IPR 2016-01209
`U.S. Patent No. 7,746,916
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`
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`UNITED STATES PATENT AND TRADEMARK OFFICE
`
`____________________
`
`BEFORE THE PATENT TRIAL AND APPEAL BOARD
`
`_____________________
`
`APPLE, INC., MICROSOFT CORPORATION, MICROSOFT MOBILE
`OY, AND MICROSOFT MOBILE INC.,
`Petitioners,
`
`V.
`
`EVOLVED WIRELESS, LLC,
`Patent Owner
`_____________________
`
`Case IPR2016-01209
`Patent 7,746,916
`_____________________
`
`
`
`PATENT OWNER’S PRELIMINARY RESPONSE TO
`PETITIONERS’ PETITION FOR INTER PARTES REVIEW OF
`UNITED STATES PATENT NO. 7,746,916
`
`
`
`
`

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`TABLE OF CONTENTS
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`IPR 2016-01209
`U.S. Patent No. 7,746,916
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`Page
`
`I.
`
`II.
`
`INTRODUCTION ........................................................................................... 1
`
`FACTUAL BACKGROUND.......................................................................... 3
`
`
`
` United States Patent No. 7,746,916 ...................................................... 3 A.
`
`B.
`
`
`C.
`
`
`Challenged Claims ................................................................................ 6
`
`Overview of Petition for Inter Partes Review ....................................10
`
`1.
`
`2.
`
`3.
`
`4.
`
`Zhuang175 (Ex. 1012) ..............................................................10
`
`Hou (Ex. 1011) ..........................................................................14
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`Fukuta (Ex. 1013) .....................................................................16
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`Popović (Ex. 1009) ...................................................................19
`
`III.
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`PROSECUTION HISTORY .........................................................................19
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`IV. CLAIM CONSTRUCTION ..........................................................................23
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`V.
`
`PETITIONERS FAIL TO ESTABLISH A REASONABLE
`LIKELIHOOD OF SUCCESS AS TO ANY CHALLENGED
`CLAIM...........................................................................................................30
`
`A.
`
`
`B.
`
`
`C.
`
`
`D.
`
`
`Legal Standard .....................................................................................30
`
`Zhuang175 is redundant in view of the prosecution history.
`[Grounds 1 and 2] ................................................................................32
`
`Zhuang175 does not disclose the claimed “circular shift.”
`[Grounds 1 and 2] ................................................................................34
`
`Petitioners have failed to show how the combination of
`Zhuang175 and Hou discloses the claimed circular shift.
`[Grounds 3 and 4] ................................................................................41
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`i
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`E.
`
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`F.
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`IPR 2016-01209
`U.S. Patent No. 7,746,916
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`Petitioners have failed to show how the combination of
`Zhuang175 and Fukuta discloses the claimed circular shift.
`[Grounds 5 and 6] ................................................................................42
`
`1.
`
`2.
