`
` 
`
` 
`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
`
`UNITED STATES PATENT AND TRADEMARK OFFICE
`_____________
`
`BEFORE THE PATENT TRIAL AND APPEAL BOARD
`_____________
`
`CISCO SYSTEMS, INC. and DISH NETWORK, LLC
`Petitioners
`
`v.
`
`TQ DELTA, LLC
`Patent Owner
`_____________
`
`
`Case No. IPR2016-01020
`Patent No. 9,014,243
`_____________
`
`
`PATENT OWNER RESPONSE UNDER 37 CFR § 42.120
`
`
`
`
`
`

`

`Patent Owner Response
`IPR2016-01020
`
` 
`
`I. 
`
`II. 
`
`TABLE OF CONTENTS
`
`
`INTRODUCTION ........................................................................................... 1 
`
`INTRODUCTION TO TECHNOLOGICAL CONCEPTS ............................ 3 
`
`A.  Multicarrier Systems ............................................................................. 3 
`
`B. 
`
`C. 
`
`Peak-to-Average Power Ratio (“PAR”) ................................................ 5 
`
`PAR “Problem” ..................................................................................... 7 
`
`D.  A Note On Terminology ..................................................................... 11 
`
`III.  CLAIM CONSTRUCTION .......................................................................... 13 
`
`A. 
`
`B. 
`
`C. 
`
`“Multicarrier” ...................................................................................... 13 
`
`“Transceiver” ....................................................................................... 13 
`
`“Scrambling…a Plurality of Carrier Phases” ...................................... 14 
`
`IV.  OVERVIEW OF ASSERTED REFERENCES—SHIVELY AND
`STOPLER ...................................................................................................... 19 
`
`A. 
`
`B. 
`
`Shively ................................................................................................. 19 
`
`Stopler.................................................................................................. 29 
`
`V. 
`
`PETITIONERS HAVE NOT PROVEN UNPATENTABILITY FOR
`THE CLAIMS OF THE ’243 PATENT ........................................................ 44 
`
`A. 
`
`Petitioners’ Argued Reasons To Combine Shively And Stopler
`Are Without A Rational Basis, Based On Factual Errors, And
`Suffer From Hindsight Bias ................................................................ 45 
`
`1. 
`
`2. 
`
`Petitioners Provide No Explanation For The “Use Of A
`Known Technique To Improve A Similar Device”
`Rationale To Combine Shively And Stopler ............................ 45 
`
`Petitioners Wrongly Claim That Shively’s Transmitter
`Suffers From An Increased PAR .............................................. 47 
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`Patent Owner Response
`IPR2016-01020
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`3. 
`
`4. 
`
`5. 
`
`6. 
`
`7. 
`
`Petitioners’ Justification For Combining Shively And
`Stopler Uses The ’243 Patent As A Roadmap And
`Suffers From Hindsight Bias .................................................... 49 
`
`There Is No Need To Solve Shively’s Non-Existent PAR
`Problem ..................................................................................... 50 
`
`Stopler Does Not Reduce PAR In A Multicarrier
`Transmitter ................................................................................ 51 
`
`Stopler And Shively Could Not Be Combined ......................... 51 
`
`There Were No “Market Forces” In Effect To Prompt
`The Combination Of Shively’s And Stopler’s Techniques ...... 55 
`
`B. 
`
`Stopler Does Not Disclose Phase Scrambling .................................... 57 
`
`VI.  CONCLUSION .............................................................................................. 59 
`
`CERTIFICATE OF WORD COUNT ...................................................................... 60 
`
`
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`Patent Owner Response
`IPR2016-01020
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` 
`I.
`
`INTRODUCTION
`
`Patent Owner TQ Delta, LLC submits this Patent Owner Response under 37
`
`CFR §42.120 to the Petition filed by Cisco, Inc. requesting inter partes review for
`
`claims 1–25 of U.S. Pat. No. 9,014,243 (“the ’243 patent”).
