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`UNITED STATES PATENT AND TRADEMARK OFFICE
`_____________
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`BEFORE THE PATENT TRIAL AND APPEAL BOARD
`_____________
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`CISCO SYSTEMS, INC.
`Petitioner
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`v.
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`TQ DELTA, LLC
`Patent Owner
`_____________
`
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`Case No. IPR2016-01021
`Patent No. 8,718,158
`_____________
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`PATENT OWNER PRELIMINARY RESPONSE
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`Filed on behalf of TQ Delta, LLC
`By: Peter J. McAndrews
`Thomas J. Wimbiscus
`Scott P. McBride
`Christopher M. Scharff
`Andrew B. Karp
`McAndrews, Held & Malloy, Ltd.
`500 W. Madison St., 34th Floor
`Chicago, IL 60661
`Tel: 312-775-8000
`Fax: 312-775-8100
`E-mail: pmcandrews@mcandrews-ip.com
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`I.
`II.
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`TABLE OF CONTENTS
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`INTRODUCTION ......................................................................................... 1
`INTRODUCTION TO “MULTICARRIER”
`COMMUNICATIONS TECHNOLOGY AND PEAK-TO-
`AVERAGE RATIO (“PAR”) ....................................................................... 2
`III. OVERVIEW OF ASSERTED REFERENCES—SHIVELY AND
`STOPLER ....................................................................................................... 6
`A. Shively ..................................................................................................... 6
`B. Stopler ................................................................................................... 11
`IV. CLAIM CONSTRUCTION ........................................................................ 11
`V. NO REVIEW SHOULD BE INSTITUTED WITH RESPECT
`TO THE GROUNDS RAISED BY PETITIONER .................................. 12
`A. Shively Does Not Present a PAR Problem ......................................... 13
`B. Shively’s Technique Contributes a De Minimis Amount of
`Power to the Transmission Signal ...................................................... 15
`C. Stopler is an Ambiguous Reference That Does Not Teach
`Solving PAR Problems ........................................................................ 16
`D. Petitioner’s Rationale for Combining Shively and Stopler
`Suffers From Hindsight Bias .............................................................. 18
`VI. CONCLUSION ............................................................................................ 21
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`TABLE OF AUTHORITIES
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`
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`Cases
`ActiveVideo Networks, Inc. v. Verizon Communications, Inc.,
`694 F.3d 1312 (Fed. Cir. 2012) ............................................................................ 19
`Apple Inc. v Contentguard Holdings, Inc.,
`IPR2015-00441, paper 11, p. 23 .......................................................................... 20
`Billy Goat Industries, Inc., v. Schiller Grounds Care, Inc.,
`IPR2014-00742, paper 8, p. 31 ............................................................................ 20
`Directv, LLC v. Qurio Holdings, Inc.,
`IPR2015-02006, paper 6, pp. 11–12 .................................................................... 20
`Grain Processing Corp. v. Am. Maize-Prods. Co.,
`840 F.2d 902 (Fed. Cir. 1988) .............................................................................. 20
`In re Fritch,
`972 F.2d 1260 (Fed. Cir. 1992) ............................................................................ 20
`In re Hughes,
`345 F.2d 184 (C.C.P.A. 1965) .............................................................................. 18
`In re Turlay,
`304 F.2d 893 (C.C.P.A. 1962) .............................................................................. 18
`KSR Int’l Co. v. Teleflex Inc.,
`550 U.S. 398 (2007) .............................................................................................. 19
`Masterimage 3D, Inc., v. Reald Inc.,
`IPR2015-00876, paper 10, p. 16 .......................................................................... 20
`Microsoft Corp. v. Bradiuim Technologies LLC,
`IPR2015-01435, paper 15, p. 22 .......................................................................... 20
`Milwaukee Electric Tool Corp. v. Irwin Industrial Tool Co.,
`IPR2015-01461, paper 7, p. 18 ............................................................................ 20
`Mitsubishi Chemical Corp. v. Barr Laboratories, Inc.,
`435 Fed. Appx. 927 (Fed. Cir. 2011) ................................................................... 18
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`Panduit Corp. v. Dennison Mfg. Co.,
`810 F.2d 1561 (Fed. Cir. 1987) ............................................................................ 19
`Power-One, Inc. v. Artesyn Techs., Inc.,
`599 F.3d 1343 (Fed. Cir. 2010) ............................................................................ 19
`Qualcomm, Inc. v. Parkervision, Inc.,
`IPR2015-01822, paper 8, p. 20 ............................................................................ 20
`See Wellman, Inc. v. Eastman Chem. Co.,
`642 F.3d 1355 (Fed. Cir. 2011) ............................................................................ 12
`Statutes
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`35 U.S.C. § 103(a) ........................................................................................12, 13, 22
`35 U.S.C. §§ 42.107 ................................................................................................. 24
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`Patent Owner’s Preliminary Response
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`I.