`
`Fukuta alone does not disclose the claimed “circular
`shift.” .........................................................................................43
`
`Petitioners have not articulated a reason to combine
`Zhuang175 with a modified Fukuta to disclose the
`claimed circular shift. ................................................................45
`
`Petitioners have failed to show how combining Popović with
`the remaining references renders obvious “wherein the code
`sequence having the first length is a Zadoff-Chu (ZC)
`sequence.” [Grounds 2, 4, and 6] ........................................................48
`
`VI. CONCLUSION ..............................................................................................52
`
`
`
`ii
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`IPR 2016-01209
`U.S. Patent No. 7,746,916
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`TABLE OF AUTHORITIES
`
` Page(s)
`
`Cases
`ATD Corp. v. Lydall, Inc.,
`159 F.3d 534 (Fed. Cir. 1998) ............................................................................ 50
`
`CFMT, Inc. v. Yieldup Intern. Corp.,
`349 F.3d 1333 (Fed. Cir. 2003) .......................................................................... 31
`
`Continental Can Co. v. Monsanto Co.,
`948 F.2d 1264 (Fed. Cir 1991) ........................................................................... 40
`
`Cutsforth, Inc. v. MotivePower, Inc.,
`643 Fed. App’x. 1008 (Fed. Cir. 2016) .............................................................. 23
`
`In re Bigio,
`381 F.3d 1320 (Fed. Cir. 2004) .......................................................................... 29
`
`In re Cyclobenzaprine Hydrochloride Extended—Release Capsule
`Patent Litig.,
`676 F.3d 1063 (Fed. Cir. 2012) .......................................................................... 31
`
`In re Rijckaert,
`9 F.3d 1531 (Fed. Cir. 1993) .............................................................................. 38
`
`In re Suitco Surface, Inc.,
`603 F.3d 1255 (Fed. Cir. 2010) .......................................................................... 23
`
`In re Turlay,
`304 F.2d 893 (C.C.P.A. 1962) ............................................................................ 40
`
`Invitrogen Corp. v. Biocrest Mfg., L.P.,
`327 F.3d 1364 (Fed. Cir. 2003) .......................................................................... 26
`
`Kinetic Concepts, Inc. v. Smith & Nephew, Inc.,
`688 F.3d 1342 (Fed. Cir. 2012) .......................................................................... 31
`
`Mantech Envtl. Corp. v. Hudson Envtl. Servs., Inc.,
`152 F.3d 1368 (Fed. Cir. 1998) .......................................................................... 25
`
`iii
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`

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`McGinley v. Franklin Sports, Inc.,
`262 F.3d 1339 (Fed. Cir. 2001) .......................................................................... 35
`
`IPR 2016-01209
`U.S. Patent No. 7,746,916
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`Microsoft Corp. v. Proxyconn, Inc.,
`789 F.3d 1292 (Fed. Cir. 2015) .......................................................................... 23
`
`Nora Lighting, Inc. v. Juno Mfg., LLC,
`Case No. IPR2015-00601, Paper 13 (PTAB Aug. 12, 2015) ............................. 33
`
`Ortho-McNeil Pharm., Inc. v. Mylan Labs, Inc.,
`520 F.3d 1358 (Fed. Cir. 2008) .......................................................................... 49
`
`PPC Broadband, Inc. v. Corning Optical Communs. RF, LLC,
`815 F.3d 747 (Fed. Cir. 2016) ............................................................................ 23
`
`Prism Pharma Co., Ltd. v. Choongwae Pharma Corp.,
`IPR2014-00315, Paper 14 (PTAB July 8, 2014) ................................................ 33
`
`Procter & Gamble Co. v. Teva Pharm. USA, Inc.,
`566 F.3d 989 (Fed. Cir. 2009) ............................................................................ 31
`
`Sanofi-Synthelabo, Inc. v. Apotex, Inc.,
`550 F 3d 1075 (Fed. Cir. 2008) .......................................................................... 31
`
`Statutes
`
`35 U.S.C. § 314(a) ................................................................................................... 31
`
`35 U.S.C. § 325(d) ................................................................................................... 33
`
`Rules
`
`37 C.F.R. § 42.100(b) .............................................................................................. 23
`
`37 C.F.R. § 42.20(c) ................................................................................................. 30
`
`37 C.F.R. § 42.107 ..................................................................................................... 1
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`37 C.F.R. § 42.108(c) ............................................................................................... 30
`
`Other Authorities
`
`MPEP § 2112 IV ...................................................................................................... 38
`
`iv
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`IPR 2016-01209
`U.S. Patent No. 7,746,916
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`Exhibit List
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`Exhibit No.
`2001
`
`Reference
`Excerpt from IPR2016-01208, Paper 2, Petition for Inter Partes
`Review of U.S. Patent No. 7,746,916.
`
`
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`v
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`

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`Pursuant to 37 C.F.R. § 42.107, Patent Owner Evolved Wireless, LLC
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`IPR 2016-01209
`U.S. Patent No. 7,746,916
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`submits this Preliminary Response to the above-captioned Petition for Inter Partes
`
`Review of U.S. Patent No. 7,746,916 (the “’916” Patent) (“Pet.,” Paper 2).