`
`The Board instituted inter partes review on two grounds:
`
`1. whether claims 1‒3, 7‒9, 13‒16, and 20‒22 of the ’243 patent are
`unpatentable under 35 U.S.C. § 103(a) over U.S. Pat. No. 6,144,696
`(“Shively”) and U.S. Pat. No. 6,625,219 (“Stopler”); and
`
`2. whether claims 4‒6, 10‒12, 17‒19, and 23‒25 of the ’243 patent are
`unpatentable under 35 U.S.C. § 103(a) over Shively, Stopler, and U.S. Pat.
`No. 6,424,646 (“Gerszberg”).
`
`After
`
`institution, additional parties—including: Dish Network, LLC;
`
`Comcast Cable Communications, LLC; Cox Communications, Inc.; Time Warner
`
`Cable Enterprises LLC; Verizon Services Corp.; and ARRIS Group, Inc.—filed
`
`petitions that are identical in all substantive respects to the Cisco Petition. See
`
`IPR2017-00254 and IPR2017-00418. These additional parties moved to join as
`
`petitioners, and collectively with Cisco, are referred to herein as “Petitioners.” For
`
`brevity, this Patent Owner response will cite only to the Cisco Petition and its
`
`corresponding exhibits.
`
`In the Institution Decision, the Board did not reach the merits of Patent
`
`Owner’s arguments in the Patent Owner Preliminary Response, but rather
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`Patent Owner Response
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`characterized them as “attorney argument” and accepted Petitioners’ expert
`
`declarant’s testimony as true because Patent Owner did not support it’s argument
`
`with expert testimony. This Patent Owner Response is fully supported by the cited
`
`evidence, including the declaration of Dr. Robert T. Short.
`
`The Petition fails to prove, by a preponderance of the evidence, that any
`
`claim of the ’243 patent is unpatentable because there is no credible or accurate
`
`evidence demonstrating why one having ordinary skill in the art would have
`
`combined Shively and Stopler. Petitioners’ rationale for the combination
`
`fundamentally relies on the contention that Shively suffers from a problem (i.e., a
`
`problem with its “peak-to-average power ratio” or “PAR”) that Stopler solves the
`
`purported problem by performing “phase scrambling.” But, Shively does not have
`
`a PAR problem so there would have been no motivation to look for a solution.
`
`Furthermore, Stopler does not disclose phase scrambling as recited in the
`
`claims.
`
`Petitioners misunderstand
`
`the
`
`teachings of
`
`these references, make
`
`unsupported assumptions having no basis in fact, and, ultimately rely on only
`
`hindsight bias to cobble together the references.
`
`As such, Petitioners’ grounds for alleged obviousness fail. Patent Owner
`
`respectfully requests that the Board issue a Final Written Decision finding that
`
`Petitioners did not meet their burden to prove unpatentability of claims 1–25 of the
`
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`’243 patent.
`
`II.
`
`INTRODUCTION TO TECHNOLOGICAL CONCEPTS
`
`In order to understand the issues at hand in this IPR, it is first necessary to be
`
`able to answer the following questions:
`
`1) What is a multicarrier system?
`
`2) What is peak-to-average power ratio, or “PAR”?
`
`3) Under what conditions does a PAR “problem” occur?
`
`4) How are the terms “symbol” and “carrier” used in this Patent Owner
`Response and accompanying declaration?
`
`This introduction answers these questions.
`
`A. Multicarrier Systems
`The ’243 patent discloses a system that communicates using multicarrier
`
`signals. Ex. 1001 at 1:26–29. A multicarrier signal includes a number of carrier
`
`signals (or carriers) each operating at a different frequency. Each carrier is
`
`modulated to encode one or more bits (i.e., “1” or “0”). Each carrier effectively
`
`serves as a separate sub-channel for carrying data. The carriers are combined as a
`
`group to produce a transmission signal, which is transmitted across a transmission
`
`medium (e.g., phone lines, coaxial cable, the air, etc.) to a receiver. See Ex. 2003
`
`at ¶ 17.
`
`In an example illustrated below, four carriers—Carrier 1, Carrier 2, Carrier
`
`3 
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`3, and Carrier 4—are combined simultaneously into one transmission signal.
