reduces background noise to a minimum [’607 patent, 3:14-20]. However, such
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`systems were already well-known before the ’607 patent was filed.
`
`B.
`The Meaning of Certain Terms Used in the ’607 Patent’s Claims
`55. Some comments on the terms used in the Claims in the ’607 patent are
`
`warranted. I reproduce Claim 1 (emphasis added) here for easy reference.
`
`Claim 1. An interference canceling apparatus for canceling, from a
`target signal generated from a target source, an interference signal
`generated by an interference source, said apparatus comprising:
`a main input for inputting said target signal;
`a reference input for inputting said interference signal;
`a beam splitter for beam-splitting said target signal into a plurality of
`band-limited target signals and beam-splitting said interference
`signal into band-limited interference signals, wherein the amount and
`frequency of bandlimited target signals equal the amount and
`frequency of band-limited interference signals, whereby for each
`band-limited target signal there is a corresponding band-limited
`interference signal;
`an adaptive filter for adaptively filtering, each band-limited interference
`signal from each corresponding band-limited target signal.
`
`
`56. A person of ordinary skill in the art at the time of filing of the ’607
`
`patent would interpret this claim as an apparatus for canceling a source of
`
`interference in an audio signal that uses a “beam-splitter” and an “adaptive filter”.
`
`Petitioner Apple Inc.
`Exhibit 1003, p. 19
`
`

`

`IPR2017-00628
`
`Declaration of Dr. Bertrand Hochwald
`
`The beam-splitter functions to split the “target-signal” into multiple band-limited
`
`signals. An adaptive filter is used for each such band-limited signal.
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`57. Some terms are not defined in this claim, such as “beam-splitter”.
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`The word “beam” suggests an apparatus that will form directional beams. Given
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`this, the association in the claim with multiple band-limited signals is not clear.
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`The Specification also does not make this connection. It instead shows a beam-
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`splitter (block 114 in Fig. 1) being applied to the “far-end signal” (block 128 in Fig.
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`1). Because there is no association of “beams” and the far-end signal, I interpret
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`the “beam-splitter” to be an apparatus that sim