UNITED STATES PATENT AND TRADEMARK OFFICE
`__________________
`
`BEFORE THE PATENT TRIAL AND APPEAL BOARD
`___________________
`
`ERICSSON INC. AND TELEFONAKTIEBOLAGET
`LM ERICSSON,
`Petitioner
`
`v.
`
`INTELLECTUAL VENTURES II LLC,
`Patent Owner
`___________________
`
`Patent 7,787,431
`
`Title: METHODS AND APPARATUS FOR MULTI-CARRIER
`COMMUNICATIONS WITH VARIABLE CHANNEL
`BANDWIDTH
`_____________________
`
`PETITION FOR INTER PARTES REVIEW
`
`Under 35 U.S.C. §§ 311-319
`
`U.S. Patent No. 7,787,431
`
`Claims 8-12 and 18-22
`
`
`
`
`
`
`
`

`
`Petition for Inter Partes Review of U.S. 7,787,431
`
`
`TABLE OF CONTENTS
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`I.  Mandatory Notices ............................................................................................... 1 
`
`II.  Grounds for Standing ........................................................................................... 2 
`
`III.  The Board Should Consider the New Prior Art and Arguments Presented
`in This Petition ........................................................................................................... 2 
`
`IV. This Petition is Timely Under 35 U.S.C. § 315(b) .............................................. 6 
`
`V.  Relief Requested .................................................................................................. 8 
`
`VI. The Reasons for the Requested Relief ................................................................. 8 
`
`A.  Summary of the Related Technology and the ’431 Patent ........................ 8 
`
`B.  The Prosecution History .......................................................................... 12 
`
`C.  The Prior Art of the Present Petition ....................................................... 13 
`
`VII. 
`
`Identification of Challenges and Claim Construction ............................. 22 
`
`A.  Challenged Claims ................................................................................... 22 
`
`B.  Claim Construction .................................................................................. 22 
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`1. Core-Band ................................................................................................ 22 
`
`2. Primary Preamble .................................................................................... 23 
`
`3. Peak-to-Average Ratio ............................................................................ 24 
`
`C.  Statutory Grounds for Challenges – Challenge #1: Claims 8-12 and
`18-22 are unpatentable under 35 U.S.C. § 103(a) over Dulin,
`Yamaura, Hwang, and Zhuang ................................................................ 25 
`
`VIII. 
`
`Conclusion ............................................................................................... 60 
`
`
`
`i
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`

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`Petition for Inter Partes Review of U.S. 7,787,431
`
`
` I. Mandatory Notices
`
`
`The real party-in-interest is: Ericsson Inc. and Telefonaktiebolaget LM
`
`Ericsson (collectively “Petitioner”).
`
`Related Matters: As of the filing date of this petition and to the best
`
`knowledge of Petitioner, the ’431 Patent is involved in the following litigations, all
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`located in Delaware, and inter partes reviews (IPRs): IV I LLC et al. v. AT&T
`
`Mobility LLC et al., 1-13-cv-01668; IV I LLC et al. v. Leap Wireless Int’l et al., 1-
`
`13-cv-01669; IV I LLC et al. v. Nextel Operations, et al., 1-13-cv-01670; IV I LLC
`
`et al. v. T-Mobile USA Inc. et al., 1-13-cv-01671; IV I LLC et al. v. U.S. Cellular
`
`Corp., 1-13-cv-01672; IV II LLC v. AT&T Mobility LLC, 1:14-cv-01229; IV II LLC
`
`v. Leap Wireless International Inc., 1:14-cv-01230; IV II LLC v. Nextel Operations
`
`Inc., 1:14-cv-01231; IV II LLC v. T-Mobile USA Inc., 1:14-cv-01232; IV II LLC v.
`
`U.S. Cellular Corp., 1:14-cv-01233-LPS; and Ericsson v. IV II LLC, IPR2014-
`
`01195.
`
`Lead and Back-up Counsel: Petitioner appoints J. Andrew Lowes (Reg.
