UNITED STATES PATENT AND TRADEMARK OFFICE
`_______________
`
`BEFORE THE PATENT TRIAL AND APPEAL BOARD
`
`_______________
`
`REALTEK SEMICONDUCTOR CORPORATION
`Petitioner
`
`v.
`
`ANDREA ELECTRONICS CORPORATION
`Patent Owner
`_______________
`
`Case: IPR2015-01393
`
`Patent 6,049,607
`
`
`
`PETITION FOR INTER PARTES REVIEW
`OF U.S. PATENT NO. 6,049,607
`
`
`
`

`
`PETITION FOR INTER PARTES REVIEW OF U.S. PATENT NO. 6,049,607
`
`
`TABLE OF CONTENTS
`
`Page
`
`
`
`I.
`
`MANDATORY NOTICES ........................................................................... 1
`
`II.
`
`PAYMENT OF FEES ................................................................................... 3
`
`III.
`
`STANDING .................................................................................................. 3
`
`IV. REQUEST TO HOLD CLAIMS 1-12 AND 25-37 OF THE ’607 PATENT
`UNPATENTABLE ....................................................................................... 4
`
`A.
`
`The Alleged Invention Of The ’607 Patent ........................................ 4
`
`B.
`
`Summary Of The Prosecution History Of The ’607 Patent ................ 5
`
`V.
`
`CLAIM CONSTRUCTION .......................................................................... 6
`
`A.
`
`Standards For Claim Construction ..................................................... 6
`
`1.
`
`Broadest Reasonable Construction ............................................6
`
`A.
`
`“interference signal” (claims 1-2 and 25-26)...................................... 7
`
`VI. PRIOR ART TO THE ’607 PATENT FORMING THE BASIS FOR
`THIS PETITION .......................................................................................... 9
`
`A.
`
`Prior Art Documents .......................................................................... 9
`
`B.
`
`Summary of Unpatentability Arguments.......................................... 10
`
`VII. GROUNDS FOR UNPATENTABILITY OF EACH CLAIM .................... 13
`
`A. Ground 1: Claims 1-4 And 25-28 Are Unpatentable Under
`35 U.S.C. § 103 As Being Obvious Over Chu ................................. 13
`
`B.
`
`C.
`
`Ground 2: Claims 5, 6, 12, 29, 30, 36 And 37 Are Unpatentable
`Under 35 U.S.C. § 103 As Being Obvious Over Chu In View
`Of Wu .............................................................................................. 23
`
`Ground 3: Claims 7 And 31 Are Unpatentable Under 35 U.S.C.
`§ 103 As Being Obvious Over Chu In View Of Crochiere ............... 36
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`PETITION FOR INTER PARTES REVIEW OF U.S. PATENT NO. 6,049,607
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`D. Ground 4: Claims 8, 10, 32, And 34 Are Unpatentable Under 35
`U.S.C. § 103 As Being Obvious Over Chu In View
`Of Kellermann ................................................................................. 38
`
`E.
`
`F.
`
`Ground 5: Claims 9 And 33 Are Unpatentable Under 35 U.S.C.
`§ 103 As Being Obvious Over Chu And Kellermann In
`Further View Of Koizumi ................................................................ 42
`
`Ground 6: Claims 11 and 35 Are Unpatentable Under 35 U.S.C.
`§ 103 As Being Obvious Over Chu And Kellermann In
` Further View Of Kuo ...................................................................... 45
`
`G. Ground 7: Claims 1-4, 8, 10, 25-28, 32, And 34 Are
`Unpatentable Under 35 U.S.C. § 103 As Being Obvious Over
`Kellerman In View Of Chu .............................................................. 48
`
`H. Ground 8: Claims 5, 6, 12, 29, 30, 36 and 37 Are Unpatentable
`Under 35 U.S.C. § 103 As Being Obvious Over Kellerman
`And Chu In Further View Of Wu .................................................... 57
`
`I.
`
`J.
`
`Ground 9: Claims 7 and 31 Are Unpatentable Under 35 U.S.C.
`§ 103 As Being Obvious Over Kellermann And Chu In Further
`View Of Crochiere .......................................................................... 57
`
`Ground 10: Claims 9 and 33 Are Unpatentable Under 35 U.S.C.
`§ 103 As Being Obvious Over Kellermann And Chu In Further
`View Of Koizumi ............................................................................ 58
`
`K. Ground 11: Claims 11 And 35 Are Unpatentable Under 35 U.S.C.