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`Patent Owner Response
`IPR2016-01020
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`
`
`See Ex. 2003 at ¶ 18.
`
`Multicarrier systems may use the phase of carriers to encode different bit
`
`values. In the example illustrated above, a carrier with a phase of zero represents a
`
`bit value of “0”; conversely, a carrier with a phase-shift of π (or 180°) represents a
`
`bit value of “1”. In this example, Carriers 1, 2, and 4 have a phase-shift of π, and
`
`therefore each represent a “1”. Carrier 3 has as phase of zero, and therefore
`
`represents a “0”. Together, these four carriers encode input bits having binary
`
`values of 1, 1, 0, and 1. This information is transmitted as a single transmission
`
`signal—that is, the irregular waveform shown above on the right side of the figure.
`
`In practice, a multicarrier
`
`transmission signal will
`
`typically comprise a
`
`combination of many more than four carriers (e.g., hundreds or even thousands of
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`carriers) and in this way can substantially increase the “speed” or data carrying
`
`capacity of the system. See Ex. 2003 at ¶ 19.
`
`Peak-to-Average Power Ratio (“PAR”)
`
`B.
`A multicarrier transmission signal can be characterized by a metric known as
`
`“PAR,” which stands for peak-to-average ratio or peak-to-average power ratio. Ex.
`
`1001 at 1:60–65. As the ’243 patent explains, “The PAR of a transmission signal
`
`is the ratio of the instantaneous peak value (i.e., maximum magnitude) of a signal
`
`parameter (e.g., voltage, current, phase, frequency, power) to the time-average
`
`value of the signal parameter.” Id. at 1:65–2:2 (emphasis added). References to
`
`PAR herein relate to PAR for the power of a transmission signal. See Ex. 2003 at
`
`¶ 20.
`
`One of the central issues in this IPR relates to PAR. In the following
`
`illustration, a signal (blue) has a peak power (red line) and an average power (black
`
`line). The ratio of the peak power to the average power of the signal is the PAR.
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`
`
`See Ex. 2003 at ¶ 21.
`
`
`
`A high PAR can occur when a large number (or percentage) of the carriers
`
`have the same phase. The ’243 patent recognized that: “If the phase of the
`
`modulated carriers [in a transmission signal] is not random, then the PAR can
`
`increase greatly.” Ex. 1001 at 2:15–16. The phases of the carriers would not be
`
`“random,” for example, when the underlying data being modulated is repetitive
`
`(e.g., a long string of 0s or a long string of 1s), or where the same bit or bits is/are
`
`purposely sent in a redundant manner on multiple carriers. In the example below,
`
`all 25 of the carriers have the same phase of zero (which would be the case if the
`
`same bit or bits was/were sent on every carrier). Because the carrier signals are
`
`“in-phase,” their amplitudes will add together to create a transmission signal
`
`6 
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`(illustrated on the right side of the figure below) having large spikes in amplitude
`
`and, therefore, a high PAR.
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`Patent Owner Response
`IPR2016-01020
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`
`
`See Ex. 2003 at ¶ 22.
`
`PAR “Problem”
`
`C.
`Because a multicarrier transmission signal is the sum of many carrier
`
`signals, the transmission signal is expected to have a significant PAR.
`
`Conventional multicarrier systems, therefore, were designed to accommodate a
`
`degree PAR. There is only a PAR “problem,” however, when an undue amount of
`
`PAR-induced errors occur in a multicarrier transmitter. See Ex. 2003 at ¶ 23.
`
`Electronic components in a multicarrier transceiver are ideally designed to
`
`process multicarrier signals without distortion. Distortion occurs when a signal
`
`exceeds the capacity (or dynamic range) of an electronic component, such as an
`
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`amplifier, a digital-to-analog converter, or an analog-to-digital converter. When
`
`the maximum dynamic range of a component is exceeded, the signal will become
`
`distorted or will “clip.”
`
`
`
`See Ex. 2003 at ¶ 24.