`
`No. 40,706) as its lead counsel and David M. O’Dell (Reg. No. 42,044), Russ
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`Emerson (Reg. No. 44,098), and Clint Wilkins (Reg. No. 62,448) as its back-up
`
`counsel. The phone number for Mr. Lowes is (972) 680-7557, the phone number
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`for Mr. O’Dell is (972) 739-8635, the phone number for Mr. Emerson is (214) 651-
`
`5328, and the phone number for Mr. Wilkins is (972) 739-6927.
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`1
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`

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`Petition for Inter Partes Review of U.S. 7,787,431
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`The mailing address and fax number for all attorneys is HAYNES AND
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`BOONE, LLP, 2323 Victory Ave, Suite 700, Dallas, TX 75219 and (214) 200-
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`0853, respectively.
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`Service Information: Petitioner consents to electronic service by email at
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`the
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`following
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`email
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`addresses:
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`andrew.lowes.ipr@haynesboone.com,
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`david.odell.ipr@haynesboone.com, russell.emerson.ipr@haynesboone.com, and
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`clint.wilkins.ipr@haynesboone.com.
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`II. Grounds for Standing
`
`Petitioner certifies that the ’431 patent is available for IPR and that
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`Petitioner is not barred or estopped from requesting IPR.
`
`III. The Board Should Consider the New Prior Art and Arguments
`Presented in This Petition
`
`In connection with Petitioner’s initial petition for IPR of the ’431 Patent (the
`
`“Initial Petition”), the Board instituted review of claims 1 and 2 but declined
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`review of claim 8-12 and 18-22. See IPR2014-01195, Paper 11. The present
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`Petition challenges claims 8-12 and 18-22 (i.e., the claims that were not instituted
`
`in connection with the Initial Petition). Although the Board has discretion to reject
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`a petition that raises substantially the same prior art or arguments presented
`
`previously (see 35 U.S.C. § 325(d)), it would be inappropriate to exercise that
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`discretion for the challenges in this Petition. Specifically, this Petition presents
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`new prior art that (1) was not reasonably available to Petitioner when the Initial
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`2
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`Petition for Inter Partes Review of U.S. 7,787,431
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`Petition was filed, (2) was accessible to the named inventors of the ‘431 Patent yet
`
`was not disclosed during prosecution, and (3) does not suffer from the deficiency
`
`relied on by the Board in denying institution of these claims from the Initial
`
`Petition.
`
`First, the challenges in this Petition present new prior art—the Hwang
`
`(ERIC-1005) and Kerr (ERIC-1009) references—which Petitioner could not have
`
`reasonably raised in the Initial Petition. Petitioner reviewed the file history of the
`
`’431 patent and the references therein and conducted a thorough prior art search in
`
`preparation of the Initial Petition. Despite diligent search efforts, Petitioner did not
`
`identify the new prior art presented in this Petition until after the Initial Petition
`
`was filed. As explained further below, a recently concluded investigation into the
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`inventors’ activities revealed new prior art for the ’431 Patent that (1) was
`
`unknown to Petitioner when the Initial Petition was filed, and (2) was accessible to
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`the inventors but was not made of record in the ’431 patent file history. Thus,
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`Petitioner simply could not have raised this new prior art in its Initial Petition.
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`An investigation into the inventors’ activities revealed prior art that was
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`accessible to the inventors but was never disclosed to the PTO. Petitioner
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`discovered that the first two named inventors, Xiaodong Li and Titus Lo, were
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`repeat attendees in standards-setting sessions for the IEEE 802.16 Broadband
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`Wireless Access Standards. See, e.g., ERIC-1008, Appendix C. One such session
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`3
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`Petition for Inter Partes Review of U.S. 7,787,431
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`attended by the aforementioned inventors took place from March 15 to 18, 2004,
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`approximately six weeks before the inventors filed the provisional application for
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`the ’431 Patent. See ERIC-1008, Appendix F, p. 1.