`§ 103 As Being Obvious Over Kellermann And Chu In Further
`View Of Kuo ................................................................................... 59
`
`VIII. CONCLUSION .......................................................................................... 60
`
`
`
`
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`PETITION FOR INTER PARTES REVIEW OF U.S. PATENT NO. 6,049,607
`
`
`PETITIONER’S EXHIBIT LIST
`
`Description
`
`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”)
`
`Andrea Electronics Corp. v. Acer Inc. and Acer America, Civil Action
`No. 2:14-cv-04488, Plaintiff’s First Amended Complaint, Dkt. No. 28
`(E.D.N.Y. Nov. 10, 2014)
`
`Andrea Electronics Corp. v. Acer Inc. and Acer America, Civil Action
`No. 2:14-cv-04488, Defendants’ Answers and Defenses, Dkt. No. 32
`(E.D.N.Y. Nov. 24, 2014)
`
`Andrea Electronics Corp. v. Lenovo Holding Co. and Lenovo (U.S.)
`Inc., Civil Action No. 2:14-cv-04489, Plaintiff’s First Amended
`Complaint, Dkt. No. 35 (E.D.N.Y. Nov. 10, 2014)
`
`Andrea Electronics Corp. v. Lenovo Holding Co. and Lenovo (U.S.)
`Inc., Civil Action No. 2:14-cv-04489, Defendants’ Answer and
`Counterclaims, Dkt. No. 39 (E.D.N.Y. Nov. 24, 2014)
`
`Andrea Electronics Corp. v. Lenovo Holding Co. and Lenovo (U.S.)
`Inc., Civil Action No. 2:14-cv-04489, Plaintiff’s Answer to
`Defendants Lenovo Holding Company Inc., and Lenovo (United
`States) Inc.’s Counterclaims, Dkt. No. 45 (E.D.N.Y. Dec. 15, 2014)
`
`Andrea Electronics Corp. v. Toshiba Corp., Civil Action No. 2:14-cv-
`04492, Plaintiff’s First Amended Complaint, Dkt. No. 34 (E.D.N.Y.
`Nov. 10, 2014)
`
`Andrea Electronics Corp. v. Toshiba Corp., Civil Action No. 2:14-cv-
`04492, Toshiba Corp.’s Answer and Affirmative Defenses, Dkt. No.
`38 (E.D.N.Y. Nov. 24, 2014)
`
`Andrea Electronics Corp. v. Toshiba Corp., Civil Action No. 2:14-cv-
`04492, Toshiba America Info. Sys., Inc.’s Answer and Affirmative
`Defenses, Dkt. No. 39 (E.D.N.Y. Nov. 24, 2014)
`
`Exhibit #
`
`1001
`
`1002
`
`1003
`
`1004
`
`1005
`
`1006
`
`1007
`
`1008
`
`1009
`
`Andrea Electronics Corp. v. Hewlett-Packard Co., Civil Action No.
`
`1010
`
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`PETITION FOR INTER PARTES REVIEW OF U.S. PATENT NO. 6,049,607
`
`
`Description
`
`Exhibit #
`
`2:15-cv-00208, Plaintiff’s Complaint For Patent Infringement, Dkt.
`No. 1 (E.D.N.Y. Jan. 14, 2015)
`
`Andrea Electronics Corp. v. Dell Inc., Civil Action No. 2:15-cv-
`00209, Plaintiff’s Complaint For Patent Infringement, Dkt. No. 1
`(E.D.N.Y. Jan. 14, 2015)
`
`1011
`
`Andrea Electronics Corp. v. ASUSTek Computer Inc., Civil Action No.
`2:15-cv-00214, Plaintiff’s Complaint For Patent Infringement, Dkt.
`No. 1 (E.D.N.Y. Jan. 14, 2015)
`
`1013
`
`Andrea Electronics Corp. v. Realtek Semiconductor Corp., Civil
`Action No. 2:15-cv-00215, Court’s Notice of Related Case, Dkt. No. 4
`(E.D.N.Y. Jan. 21, 2015)
`
`1014
`
`In re Certain Audio Processing Hardware and Software and Products
`Containing Same, Inv. No. 337-TA-949, Verified Complaint Under
`Section 337 of the Tariff Act of 1930 (U.S.I.T.C. Jan. 23, 2015)
`
`In re Certain Audio Processing Hardware and Software and Products
`Containing Same, Inv. No. 337-TA-949, Notice of Institution of
`Investigation (U.S.I.T.C. Mar. 12, 2015)
`
`Table 1 – List Of Each Claim Element Annotated With Its Claim
`Number and A Reference Letter
`
`1015
`
`1016
`
`1017
`
`Petitioner’s List of Related Litigation Matters, And Patents at Issue
`
`1018
`
`Petitioner’s List of IPR Petitions and Challenged Patent Claims of the
`Andrea Patents
`
`1019
`
`Prosecution History of U.S. Patent Application No. 09/157,035 which
`issued as U.S. Patent No. 6,049,607
`
`1020
`
`International Application No. PCT/US99/21186, “Interference
`Canceling Method and Apparatus,” to Joseph Marash and Baruch
`Berdugo, issued on Mar. 30, 2000 as International Publication No.
