UNITED STATES PATENT AND TRADEMARK OFFICE
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`
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`
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`Paper No. 1
`
`BEFORE THE PATENT TRIAL AND APPEAL BOARD
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`
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`
`
`
`
`APPLE INC.,
`Petitioner,
`
`v.
`
`ANDREA ELECTRONICS CORP.,
`Patent Owner
`
`Patent No. 6,049,607
`Issued: April 11, 2000
`Filed: September 18, 1998
`Inventor: Joseph Marash and Baruch Berdugo
`Title: INTERFERENCE CANCELING METHOD AND APPARATUS
`____________________
`Inter Partes Review No. IPR2017-00628
`
`
`
`
`
`
`
`Petition for Inter Partes Review of
`U.S. Patent No. 6,049,607
`
`________________________
`
`
`
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`

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`Petition in IPR2017-00628
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`U.S. Patent No. 6,049,607
`
`TABLE OF CONTENTS
`
`Introduction .................................................................................................... 1
`I.
`II. Regulatory Information ................................................................................ 4
`A. Certification that Petitioner May Contest the ’607 Patent
`(§ 42.104(a)) ........................................................................................... 4
`B.
`Identification of Claims Being Challenged (§ 42.104(b)) .................. 5
`C. Fee for Inter Partes Review (§ 42.15(a)) ............................................. 5
`III. The ’607 Patent and Challenged Claims ..................................................... 5
`A. Overview of the ’607 Patent ................................................................. 5
`B. Effective Filing Date of the ’607 Patent .............................................. 9
`C. Person of Ordinary Skill in the Art .................................................... 9
`D. Prosecution History .............................................................................. 9
`IV. Construction of Terms Used in the Claims ............................................... 10
`A.
`“target signal” ..................................................................................... 11
`B.
`“interference signal” ........................................................................... 12
`C.
`“beam splitter”/“beam splitting” (Claims 1 and 25) ....................... 16
`D.
`25) ......................................................................................................... 18
`E. Observation on Dependent Claims 2-12 and 26-37 ......................... 20
`V. Analysis of the Patentability of the ’607 Patent ........................................ 23
`A. Overview of U.S. Patent No. 5,263,019 (“Chu”) (Ex. 1005) ............ 23
`B. Claims 1 and 25 Are Anticipated by Chu ......................................... 26
`1.
`Claims 1 and 25 Are Anticipated by Chu .................................. 26
`
`“main input”/“reference input” (Claim 1) and “inputting” (Claim
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`Petition in IPR2017-00628
`
`U.S. Patent No. 6,049,607
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`a)
`b)
`c)
`d)
`
`“An interference canceling [apparatus / method] for
`canceling, from a target signal generated from a target
`source, an interference signal generated by an
`
`interference source” ....................................................... 26
`“[a main input for] inputting said target signal” .......... 27
`signal” ............................................................................ 28
`
`“[a reference input for] inputting said interference
`
`“[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 band-limited target signals equal the amount and
`frequency of band-limited interference signals, whereby
`for each band-limited target signal there is a
`
`“[an adaptive filter for] adaptively filtering, each band-
`limited interference signal from each corresponding
`
`corresponding band-limited interference signal” .......... 29
`e)
`band-limited target signal.” ........................................... 30
`C. Claims 1 and 25 Would Have Been Obvious Based on Chu in View
`of Kellermann ...................................................................................... 31
`1. Kellermann Suggests Combining Acoustic Echo Cancellation
`(Ex. 1007) ................................................................................... 32
`2. A Person of Ordinary Skill Would Have Considered Chu with
`Kellermann ................................................................................. 35
`3.
`Use of Beam Selectors in Microphone Arrays ........................... 38
`VI. NO SECONDARY INDICIA OF NON-OBVIOUSNESS ....................... 39
`VII. CONCLUSION ............................................................................................ 40
`
`and Adaptive Beamforming Microphone Arrays (“Kellermann”)
`
`Chu in View of Kellermann Would Have Rendered Obvious
`
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`Petition in IPR2017-00628
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`U.S. Patent No. 6,049,607
`
`Exhibit List
`
`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
`
`1003
`
`1004
`
`1005
`
`1006
`
`1007
`
`1008
`
`1009
`
`1010
`
`1011
`
`1012
`
`Prosecution History of U.S. Patent Application No. 09/157,035
`which issued as U.S. Patent No. 6,049,607
`
`Declaration of Bertrand Hochwald
`
`[RESERVED]
`
`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”)
`
`Andrea Electronics Corporation v. Apple Inc., Case No. 2:16-cv-
`05220-JMA-SIL, Affidavit of Service and Complaint for Patent
`Infringement (E.D.N.Y.)