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`That IEEE meeting involved the same subject matter as the provisional
`
`application that these inventors filed shortly after attending. For example, many
`
`technical submissions from that meeting address preamble structures in variable
`
`bandwidth communication systems. As explained in Section VI.B, the Examiner
`
`allowed claims 8-12 and 18-22 based on the addition of the preamble properties
`
`recited by those claims (i.e., the auto-correlation, cross-correlation, and peak-to-
`
`average ratio properties). Those preamble properties were disclosed by many of
`
`the submissions for that IEEE meeting. See, e.g., ERIC-1009 (Kerr) at 4-5; ERIC-
`
`1017 at 14; and ERIC-1016 at 1-2.
`
`Furthermore, another submission from that IEEE meeting—the Hwang
`
`reference (ERIC-1005)— helps overcome the very deficiency relied on by the
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`Board in denying the challenges from the Initial Petition. Specifically, the Board
`
`concluded that the challenges from the Initial Petition failed to demonstrate “a
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`core-band that is not greater than the smallest operating channel bandwidth among
`
`all the possible spectral bands with which the receiver is designed to operate.” See
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`IPR2014-01195, Institution Decision, Paper 11 at 10-11. As demonstrated
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`4
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`Petition for Inter Partes Review of U.S. 7,787,431
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`throughout this Petition, however, the Hwang reference (in combination with other
`
`prior art) renders that limitation obvious.
`
`Despite having personally attended the IEEE meeting, the aforementioned
`
`inventors did not disclose the prior art from that meeting to the PTO. Had the
`
`inventors disclosed this prior art to the PTO, it could have been considered by the
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`Examiner during prosecution or presented to the Board in Petitioner’s Initial
`
`Petition. Patent Owner cannot now escape invalidating prior art simply because it
`
`was discovered by Petitioner after the Initial Petition was filed, particularly when
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`the inventors’ own omissions are what prevented the PTO and the Board from
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`previously considering that prior art. Patent Owner, having benefitted from the
`
`inventors’ omissions, cannot credibly complain that it is being harassed with
`
`multiple petitions or that Petitioner is being unfairly given multiple bites at the
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`apple.
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`In addition to Hwang and Kerr, additional searching also revealed the Dulin
`
`reference (ERIC-1002), which was unknown to Petitioner prior to filing the Initial
`
`Petition. This Petition presents only one challenge, which utilizes the newly
`
`discovered Dulin, Hwang and Kerr references, to render the claims obvious.
`
`Accordingly, this Petition does not constitute a scattershot approach nor does it
`
`represent an attempted redo with Petitioner’s “back-up” references.
`
`
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`5
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`Petition for Inter Partes Review of U.S. 7,787,431
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`The Board’s power to deny successive petitions under Section 325(d) is
`
`discretionary, and the present circumstances weigh strongly against use of that
`
`discretion. See, e.g., Valeo North America, Inc. et al. v. Magna Electronics, Inc.,
`
`IPR2014-01203, Paper 13 at 9-11 (Jan. 28, 2015) (instituting review for claims in
`
`subsequent petition that were denied in earlier petition using different combination
`
`of art and noting that “35 U.S.C. § 325(d) is discretionary”);Oxford Nanopore
`
`Tech., Ltd. v. Univ. of Washington et al., IPR2015-00057, Paper 10 at 21 (Apr. 27,
`
`2015) (instituting review for claims in subsequent petition that were denied in an
`
`earlier petition and noting that “the decision whether to deny a petition under §
`
`325(d) is discretionary”). Accordingly, because this Petition presents only one
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`challenge using new prior art and arguments that Petitioner could not have
`
`reasonably raised in its Initial Petition, Petitioner respectfully requests that the
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`Board consider this Petition on the merits and institute review of the challenged
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`claims.
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`IV. This Petition is Timely Under 35 U.S.C. § 315(b)
`
`This Petition is timely under the one-year bar of 35 U.S.C. § 315(b). The
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`clock for the one-year bar for Petitioner Ericsson could not have started until the
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`Court allowed Ericsson to intervene in the litigation against its customers, which
`
`occurred on September 8, 2014. Prior to that date, Ericsson was not a party to the
`
`litigation and thus could not possibly have been considered served with a
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`6
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`complaint for patent infringement,1 as is required to trigger the clock for the one-
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`Petition for Inter Partes Review of U.S. 7,787,431
`
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`year bar. See 35 U.S.C. § 315(b). Thus, the earliest conceivable one-year bar date
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`for Petitioner Ericsson would be September 8, 2015, i.e., one year after its
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`intervention2—the present Petition has been timely filed before that date.