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`INTRODUCTION
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`Patent Owner TQ Delta, LLC (“TQ Delta” or “Patent Owner”) submits this
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`preliminary response to the Petition filed by Cisco Systems, Inc. (“Cisco” or
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`“Petitioner”) requesting inter partes review of claims 1–30 of U.S. Pat. No.
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`8,718,158 (“the ’158 patent”).
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`The Petition fails to demonstrate a reasonable likelihood that any of claims
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`1–30 of the ’158 patent are unpatentable. In every instance, Petitioner alleges that
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`the challenged claims are unpatentable as being obvious over at least U.S. Pat. No.
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`6,144,696 (“Shively”) in view of U.S. Pat. No. 6,625,219 (“Stopler”).
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`But Petitioner’s rationale for combining Shively and Stopler is insufficient
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`because it is premised on flawed assumptions and hindsight.
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`In particular, Petitioner and its expert incorrectly assume that Shively
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`transmits signals having a high peak-to-average power ratio (“PAR”). According
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`to Petitioner, a person having ordinary skill in the art (“PHOSITA”) would have
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`looked to Stopler to cure Shively’s PAR problem. Shively’s transmission signals,
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`however, do not have a problem with PAR. Without Petitioner’s incorrect
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`assumption, Petitioner’s rationale for combining Shively and Stopler falls apart.
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`And even if Shively did disclose signals with high PAR (it plainly does not),
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`a PHOSITA would not have looked to Stopler, which does not even mention the
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`word “power” or PAR, or purport to address issues relating to PAR. Because of
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`this, the only reason Petitioner and its expert are able to provide for looking to
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`Stopler to address a (nonexistent) PAR issue with Shively is based exclusively on
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`the roadmap provided by the ’158 patent. Petitioner’s argument for combining
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`Shively and Stopler is nothing more than impermissible hindsight.
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`II.
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`INTRODUCTION TO “MULTICARRIER” COMMUNICATIONS
`TECHNOLOGY AND PEAK-TO-AVERAGE RATIO (“PAR”)
`The ’158 patent discloses a system that communicates using multicarrier
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`signals. Ex. 1001 at 1:28–31. A multicarrier signal includes a number of carrier
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`signals (or carriers) each operating at a different frequency. Each carrier signal is
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`modulated to encode one or more bits (i.e., “1” or “0”). The carrier signals
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`effectively serve as separate sub-channels for carrying data. The carrier signals are
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`combined as a group to produce a transmission signal, which is transmitted across
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`a transmission medium (e.g., phone lines, coaxial cable, the air, etc.) to a receiver.
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`In an example illustrated below, four carriers—Carrier 1, Carrier 2, Carrier
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`3, and Carrier 4—are combined simultaneously into one transmission signal.
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`Multicarrier systems may use the phase of carriers to encode different bit
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`values. In the example above, a carrier with a phase of zero represents a bit value
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`of “0”; conversely, a carrier with a phase-shift of π (or 180°) represents a bit value
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`of “1”. In this example, Carriers 1, 2, and 4 have a phase-shift of π, and therefore
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`each represent a “1”. Carrier 3 has as phase of zero, and therefore represents a “0”.
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`Together, these four carriers encode input bits having binary values of 1, 1, 0, and
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`1. This information is transmitted as a single transmission signal—that is, the
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`irregular waveform shown above on the right side of the figure. In practice, a
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`multicarrier transmission signal will typically comprise a combination of many
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`more than four carriers (e.g., hundreds or even thousands of carriers) and in this
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`way can substantially increase the “speed” or data carrying capacity of the system.1
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`A multicarrier transmission signal can be characterized by a metric known
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`as “PAR,” which stands for peak-to-average ratio or peak-to-average power ratio.