`
`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 re Certain Audio Processing Hardware and Software and
`Products Containing Same, Inv. No. 337-TA-949, Claim
`Construction Order (U.S.I.T.C. Jan. 27, 2016) (“949 CC Order”)
`
`In re Certain Audio Processing Hardware and Software and
`Products Containing Same, Inv. No. 337-TA-949, Complainant
`
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`Petition in IPR2017-00628
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`U.S. Patent No. 6,049,607
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`Exhibit # Description
`Andrea Electronics Corp.’s Initial Claim Construction Brief
`(U.S.I.T.C. Oct. 19, 2015) (“Andrea CC Br.”)
`
`1013
`
`1014
`
`1015
`
`1016
`
`1017
`
`1018
`
`1019
`
`1020
`
`
`
`
`
`In re 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)”
`
`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)
`
`In the Matter of Certain Audio Processing Hardware, Software,
`and Products Containing The Same, Inv. No. 337-TA-1026,
`Verified Complaint Against Apple Inc. and Samsung Inc. Under
`Section 337 of the Tariff Act of 1930, as Amended (U.S.I.T.C.
`Sept. 19, 2016
`
`
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`Petition in IPR2017-00628
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`U.S. Patent No. 6,049,607
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`I.
`
`Petitioner’s Mandatory Notices
`A. Real Party in Interest (§42.8(b)(1))
`The real party in interest of this petition pursuant to § 42.8(b)(1) is Apple
`
`Inc. (“Apple”) located at One Infinite Loop, Cupertino, CA 95014.
`
`B. Other Proceedings (§42.8(b)(2))
`1.
`Patents and Applications
`U.S. Patent No. 6,049,607 (“’607 patent”) is not related to any other issued
`
`patents or pending applications.
`
`Related Litigation
`
`2.
`Andrea Electronics Corporation (“Andrea”), the owner of the ’607 patent,
`
`has asserted it in the following distriction court actions, all in the Eastern District
`
`of New York:
`
`• Andrea v. Apple Inc., Action No. 2-16-cv-05220;
`
`• Andrea v. Samsung Elec. Co., Action No. 2-16-cv-05217;
`
`• Andrea v. Hewlett-Packard Co., Action No. 2-15-cv-00208;
`
`• Andrea v. Dell Inc., Action No. 2-15-00209;
`
`• Andrea v. Acer Inc., Action No. 2-15-cv-00210;
`
`• Andrea v. Toshiba Corp., Action No. 2-15-cv-00211;
`
`• Andrea v. Lenovo Holding Co., Inc., Action No. 2-15-cv-00212;
`
`• Andrea v. ASUSTeK Computer Inc., Action No. 2-15-cv-00214; and
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`U.S. Patent No. 6,049,607
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`• Andrea v. Realtek Semiconductor Corp., Action No. 2-15-cv-00215.
`
`The ’607 patent has been asserted against Petitioner Apple Inc. in the
`
`following administrative proceeding before the ITC:
`
`• 337-TA-1026 (Apple Inc. and Samsung Inc., respondents) (pending).
`
`The ’607 patent has been asserted against other entities in the following
`
`administrative proceedings before the ITC:
`
`• 337-TA-949 (Waves Audio; ASUS Computer Int’l Inc.; Acer Am. Corp.;
`
`Acer Inc.; Dell Inc.; Hewlett-Packard Co.; Lenovo (United States) Inc.;
`
`Lenovo Group Ltd.; Lenovo Holding Co., Inc.; Realtek Semiconductor
`
`Corp.; Toshiba Am. Info. Sys., Inc.; Toshiba Am., Inc.; and Toshiba
`
`Corp., respondents) (terminated); and
`
`• 337-TA-3053 (ASUS Computer Int’l Inc.; ASUSTeK Computer Inc.;
`
`Acer Am. Corp.; Acer Inc.; Dell Inc.; Hewlett-Packard Co.; Lenovo
`
`(United States) Inc.; Lenovo Group Ltd.; Lenovo Holding Co., Inc.;
`
`Realtek Semiconductor Corp.; Toshiba Am. Info. Sys., Inc.; Toshiba
`
`Am., Inc.; and Toshiba Corp., respondents) (terminated).