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`I.
`
`INTRODUCTION
`
`The present Petition should be denied because it fails to establish a
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`reasonable likelihood that Petitioners would prevail with respect to any claim
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`challenged in the Petition. The challenged ’916 Patent claims relate to a method
`
`and apparatus for generating code sequences in a wireless communication system.
`
`The independent claims recite three key aspects of the invention: first, base
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`sequences are generated from a code sequence of a prime number length that is the
`
`greatest prime number smaller than a desired length; second, the base sequences
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`are cyclically extended to reach the desired length; and third, the cyclically
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`extended code sequences are circularly shifted. Dependent claims 4 and 9
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`specifically claim an embodiment of the invention wherein the base sequences are
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`Zadoff-Chu code sequences.
`
`The Petition asserts six Grounds. All Grounds rely on a primary reference,
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`Zhuang175, that was previously considered by the Examiner and overcome during
`
`prosecution. Just as the Examiner found in the first instance, Zhuang175 fails to
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`disclose the limitation “performing a circular shift to the code sequence having the
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`second length . . . wherein the circular shift is performed to the code sequence
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`1
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`

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`having the second length such that either a rear portion of the code sequence
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`IPR 2016-01209
`U.S. Patent No. 7,746,916
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`having the second length moves to a start of the code sequence having the second
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`length, or a front portion of the code sequence having the second length moves to
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`an end of the code sequence having the second length.” (Ex. 1001 at 17:40-41,
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`17:51-57, 18:11-12, 18:22-28.) In particular, Zhuang175 fails to expressly or
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`inherently disclose the claimed circular shift and is ambiguous as to whether the
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`circular shift is performed to “the code sequence having the second length.”
`
`Accordingly, Grounds 1 and 2 of the Petition fail because Zhuang175 alone does
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`not anticipate the challenged claims.
`
`Petitioners’ proposed combinations with Zhuang175 also fail because
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`neither the secondary references, nor the combinations resolve the ambiguity as to
`
`whether the circular shift is performed to “the code sequence having the second
`
`length.” Finally, the Petitioners fail to articulate a reason to combine the asserted
`
`references to disclose the dependent claims 4 and 9, wherein the base sequence is a
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`Zadoff-Chu sequence.
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`Because Petitioners do not meet their burden on any of the challenged
`
`method and apparatus claims, the Petition for Inter Partes Review should be
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`denied.
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`2
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`II.
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`IPR 2016-01209
`U.S. Patent No. 7,746,916
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`FACTUAL BACKGROUND
`
` United States Patent No. 7,746,916 A.
`The ’916 Patent issued from Application No. 11/563,909 (the “’909
`
`Application”), originally filed on November 28, 2006 by LG Electronics Inc. (“LG
`
`Electronics”). The ’909 Application claims the benefit of Korean Application No.
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`P2005-114306, filed on Nov. 28, 2005, Korean Application No. P2006-62467,
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`filed on Jul. 4, 2006, and Korean Application No. P2006-64091, filed on Jul. 7,
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`2006. In addition to the ’916 Patent, which issued on June 29, 2010, U.S. Patent
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`RE45522 reissued from U.S. Patent No. 8,036,256 on May 19, 2015 from a
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`continuation application with the same specification as the ’909 Application.
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`LG Electronics, the original assignee of the ’916 Patent, is a global leader
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`and technology innovator in consumer electronics and mobile communications. LG
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`Electronics is an active participant in the 3rd Generation Partnership Project
`
`(“3GPP”), the standards-setting organization that developed the Long-Term
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`Evolution, or LTE, standard. The inventions disclosed in the ’916 Patent
`
`specification relate to LG Electronics’ contributions to the development of that
`
`standard, and the specific inventions claimed by the ’916 Patent have been adopted
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`as part of the 3GPP LTE standard. By being adopted into the 3GPP LTE standard,
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`members of 3GPP recognized and agreed that the claimed inventions in the ’916
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`3
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`

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`Patent were innovative solutions to the problems faced during the development of
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`IPR 2016-01209
`U.S. Patent No. 7,746,916
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`the standard.