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`Ex. 1001 at 1:64–67. As the ’158 patent explains, “The PAR of a transmission
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`signal is the ratio of the instantaneous peak value (i.e., maximum magnitude) of a
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`signal parameter (e.g., voltage, current, phase, frequency, power) to the time-
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`average value of the signal parameter.” Id. at 1:67–2:4. The ’158 patent
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`continues: “The PAR of a transmission signal transmitted and received in a DMT
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`[multicarrier] communication system is an important consideration in the design
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`of the DMT communication system because the PAR of a signal affects the
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`communication system’s total power consumption and component linearity
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`requirements of the system.” Id. at 2:10–16. “An increased PAR can result in a
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`system with high power consumption and/or with high probability of clipping the
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`transmission signal.” Id. at 2:27–29.
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`1 An additional way in which the data carrying capacity of a multicarrier system
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`may be increased is the use of modulation schemes that allow sending more than
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`one bit at a time on each carrier. For example, using QPSK (“Quadrature Phase
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`Shift Keying”) modulation on a carrier would allow sending two bits to be sent at a
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`time on that carrier; using QAM (“Quadrature Amplitude Modulation”) on a
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`carrier would allow sending four or more bits at a time on that carrier.
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`A high PAR can occur when a large number (or percentage) of the carriers
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`have the same phase. The ’158 patent recognized that: “If the phase of the
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`modulated carriers [in a transmission signal] is not random, then the PAR can
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`increase greatly.” Id. at 2:17–18. The phases of the carriers would not be
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`“random,” for example, when the underlying data being modulated is repetitive
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`(e.g., a long string of 0s or a long string of 1s), or where the same data is
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`purposely sent in a redundant manner on multiple carriers. In the example below,
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`all 25 of the carriers have the same phase of zero. Because the carrier signals are
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`“in-phase,” their amplitudes will add together to create a transmission signal
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`(illustrated on the right side of the figure below) having large spikes in amplitude
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`and, therefore, a high PAR.
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`III. OVERVIEW OF ASSERTED REFERENCES—SHIVELY AND
`STOPLER
`In every instance, Petitioner alleges that the challenged claims are
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`unpatentable at least over Shively in view of Stopler.
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`A.
`Shively
`Shively discloses a technique that increases the useable bandwidth in a
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`multicarrier communications system. Ex. 1011 at 1:5–20. Shively teaches a
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`technique to transmit data over very noisy or attenuated carriers (also referred to
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`as subcarriers, sub-bands, bins, or channels).2 According to Shively’s technique,
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`data can be transmitted on carriers “with otherwise insufficient power margins to
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`carry a single bit….” Ex. 1011 at 3:61–63. To do this, Shively “spreads” a single
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`bit across several carriers. Id. at Abstract and 11:16–20.
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`Shively explains the problem of reduced capacity carriers with reference to
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`FIG. 1, which is annotated and illustrated in color below.
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`2 Shively, and the art in general, uses the terms “carrier,” “subcarrier,” “sub-band,”
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`“bin,” and “channel” interchangeably. Ex. 1011 at 1:42–43 (“a transmission
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`frequency band is separated into N sub-bands or frequency bins”); id. at 1:48
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`(“sub-band channels”); id. at 5:13–15 (“carrier”); id. at 10:40–41 (“subcarriers”);
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`id. at 12:39 (“bin (channel)”). For consistency, Patent Owner has used the term
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`“carrier” as much as possible in this Patent Owner Preliminary Response.
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`FIG. 1 of Shively shows carriers at increasing frequencies along the x-axis.
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`Each sub-band is delineated by vertical lines. Power level is indicated along the y-
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`axis. The green line (A) represents an attenuation/noise floor, which increases as a
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`function of frequency. Id. at 2:1–12. Attenuation may particularly be a problem
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`across long cables. Id. at 9:65–10:2. Green line (A) is a characteristic of a
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`communications channel, and it does not illustrate a transmitted signal. Id. at
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`10:61–11:12.
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`The blue line (B) is the minimum margin that is required to transmit a single
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`bit. Id. at 2:8–10. The red line (C) represents the signal power limit imposed by
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`system design. More particularly, the red line (C) “represents the limits imposed
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`by a power spectral density mask imposed by an external communications
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`standard.” Id. at 2:10–12.