`
`Patent Office Proceedings
`
`3.
`The ’607 patent was subject to the following proceedings before the Office:
`
`• Realtek Semiconductor Corp. v. Andrea Elecs. Corp., IPR2015-
`
`01393;
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`U.S. Patent No. 6,049,607
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`• Waves Audio, Ltd. v. Andrea Elecs. Corp., IPR2016-00461; and
`
`• Waves Audio, Ltd. v. Andrea Elecs. Corp., IPR2016-00474.
`
`All three proceedings were terminated prior to institution.
`
`C. Lead and Back-up Lead Counsel (§42.8(b)(3))
`Lead Counsel is: Jeffrey P. Kushan (Reg. No. 43,401), jkushan@sidley.com,
`
`(202) 736-8914. Back-Up Lead Counsel are: Steven S. Baik (Reg. No. 42,281),
`
`sbaik@sidley.com, (650) 565-7016; and Thomas A. Broughan III (Reg. No.
`
`66,001), tbroughan@sidley.com, (202) 736-8314.
`
`Service Information (§42.8(b)(4))
`
`D.
`Service on Petitioner may be made by e-mail (iprnotices@sidley.com), mail
`
`or hand delivery to: Sidley Austin LLP, 1501 K Street, N.W., Washington, D.C.
`
`20005. The fax number for lead and backup lead counsel is (202) 736-8711.
`
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`Petition in IPR2017-00628
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`U.S. Patent No. 6,049,607
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`I.
`
`Introduction
`
`The ’607 patent concerns techniques for cancelling echoes in two-way
`
`teleconferencing systems. In such systems, a person at one end of a teleconference
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`(the “near end”) uses a device to communicate with a person at the other (“far
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`end”) of the teleconference. Each device includes a microphone, which captures
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`sounds generated in its local environment, as well as a loudspeaker, which
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`broadcasts sounds captured at the far end of the teleconference. Sounds captured
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`at each end will include the voice of the person speaking in that location, as well as
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`other sounds in that environment, such as sounds broadcast by the loudspeaker of
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`the device at that end of the teleconference.
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`Sounds from one end of a teleconference (e.g., the “near end”) are
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`transmitted to the other end (e.g., the “far end”) as a signal, which is then broadcast
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`over the loudspeaker of the device at the other end. Because that signal contains
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`all of the sounds captured from the environment of the near end, when it is
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`broadcast at the far end, the far-end person will hear not only the desired sound –
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`the speech from the near-end speaker – but also a disturbing echo of his or her own
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`voice that was created when it was broadcast over the near-end loudspeaker and
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`picked up by the near-end microphone. Without an echo cancellation mechanism
`
`in each device to remove the unwanted echo or interference from the signal, a
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`person at the far end thus will hear an echo of his or her voice.
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`U.S. Patent No. 6,049,607
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`The goal of echo cancellation techniques is to remove the echo in the signal
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`going from the near-end device to the far-end device in the teleconference. Many
`
`such techniques to address this problem were known prior to September 1998,
`
`including those that use the “adaptive filtering” technique used in the ’607 patent.
`
`Ex. 1001, 2:14-23 (describing an “echo-cancelling system” that uses an “adaptive
`
`filter” published in 1967), 2:35-41. That technique involves mathematically
`
`removing the portion of the signal representing the echo, leaving a signal
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`containing only near-end speech. Indeed, the ’607 patent portrays the invention as
`
`being an improvement of these older echo cancellation techniques.
`
`One of the supposedly inventive features of the ’607 patent involves how
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`echo cancellation is applied to signals. In it, the signal picked up by the near-end
`
`microphone and the signal sent from the far-end are each split into a common set
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`of frequency bands using a splitter. Ex. 1001, 5:36-40, 5:63-67, Fig. 1. Each of
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`the bands of the far-end signal is used to estimate the echo that will be present in
`
`the corresponding band of the signal from the near-end microphone, and then the
`
`estimated echo is subtracted from each band of the microphone to remove the
`
`echo. Id., 4:4-6, 7:30-36.