`WO00/18099
`
`1021
`
`U.S. Patent No. 5,263,019, “Method And Apparatus For Estimating
`The Level of Acoustic Feedback Between A Loudspeaker And
`
`1022
`
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`PETITION FOR INTER PARTES REVIEW OF U.S. PATENT NO. 6,049,607
`
`
`Description
`
`Exhibit #
`
`Microphone,” to Peter L. Chu, issued on Nov. 16, 1993 (“Chu”)
`
`U.S. Patent No. 6,125,179, “Echo Control Device With Quick
`Response To Sudden Echo-Path Change,” to Ying Wu, issued on Sept.
`26, 2000 (“Wu”)
`
`1023
`
`R. E. Crochiere et al., “Multirate Digital Signal Processing,” Prentice
`Hall, Englewood Cliffs, N.J. (1983) (“Crochiere”)
`
`Walter Kellermann “Strategies for Combining Acoustic Echo
`Cancellation and Adaptive Beamforming Microphone Arrays” (1997)
`(“Kellermann”)
`
`Nobuo Koizumi et al., “Acoustic echo canceller with multiple echo
`paths”, J. Acoust. Soc. Jpn. (E) 10, 1 (1989)” (“Koizumi”)
`
`Sen M. Kuo and Jier Chen, “Multiple-Microphone Acoustic Echo
`Cancellation System with the Partial Adaptive Process”, Digital Signal
`Processing 3, 54-63 (1993) (“Kuo”)
`
`U. S. Patent 4,894,820, “Double-Talk Detection In An Echo
`Canceller,” to Ryoichi Miyamoto et al., issued on Jan. 16, 1990
`(“Miyamoto”)
`
`Declaration of David V. Anderson (“Anderson Decl.”)
`
`Realtek Semiconductor Corporation v. Andrea Electronics Corp., Civil
`Action No. 5:15-cv-03184, Complaint For Breach Of Contract And
`Declaratory Judgment, Dkt. No. 1 (N.D. Cal. July 9, 2015)
`
`1024
`
`1025
`
`1026
`
`1027
`
`1028
`
`1029
`
`1030
`
`IPR2015-01393
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`PETITION FOR INTER PARTES REVIEW OF U.S. PATENT NO. 6,049,607
`
`
`Pursuant to 35 U.S.C. § 311, Petitioner hereby respectfully requests inter
`
`partes review of claims 1-12 and 25-37 of Ex. 1001, U.S. Patent No. 6,049,607
`
`(“the ’607 Patent”) which issued on April 11, 2000. The challenged claims are
`
`unpatentable under 35 U.S.C. § 103 over the prior art publications identified and
`
`applied in this Petition.
`
`I. MANDATORY NOTICES
`
`Pursuant to 37 C.F.R. §42.8, Petitioner provides the following mandatory
`
`disclosures:
`
`A. Real Parties-In-Interest. Petitioner, Realtek Semiconductor Corporation,
`
`No. 2, Innovation Road II, Hsinchu Science Park, Hsinchu 300, Taiwan is a real
`
`party-in-interest for the instant petition.
`
`B. Related Matters.
`
`Pursuant to 37 C.F.R. § 42.8(b)(2), Petitioner submits that the ’607 Patent is
`
`the subject of a series of seven related patent infringement lawsuits brought by
`
`Andrea Electronics Corporation (“Andrea”) in the U.S. District Court for the
`
`Eastern District of New York (“EDNY Actions”) and one action in the U.S.
`
`International Trade Commission (“USITC Action”). See Ex. 1014 (the court’s
`
`notice of related EDNY Actions); see also, Ex. 1016 (the court’s notice of
`
`instituted USITC Action ). Andrea filed amended complaints in the EDNY
`
`Actions on November 10, 2014 and January 14, 2015 (Exs. 1002, 1004, 1007,
`
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`PETITION FOR INTER PARTES REVIEW OF U.S. PATENT NO. 6,049,607
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`1010-1013); and filed a verified complaint in the USITC Action on January 23,
`
`2015 (Ex. 1015). Defendants’ in the EDNY Actions filed answers and
`
`counterclaims on November 24, 2014. See Exs. 1003, 1005, 1008 and 1009.