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`As FIG. 1 illustrates, the blue line (B) is below the red line (C) for the
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`carriers shaded in purple. In these carriers, there is sufficient headroom to transmit
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`a signal representing at least one bit without exceeding a power limit. For the
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`carriers shaded in orange, however, the blue line (B) exceeds the red line (C).
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`Because the noise and attenuation for these carriers is so high (A), a bit cannot be
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`reliably transmitted without exceeding the imposed limit. In other words, the
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`minimum required margin (B) is greater than the signal power limit (C). Id. at
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`10:65–11:3.
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`Shively proposes a way to transmit data on the otherwise unusable carriers
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`(shaded in orange). Specifically, signals with an identical phase are sent across
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`multiple carriers at reduced power or energy levels. These signals sent at reduced
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`power levels are recombined at the receiver to recover the information.
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`replicates
`invention, digital modulator 14
`the
`to
`According
`(“spreads”) a k-bit symbol over multiple adjacent bands with
`correspondingly less energy in each band. At the receiving end,
`detector 49 coherently recombines (“despreads”) the redundant
`symbols in the noisy/attenuated sub-bands. In recombining the
`symbols, the symbols are simply arithmetically added. Because the
`noise is incoherent while the signal is coherent, the noise tends to be
`averaged out while the signal is reinforced by the addition process.
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`Id. at 11:16–24.
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`In numerous other places, Shively confirms that transmission of signals with
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`the same phase on impaired carriers is performed at reduced power levels. Id. at
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`Abstract (“assigning additional bits to sub-bands with otherwise insufficient power
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`margins to carry a single bit, by frequency-domain-spreading a single bit across
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`several sub-bands at correspondingly reduced power levels”); 3:61–65 (“assigning
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`additional bits to sub-bands with otherwise insufficient power margins to carry a
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`single bit, by frequency-domain-spreading a single bit across several sub-bands at
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`correspondingly reduced power levels”); 5:13–15 (“In both of the above schemes,
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`the signal power in each frequency carrier is reduced in proportion to the number
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`of carriers used.”); 6:54–56 (“allocating bits to multiples of the channel
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`frequencies for transmission at reduced power rates per channel frequency”).
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`Shively explains in detail how the power level of the reduced-power carriers
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`is chosen. Initially, the number of bins for spreading is selected. This number is
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`preferably four. Id. at 13:35–52 (“An index is set to 1 and a number of bins for
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`spreading
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`(the number of channels over which each block will be
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`spread)…Empirical studies of actual telephone loop propagation characteristics
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`indicates the payoff is greatest for making the number of bins, m, equal to 4 under
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`this set of conditions.”).
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`Then, the transmission power required to transmit one bit in a bin used for
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`“spreading” is calculated. Generally, as Shively explains, the power required to
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`transmit bk bits is given by Eq. 1:
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`“where: bk is the number of bits carried in frequency bin k, Ek is the power required
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`in bin k to transmit the bk bits, gk/Nk is the measured gain to noise ratio in bin K,
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`and Gc is the coding gain.” Id. at 13:58–14:2 (emphasis added).
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`In Shively’s spreading technique, a single bit is spread across several
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`carriers at reduced power levels:
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`Since the second procedure for allocating bits to the impaired
`channels (the channels for which the SNR ratio does not permit a bit
`to be transmitted without hitting the PSD mask limit) allocates one bit
`at a time, bk can be set to 1 and equation (1) thus reduces to (also
`dividing by 4 to account for the spreading):
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`Id. at 14:23–32 (referencing Eq. 5) (emphasis and color annotation added).
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`Therefore, Shively teaches that when a signal with the same phase is sent
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`over multiple impaired carriers (e.g., four carriers), the power used to transmit on a
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`given carrier is reduced proportionally (divided) by the number of carriers used for
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`spreading (e.g., divided by four as shown in Eq. 5 above).
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`Thus, despite the fact that a signal with the same phase will be transmitted
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`on multiple carriers, high spikes or peaks in the combined signal will not result
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`because the additive in-phase signals each individually have a reduced power. In
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`other words, contrary to Petitioner’s assumption, Shively does not present a high
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`PAR problem.
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`B.
`Stopler
`Stopler discloses a multicarrier (or multitone modulated) communications
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`system that improves impulse burst immunity by performing interleaving. Ex.