`
`That approach of splitting the signals into segments and applying echo
`
`cancellation to each segment individually, however, was known well before the
`
`’607 patent. For example, U.S. Patent No. 5, 263, 019 (“Chu”) (Ex. 1005), filed in
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`U.S. Patent No. 6,049,607
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`1992, describes “[a]n improved echo cancelling device for reducing the effects of
`
`acoustic feedback between a loudspeaker and a microphone in a communication
`
`system.” Ex. 1005, Abstract. In fact, the approach taken in Chu is
`
`indistinguishable from the scheme that is depicted in the ’607 patent – it splits the
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`“target” signal (the signal from the near end microphone) and a signal from the far-
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`end device into a common set of frequency bands, and then passes each to an
`
`adaptive filter bank that filters the latter from the former for corresponding
`
`segments of each signal. Ex. 1005, 5:8-16, 7:64-8:4, Figs. 1, 3.
`
`There are extensive similarities in the methods used in Chu and the ’607
`
`patent to carry out this echo cancellation technique. For example, both Chu and
`
`the ’607 patent split the signals using the single sideband filter bank technique
`
`taught in R. E. Crochiere et al., “Multirate Digital Signal Processing,” Prentice
`
`Hall, Englewood Cliffs, N.J. (1983) (“Crochiere”) (Ex. 1009). Compare Ex. 1005,
`
`7:26-31 (“Bandpass filters . . . are implemented in a Weaver single sideband
`
`modulator structure as proposed in [Crochiere]”) with Ex. 1001, 6:65-7:5 (“[I]t is
`
`preferred that the generalized DFT filter bank using single side band modulation be
`
`employed as described . . . in [Crochiere]”). Chu and the ’607 patent also use the
`
`same adaptive filter technique. Compare Ex. 1005, 8:4-8 (“[A]daptive filter 50
`
`includes a least-means-square (‘LMS’) filter”) with Ex. 1001, 6:1-4 (“Normalized
`
`LMS filters are preferred”), 7:37-38 (“filter 506 is adjusted by the NLMS
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`U.S. Patent No. 6,049,607
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`(Normalized Least Mean Square) processor”), 8:10-13 (adjusting “LMS
`
`coefficients”).
`
`The methods and apparatus defined by independent claims 1 and 25 of the
`
`’607 patent, thus, are either indistinguishable from the scheme taught by Chu, or
`
`represent nothing more than an obvious variation of that scheme when Chu is
`
`considered with one or more well known echo cancellation techniques known in
`
`the prior art to a skilled person in September 1998. Because each of the contested
`
`claims is unpatentable, the Board should institute trial and cancel the contested
`
`claims.
`
`II. Regulatory Information
`A. Certification that Petitioner May Contest the ’607 Patent
`(§ 42.104(a))
`
`Petitioner certifies that the ’607 (Ex. 1001) is available for inter partes
`
`review. Petitioner also certifies it is not barred or estopped from requesting inter
`
`partes review of the claims of the ’607 patent. Neither Petitioner, nor any party in
`
`privity with Petitioner, has filed a civil action challenging the validity of any claim
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`of the ’607 patent. The ’607 patent has not been the subject of a prior inter partes
`
`review by Petitioner or a privy of Petitioner.
`
`Petitioner also certifies this petition for inter partes review is timely filed as
`
`this petition was filed less than one year after November 1, 2016, the date
`
`Petitioner was first served with a complaint alleging infringement of a claim of the
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`Petition in IPR2017-00628
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`U.S. Patent No. 6,049,607
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`’607 patent. See 35 U.S.C. § 315(b); Ex. 1006. Petitioner was served with an ITC
`
`complaint no earlier than September 19, 2016, but administrative complaints do
`
`not start the one year period of § 315(b). LG Elecs., Inc. v. Straight Path IP Grp.,
`
`Inc., IPR2015-00196, Paper 20 at 7-9 (May 15, 2015); Ex. 1020.
`
`Identification of Claims Being Challenged (§ 42.104(b))
`
`B.
`This petition addresses independent claims 1 and 25 of the ’607 patent,
`
`which are unpatentable for the following reasons:
`
`Claims 1 and 25 are anticipated under 35 U.S.C. § 102 by
`(i)
`U.S. Patent No. 5,263,019 (“Chu”) (Ex. 1005); and
`
`(ii) Claims 1 and 25 would have been obvious under 35 U.S.C.