`
`As a result of clipping, the portion of the signal exceeding the component’s
`
`dynamic range is truncated and the information in the cut off signal portion is lost.
`
`See Ex. 2003 at ¶ 25.
`
`One way to reduce the probability of clipping is to use transceiver
`
`components with larger dynamic ranges. Such components, however, can be
`
`expensive and may consume a relatively large amount of power. Increasing the
`
`dynamic ranges of the components to eliminate any possibility of clipping,
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`Patent Owner Response
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`therefore, can be impractical. See Ex. 2003 at ¶ 26.
`
`Instead of demanding ideal circuitry, multicarrier systems are designed to
`
`actually allow a certain amount of clipping. This design criterion is specified as a
`
`“clipping rate.” One such multicarrier system is digital subscriber line (“DSL”).1
`
`In DSL at the time of the invention (referred to herein as “ADSL-1995”) the
`
`maximum allowable clipping rate is one in every 107 (ten million) samples, which
`
`corresponds to a clipping probability of 10-7 (or one in ten million). Ex. 1017 at p.
`
`48, § 6.11.1. This exact clipping probability is also referenced in the ’243 patent.
`
`See Ex. 1001 at 2:6–8. See Ex. 2003 at ¶ 27.
`
`In ADSL-1995, the ideal sampling rate is approximately 2.2 million
`
`samples/second. Given this sampling rate and a clipping probability of 10-7, there
`
`would be a clipping error when processing a transmission signal about once every
`
`                                                            
`1 This is an apt example, as DSL is the subject technology of a preferred
`
`embodiment in the ’243 patent (Ex. 1001 at 3:25–26), Shively (Ex. 1011 at 1:4–5),
`
`Stopler (Ex. 1012 at 12: 23–24), and Gerszberg (Ex. 1013 at 1:19–26). A
`
`particular DSL standard in use at the time of the invention is defined in Petitioners’
`
`Exhibit 1017—ANSI standard T1.413-1995 (“ADSL-1995”). The ADSL-1995
`
`standard is described in Shively (Ex. 1011 at 1:51–53 and 2:12–24) and is
`
`discussed in the Petition at p. 46. See Ex. 2003 at ¶ 28.
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`4.55 seconds on average. This clipping rate is deemed acceptable because, at this
`
`rate, error correction methods are capable of fixing the errors cause by clipping.
`
`See Ex. 2003 at ¶ 29.
`
`A PAR “problem” exists when the probability of clipping or average
`
`clipping rate exceeds the maximum allowable rate. In the example above, if there
`
`is a clipping error once every 3 seconds (on average), then a PAR problem exists—
`
`because the rate of clipping is unacceptably high since 3 seconds is less than 4.55
`
`seconds. As the inventor of the ’243 patent recognized, “If the phase of the
`
`modulated carriers is not random, then the PAR can increase greatly.” Ex. 1001 at
`
`2:15–16. “An increased PAR can result in a system with high power consumption
`
`and/or with high probability of clipping the transmission signal.” Id. at 2:25–27
`
`(emphasis added). Contrarily, if probability of clipping or average clipping rate
`
`does not increase above the acceptable rate of the system (e.g., 10-7 or once every
`
`4.55 seconds on average in ADSL-1995), then there is no PAR problem. See Ex.
`
`2003 at ¶ 30.
`
`One way to decrease the impact of PAR and reduce the probability of
`
`clipping is by reducing the overall signal power below the maximum overall signal
`
`power for which the system was designed, as depicted below.
`
`10 
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`Patent Owner Response
`IPR2016-01020
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`
`
`See Ex. 2003 at ¶ 31.
`
`
`
`As discussed below in § IV.A, the system disclosed in Shively is an example
`
`of a system in which the overall signal power is reduced below the maximum
`
`overall signal power for which the system was designed. Such power reduction is
`
`shown by Shively, and it results in a system with virtually no clipping at all. See
`
`Ex. 2003 at ¶ 32.