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`Patent Owner seemingly hopes to impose the one-year bar on Petitioner
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`Ericsson anyway, despite its strategic decision not to serve a complaint against
`
`Ericsson. Specifically, in the related district court litigation, Patent Owner recently
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`resorted to unfounded allegations that Ericsson is in privity with the other
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`defendants in the litigation, citing factors such as participation in a joint defense
`
`group and sharing litigation counsel. These factors, however, do not establish
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`privity. See The Brinkmann Corp. v. A&J Manufacturing, LLC, IPR2015-00056,
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`Paper No. 10 at 8 (PTAB Mar. 23, 2015) (finding privity was not established from
`
`entering a joint defense agreement, re-using arguments from invalidity contentions,
`
`and sharing invalidity expert witnesses). Privity, instead, requires some form or
`
`1 For example, the Board previously concluded that, for purposes of the one-year
`
`bar, an amended complaint cannot be “served” until the corresponding motion for leave
`
`is granted by the court. See TRW Automotive US LLC v. Magna Electronics, Inc.,
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`IPR2014-00293, Paper 18 at 7 (PTAB Jun. 27, 2014).
`
`2 Patent Owner, however, strategically chose not to serve a complaint on
`
`Ericsson, even after its intervention.
`
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`7
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`Petition for Inter Partes Review of U.S. 7,787,431
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`exercise of control over the IPR proceedings. Id. (rejecting privity argument where
`
`there was no evidence that non-petitioning defendants were involved in preparation
`
`of IPR petition); see also Official Patent Trial Guide, 77 Fed. Reg. at 48759-60.
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`Here, Ericsson is a completely distinct entity from the wireless-carrier defendants,
`
`was solely responsible for the pursuit of the IPR petitions, and funded and prepared
`
`the IPR petitions entirely on its own.
`
`V. Relief Requested
`
`Petitioner asks that the Board review the accompanying prior art and
`
`analysis, institute a trial for inter partes review of claims 8-12 and 18-22 of the
`
`’431 patent, and cancel those claims as unpatentable.
`
`VI. The Reasons for the Requested Relief
`
`A.
`
`Summary of the Related Technology and the ’431 Patent
`
`The ’431 patent relates generally to multi-carrier communication systems,
`
`such as systems that employ orthogonal frequency division multiplexing (OFDM).
`
`See ERIC-1001, 1:43-47 and 2:36-38; see also ERIC-1012, ¶ 19. “A basic
`
`structure of a multi-carrier signal in the frequency domain is made up of
`
`subcarriers and, illustrated in FIG. 3, which shows three types of subcarriers” –
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`data subcarriers, pilot subcarriers, and silent subcarriers. ERIC-1001, 3:23-32.
`
`Note that in Fig. 3, which is admitted prior art, subcarriers are grouped as various
`
`subchannels. The ’431 patent describes a rationale for the subcarrier groupings
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`
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`8
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`Petition for Inter Partes Review of U.S. 7,787,431
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`that “[t]he data subcarriers can be arranged into groups called subchannels to
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`support scalability and multiple-access.” Id., 3:33-34.
`
`The claims of the ’431 patent conceptually relate to and can be divided into
`
`three aspects of communication technology: (1) characteristics of a core-band; (2)
`
`a primary preamble, which is transmitted in the core-band; and (3) variable
`
`bandwidth multi-carrier systems. For the sake of example, claim 8 is reproduced
`
`below, annotated to show the three aspects identified above. These aspects form a
`
`conceptual framework for understanding the claims. See ERIC-1012, ¶¶ 24-25.