`§ 103 based on based on Chu in view of W. Kellermann, “Strategies
`for Combining Acoustic Echo Cancellation and Adaptive
`Beamforming Microphone Arrays,” Int’l Conf. on Acoustics, Speech
`& Signal Proc., 219-22 (1997) (“Kellermann”) (Ex. 1007).
`
`Fee for Inter Partes Review (§ 42.15(a))
`
`C.
`The Director is authorized to charge the fee specified by 37 CFR § 42.15(a)
`
`to Deposit Account No. 50-1597.
`
`III. The ’607 Patent and Challenged Claims
`A. Overview of the ’607 Patent
`The ’607 patent is generally directed to techniques for cancelling or reducing
`
`interference (i.e., echo) in two way communication systems. Ex. 1001, Abstract.
`
`Like other known echo cancellation techniques, the scheme in the ’607 patent
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`Petition in IPR2017-00628
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`U.S. Patent No. 6,049,607
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`removes unwanted interference sound from an audio signal (the “target” signal) by
`
`subtracting an estimate of the interference signal from the target signal. Id. This is
`
`done by separating the target signal and a reference signal (e.g., a signal from the
`
`far end) into respective frequency-limited bands (id., 5:36-40, 5:63-67), using a set
`
`of filters to form an estimate of the interference, and then subtracting out the
`
`estimated interference from the target signal on a sub-band by sub-band basis, (id.,
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`7:30-36).
`
`Figure 1 of the ’607 patent depicts an echo cancellation scheme
`
`corresponding to this description (annotated version shown below). In it, a
`
`microphone array 102 is shown as inputting a near-end audio signal (gold
`
`highlighting), while a wire or other connection is shown as inputting a far-end
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`signal (purple). Figure 1 also shows two components for splitting the near-end
`
`signal and the far-end signal, identified as “split 114” (red) and “split 128” (green),
`
`respectively. The specification indicates splitting operations are performed using a
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`Discrete Fourier Transform (“DFT”) filter bank using single side band modulation.
`
`Ex. 1001, Fig. 1, 6:64-7:5.
`
`Figure 1 also shows that each band-limited signal from the near-end and
`
`each band-limited signal from the far end signal is processed by a corresponding
`
`one band echo canceller (element 1160-15 (blue) in Fig. 1). Ex. 1001, 5:36-40.
`
`Each echo canceller performs adaptive filtering of the band-limited far-end signal
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`U.S. Patent No. 6,049,607
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`based upon a “Normalized Least Means Square” (NLMS) algorithm, and subtracts
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`out the estimated echoes from each band-limited near-end signal. See Ex. 1001,
`
`Figs. 1, 5. The resultant band-limited signals are then recombined into an output
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`digital signal by a recombiner (element 118 in Fig. 1 (orange)), which employs an
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`Inverse Fast Fourier Transform (“IFFT”) “which is symmetrical, i.e., opposite, to
`
`the band splitting technique described above.” See Ex. 1001, Fig. 1 (annotated
`
`below), 9:1-3.
`
`
`
`The ’607 patent acknowledges that the various techniques used in its scheme
`
`were well known in the prior art.
`
`First, it acknowledges that the well-known NLMS technique, which involves
`
`measuring the sound environment at the near end, and then subtracting an
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`Petition in IPR2017-00628
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`U.S. Patent No. 6,049,607
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`adaptively filtered version of the far-end signal based upon an NLMS estimate of
`
`the transfer function of the loudspeaker in the near-end sound environment. Ex.
`
`1001, 7:30-44; id., 2:34-41 (citing S.C. Douglas, “A Family of Normalized LMS
`
`algorithms,” IEEE Signal Processing Letters, pp. 49-51 (1994) (“Douglas”)) (Ex.
`
`1008)).
`
`Next, it acknowledges that techniques to provide more precise adaptive
`
`filtering to address sudden changes in the interference signal or changes in the
`
`near-end room, either of which may cause the filter coefficients to diverge or be
`
`very slow to adapt, were known. Ex. 1001, 2:41-61.
`
`The ’607 patent also admits that problems caused by changes in which a
`
`person in the room is speaking can lead to echoes until the beam steering system
`
`catches up with the change in speakers, had been solved by techniques such as the
`
`use of multiple microphones and improved beam steering to determine the best
`
`microphone(s) to use. Id., 2:62-3:13.