`
`Andrea responded to one of the EDNY Action counterclaims on December 15,
`
`2014. See Ex. 1006. In addition, Realtek filed a breach of contract lawsuit
`
`concerning a license agreement against Andrea in the U.S. District Court for the
`
`Northern District of California on July 9, 2015 (“NDCA Action”). See Ex. 1030.
`
`Petitioner is not aware of any reexamination certificates or pending prosecution
`
`concerning the ’607 patent.
`
`Petitioner further states that the EDNY, USITC and NDCA Actions also
`
`involve Andrea’s U.S. Patent Nos. 5,825,898; 6,363,345; 6,483,923; and 6,377,637
`
`(collectively and including the ‘607 patent “Andrea patents”). Concurrently,
`
`Petitioner is filing six inter partes review petitions, challenging certain claim
`
`elements of above referenced Andrea patents, which are: (1) subject to additional
`
`prior art references; and (2) may affect, or be affected by, decision(s) in the
`
`proceedings of the Andrea patents. For further references, Petitioner includes as
`
`Exhibit 1018 (list of related litigation matters); and Exhibit 1019 (list of
`
`concurrently filed IPR2015 petitions and challenged patent claims).
`
`C. Lead and Back-up Counsel and Service Information – 37 C.F.R.
`§42.8(b)(3) & (4).
`
`John M. Caracappa (Reg. No. 43,532) is lead counsel. Tremayne M. Norris
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`PETITION FOR INTER PARTES REVIEW OF U.S. PATENT NO. 6,049,607
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`(Reg. No. 58,683), Stanley C.T. Kuo (pro hac vice motion to be filed), Trevor C.
`
`Hill (pro hac vice motion to be filed), and David L. Hecht (Reg. No. 61,618) are
`
`backup counsel. The Petitioner may be served in this matter as follows:
`
`Post and Hand
`Delivery
`
`Steptoe & Johnson LLP
`1330 Connecticut Ave. NW
`Washington, DC 20036
`
`Email
`
`jcaracap@steptoe.com; tnoris@steptoe.com;
`skuo@steptoe.com; thill@steptoe.com; dhecht@steptoe.com;
`Realtek607IPR@steptoe.com
`
`Telephone No.
`
`202-429-6267
`
`Facsimile No.
`
`202-261-0597
`
`
`PAYMENT OF FEES
`
`II.
`
`Pursuant to 37 C.F.R. §42.103(a) and 42.15(a), the required filing fees for
`
`this petition are submitted and charged to Deposit Account 19-4293. Should any
`
`further fees be required by the present Petition, the Patent Trial and Appeal Board
`
`(“the Board”) is hereby authorized to charge the above referenced Deposit
`
`Account.
`
`III. STANDING
`
`Pursuant to 37 C.F.R. § 42.104(a), Petitioner certifies that the patent sought
`
`for review, U.S. Patent No. 6,049,607, is available for inter partes review and that
`
`Petitioner is not barred or estopped from requesting an inter partes review of the
`
`patent.
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`PETITION FOR INTER PARTES REVIEW OF U.S. PATENT NO. 6,049,607
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`IV. REQUEST TO HOLD CLAIMS 1-12 AND 25-37 OF THE ’607
`PATENT UNPATENTABLE
`
`Pursuant to 37 C.F.R. § 42.104(b), Petitioner requests that the Board claims
`
`1-12 and 25-37 of the ’607 Patent unpatentable. Such relief is justified as the
`
`alleged invention of the ’607 Patent was described by others prior to the effective
`
`filing date of the ’607 Patent. Attached hereto as Exhibit 1017, is a Table that
`
`provides the ‘607 patent claim elements challenged, each limitation annotated with
`
`its claim number and a reference letter.
`
`A. The Alleged Invention Of The ’607 Patent
`
`The ’607 Patent describes an apparatus and method for echo-cancelling in a
`
`full duplex communication system like a teleconference. A teleconference
`
`typically involves sounds present at a “near-end” location, such as those of a near-
`
`end loudspeaker, that are received by a microphone or by microphones. These
`
`sounds are transmitted to a “far-end” system and subsequently broadcast by a far-
`
`end loudspeaker. At the far-end system, sounds emanating from the far-end
`
`loudspeaker are also received by the far-end microphone and transmitted to the
`
`near-end system where they are broadcast by the near-end loudspeaker. As a
`
`result, a disturbing echo will be heard in the system. Without an echo cancellation
`
`mechanism in the system, a person speaking into the microphone will hear himself
`
`as a result of his or her voice being transmitted over the far-end loudspeaker, into
`
`the far-end microphone and back out of the near-end loudspeaker.