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`1012 at 1:8–11 and 1:42–49. Stopler also discloses that phases of symbols can be
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`scrambled. Id. at 12:24–28. The only stated reason for scrambling phases in
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`Stopler is “to randomize the overhead channel symbols.” Id. at 12:24-26. Stopler
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`is silent on issues related to PAR, and, in fact, does not mention the word “power”
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`or PAR, or teach that its disclosure could be used to resolve PAR problems.
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`IV. CLAIM CONSTRUCTION
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`It is not necessary at this stage of the proceedings to construe any claim
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`terms.3
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` While Petitioner proposes claim constructions
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`for
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`two
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`terms
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`(“multicarrier” and “transceiver”), it is not necessary to construe these terms to
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`decide whether or not to institute trial. See Wellman, Inc. v. Eastman Chem. Co.,
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`3 In a related litigation, Patent Owner has proposed constructions for a number of
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`claim terms in the ’158 patent. See Ex. 2001. The district court in that case has
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`not yet construed any of these terms.
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`642 F.3d 1355, 1361 (Fed. Cir. 2011) (“[C]laim terms need only be construed to
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`the extent necessary to resolve the controversy.”) (internal quotation omitted).
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`Rather, for the reasons discussed below, even under the claim constructions
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`proposed by Petitioner, no trial should be instituted.
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`V. NO REVIEW SHOULD BE INSTITUTED WITH RESPECT TO THE
`GROUNDS RAISED BY PETITIONER
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`The Petition alleges five grounds of unpatentability against the claims of
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`the ’158 patent:
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` Ground 1: Unpatentability of claims 1, 2, 4, 15, 16, and 18 under 35
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`U.S.C. § 103(a) over Shively and Stopler;
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` Ground 2: Unpatentability of claims 3, 5, 14, 17, 19, and 28–30
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`under 35 U.S.C. § 103(a) over Shively, in view of Stopler, and further
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`in view of U.S. Pat. No. 6,424,646 (“Gerszberg”);
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` Ground 3: Unpatentability of claims 6, 9, 10, 12, 20, 23, 24, and 26
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`under 35 U.S.C. § 103(a) over Shively, in view of Stopler, and further
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`in view of U.S. Pat. No. 4,924,516 (“Bremer”);
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` Ground 4: Unpatentability of claims 8, 11, 13, 22, 25, and 27 under
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`35 U.S.C. § 103(a) over Shively, in view of Stopler, in view of
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`Bremer, and further in view of Gerszberg; and
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` Ground 5: Unpatentability of claims 7 and 21 under 35 U.S.C.
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`§ 103(a) over Shively, in view of Stopler, and in view of Bremer, and
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`further in view of U.S. Pat. No. 5,515,369 (“Flammer”).
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`All five grounds rely on a combination of Shively and Stopler.
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`However, no review should be instituted because Petitioner has not provided a
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`sufficient rationale to combine Shively and Stopler.
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`A.
`Shively Does Not Present a PAR Problem
`Petitioner’s assertion of unpatentability
`relies on an
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`incorrect
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`assumption—namely, that Shively’s transmitter suffers from an increased
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`peak-to-average power ratio (PAR). Petition at p. 14. This is not true. Shively
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`is silent on the issue of PAR. The entirety of Petitioner’s rationale to combine
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`Shively and Stopler rests on the untenable assertion that Shively has a PAR
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`problem. Id. at pp. 14–16. Because Petitioner has failed to show that a
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`PHOSITA would have concluded that Shively’s transmitter suffers from
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`increased PAR, Petitioner’s theory of unpatentability unravels.
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`Claim 1 is illustrative, and recites:
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`1. In a multicarrier modulation system including a first transceiver
`in communication with a second transceiver using a transmission
`signal having a plurality of carrier signals for modulating a
`plurality of data bits, each carrier signal having a phase
`characteristic associated with at least one bit of the plurality of
`data bits, a method for scrambling the phase characteristics of
`the carrier signals comprising:
`transmitting the plurality of data bits from the first transceiver to
`the second transceiver;
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`signal with a value determined
`associating a carrier
`independently of any bit of the plurality of data bits carried by
`the carrier signal, the value associated with the carrier signal
`determined by a pseudo-random number generator;
`determining a phase shift for the carrier signal at least based on
`the value associated with the carrier signal;
`modulating at least one bit of the plurality of data bits on the
`carrier signal;
`modulating the at least one bit on a second carrier signal of the
`plurality of carrier signals.