`
`8. A cellular base station comprising:
`[Aspect (1) – core-band]
`circuitry configured to transmit a broadcast channel in an
`orthogonal frequency division multiple access (OFDMA) core-band,
`wherein the core-band is substantially centered at an operating
`center frequency and the core-band includes a first plurality of
`subcarrier groups,
`wherein each subcarrier group
`subcarriers,
` [Aspect (2) –primary preamble]
`wherein the core-band is utilized to communicate a primary
`preamble sufficient to enable radio operations,
`the primary preamble being a direct sequence in the time
`domain with a frequency content confined within the core-band or
`being an OFDM symbol corresponding to a particular frequency
`pattern within the core-band,
`
`includes a plurality of
`
`
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`9
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`Petition for Inter Partes Review of U.S. 7,787,431
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`
`wherein properties of the primary preamble comprise:
`an autocorrelation having a large correlation peak with
`respect to sidelobes;
`a cross-correlation with other primary preambles having a
`small cross-correlation coefficient with respect to power of other
`primary preambles; and
`a small peak-to-average ratio; and
`wherein a large number of primary preamble sequences exhibit
`the properties; and
`[Aspect (3) – variable bandwidth multi-carrier systems]
`circuitry configured to transmit control and data channels using
`a variable band including a second plurality of subcarrier groups,
`wherein the variable band includes at least the core-band.
`
`As explained later in the prosecution history section below, the Examiner
`
`concluded that the first and third aspects were part of the prior art, and the
`
`Applicant did not contest the findings. Instead, it was the second aspect relating to
`
`the specific properties of the preamble that resulted in claim allowance, specific
`
`properties that were discussed at IEEE meetings pre-dating the ’431 patent. See
`
`supra, Section III. We agree with the Examiner that aspect (1), characteristics of a
`
`core-band, and aspect (3), variable bandwidth multi-carrier systems, were well
`
`known in the art. Furthermore, additional references provided herein, which were
`
`not considered by the Examiner, disclose claim aspect (2) – a primary preamble
`
`with specific properties, which is transmitted in the core-band.
`
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`10
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`Petition for Inter Partes Review of U.S. 7,787,431
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`More specifically, and referring to claim aspect (1), the ’431 patent explains
`
`that a core-band can be used to transmit various control signals: “[i]n one
`
`embodiment relevant or essential radio control signals such as preambles, ranging
`
`signals, bandwidth request, and/or bandwidth allocation are transmitted within the
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`CB.” Id., 5:8-13 (emphasis added). An example of a narrow band to transmit
`
`control signals in an OFDM system is disclosed in U.S. Patent No. 7,782,750
`
`(“Yamaura”). Control signals in Yamaura are transmitted in a broadcast preamble
`
`using subcarriers centered at an operating frequency. Hwang discloses multiple
`
`operating bandwidths, within which Yamaura’s control signals may be centered.
`
`Referring to claim aspect (3), the ’431 patent states: “In some embodiments,
`
`the variable channel bandwidth is realized by adjusting the number of usable
`
`subcarriers.” ERIC-1001, 4:25-26. In one embodiment, “[t]he variable channel
`
`bandwidth is realized by adjusting the number of usable subcarriers, whose spacing
`
`is set constant.” Id., 4:41-42. According to the equations in Fig. 2, which is
`
`admitted prior art, bandwidth is proportional to the number of subcarriers. See id.,
`
`Fig. 2 and ERIC-1012, ¶ 21. The same concepts are disclosed in U.S. Publication
`
`No. 2002/0055356 (“Dulin”) utilized below to illustrate these prior art features.
`
`Hwang also discloses variable bands utilizing different numbers of subcarriers.
`
`Referring to claim aspect (2), which was added during prosecution to gain
`
`allowance of the claims, claim 8 recites certain properties for the preamble
`
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`11
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`Petition for Inter Partes Review of U.S. 7,787,431
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`sequences, including autocorrelation, cross-correlation, and peak-to-average ratio
`
`properties. The ’431 patent specification does not disclose any examples of
`
`preamble structures achieving the desired properties and how they would have
`
`been implemented with the other elements of the system set forth in the
`
`specifications. Nevertheless, it was well known to utilize preamble sequences with
`
`the claimed properties. For example, as explained herein, U.S. Patent No.
`
`7,426,175 (“Zhuang”) discloses a large number of preamble sequences with the
`
`requisite autocorrelation, cross-correlation, and peak-to-average ratio properties.