`
`IPR2015-01393
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`PETITION FOR INTER PARTES REVIEW OF U.S. PATENT NO. 6,049,607
`
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`The ’607 Patent specifically describes cancelling echoes in the system by (1)
`
`splitting (through splitter 114) the near-end signal from microphone array 102 and
`
`far-end signal (through splitter 128) and (2) adaptively filtering the interference
`
`signal from the target signal through adaptive filters 116x. See Ex. 1001, Fig. 1.
`
`The limited scope of the alleged invention—splitting and adaptively filtering
`
`signals—is demonstrated by the scope of the admitted prior art described in the
`
`“Background of the Invention” section of the ’607 Patent, which covers every
`
`aspect of adaptive filtering system and method recited in the claims of the ’607
`
`Patent. Id. at 1:22-3:27.
`
`B.
`
`Summary Of The Prosecution History Of The ’607 Patent
`
`The application that led to the ’607 Patent was filed on September 18, 1998
`
`and issued with no rejections. Ex. 1020 at p. 54-59 (RTL607_1020-0054-59). On
`
`December 3, 1999, the Examiner allowed all claims and stated in his reasons for
`
`allowance that the prior art of record taken alone and in combination does not
`
`disclose the “beam splitter” limitation recited in claim 1 (i.e., “a beam splitter for
`
`beam-splitting said target signal . . . whereby for each band-limited target signal
`
`there is a corresponding band-limited interference signal.”). Id. The Examiner also
`
`indicated that he had called Applicants’ representative that same day, December 3,
`
`to discuss some “minor informalities” in claims 1, 13 and 25. Id. at p. 68.
`
`(RTL607_1020-0068) The Applicants agreed to an Examiner’s amendment
`
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`PETITION FOR INTER PARTES REVIEW OF U.S. PATENT NO. 6,049,607
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`changing “equals” to “equal” in these claims. Id.at pp. 26 (see handwritten
`
`changes) (RTL607_1020-0026). The ’607 Patent issued on April 11, 2000. Id.
`
`(RTL607_1020-0081). Additionally, PCT/US99/21186 was filed on September 14,
`
`1999 which is published claims the benefit of U.S. Patent Application 09/157,035.
`
`Ex. 1021.
`
`V. CLAIM CONSTRUCTION
`
`A.
`
`Standards For Claim Construction
`
`1.
`
`Broadest Reasonable Construction
`
`Unless otherwise addressed herein, for the purposes of inter partes review
`
`only, the terms of the ‘607 Patent’s claims are to be given their broadest reasonable
`
`interpretation, as understood by one of ordinary skill in the art, in view of the ‘607
`
`patent’s specification. See 37 C.F.R. § 42.100(b).
`
`Further, while the Petitioner believes that several claims may be
`
`unpatentable under 35 USC § 112, Petitioner is still providing prior art to challenge
`
`the patentability of the requested claims to the extent the Board can determine that
`
`the claims are valid under the “broadest reasonable interpretation” standard. The
`
`Petitioner’s prior art submission, however, is not an admission on its part that all
`
`claims are valid under 35 USC § 112. Accordingly, the Petitioner reserves the
`
`right to later challenge the validity of the claims of the ‘607 patent under 35 USC §
`
`112 in federal district court or in an action before the International Trade
`
`Commission.
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`IPR2015-01393
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`PETITION FOR INTER PARTES REVIEW OF U.S. PATENT NO. 6,049,607
`
`
`A.
`
` “interference signal” (claims 1-2 and 25-26)
`
`Petitioner believes a construction of the term “interference signal” is
`
`appropriate; however, the term’s usage within the independent claims appears to be
`
`inconsistent with the teachings of the specification. Even with a proper
`
`construction of the term, Petitioner believes it may be difficult for one of ordinary
`
`skill in the art to fully comprehend what the patentee regards as its alleged
`
`invention when this term is viewed in light of the specification.