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`The ’916 Patent relates to code sequence generation and transmission in
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`wireless communication systems, such as LTE. (See, e.g., Ex. 1001 at 1:15-18,
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`6:43-48.) As the patent specification explains, “a pilot signal or preamble of a
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`wireless communication system is referred to as a reference signal used for initial
`
`synchronization, cell search, and channel estimation. Further, the preamble is
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`comprised of a code sequence, and the code sequence is further comprised of
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`orthogonal or quasi-orthogonal [codes] which represent good correlation
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`properties.” (Ex. 1001 at 1:20-26.)
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`The patent further describes problems associated with prior art code
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`sequences. “Although the [Hadamard] code sequence and a poly-phase Constant
`
`Amplitude Zero Auto-Correlation (CAZAC) code sequence are orthogonal codes,
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`[the] number of codes used to maintain orthogonality is limited.” (Id. at 1:31-34.)
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`“Accordingly, the [’916 Patent] is directed to a method and apparatus for
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`generating and transmitting code sequence[s] in a wireless communication system
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`that substantially obviates one or more problems due to limitations and
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`disadvantages of the related art.” (Id. at 1:51-55.) These limitations include
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`maximizing the number of unique code sequences available in a wireless
`
`communication system while maintaining good correlation properties for the
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`4
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`

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`generated sequences. (See, e.g., Ex. 1001 at 1:43-47, 4:63-65, 8:13-23, 10:49-60,
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`11:1-9, 11:22-33.)
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`To address these problems in the prior art, the ’916 Patent method and
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`apparatus “of generating a code sequence in a wireless communication system
`
`includes recognizing a desired length of the code sequence, generating a code
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`sequence having a length different from the desired length, and modifying the
`
`length of the generated code sequence to equal the desired length.” (Ex. 1001 at
`
`2:6-11.) In particular, the ’916 Patent claims a method of generating a code
`
`sequence of a desired length L, by cyclically extending and then circularly shifting
`
`a code sequence of length X, where the length of X is the largest prime number
`
`smaller than L. (Ex. 1001 at 11:38-42, 12:37-49, 13:53-64.)
`
`Figure 13 of the ’916 Patent describes one embodiment of this method:
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`5
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`

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`(Ex. 1001 at Fig. 13, 12:37-49.) By beginning with a code sequence of a prime
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`number length X, the method maximizes the number of available code sequences
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`of length L with desired correlation properties. (See Ex. 1001 at 8:13-22, 10:49-
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`60.) Cyclically extending the code sequence of length X preserves the correlation
`
`properties of the original sequence. (Ex. 1001 at 11:4-9.) Performing a circular
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`shift “increase[s] an amount of control information transmitted to the
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`communication system.” (Ex. 1001 at 11:22-25.)
`
`
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`The ’916 Patent thus contributes important benefits to the current cellular
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`technology, known as 4G or LTE. The transmitted code sequences according to the
`
`inventions of the ’916 Patent further maximize the number of available code
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`sequences concurrently used in a wireless communication system by reducing
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`interference with other transmitted code sequences. This provides tangible benefits
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`to the wireless network, such as maintaining good correlation properties for the
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`generated sequences (thereby minimizing interference between mobile units). (See
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`id. at 1:43-47, 4:63-65, 7:35-44, 8:13-23; 8:44-51, 10:49-60, 11:1-9, 11:22-33.)
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`
` Challenged Claims B.
`’916 Patent captures the invention in two sets of claims. Claims 1-5 claim
`
`methods of generating code sequences according to the ’916 Patent teachings.
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`Claims 6-10 claim an apparatus for generating the code sequences according to the
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`’916 Patent teachings.