`Ex. 1001 at 10:59–11:11 (emphasis added).
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`Petitioner does not allege that the primary reference (Shively) discloses
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`the above-emphasized phase scrambling recitations. Instead, Petitioner relies
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`on Stopler. Petition at pp. 22–23 and 25–26. Petitioner further asserts that a
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`combination of Shively and Stopler would have been obvious because:
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`A POSITA would have recognized that by transmitting redundant
`data on multiple carriers, Shively’s transmitter would suffer from
`an increased peak-to-average power ratio. This increase is due to
`the fact that the overall transmitted signal in a multicarrier system
`is essentially the sum of its multiple subcarriers. When N
`subcarrier signals with the same phase are added together, they
`have a peak power which is N times greater than their individual
`maximum powers.
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`***
`Stopler provides a solution for reducing PAR of a multicarrier
`transmitter.
`Id. at p. 14–15 (internal citations removed); see also Ex. 1009 at ¶¶ 63 and 67.
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`As discussed supra in Section III.A, however, Shively reduces the
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`individual power of each of the carriers that are used for spreading a single
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`bit. When a data bit is spread across multiple carriers (e.g., four), the
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`individual power on each carrier is reduced by dividing the power on each
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`carrier by the number of carriers used for spreading (e.g., dividing by four
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`when four carriers are used). Ex. 1011 at 14:23–32 (referencing Eq. 5). Thus,
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`the peak power would not be “N times greater than their individual maximum
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`powers” as asserted by Petitioner. Rather, the combined peak power of the
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`carriers used for spreading would not be more than the power required to send
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`a single bit on one of the carriers (i.e., approximately one times the individual
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`maximum power of a single carrier).
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`B.
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`Shively’s Technique Contributes a De Minimis Amount of Power
`to the Transmission Signal
`An additional, independent reason why Shively’s transmission of a
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`signal with the same phase on multiple carriers does not create a PAR problem
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`is that the number of carriers used for this “spreading” scheme is a small
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`fraction of the total number of carriers. Shively’s system would have had 256
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`total carriers.4 Yet Shively teaches using only four carriers (preferably) to
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`4 Shively, which was filed on December 31, 1997, discloses a DSL system that
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`uses discrete multitone transmission (“DMT”). At that time, such systems had 256
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`carriers. See, e.g., Ex. 1016 at pp. 2–3 (Petitioner’s exhibit; © 1998) (“The entire
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`transmit a signal having the same phase. Ex. 1011 at 13:49–52. Even if the
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`transmission power for each of the individual carriers was not reduced (as
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`incorrectly assumed by Petitioner), Petitioner does not explain how such a
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`small fraction of carriers (4/256, or 1.5%) would impact PAR, much less in a
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`manner significant enough to motivate one of skill in the art to seek out other
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`teachings for a solution.
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`C.
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`Stopler is an Ambiguous Reference That Does Not Teach Solving
`PAR Problems
`Even if Shively did present a PAR problem (it plainly does not),
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`Petitioner has failed to show that one of ordinary skill in the art would have
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`looked to Stopler for a cure. Petitioner’s argument assumes that one of skill in
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`the art would have recognized that Stopler’s disclosure of scrambling the
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`phases of symbols would reduce PAR. But, Stopler does not even mention the
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`words “power” or “PAR,” much less explain that its teachings could be used to
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`resolve a PAR issue. The only mention of any reason for scrambling phases in
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`Stopler is that “[i]n order to randomize the overhead channel symbols, a phase
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`scrambling sequence is applied to the output symbols.” Id. at 12:24–26. And
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`1.1 MHZ [DMT] bandwidth is divided into 256 subchannels.”); Ex. 1012 (Stopler,
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`filed February 26, 1999) at 1:51–52 (“In DMT, a 1.1 MHz channel is broken down
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`into 256 sub-channels or bands, each of which is 4 KHz.”).
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`it is clear that Stopler did not recognize any benefit beyond “randomiz[ing] the
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`overhead channel symbols,” because he goes on to state that “to simplify
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`implementation, the phase scrambler is applied to all symbols, not just the
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`overhead symbols.” Id. at 12:26–28.