`
`For example, claim 1 requires “a reference input for inputting said
`
`interference signal.” Ex. 1001 at 10:16. However, nowhere in the specification is
`
`the term “interference signal” described as being input from a reference input as it
`
`is used in claim 1. Aside from the Abstract and Objects and Summary of the
`
`Invention (which merely restate the claims), the term “interference signal” is only
`
`used once in the specification of the ’607 Patent. Id., 7:34-36 (“The estimated
`
`interference signal is then subtracted via subtractor 508 from the beam signal to
`
`obtain an echo free signal.”) (emphasis added). The “interference signal” contains
`
`the “estimated echo elements” present in the reference channel that contains the far
`
`end signal, or reference signal. Id. at 7:31-36; see also id. at 2:18 (“. . . with the
`
`far-end signal used as the reference signal”). Accordingly, the use of “interference
`
`signal” in claims 1 and 25 of the ’607 Patent is inconsistent with the use of this
`
`term in the specification.
`
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`PETITION FOR INTER PARTES REVIEW OF U.S. PATENT NO. 6,049,607
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`The interference signal cannot be the input at the reference input as recited
`
`in claims 1 and 25 because it is an estimated signal based on the reference signal.
`
`It is the “reference signal” that is input at the “reference input.” The reference
`
`signal (not the interference signal) is then split by the beam splitter. Id. at 6:63-67.
`
`Thus, the use of the phrase “beam-splitting said interference signal into band-
`
`limited interference signals” in claims 1 and 25 is also incorrect because it is the
`
`reference signal that is split and band-limited. (Emphasis added).
`
`Further, the ’607 Patent teaches that the adaptive filter “cancels an echo
`
`present in the reference signal broadcast to a far end of the teleconference” (the
`
`estimated interference signal). Id., Abstract. The adaptive filter obtains the
`
`estimated echo elements that comprise the interference signal by multiplying the
`
`reference signal by a filter. Id. at 7:31-36.
`
`The usage of “interference signal” in claims 1 and 25 is also inconsistent
`
`with claims 2 and 26 respectively. Claim 2, for example, defines “reference
`
`signal” as the target signal broadcast from a far end of the teleconference and that
`
`the “interference signal” represents an echo generated by the broadcast of the
`
`reference signal of the far end. Id. at 10:28-33. Thus, the interference signal is a
`
`function of the reference signal—which is otherwise absent from claim 1. As
`
`described in the specification and discussed above, the reference signal is input at
`
`the reference input not the interference signal.
`
`IPR2015-01393
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`PETITION FOR INTER PARTES REVIEW OF U.S. PATENT NO. 6,049,607
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`Thus, based on its plain meaning in light of the specification, one of ordinary
`
`skill in the art would likely consider “interference signal” to be the echo elements
`
`generated by the broadcast of the reference signal and therefore a function of the
`
`reference signal. However, for the purposes of this petition, Petitioner will assume
`
`that “interference signal” as used in claims 1 and 25 (except the “interference
`
`signal” in the preambles) is the “reference signal.”
`
`VI. PRIOR ART TO THE ’607 PATENT FORMING THE BASIS FOR
`THIS PETITION
`
`A.
`
`Prior Art Documents
`
`U.S. Patent No. 5,263,019 (“Chu”) (Ex. 1022) was published on November
`
`16, 1993. As a result, Chu is available as prior art against all claims of the ’607
`
`Patent under 35 U.S.C. § 102(b).
`
`U.S. Patent No. 6,125,179 (“Wu”) (Ex. 1023) was filed on December 13,
`
`1995. As a result, Wu is available as prior art against all claims of the ’607 Patent
`
`under 35 U.S.C. § 102(e).
`
`R. E. Crochiere et al., “Multirate Digital Signal Processing”, Prentice Hall,
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`Englewood Cliffs, N.J. (1983) (“Crochiere”) (Ex. 1024) was published in the
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`United States at least in 1983. As a result, Crochiere is available as prior art
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`against all claims of the ’607 Patent under 35 U.S.C. § 102(b).
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`Walter Kellermann “Strategies for Combining Acoustic Echo Cancellation
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`and Adaptive Beamforming Microphone Arrays”, Proc. ICASSP ’97, 1, 219-222,
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`PETITION FOR INTER PARTES REVIEW OF U.S. PATENT NO. 6,049,607
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`Munch, Germany, April 1997 (“Kellermann”) (Ex. 1025) was published in April
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`1997. As a result, Kellermann is available as prior art against all claims of the
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`’607 Patent under 35 U.S.C. § 102(b).