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`6
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`

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`As issued, Claim 1, the independent method claim, recites:
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`IPR 2016-01209
`U.S. Patent No. 7,746,916
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`A method for transmitting a code sequence from a transmitting party
`to a receiving party in a wireless communication system, the
`method comprising:
`
`acquiring a code sequence having a second length by a cyclic
`extension of a code sequence having a first length;
`
`performing a circular shift to the code sequence having the second
`length; and
`
`transmitting the circular shifted code sequence having the second
`length to the receiving party,
`
`wherein the first length is a largest prime number smaller than the
`second length, and
`
`wherein the cyclic extension of the code sequence having the first
`length is performed such that a part of the code sequence having
`the first length, having a length corresponding to a difference
`between the first length and the second length, is added to either a
`start or an end of the code sequence having the first length, and
`
`wherein the circular shift is performed to the code sequence having
`the second length such that either a rear portion of the code
`sequence having the second length moves to a start of the code
`sequence having the second length, or a front portion of the code
`sequence having the second length moves to an end of the code
`sequence having the second length.
`
`(Ex. 1001 at 17:35-57.)
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`7
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`

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`Dependent claims 2 through 5 add additional specific limitations that
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`provide further improvements over the prior art. For example, dependent claim 4
`
`requires the sequence of length X to be a Zadoff-Chu sequence. (Ex. 1001 at 18:1-
`
`3.) Claims 1-5 thus all require “performing a circular shift to the code sequence
`
`having the second length . . . such that either a rear portion of the code sequence
`
`having the second length moves to a start of the code sequence having the second
`
`length, or a front portion of the code sequence having the second length moves to
`
`an end of the code sequence having the second length.” (Ex. 1001 at 17:40-41,
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`17:51-57.)
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`Claim 6, the independent apparatus claim, recites:
`
`An apparatus for transmitting a code sequence in a wireless
`communication system, the apparatus comprising:
`
`a code sequence generator for generating a code sequence having a
`second length by cyclic extension of a code sequence having a first
`length, and performing a circular shift to the code sequence having
`the second length; and
`
`a transmitting unit for transmitting the circular shifted code sequence
`having the second length,
`
`wherein the first length is a largest prime number smaller than the
`second length,
`
`wherein the cyclic extension of the code sequence having the first
`length is performed such that a part of the code sequence having
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`IPR 2016-01209
`U.S. Patent No. 7,746,916
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`the first length, having a length corresponding to a difference
`between the first length and the second length, is added to either a
`start or an end of the code sequence having the first length, and
`
`wherein the circular shift is performed to the code sequence having
`the second length such that either a rear portion of the code
`sequence having the second length moves to a start of the code
`sequence having the second length, or a front portion of the code
`sequence having the second length moves to an end of the code
`sequence having the second length.
`
`(Ex. 1001 at 18:7-28.)
`
`Dependent claims 7 through 10 again add additional limitations that provide
`
`further improvements over the prior art. For example, dependent claim 9 requires
`
`the sequence of length X to be a Zadoff-Chu sequence. (Ex. 1001 at 18:38-40.)
`
`Claims 6-10 thus all require “a code sequence generator for generating a code
`
`sequence having a second length by cyclic extension of a code sequence having a
`
`first length, and performing a circular shift to the code sequence having the second
`
`length . . . such that either a rear portion of the code sequence having the second
`
`length moves to a start of the code sequence having the second length, or a front
`
`portion of the code sequence having the second length moves to an end of the code
`
`sequence having the second length.” (Ex. 1001 at 18:9-12, 18:22-28.)
`
`9
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`

`
` Overview of Petition for Inter Partes Review
`C.
`Petitioners base the Petition for IPR on four references: U.S. Patent No.
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`7,426,175 to Zhuang et al. (“Zhuang175”), U.S. Patent No. 8,116,195 to Hou et al.
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`(“Hou”), U.S. Patent Published Application No. 2007/0270273 to Fukuta et al.