`
`D. A Note On Terminology
`There is some overlap and apparent inconsistency with certain terminology
`
`used by Petitioners and the references of record. Particularly confusing is the use
`
`of “symbol.” Generally, “symbol” can have two meanings. First, “symbol” can
`
`refer to information transmitted on one carrier during a predefined time period (i.e.,
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`Patent Owner Response
`IPR2016-01020
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`a “symbol period”). Second, “symbol” can refer to all of the information
`
`transmitted on all of the carriers in a symbol period. The individual carrier
`
`symbols are often referred to as “QAM symbols,” where “QAM” (Quatrature
`
`Amplitude Modulation) is a commonly-used type of modulation used to modulate
`
`a carrier symbol onto a carrier. A multicarrier “symbol” (i.e., the collection of
`
`multiple carrier symbols) is often referred to as a “DMT symbol,” where “DMT”
`
`(Discrete Multitone) is a type of multicarrier technology. See Ex. 2003 at ¶ 33.
`
`In order to keep things clear and to avoid apparent inconsistency/overlap
`
`with the term “symbol,” this Patent Owner Response and accompanying
`
`declaration employ the terms “carrier” and “symbol” as follows:
`
` “carrier” means a carrier symbol (e.g., a QAM symbol); and
`
` “symbol” means a collective multicarrier symbol in a single symbol
`
`period (e.g., a DMT symbol).
`
`See Ex. 2003 at ¶ 34. This Patent Owner Response and accompanying declaration
`
`also use appropriate editorializing to distinguish between a “carrier” and a
`
`“symbol” in the references of record, the Petition, and Petitioners’ expert’s
`
`declaration. See id. at ¶ 35.
`
`Further adding
`
`to potential confusion
`
`is
`
`that
`
`the
`
`terms “carrier,”
`
`“subcarrier,” “band,” “sub-band,” “bin,” “channel,” and “tone” are often used
`
`interchangeably. Ex. 1011 at 1:42–43 (“sub-bands or frequency bins”); id. at 1:48
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`Patent Owner Response
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`(“sub-band channels”); id. at 5:13–15 (“carrier”); id. at 10:40–41 (“subcarriers”);
`
`id. at 12:39 (“bin (channel)”); Ex. 1012 at 1:41 (“tones or bands”). For
`
`consistency, Patent Owner has used the term “carrier” as much as possible in this
`
`Patent Owner Response and accompanying declaration. See Ex. 2003 at ¶ 36.
`
`III. CLAIM CONSTRUCTION
`Petitioners proposed to construe two claim terms: “multicarrier” and
`
`“transceiver.” Patent Owner maintains that it is not necessary to construe either of
`
`these terms to resolve the issues at hand.
`
`Additionally, Patent Owner proposes to construe “scramble…a plurality of
`
`carrier phases” to mean “scramble a plurality of carrier phases in a single
`
`multicarrier symbol.”
`
`“Multicarrier”
`
`A.
`With respect to “multicarrier,” the Board agreed with Patent Owner that
`
`there is no need to construe this term for the purposes of the institution decision.
`
`“Transceiver”
`
`B.
`While the Board opted to construe “transceiver,” Patent Owner maintains
`
`that a construction is not necessary to evaluate the grounds of unpatentability
`
`presented by the Petitioners. The Board adopted Petitioners’ proposal, namely that
`
`a “transceiver” is “a device, such as a modem, with a transmitter and a receiver.”
`
`Institution Decision, Paper No. 7 at p. 6. In a corresponding district court matter,
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`Patent Owner proposed to construe “transceiver” to mean “a communications
`
`device capable of transmitting and receiving data over the same physical medium
`
`wherein the transmitting and receiving functions are implemented using at least
`
`some common circuitry.” Ex. 2007 at p. 8. The district court construed
`
`“transceiver” to mean “a communications device capable of transmitting and
`
`receiving data wherein the transmitter portion and receiver portion share at least
`
`some common circuitry.” See id. at pp. 8–9. Petitioners’ arguments fail
`
`irrespective of which of the foregoing constructions for “transceiver” is used.
`
`“Scrambling…a Plurality of Carrier Phases”
`
`C.