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`Nobuo Koizumi et al., “Acoustic echo canceller with multiple echo paths”,
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`J. Acoust. Soc. Jpn. (E) 10, 1 (1989)” (“Koizumi”) (Ex. 1026) was published at
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`least in 1989. Therefore, Koizumi is available as prior art against all claims of the
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`’607 Patent under 35 U.S.C. § 102(b).
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`Sen M. Kuo and Jier Chen, “Multiple-Microphone Acoustic Echo
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`Cancellation System with the Partial Adaptive Process,” Digital Signal Processing
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`3, 54-63 (1993) (“Kuo”) (Ex. 1027) was published at least in 1989. Therefore,
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`Kuo is available as prior art against all claims of the ’607 Patent under 35 U.S.C. §
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`102(b).
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`None of the references relied upon in this Petition were considered during
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`prosecution of the application of the ’607 Patent.
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`B.
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`Summary of Unpatentability Arguments
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`According to the ’607 Patent, the essential feature of the alleged invention is
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`limited to splitting the selected beam through a splitter (Ex. 1001 at 5:36-40, 5:63-
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`66), and adaptively filtering these signals (see, e.g., id. at 4:4-6) using a transfer
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`function that is updated continuously in real time (see, e.g., id. at 2:10-13). The
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`inventors sought to avoid a half-duplex communication system (see, e.g., id. at
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`PETITION FOR INTER PARTES REVIEW OF U.S. PATENT NO. 6,049,607
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`1:15-19, 1:60-61; 3:33-35) and avoid the computational load required to perform
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`numerous echo-cancelling systems concurrently on each of the microphones in an
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`array (id. at 3:10-13). The ’607 Patent describes that half-duplex communication
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`is problematic because if the microphone is blocked for a prolonged period to
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`avoid transmission of the reverberations, the far-end speaker will lose too much of
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`the speech of the near-end speaker (id. at 1:54-61). The ’607 Patent also describes
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`that, where a microphone array is used, a problem arises when the system
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`transitions between the transfer function of the loudspeaker signal and the audio
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`signal obtained by the microphones (either through multiplexing or steering the
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`directional audio beam) (id. at 2:66-3:3). Each time the transition takes place, an
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`echo will “leak into the system until adaptive filter adapts to the new condition”
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`(id. 3:3-5).
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`The problems discussed above, however, were well known at the time of the
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`alleged invention, and had already been solved. For instance, Chu recognized the
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`need for “an improved echo cancelling device for reducing the effects of acoustic
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`feedback between a loudspeaker and a microphone in a communication system.”
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`Ex. 1022 at 3:23-25. To achieve this objective, Chu discloses that a loudspeaker
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`signal and microphone signal are split into frequency bands and then passed to an
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`adaptive filter bank 18 identical to that of the ’607 patent. Id. at 7:64-67; Fig. 3.
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`PETITION FOR INTER PARTES REVIEW OF U.S. PATENT NO. 6,049,607
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`Wu recognized needs for controlling filter weight adaptation and for
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`controlling the noise gate with a variety of measures. Ex. 1023, Abstract.
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`Crochiere recognized the need for implementing the bandpass filters using a
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`single sideband modulator structure. Ex. 1024 at p. 289, Introduction
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`(RTL607_1024-0012).
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`Kellermann recognized the need for beamforming and/or beamsteering prior
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`to adaptive filtering. Ex. 1025 at p. 2, § 3.1 “Beamforming methods”
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`(RTL607_1025-0002).
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`Kuo recognized problems in selecting signals for adaptive filtering. Ex.
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`1027 at pp. 56-57, Figure 4 (RTL607_1027-0003-4). Kuo solved the problem, in
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`one aspect, by updating the adaptive filters to keep track of the various channels.
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`Id., Figure 4 (RTL607_1027-0003).
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`Koizumi also describes an acoustic echo canceller for multiple microphone
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`teleconferencing systems. Ex. 1026 at pp. 40, 42 (RTL607_1026-0002-4). Koizumi
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`discloses that filter coefficients for the adaptive filter are calculated as different
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`microphones are selected. Id. at p. 40 (RTL607_1026-0002.
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`In short, the ’607 Patent claims no inventive matter and discloses no novel
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`signal processing technology or techniques to cancel interference signals related to
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`the same. Instead, the ’607 Patent claims matter that was already well-known to
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`those of skill in the art at the time of the alleged invention. To the extent that any
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`PETITION FOR INTER PARTES REVIEW OF U.S. PATENT NO. 6,049,607
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`element can be argued as “novel,” it is a predictable and obvious application of
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`known techniques disclosed in the closely-related field of signal processing and
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`noise suppression for precisely the same purposes disclosed in that art, namely to
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`reduce echoes transmitted over a telecommunication system. In light of the
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`disclosures detailed below, the ’607 Patent is unpatentable because at least six
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`references anticipate or render obvious one or more claims.