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`(“Fukuta”), and an article by Branislav M. Popović, Generalized Chirp-Like
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`Polyphase Sequences with Optimum Correlation Properties, Vol. 38 No. 4 IEEE
`
`Transactions on Information Theory (1992) (“Popović”).
`
`None of these references, either alone or in combination, disclose
`
`“performing a circular shift to the code sequence having the second length . . .
`
`wherein the circular shift is performed to the code sequence having the second
`
`length such that either a rear portion of the code sequence having the second length
`
`moves to a start of the code sequence having the second length, or a front portion
`
`of the code sequence having the second length moves to an end of the code
`
`sequence having the second length.” (Ex. 1001 at 17:35-57, 18:7-28.) Nor do the
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`references disclose “wherein the code sequence having the first length is a Zadoff-
`
`Chu (ZC) sequence.” (Ex. 1001 at 18:1-3, 18:38-40.)
`
`1. Zhuang175 (Ex. 1012)
`Petitioners rely on Zhuang175 as an anticipatory reference for Ground 1, and
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`a primary reference for all other Grounds. Pet. at 3. Zhuang175 states that it relates
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`to a method and apparatus “for pilot signal transmission in a communication
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`10
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`system.” (Ex. 1012 at 1:6-8.) “A pilot signal (or preamble),” Zhuang175 explains,
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`is “commonly used for communication systems to enable the receiver to perform a
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`number of critical functions, including but not limited to, the acquisition and
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`tracking of timing and frequency synchronization, the estimation and tracking of
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`desired channels for subsequent demodulation and decoding of the information
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`data, the estimation and monitoring of the characteristics of other channels for
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`handoff, interference suppression, etc.” (Ex. 1012 at 1:11-19.) Zhuang175
`
`indicates that among the criteria important for generating pilot signals, are “the
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`ability to have good auto-correlation for each of the pilot sequences utilized, and at
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`the same time the ability to have good cross-correlation between any two different
`
`pilot sequences.” (Ex. 1012 at 1:24-30.) In particular, Zhuang175 is concerned
`
`with a need for “a method and apparatus for pilot signal or preamble transmission
`
`that optimizes both the cross correlation between pilot signals, as well as
`
`optimizing each pilot signal’s auto correlation.” (Ex. 1012 at 2:7-10.)
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`11
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`Petitioners rely on Zhuang175’s method and apparatus of assigning pilot
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`sequences to base units as disclosing the ’916 Patent independent method and
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`apparatus claims. See generally Pet. at 15-35. This method of assigning pilot
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`sequences in Zhuang175 is generally described in three steps: (1) determine the
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`number of pilot sequences needed; (2) compute the pilot sequences; and (3) assign
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`the pilot sequences to base units.
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`
`
`(Ex. 1012 at Fig. 3, 8:52-9:18.) Zhuang175 explains that pilot sequences are
`
`computed by first determining a desired pilot length Np, and then selecting a
`
`starting sequence of prime number length NG and performing modifications. (Ex.
`
`1012 at 3:64-4:13.) One of two proposed modifications is to “[c]hoose NG to be the
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`largest prime number that is smaller than Np and generate the sequence set. Repeat
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`the beginning elements of each sequence in the set to append at the end to reach
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`the desired length Np.” (Ex. 1012 at 4:18-21.) “Further modifications to the
`12
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`truncated/extended sequences may also be applied, such as applying a unitary
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`U.S. Patent No. 7,746,916
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`transform to them.” (Id. at 1012 at 4:44-46.) Zhuang175 explains that such unitary
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`transformations include “the NG-point DFT/IDFT operation” wherein “sequences
`
`formed based on unitary transformations performed on the GCL sequences still fall
`
`within the scope of the invention, because the final sequences are still constructed
`
`from GCL sequences. That is, the final sequences are substantially based on (but
`
`are not necessarily equal to) the GCL sequences.” (Id. at 5:35-51.)