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`Moreover, it is unclear from Stopler’s disclosure whether phases of the
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`individual carriers are being scrambled with respect to each other during one
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`symbol period, or if the phases of all carriers are being scrambled from
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`symbol-to-symbol over time (but not with respect to each other during a
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`symbol period). Stopler is ambiguous and the Petition makes no attempt to
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`clarify. Instead, Petitioner, citing only Ex. 1012 (Stopler) at 12:24-28,
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`baselessly characterizes Stopler, saying: “Stopler teaches that a phase
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`scrambler can be employed to randomize the phase of the individual
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`subcarriers.” Petition at p. 15 (emphasis added); see also Ex. 1009 at ¶ 67.
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`This section of Stopler (Ex. 1012), however, says nothing about “individual
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`subcarriers.” Stopler only mentions “output symbols” or “symbols,” not
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`“individual subcarriers”: “In order to randomize the overhead channel symbols,
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`a phase scrambling sequence is applied to the output symbols. However, to
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`simplify implementation, the phase scrambler is applied to all symbols, not just
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`the overhead symbols.” Ex. 1012 at 12:24–28.
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`Petitioner has provided no evidence or explanation whether these “output
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`symbols” or “symbols” are individual carriers or are separate transmissions
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`over time across multiple symbol periods. Stopler is ambiguous. A finding of
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`unpatentability cannot be based on an ambiguous reference. See Mitsubishi
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`Chemical Corp. v. Barr Laboratories, Inc., 435 Fed. Appx. 927, 933 (Fed. Cir.
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`2011); In re Hughes, 345 F.2d 184, 188 (C.C.P.A. 1965) (“[A] reference in any
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`event is good only for that which it clearly and definitely discloses.”); In re
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`Turlay, 304 F.2d 893, 899 (C.C.P.A. 1962).
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`D.
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`Petitioner’s Rationale for Combining Shively and Stopler Suffers
`From Hindsight Bias
`Even if Shively did present a PAR problem (it does not as explained in
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`Section V.A.), Petitioner’s theory of obviousness is a classic case of hindsight.
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`Petitioner’s reason for combining Shively and Stopler is based on the
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`unsupported assumption that one having skill in the art “would have
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`recognized” that Stopler’s alleged carrier phase randomization would reduce
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`PAR. Petition at p. 15; Ex. 1009 at ¶ 67. Instead of identifying prior art that
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`explains how to reduce PAR by using phase scrambling, Petitioner has
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`improperly relied on the ’158 patent as a roadmap in making its unpatentability
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`arguments. None of the prior art asserted in the Petition teaches the use of
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`phase scrambling as a means for reducing PAR. Not Shively. Not Stopler. In
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`fact, Petitioner (including its expert) does not cite to a single reference to
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`support its assertion that one having ordinary skill in the art would have
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`identified phase scrambling as a solution to high PAR. See Petition at p. 15;
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`Ex. 1009 at ¶ 67. Only the challenged ’158 patent provides this teaching. This
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`demonstrates improper hindsight bias. See ActiveVideo Networks, Inc. v.
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`Verizon Communications, Inc., 694 F.3d 1312, 1327 (Fed. Cir. 2012) (“[T]he
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`expert’s testimony on obviousness was essentially a conclusory statement that
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`a person of ordinary skill in the art would have known, based on the ‘modular’
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`nature of the claimed components, how to combine any of a number of
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`references to achieve the claimed inventions. This is not sufficient and is
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`fraught with hindsight bias.”).
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`“A factfinder should be aware, of course, of the distortion caused by
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`hindsight bias and must be cautious of arguments reliant on ex post reasoning.”
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`KSR Int’l Co. v. Teleflex Inc., 550 U.S. 398, 421 (2007). “[A] patent composed
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`of several elements is not proved obvious merely by demonstrating that each of
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`its elements is, independently, known in the prior art.” Power-One, Inc. v.
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`Artesyn Techs., Inc., 599 F.3d 1343, 1352 (Fed. Cir. 2010). That is because
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`“[v]irtually all inventions are necessarily combinations of old elements. The
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`notion, therefore, that combination claims can be declared invalid merely upon
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`finding similar elements in separate prior patents would necessarily destroy
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`virtually all patents and cannot be the law under the statute, § 103.” Panduit
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`Corp. v. Dennison Mfg. Co., 810 F.2d 1561, 1575 (Fed. Cir. 1987). In
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`conducting a proper obviousness analysis, therefore, “[c]are must be taken to
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`avoid hindsight reconstruction by using the pa
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