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`VII. GROUNDS FOR UNPATENTABILITY OF EACH CLAIM
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`A. Ground 1: Claims 1-4 And 25-28 Are Unpatentable Under 35
`U.S.C. § 103 As Being Obvious Over Chu
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`The features in claims 1-4 and 25-28 are unpatentable as being obvious over
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`U.S. Patent No. 5,263,019 (“Chu”) (Ex. 1022). Claims 1 and 25 concern splitting
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`target and interference signals which are then adaptively filtered. See Ex. 1029,
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`Anderson Decl., ¶¶ 34-43.
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`Like the ’607 Patent, an objective of Chu is to provide “an improved echo
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`cancelling device for reducing the effects of acoustic feedback between a
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`loudspeaker and a microphone in a communication system.” Ex. 1022 at 3:23-25.
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`To achieve this objective, the loudspeaker signal and the microphone signal are
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`first split into frequency bands. Specifically, Chu discloses that the digitized
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`microphone signal, m(z), is passed through a “whitening filter” and then applied to
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`a splitter 16 which separates the signal into twenty-nine distinct frequency bands.
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`Id. at 5:8-16; Figure 1. Similarly, the loudspeaker signal, s(z), is band filtered
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`PETITION FOR INTER PARTES REVIEW OF U.S. PATENT NO. 6,049,607
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`through a signal splitter 30 in the same manner as the microphone signal, into
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`twenty-nine bandpass loudspeaker signals. Id. 5:25-31; see also id., Figure 1.
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`While Chu does not specifically disclose the use of a “beam splitter,” it
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`broadly describes a “splitter.” It would have been obvious to one of ordinary skill
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`in the art to utilize a beam splitter for the splitter 16 and splitter 30, if the system
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`were to utilize a beam as input. However, a splitter is broad enough to encompass
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`any type of splitter, including a beam-splitter. See Ex. 1029, Anderson Decl., ¶ 41.
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`Notably, the claims of the ’607 Patent do not specify that the microphone (input) or
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`far end (reference/interference) signals are “beams.” Further, the specification of
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`the ’607 Patent describes that a “splitter” – not a “beam splitter” – is used to split
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`the reference/interference signal. See e.g. Ex. 1001, Figure 1; see also id at 5:63-
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`67 (“Meanwhile, the far end signal (referred to as the reference channel) is …
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`conditioned, sampled, decimated and split in the manner discussed above by …
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`splitter 128”).
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`After the signals are split, Chu discloses that the microphone and
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`loudspeaker signals are passed to an adaptive filter bank 18 identical to that of the
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`’607 patent which includes an adaptive filter for each bandlimited microphone
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`signal. Ex. 1022 at 7:64-67; Fig. 3. Each adaptive filter estimates the echo in a
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`corresponding band and removes the estimated echo from the corresponding
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`PETITION FOR INTER PARTES REVIEW OF U.S. PATENT NO. 6,049,607
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`bandlimited microphone signal. Id. at 7:64- 8:5; Fig. 3; Ex. 1029, Anderson Decl.,
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`¶ 42.
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`
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`A person of ordinary skill in the art would be motivated to combine Chu with
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`a well-known “beam-splitter” because Chu already discloses splitting signals. If a
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`person of ordinary skill in the art wished to utilize a beam, instead of a non-
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`directional signal, in Chu’s system, it would have been obvious to use a well-
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`known beam splitter instead of the regular signal splitter disclosed in Chu. See Ex.
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`1001 at 7:64-67; Ex. 1029, Anderson Decl., ¶ 41.
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`In addition to the elements of claim 1 (or 25), claims 2 and 26 further define
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`the target and interference signal, and introduce the “reference signal.” 1 Figure 1
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`in Chu shows the digitized electronic speaker signal, s(z), which is used to derive
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`loudspeaker signal 32 (reference signal) and which represents the voices of people
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`at a far end of the communication system. Ex. 1022, 1:24-26; 4:65-5:7; Fig. 1.
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`Chu describes that the adjustable filter receives a loudspeaker (reference 2) signal
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`
`1 The term “reference signal” lacks antecedent basis. While Petitioner has
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`substituted “reference signal” for “interference signal” in claim 1 for purposes of
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`this petition, Petitioner notes that these terms are used consis