`
`Zhuang175 also explains that the same pilot sequence may be assigned to
`
`multiple communication units. Once assigned, “[h]owever, the actual signals may
`
`be the results of different functions of the same assigned sequence. Examples of
`
`the functions applied are circular shifting of the sequence, rotating the phase of the
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`sequence elements, etc.” (Ex. 1012 at 6:25-32.)
`
`
`
`Zhuang175 is cited on the face of the ’916 Patent and was substantively
`
`addressed by the examiner during prosecution of the ’916 Patent. (Ex. 1002 at 127-
`
`131; Ex. 1001.) The ’916 Patent claims were allowed over Zhuang175 after the
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`independent claims were amended to include a circular shift of the code sequence
`
`having a second length. (Ex. 1002 at 113-121, 87-89.) Just as the examiner found,
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`Zhuang 175 does not expressly or inherently disclose the claimed circular shift of
`
`the ’916 Patent. In addition, Zhuang175 is unclear whether any circular shift
`
`occurs after an DFT/IDFT operation such that the shifted code sequence is
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`13
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`“substantially based on (but . . . not necessarily equal to)” the cyclically extended
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`code sequence. Nor is there any disclosure or suggestion in Zhuang175 of using
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`Zadoff-Chu sequences to generate pilot sequences.
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`2. Hou (Ex. 1011)
`Petitioners rely on Hou as a secondary reference for Grounds 3 and 4. Pet. at
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`3. Hou states that it “relates to orthogonal frequency division multiplexing
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`(OFDM) and orthogonal frequency division multiple access (OFDMA)
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`communication systems, and more particularly to generation and transmission of
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`preamble signals for fast cell searching, time-synchronization, and correcting
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`initial frequency offset in an OFDM or OFDMA communication system.” (Ex.
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`1011 at 1:19-25.)
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`Petitioners specifically rely on Hou to remedy the shortcomings of
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`Zhuang175’s “circular shift.” See Pet. at 48-51. In particular, two figures from
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`Hou, and their descriptions, are cited:
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`Pet. at 44-45 (citing Ex. 1011 at Figure 2A, Figure 2B). Hou explains that “FIG.
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`2A shows an example of using the cyclic shift of initial CAZAC sequence in the
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`frequency domain to generate two new initial CAZAC sequences in the frequency
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`domain.” (Ex. 1011 at 3:11-13.) “FIG. 2B shows an example of using the cyclic
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`shift of the preamble sequence in the time domain to generate two new preamble
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`sequences in the time domain.” (Ex. 1011 at 3:18-19.)
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`A published version of the Hou patent application was submitted to the
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`Patent Office in an IDS during prosecution of the ’916 Patent, (Ex. 1002 at 97;
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`compare Ex. 1002 at 97 (lists “20060050799 2006-03-09 Hou, et al.”) with Ex.
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`1011 (Prior Publication Data lists “US 2006/0050799 A1 Mar. 9, 2006”)), and is
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`cited on the face of the patent. (Ex. 1001.)
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`The combination of Hou with Zhuang175 does not resolve the ambiguity in
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`Zhuang175 as to whether a circular shift occurs after an DFT/IDFT operation such
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`that the shifted code sequence is “substantially based on (but . . . not necessarily
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`equal to)” the cyclically extended code sequence. As with Zhuang175, Hou does
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`not disclose or suggest using Zadoff-Chu sequences to generate pilot sequences.
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`3. Fukuta (Ex. 1013)
`Petitioners rely on Fukuta as a secondary reference for Grounds 5 and 6. Pet.
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`at 3. Fukuta “relates generally to fast cell search, and in particular to a method and
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`apparatus for fast identification of a service cell or sector during initial or periodic
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`access, or handover in a mobile communication system.” (Ex. 1013 at ¶ 0001.)
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`Fukuta explains that “[i]n a system deployment that uniquely maps sequences of
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`certain class indices along with a circular shift amount in time domain to certain
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`cells/cell IDs, the identification of a sequence index, and its circular shift will
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`therefore provide an identification of the cell ID.” (Ex. 1013 at Abstract.)