`
`Finally, the ’607 patent cites references that describe the filter bank
`
`technique it uses to split and recombine signals. See Ex. 1001, 6:64-7:5
`
`(referencing R. E. Crochiere et al., “Multirate Digital Signal Processing,” Prentice
`
`Hall, Englewood Cliffs, N.J. (1983) (“Crochiere”) (Ex. 1009) and P.P.
`
`Vaidyanathan, “Multirate Digitals Filters, Filter Banks, Polyphase Networks, and
`
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`Petition in IPR2017-00628
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`U.S. Patent No. 6,049,607
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`Applications A Tutorial,” Proceedings of the IEEE, Vol. 78, No. 1, January 1990
`
`(“Vaidyanathan”) (Ex. 1010)).
`
`Effective Filing Date of the ’607 Patent
`
`B.
`The ’607 patent does not claim benefit or priority to any earlier filed
`
`application. The effective filing date of the claims is thus September 18, 1998.
`
`Person of Ordinary Skill in the Art
`
`C.
`The ’607 patent relates to the field of echo cancellation and reduction in
`
`using adaptive filters and other digital signal processing techniques. Consequently,
`
`a person of ordinary skill for the ’607 patent in September of 1998 would have
`
`been a person with a good working knowledge of digital signal processing
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`techniques and their applications. The person would have gained this knowledge
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`through an undergraduate education in electrical engineering or a comparable field,
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`in combination with either a graduate degree (or two years of graduate work) in
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`electrical engineering or a comparable field, or through two years of practical work
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`experience, where such graduate education or work experience focused on or
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`involved the use of digital signal processing techniques. Ex. 1003 ¶ 37.
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`Prosecution History
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`D.
`The ’607 patent issued from U.S. Patent Application No. 09/157,035, filed
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`on September 18, 1998. Ex. 1001. In the notice of allowance, the Examiner stated
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`that the prior art of record did not disclose the “beam splitter” limitation recited in
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`claim 1 (i.e., “a beam splitter for beam-splitting said target signal . . . whereby for
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`each band-limited target signal there is a corresponding band-limited interference
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`signal.”). Ex. 1002, 58. The ’607 patent issued on April 11, 2000. Ex. 1001.
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`IV. Construction of Terms Used in the Claims
`In this proceeding, claims must be given their broadest reasonable
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`construction in light of the specification. 37 CFR § 42.100(b); Cuozzo Speed
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`Techs., LLC v. Lee, 136 S. Ct. 2131 (2016). If Patent Owner contends any claim
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`terms should be read as having a special meaning, those contentions should be
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`disregarded unless Patent Owner also amends the claims compliant with 35 U.S.C.
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`§ 112 to make them expressly correspond to those contentions. See 77 Fed. Reg.
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`48764 at II.B.6 (Aug. 14, 2012); cf. In re Youman, 679 F.3d 1335, 1343 (Fed. Cir.
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`2012).
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`This petition challenges independent claims 1 and 25. The language of
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`claim 1 parallels that in claim 25, and reads:
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`An interference canceling apparatus for canceling, from a target
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`signal generated from a target source, an interference signal generated
`by an interference source, said apparatus comprising:
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`a main input for inputting said target signal;
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`a reference input for inputting said interference signal;
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`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 band-limited target signals equal the amount
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`and frequency of band-limited interference signals, whereby for
`each band-limited target signal there is a corresponding band-
`limited interference signal;
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`an adaptive filter for adaptively filtering, each band-limited
`interference signal from each corresponding band-limited target
`signal.
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`The terms for which constructions are proposed in this petition are: (i) target
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`signal; (ii) interference signal; (iii) main input; (iv) reference input; (v) beam
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`splitter; and (vi) adaptive filter. Terms other than these have their ordinary
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`meaning, and do not require a special construction.
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`A.
`“target signal”
`The broadest reasonable interpretation of “target signal” is “a signal
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`containing signals from a target source and an interference source.”
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`In claims 1 and 25, the term “target signal” refers to the signal input by the
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`main input, and which is processed to remove an interference signal created by an
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`interference source using an adaptive filter. Once processed in this manner, the
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`target signal contains speech but not the interference signal.