`In the context of the ’243 patent, “scrambl[e/ing]…a plurality of carrier
`
`phases”—or the variant “scramble…a plurality of phases”—should be construed to
`
`mean “adjusting the phases of a plurality of carriers in a single multicarrier symbol
`
`by pseudo-randomly varying amounts.” This construction is fully supported by the
`
`specification of the ’243 patent, and it clarifies that the claimed phase scrambling
`
`must be performed amongst the individual carrier phases in a single multicarrier
`
`symbol. In other words, the claimed phase scrambling is not met if the phase
`
`adjustment only occurs over time from one symbol to the next.   See Ex. 2003 at
`
`¶ 37.
`
`The ’243 patent is directed exclusively to multicarrier modulation systems.
`
`See Ex. 1001 at 1:26–29 (“This invention relates to communications systems using
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`multicarrier modulation. More particularly, the invention relates to multicarrier
`
`communications systems that lower the peak-to-average power ratio (PAR) of
`
`transmitted signals.”); 3:32–37 (“Although described with respect to discrete
`
`multitone modulation, the principles of the invention apply also to other types of
`
`multicarrier modulation, such as, but not limited to, orthogonally multiplexed
`
`quadrature amplitude modulation (OQAM), discrete wavelet multitone (DWMT)
`
`modulation, and orthogonal
`
`frequency division multiplexing
`
`(OFDM).”).
`
`Furthermore, every
`
`independent claim
`
`is directed
`
`to a “multicarrier
`
`communications transceiver” (claims 1, 7, and 20) or a “multicarrier transmitter”
`
`(claim 13). The ’243 patent discloses several multicarrier techniques and uses
`
`“discrete multitone modulation” (“DMT”) as an example. Id. at 3:32–37. See Ex.
`
`2003 at ¶ 38.
`
`As discussed above in § II.A, a multicarrier signal includes the combination
`
`of a plurality of carriers, where each carrier has a different frequency and its own
`
`phase. In the embodiment of the ’243 patent, each of the plurality of carriers
`
`corresponds to a different QAM symbol. See, e.g., Ex. 1001 at 4:13–14 (“The
`
`modulator 46 modulates each carrier signal with a different QAM symbol 58.”).
`
`Each carrier (or QAM symbol) has its own phase or phase characteristic.2 See,
`
`                                                            
`2 The term “phase characteristic” in the ’243 patent is interchangeable with
`
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`e.g., id. at 4:7–9 (“The QAM symbols 58 represent the amplitude and the phase
`
`characteristic of each carrier signal.”). The combination of these carriers (or QAM
`
`symbols) is referred to as a DMT symbol (which is an exemplary type of
`
`multicarrier symbol). See, e.g., id. at 9:8–9 (“…a set of QAM symbols 58
`
`produces a DMT symbol 70….”). See Ex. 2003 at ¶ 39.
`
`The ’243 patent repeatedly discloses a “phase scrambler” that scrambles the
`
`phases or phase characteristics of carriers within a single DMT symbol. See Ex.
`
`1001 at 6:52–8:13. As the ’243 patent explains, PAR in the transmission signal is
`
`reduced by adjusting the carrier phases within a single DMT symbol. See, id., at
`
`6:30–53. If the carrier phases were only adjusted from one symbol to the next,
`
`PAR would not be reduced. See Ex. 2003 at ¶¶ 41–42.
`
`In a corresponding district court matter, the court construed “scrambling the
`
`phase characteristics of the carrier signals” to mean “adjusting the phase
`
`characteristics of the carrier signals by pseudo-randomly varying amounts.” Ex.
`
`2007 at pp. 10–11. During prosecution of the ’243 patent, the applicant explained
`
`that a “scrambler” operates “by pseudo-randomly selecting bits to invert.” Ex.
`
`                                                                                                                                                                                                
`“phase.” See Ex. 1001 at 1:40–42 (“The DMT transmitter typically modulates the
`
`phase characteristic, or phase, and amplitude of the carrier signals….”). See Ex.
`
`2003 at ¶ 40.