`
`Additionally, Kerr discloses that a POSA would have recognized that these
`
`properties are desirable.
`
`Accordingly, as demonstrated herein, features of the claims of the ’431
`
`patent related to these three aspects – (1) characteristics of a core-band; (2) a
`
`primary preamble, which is transmitted in the core-band; and (3) variable
`
`bandwidth multi-carrier systems – were well-known in the art at the time the ’431
`
`patent was filed.
`
`B.
`
`The Prosecution History
`
`Prosecution claim 22 added in a Response to a Non-Final Office Action,
`
`filed on September 28, 2009, eventually became claim 8 of the ’431 patent. See
`
`ERIC-1010, p. 152. Prosecution claim 22 was rejected as being unpatentable over
`
`two publications in an office action dated January 7, 2010. ERIC-1010, pp. 118-
`
`
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`12
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`Petition for Inter Partes Review of U.S. 7,787,431
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`120. According to the Examiner, one reference disclosed a core-band, and the
`
`second reference disclosed a variable band. Id. After a final rejection, the
`
`Applicants amended claim 22 (see id., p. 53) to add the entirety of aspect (2) (i.e., a
`
`primary preamble with
`
`the recited autocorrelation/cross-correlation/peak-to-
`
`average power properties), described above with reference to claim 8. See id., pp.
`
`71-72. In explaining the allowable subject matter, the Examiner stated that the
`
`prior art “discloses a variable bandwidth system by adjusting the number of
`
`subcarriers,” and “discloses a primary channel with a central channel in which
`
`dynamic link assignment is constrained in the central channel to maintain
`
`synchronization,” which correspond to aspects (1) and (3), above. See id., pp. 53-
`
`54. As explained in further detail below, references provided herein, which were
`
`not before the Examiner, teach the features of aspects (1), (2) and (3).
`
`C. The Prior Art of the Present Petition
`
`Dulin. U.S. Publication No. 2002/0055356 (“Dulin”), having a publication
`
`date of May 9, 2002, qualifies as prior art under 35 U.S.C. § 102(b)(pre-AIA).
`
`Dulin relates to scheduling data transmissions in frequency blocks and time slots in
`
`a base station. For example, Dulin states:
`
`the invention is embodied in an apparatus and a method for
`scheduling wireless transmission of data blocks… The scheduling
`generally includes assigning frequency blocks and time slots to each
`of the receiver units for receiving or transmitting data blocks.
`
`
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`13
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`ERIC-1002, ¶ [0048] (emphasis added).
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`Petition for Inter Partes Review of U.S. 7,787,431
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`Dulin’s frequency blocks are presented in the context of cellular wireless
`
`communication systems that employ OFDM modulation along with multiple
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`access (“OFDMA”). See id. at ¶¶ [0121-0124]; see also ERIC-1012, ¶¶ 44-49.
`
`For example, Dulin’s Fig. 12 illustrates an OFDM signal with multiple subcarriers.
`
`Dulin provides a further example in which “[a]n example OFDM signal occupying
`
`6 MHz is made up of 1224 individual carriers (or tones), each carrying a single
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`QAM symbol per burst.” ERIC-1002, ¶ [0124]. “Data blocks […] are transmitted
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`[…] over different frequency ranges or blocks than each other. The different
`
`frequency ranges can be defined as different groupings or sets of the above-
`
`described OFDM symbols.” Id., ¶ [0126]. Each of the aforementioned QAM
`
`symbols corresponds to a single carrier or tone, so the different frequency ranges
`
`refer to different groups of subcarriers or tones. See ERIC-1012, ¶ 47.
`
`Dulin describes assigning (or scheduling) frequency blocks and time slots in
`
`a frame to various subscriber units using a frame map. For example, Dulin recites,
`
`“[a] map of the schedule is include within every frame for the purpose of
`
`indicating to each receiver unit when and at what frequency data blocks requested
`
`by the receiver unit will be transmitted, and when and at what frequency data
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`blocks can be transmitted from the receiver unit.” ERIC-1002, ¶ [0056]. The map
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`
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`Petition for Inter Partes Review of U.S. 7,787,431
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`provides flexibility in which frequency blocks and at what time slots are assigned
`
`to a receiver. See ERIC-1012, ¶ 45.