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`Aside from the abstract and summary of invention, the ’607 specification
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`does not use the term “target signal.” Instead, the ’607 specification describes a
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`“beam signal” as the signal containing interference. See, e.g., Ex. 1001, 5:32-40,
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`5:67-6:1, 7:30-36 (explaining beam signal contains speech and interference (“echo
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`elements”) and is processed to remove the interference); id., 8:4-5 (“It is preferred
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`that the adaptation process will occur when relevant echo signals are present in the
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`beam signal.”). The term target signal, as used in the ’607 patent, encompasses the
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`beam signal.
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`Under its broadest reasonable interpretation, therefore, the target signal
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`encompasses signals that contain both target source and interference signals.
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`B.
`“interference signal”
`The broadest reasonable interpretation of the term “interference signal” as
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`used in claims 1 and 25 is “a signal from the far end, or a signal representing the
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`echo generated by the broadcast of the far end signal.” This construction is
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`consistent with how the term is used in claims 1 and 25, with what is depicted in
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`the specification, and with Patent Owner’s representations in litigation regarding
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`the meaning of this term.
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`Claims 1 and 25 refer to two signals, a target signal and an interference
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`signal. Ex. 1001, 10:11-16. The first, the “target signal” is input to a “main
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`input.”
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`The second signal, the “interference signal,” is input to a “reference input”
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`in the apparatus. The “interference signal” then is split “into band-limited
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`interference signals” that are adaptively filtered from corresponding segments of
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`the band-split target signal. Id., 10:17-27.
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`The term “interference signal” as used in claims 1 and 25 creates ambiguity
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`when that term is read in light of the ’607 specification, which uses the term
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`“reference signal” (or “far end signal”) to describe the signal that is input via a
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`reference channel, split into band-limited segments which are adaptively filtered to
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`estimate echoes, and then subtracted out from the band-limited target signals.1 Id.,
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`5:63-64 (“[T]he far end signal (referred to as the reference channel)”), 6:17-18
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`(“[T]he signal present at the reference channel (far end)”), 7:59-61 (“When a fast
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`attack in the reference signal appears, such as when an abrupt sound . . . is
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`generated at the far end”), 8:1-4. The specification states that the far-end signal is
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`split and provided to the adaptive filters to “obtain the estimated echo elements
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`present in the beam signal [i.e., target signal] [and] [t]he estimated interference
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`signal is subtracted . . . from the beam signal to obtain an echo free signal.” Id.,
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`7:33-36 (emphases added). Thus, the specification provides that the far end signal
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`is used to generate an estimate of the interference signal in the target signal (i.e.,
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`the echo in the target signal).
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`The ’607 specification does not use the term “interference signal” to refer to
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`the far end signal. Instead, the specification uses the term “interference signal” to
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`
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`1 Petitioners reserve the right to challenge these claims under 35 U.S.C. § 112 in
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`litigation, where a different claim construction standard is applied.
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`refer to a portion of the target signal – the portion that represents the echo. The
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`specification states that the interference signal is removed from the target signal by
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`subtracting the estimated interference. For example, in describing the adaptive
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`filtering process shown in Figure 5, the ’607 patent explains:
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`FIG. 5 illustrates the adaptive filter 500 (FIG. 1, 1161-n) of the
`present invention. The reference channel that contains the far end
`signal is stored in a tap delay line 502 and multiplied via a multiplier
`504 by a filter 506 to obtain the estimated echo elements present in
`the beam signal [“target signal”]. The estimated interference signal
`is then subtracted via subtractor 508 from the beam signal to obtain an
`echo free signal.
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`Ex. 1001, 7:30-36 (emphases and annotation added).
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`The description in the specification also corresponds to the scheme depicted
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`in Figure 1 of the ’607 patent, in which a “far end signal” is shown being input to a
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`separate input than the main input (“microphone array 102”) that captures the
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`“beam” or “target” signal. Figure 1 also shows this far end signal being split
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`independently (i.e., by element 128) from the splitting of the target signal (i.e., by
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`element 114), and being used in the adaptive filtering step performed by elements
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`1161 to 116n to remove the interference signal from each corresponding sub-band
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`of the “target” or “beam” signal.
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`In view of these observations, the broadest reasonable interpretation of the
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`phrase “interference signal” used in the body of claims 1 and 25 must include what
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`the specification describes as the “far end signal” (also referred to as the “reference
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`signal”). That is because the far end signal is the only signal described in the ’607
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`patent disclosure being subjected to the operations specified in the