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`Petitioners specifically rely on Fukuta to disclose the limitation in claims 6-
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`10 of “a code sequence generator for generating a code sequence having a second
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`length by cyclic extension of a code sequence having a first length, and performing
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`a circular shift to the code sequence having the second length.” See Pet. at 52-64.
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`In particular, Figures 4 and 8 from Fukuta, and their descriptions, are cited:
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`(Ex. 1013 at Figure 4 (cited by Pet. at 56).)
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`
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`(Ex. 1013 at Figure 8 (cited by Pet. at 57).) Fukuta explains that Figure 4 “is a
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`block diagram of a transmitter transmitting a primary synchronization channel and
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`a secondary synchronization channel.” (Ex. 1013 at ¶ 0010; see also id. at ¶ 0053.)
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`“During operation, a cell common sequence is generated by generator 401 and is
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`passed to IFFT 403, where the sequence is transformed to a time domain signal.
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`Cell specific GCL sequence with unique sequence index (u) is generated by
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`generator 402 and is passed to IFFT 404, where the sequence is transformed to
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`time domain signal. The cell specific time domain signal is circularly shifted by
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`shifter 405.” (Ex. 1013 at ¶ 0054.) Figure 10 of Fukuta further describes the
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`operation of the transmitter 107 as described in Figure 4. (Ex. 1013 at ¶ 0073.)
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`
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`Fukuta explains that Figure 8 “is a block diagram of a transmitter.” (Ex.
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`1013 at ¶ 0014; see also id. at ¶ 0065.) In operation, “[t]he GCL index enters cell
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`specific sequence generator 801 and a GCL sequence with the particular index (u)
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`is output to IFFT circuitry 802, where an IFFT of the GCL sequence takes place
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`and the sequence is transformed to time domain signal. The transformed GCL
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`sequence is output to circular shifter 803 where it is shifted by an amount m*Q in
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`time domain.” (Ex. 1013 at ¶ 0066.)
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`
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`In both transmitters 107 described by Fukuta, a cell-specific sequence is
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`generated in the frequency domain, but before a cyclic shift is applied, an Inverse
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`Fast-Fourier Transform (IFFT) is performed transforming the generated sequence
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`into a time domain signal. (Ex. 1013 at ¶¶ 0054, 0066, 0073, 0076, Figures 4, 8,
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`10, and 13.) Fukuta, thus, does not expressly or inherently disclose the claimed
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`circular shift of the ’916 Patent, wherein the circular shift is performed to “the code
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`sequence having the second length.” As with Zhuang175 and Hou, Fukuta does not
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`disclose or suggest using Zadoff-Chu sequences to generate pilot sequences.
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`4. Popović (Ex. 1009)
`Petitioners rely on Popović as a secondary reference for Grounds 4 and 6.
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`Pet. at 3. Popović is an article published by IEEE presenting “[a] new general class
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`of polyphase sequences with ideal periodic autocorrelation function . . . .. The new
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`class of sequences is based on the application of Zadoff-Chu polyphase sequences
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`of length N = sm2, where s and m are any positive integers.” (Ex. 1009 at 1.)
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`Petitioners rely specifically on Popović to disclose claims 4 and 9, “wherein the
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`code sequence having the first length is a Zadoff-Chu (ZC) sequence.” (Ex. 1001 at
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`18:1-3, 18:38-40.) Popović, however, presents this new general class of polyphase
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`sequences, but does not describe any algorithm for generation of code sequences
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`used in a wireless communication system.
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`III. PROSECUTION HISTORY
`As noted above, Zhuang175 was substantively discussed and overcome
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`during prosecution of the ’916 Patent. The examiner rejected then pending claims
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`in the ’916 Patent application as anticipated over Zhuang175. (Ex. 1002 at 126-
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`131.) Then pending claim 24 recited:
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`24. (New) A method for generating a code sequence