`
`Bandwidth dedicated to a user is variable because the map provides
`
`flexibility in the number of frequency blocks assigned to a user per time slot and
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`also because the maximum occupied bandwidth can vary. Regarding bandwidth,
`
`Dulin states: “It is to be understood that the number of frequency blocks allocated
`
`per time slot is variable. An embodiment of the scheduler includes the scheduler
`
`taking into consideration constraints on the frequency bandwidth on either the up
`
`link or the down link transmission. The frequency bandwidth allocations can be
`
`adjusted by varying the number of frequency blocks within a time slot.” ERIC-
`
`1002, ¶ [0158]. Thus, a number of either or both of the available frequency
`
`blocks (or groups of subcarriers) and the occupied frequency slots can be varied
`
`from time slot to time slot.
`
`Hwang. I. Hwang et al., IEEE C802.16d-04/19, “A New Frame Structure
`
`for Scalable OFDMA Systems,” pp. 0-12, March 11, 2004 (“Hwang”) qualifies as
`
`prior art under 35 U.S.C. § 102(a) (pre-AIA).
`
`Hwang is directed to a frame structure for scalable OFDMA cellular
`
`systems. For example, the title states “A New Frame Structure for Scalable
`
`OFDMA Systems.” ERIC-1005, Title. Hwang further discloses OFDMA systems
`
`having a plurality of possible system bandwidths, which are example operating
`
`
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`15
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`channel bandwidths. See, e.g., ERIC-1005, Table 1; see also ERIC-1012, ¶ 85.
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`Petition for Inter Partes Review of U.S. 7,787,431
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`As seen from Table 1 of Hwang, the disclosed OFDMA systems have a
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`plurality of operating channel bandwidths (e.g., 2.5 MHz, 5 MHz, 10 MHz, and 20
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`MHz). The bandwidth is varied by varying the number of subcarriers. See ERIC-
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`1012, ¶ 86. For example, the number of used subcarriers is 216 for a 2.5 MHz
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`bandwidth, 432 for a 5 MHz bandwidth, and so on. See id.
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`Yamaura. U.S. Patent No. 7,782,750 (“Yamaura”), having a priority date of
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`February 20, 2003, qualifies as prior art under 35 U.S.C. § 102(e)(pre-AIA).
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`Yamaura “relates to a radio communication method, a radio communication
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`system, [and] a radio communication base station … particularly suitable for radio
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`transmission based on OFDM modulation (Orthogonal Frequency Division
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`Multiplexing).” ERIC-1003, 1:10-18. Furthermore, “[t]he present invention was
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`completed to reduce loads in a base station or a terminal station when control
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`signals are transmitted from a base station to a terminal station in the radio
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`communication system of the type mentioned above.” Id., 5:64-67.
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`Yamaura discloses the use of a 20 MHz transmission band that is either
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`processed in full by the terminal station receivers or a narrow band less than 20
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`MHz, but within the same 20 MHz transmission band, that is processed for control
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`signals by the terminal station receivers. See ERIC-1012, ¶ 57. Yamaura’s control
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`signals are transmitted in a band narrower than that for the 20 MHz transmission
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`16
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`Petition for Inter Partes Review of U.S. 7,787,431
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`band data signals as a way to “reduce loads in a base station or a terminal station.”
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`ERIC-1003, 5:64-65.
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`Yamaura points out that in conventional OFDM systems “the signal to call a
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`terminal station from a base station is transmitted, with all information placed on
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`subcarriers in the transmission band, and the called terminal station receives all the
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`subcarriers to receive the calling signal. This means that the terminal station has to
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`receive and decode the band signal (corresponding to 20 MHz) every 2 ms
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`regardless of presence or absence of data being transmitted and received. It
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`follows, therefore, that large quantities of signals have to be processed even when
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`no information data is transmitted and received.” Id., 5:39-46. In order to address
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`this issue, Yamaura discloses a system in which “part of control signals addressed
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`to a terminal station from a base station is transmitted by means of a carrier whose
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`band is narrower than that for said multi-carrier signals […]” Id., 6:5-8. An
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`example of control signals narrower than that for a multi-carrier signal is presented
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`in Fig. 16, reproduced below. In the figure, subcarriers SC1 and SC2 carry control
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`signals. See, e.g., id., 21:11-15.