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`2008 at p. 18. There was no fundamental disagreement between parties that
`
`scrambling involves adjusting the phase characteristics of a carrier signal by
`
`pseudo-randomly varying amounts. Ex. 2007 at pp. 10–11.
`
`Furthermore, when Petitioners’ expert was asked about his application of the
`
`claims to the asserted Stopler reference, he expressed his opinion that the claims
`
`require phase scrambling within a single multicarrier symbol. In his declaration,
`
`he contends that the claims are invalid over a combination of at least Shively and
`
`Stopler. Ex. 1009 at ¶¶ 54 and 72. Pertinently, he alleges that Stopler discloses the
`
`claim recitations of “scramble…a plurality of carrier phases” and “scramble…a
`
`plurality of phases.” Id. at p. 38–42 (element “1.4a”) and p. 61 (element “13.4a”).
`
`During cross-examination, Petitioners’ expert discussed his opinion that
`
`Stopler discloses scrambling within a single multicarrier symbol. Indeed, he
`
`specifically rejected that Stopler’s phase scrambling could be performed from one
`
`multicarrier symbol to the next. Note, in the transcript excerpt below, a “DMT
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`symbol” refers to a single multicarrier symbol, while a “QAM symbol” refers to a
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`single carrier in the DMT (or multicarrier) symbol.
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`Q. But you didn't take into consideration when you interpreted that
`[section of Stopler], that it may be talking about randomizing
`overhead channels from [one] DMT symbol to the next, did you?
`A. The natural interpretation, since Stopler is teaching how to
`randomize plural overhead channel symbols [i.e., “carriers”], the
`natural interpretation is that each symbol [i.e., “carrier”] would have a
`different phase rotation.
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`Patent Owner Response
`IPR2016-01020
`
`Q. So you're suggesting that each symbol from one symbol to the
`next would have a different phase rotation?
`A. No. No. Individual QAM symbols [i.e., “carrier”] within the same
`modulation block [i.e., “symbol”].
`Q. Where does it say that?
`A. If you read the paragraph, “The input to the QAM mapper 82”—
`we’re on column 12, line 21. “The input to the QAM mapper 82 is
`data in the form of m-tuples which are to be mapped into QAM
`symbols”—basically getting m-tuples, mapping them to one QAM
`symbol—“for example, ranging from QPSK to 256-QAM tone by
`tone.” So in the context of QAM mapper 82, which is in Figure 5, this
`block is processing at the QAM symbol by the QAM symbol, so each
`QAM symbol is processed individually. The constellation mapping
`may be the same as that used in ADSL. So again, it uses ADSL as an
`example. “In order to randomize the overhead channel symbols, a
`phase scrambling sequence is applied to the output symbols.” It’s in
`the context of QAM mapper 82 mapping m-tuples groups of bits into
`QAM symbols, one symbol at a time, tone by tone, inserting overhead
`channel symbols, which are plural, and phase scrambling is applied to
`these symbols. My interpretation has been applied on a QAM symbol
`by QAM symbol [i.e., “carrier by carrier”].
`Ex. 2002 at 107:7–108:18 (emphasis added). See, more generally, id. at 104:20–
`
`109:5.
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`Thus, Petitioners’ expert has interpreted the claim terms “scrambl[e/ing]…a
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`plurality of carrier phases” and “scramble…a plurality of phases” to require
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`adjusting the phases of a plurality of carriers within a single multicarrier symbol.
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`Consequently, the term “scrambl[e/ing]…a plurality of carrier phases”—or the
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`variant “scramble…a plurality of phases”—should be construed to mean “adjusting
`
`the phases of a plurality of carriers in a single multicarrier symbol by pseudo-
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`Patent Owner Response
`IPR2016-01020
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`randomly varying amounts.” See Ex. 2003 at ¶ 37.
`
`IV. OVERVIEW OF ASSERTED REFERENCES—SHIVELY AND
`STOPLER
`
`In every instance, Petitioners allege that the challenged claims are
`
`unpatentable at least over Shively in view of Stopler.
`
`Shively
`
`A.
`Shively discloses a concept intended to increase 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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`theoretical way to transmit data over a transmission medium having high signal
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`attenuation at frequencies corresponding to a significant number of carriers. See
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`Ex. 2003 at ¶ 43.
`
`To appreciate Shively’s teachings, it necessary to understand such impaired
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`transmission mediums. Shively specifically describes “long loop” systems, where
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`the length of cable between transmitting and receiving DSL modems is at least
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`18,000 feet (about 3.4 miles):
`
`Referring to FIGS. 1 and 2, a transmitting modem 31 is connected to a
`receiving modem 32 by a cable 33 having four twisted pairs of
`conductors. In long loop systems where cable 3 is of length of the
`order 18,000 feet or more, high signal attenuation at higher
`frequencies (greater than 500 kHz) is usually observed. This
`characteristic of cable 33 is represented graphically by curve A in
`FIG. 1.
`
`Ex. 1011 at 9:63–10:2 (emphasis added); see also, id., at 11:11–12 (“Such noisy
`
`and/or highly attenuated sub-bands can occur for example in long-run twisted pair
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`conductors.”). See Ex. 2003 at ¶ 44.
`
`FIG. 1 of Shively, which is annotated with color below, is illustrative:
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`Patent Owner Response
`IPR2016-01020
`
`
`
`FIG. 1 of Shively shows carriers at increasing frequencies along the x-axis. Each
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`carrier is delineated by vertical lines. Power level is indicated along the y-axis.
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`Green line (A) represents an attenuation/noise floor, which increases as a function
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`of frequency. Ex. 1011 at 2:1–12. Shively explains that attenuation at higher
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`frequencies is a problem across long cables. Id. at 9:65–10:2 (“In long loop
`
`systems where cable 3 is of length of the order 18,000 feet or more, high signal
`
`attenuation at higher frequencies (greater than 500 kHz) is usually observed.”).
`
`Green line (A) is a characteristic of a communications channel, and it does not
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`Patent Owner Response
`IPR2016-01020
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`illustrate a transmitted signal. Id. at 10:61–11:12. See Ex. 2003 at ¶ 45–46.
`
`Blue line (B) is the minimum power margin above the attenuation/noise
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`floor (green line (A)) that is required to transmit a single bit on a given carrier. Ex.
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`1011 at 2:8–10. Red line (C) illustrates a “spectral density mask,” which is a type
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`of power limit imposed by system design. Id. at 2:10–12 (“Curve C represents the
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`limits imposed by a power spectral density mask imposed by an external
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`communications standard.”). Power transmitted on a given individual carrier
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`cannot exceed red line (C). See Ex. 2003 at ¶ 47.
`
`As FIG. 1 illustrates, blue line (B) is below red line (C) for the carriers
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`shaded in purple. In these purple-shaded carriers, there is sufficient headroom to
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`transmit a signal representing at least one bit without exceeding the power limit
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`imposed by the spectral density mask (red line (C)). For the carriers shaded in
`
`orange, however, blue line (B) exceeds red line (C). Because the attenuation/noise
`
`(green line (A)) for these orange-shaded carriers is too high, a bit cannot be
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`reliably transmitted without exceeding the imposed spectral density mask (red line
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`(C)). In other words, the minimum required power margin (blue line (B)) is
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`greater than the spectral density mask (red line (C)). Ex. 1011 at 10:65–11:3. See
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`Ex. 2003 at ¶ 48.
`
`Shively proposes a way to transmit data using some of the impaired (orange-
`
`shaded) carriers. Specifically, some of the impaired carriers, although having
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`Patent Owner Response
`IPR2016-01020
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`insufficient channel quality to transmit a single bit, have some limited power
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`available between the attenuation/noise floor (green line (A)) and the spectral
`
`density mask (red line (C)). Shively makes use of this available power by
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`“spreading” a single bit of data across multiple impaired carriers. See Ex. 2003 at
`
`¶ 49.
`
`Shively’s receiver combines (adds) the signals that were sent on the
`
`impaired carriers to recover the information:
`
`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.
`
`Id. at 11:16–24. See Ex. 2003 at