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`The control signals in Yamaura are transmitted in a broadcast preamble
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`using the subcarriers centered at an operating frequency. See ERIC-1012, ¶ 63.
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`For example, referring to Fig. 17, “[t]he broadcast burst consists of BCH for the
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`multiple addressing of broadcast preamble and base station information, FCH to
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`Petition for Inter Partes Review of U.S. 7,787,431
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`inform each terminal station of the traffic channel allocation in the same frame,
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`and ACH for reply to RCH used for calling from the terminal station. In the case of
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`this embodiment, the two subcarriers SC1 and SC2 shown in FIG. 16 are used for
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`transmission of specific control signals in the sections of broadcast preamble,
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`BCH, and FCH in the broadcast burst.” ERIC-1003, 21:7-15 (emphasis added).
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`Fig. 17 is reproduced below (color annotations added). See ERIC-1012, ¶ 63.
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`In Yamaura, the narrowband control signals, such as those transmitted using
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`SC1, and SC2 above, are used to provide a call signal to a terminal station so that
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`the terminal station can judge whether the terminal station is being called. See
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`ERIC-1012, ¶ 73. “Part of the control signals to be transmitted from the base
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`station to the terminal station by means of the narrow-band carrier is, for example,
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`a call signal to call terminal stations individually or as a group. Upon reception of
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`this call signal, the terminal station can judge that there is a call from the base
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`station.” ERIC-1003, 10:58-63.
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`18
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`Petition for Inter Partes Review of U.S. 7,787,431
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`Cross correlation detection is used to detect the narrowband control signal.
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`ERIC-1012, ¶ 71. For example, “FIG. 15 shows the constitution of the control
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`signal receiving unit 242 in the terminal station shown in FIG. 6. It is so
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`constructed as to receive the control signal by means of simple cross correlation
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`detection.” ERIC-1003, 19:64-67 (emphasis added). Thus, Yamaura recognizes the
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`transmission of preambles in a narrowband frequency segment as well as using
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`cross correlation to detect the presence of the control signals in the preamble.
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`Zhuang. U.S. Patent No. 7,426,175 (“Zhuang”), having a priority date of March
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`30, 2004, qualifies as prior art under 35 U.S.C. § 102(e)(pre-AIA). Zhuang
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`addresses a “need [that] exists for a method and apparatus for pilot signal or
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`preamble transmission that optimizes both the cross correlation between pilot
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`signals, as well as optimizing each pilot signal’s auto correlation.” ERIC-1004,
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`2:7-10. Zhuang describes properties of “Generalized Chirp-Like” sequences,
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`which are used as preambles in an OFDM system and include good autocorrelation
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`and crosscorrelation, and low PAPR. See ERIC-1004 2:55-58, 5:9-15, and 5:55-
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`6:15; see also ERIC-1012, ¶ 79.
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`Kerr. A. Kerr, IEEE C802.16d-04/36r2, “Additional Preamble Definitions for
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`802.16d OFDM-256,” March 17, 2004 (“Kerr”) qualifies as prior art under 35
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`U.S.C. § 102(a) (pre-AIA).
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`Petition for Inter Partes Review of U.S. 7,787,431
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`Kerr explains that the following properties were desirable in preambles:
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`“Low PAR [peak-to-average ratio] required” and “[g]ood auto-correlation and
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`cross-correlation properties required.” ERIC-1009, p. 5. Kerr is a published
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`invitation to 802.16 members interested in preamble design to discuss preambles
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`with the desired properties at an IEEE meeting. See id., p. 6.
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`Hwang and Kerr are Prior Art Under At Least 35 U.S.C. § 102(a)
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`Under 35 U.S.C. § 102(a), “a printed publication in this or a foreign country,
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`before the invention . . . by the applicant for patent”