`U.S. Patent 7,848,439
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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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`APPLE INC.,
`ZTE (USA) INC.
`Petitioners
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`v.
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`INVT SPE LLC
`Patent Owner
`____________
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`
`Case No. 2018-01477
`U.S. Patent No. 7,848,439
`____________
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`PETITION FOR INTER PARTES REVIEW
`OF U.S. PATENT NO. 7,848,439
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`IPR2018-01477
`U.S. Patent No. 7,848,439
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`TABLE OF CONTENTS
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`INTRODUCTION .......................................................................................... 1
`I.
`II. SUMMARY OF THE ’439 PATENT ........................................................... 1
`A. DESCRIPTION OF THE ALLEGED INVENTION OF THE ’439 PATENT ..................... 1
`B. SUMMARY OF THE PROSECUTION HISTORY OF THE ’439 PATENT ..................... 5
`C. LEVEL OF SKILL OF A PERSON HAVING ORDINARY SKILL IN THE ART ................ 7
`III. REQUIREMENTS FOR INTER PARTES REVIEW UNDER 37 C.F.R.
`§ 42.104 .................................................................................................................... 7
`A. GROUNDS FOR STANDING UNDER 37 C.F.R. § 42.104(A) ................................. 7
`B. IDENTIFICATION OF CHALLENGE UNDER 37 C.F.R. § 42.104(B) AND RELIEF
`REQUESTED ............................................................................................................ 7
`C. CLAIM CONSTRUCTION UNDER 37 C.F.R. § 42.104(B)(3) ................................ 8
`IV. THERE IS A REASONABLE LIKELIHOOD THAT THE
`CHALLENGED CLAIMS OF THE ’439 PATENT ARE UNPATENTABLE 9
`A. GROUND 1: LI IN VIEW OF WALTON RENDERS CLAIMS 1, 3, 5-11 OBVIOUS ........ 9
`B. GROUND 2: LI IN VIEW OF WALTON IN FURTHER VIEW OF VIJAYAN RENDERS
`CLAIMS 2 AND 4 OBVIOUS ..................................................................................... 41
`V. CONCLUSION ............................................................................................. 46
`VI. MANDATORY NOTICES UNDER 37 C.F.R. § 42.8(A)(1) ..................... 47
`A. REAL PARTY-IN-INTEREST, 37 C.F.R. § 42.8(B)(1) ....................................... 47
`B. RELATED MATTERS ....................................................................................... 47
`C. LEAD AND BACK-UP COUNSEL ..................................................................... 48
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`IPR2018-01477
`U.S. Patent No. 7,848,439
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`I.
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`INTRODUCTION
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`Petitioners Apple Inc. and ZTE (USA) Inc. (“Petitioners”) request an Inter
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`Partes Review (“IPR”) of claims 1-11 (collectively, the “Challenged Claims”) of
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`U.S. Patent No. 7,848,439 (“the ’439 Patent”). ’439 Patent (Ex. 1001).
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`II.
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`SUMMARY OF THE ’439 PATENT
`A. Description of the alleged invention of the ’439 Patent
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`The ’439 Patent generally describes an Orthogonal Frequency Division
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`Multiplexing (OFDM) communication system in which subcarriers are allocated
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`and a modulation/coding scheme assigned based on measured channel quality
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`between a base station and handset. ’439 Patent (Ex. 1001) at 1:9-26. The
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`following excerpt explains the Applicant Admitted Prior Art (AAPA) process for
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`adaptive modulation and coding (AMC), which forms the foundation of the ’439
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`Patent disclosure:
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`[T]he meaning of adaptive modulation and coding is to adaptively
`adjust modulation and coding parameters on the transmission side
`based on channel characteristics at the current time and to carry out
`demodulation and decoding using parameters corresponding to the
`transmission side on the receiving side. In a typical system, adaptive
`parameters
`required
`by
`adaptive
`demodulating/decoding
`section 311 depend on feedback from the receiving side. Before
`transmitting each data block, the receiving side always first
`estimates transmission channel from the transmission side to the
`receiving side at the current time by channel estimating section 319,
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`IPR2018-01477
`U.S. Patent No. 7,848,439
`and obtains channel characteristics of the subcarriers of the
`OFDM. Based on these channel characteristics, the receiving side
`then decides modulation and coding parameters used for the
`OFDM subbands
`in
`the case of
`transmitting data from
`the
`transmission side at the current point by parameter selecting
`section 318.
`. . .
`After selecting modulation and coding parameters of the OFDM
`subbands, subband AMC parameter selecting section 318 on the
`receiving side then transmits these parameters back to the
`transmission side via a feedback path[.]
`Id. at 3:18-43 (emphasis added). The available frequency bandwidth of an OFDM
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`system “is divided into a plurality of narrow subcarrier frequency bandwidths.”
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`Id. at 1:25-26 (emphasis added).
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`To simplify processing, “all of the subcarriers on the OFDM frequency
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`domain are [further] divided into several subbands.” Id. at 2:18-19 (emphasis
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`added). The ’439 explains that prior art techniques perform AMC on both
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`subcarriers and on subbands, but notes that “AMC based on subcarriers is very
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`difficult to be implemented, and, in addition, has the problem that feedback
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`overhead is too large.” Id. at 2:2-15.
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`To further simplify the process and reduce feedback overhead, the ’439
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`Patent proposes combining subbands into subband groups based on a predefined
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`rule, whereby a single modulation and coding scheme is selected for the entire
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`U.S. Patent No. 7,848,439
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`group:
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`The object of the present invention is therefore to provide
`communication apparatus, a communication system and a
`communication method capable of increasing spectrum utilization
`rate of a system and particularly increasing spectrum utilization rate
`based on high-speed fading and channel estimation error, reducing
`the degree of difficulty of adaptivity, and reducing the feedback
`overhead compared with subband adaptive methods of the related
`art by combining all of the subbands on a frequency domain of a
`subcarrier communication system based on a fixed rule to as to give
`several subband groups, and then selecting modulation and coding
`parameters for use during joint coding with respect to each subband
`group.
`Id. at 5:32-44 (emphasis added); see also id. at 7:39-46, 8:2-15, 8:57-60
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`(“differences with subband adaptivity of the related art shown in FIG. 4B is
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`that the unit of adaptive demodulation and coding is a subband group rather
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`than a subband.”) (emphasis added).
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`The ’439 Patent describes three examples of how subbands are to be
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`grouped, and leaves open the possibility that other rules may be employed to
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`define these subband groups:
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`[W]ith the method of the present application, selection of adaptive
`parameters for the OFDM subband groups in step 903 is achieved by
`providing subband groups as the units of adaptive transmission rather
`than subbands. All of the subbands in an OFDM frequency domain
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`U.S. Patent No. 7,848,439
`are first taken to be several subband groups based on a certain
`combination method (or combination pattern)[.] A method of
`combining neighboring subbands, a method of combining subbands
`spaced at intervals, a method of combining all of the subbands, or a
`method of combining in accordance with another rule may be
`given as methods of combining.
`Id. at 23-33 (emphasis added); see also id. at s 8-10.
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`
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`Table 2 below provides an exemplary set of modulation and coding schemes
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`that may be applied to a subband group in accordance with the ’439 Patent AMC
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`technique.
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`The illustrated classifications are listed, from top to bottom, in order of
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`lowest channel quality to highest channel quality. For example, classification 0
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`represents
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`the worst (inoperable) channel for which no
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`information
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`is
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`transmitted—resulting in a “throughput performance” of zero. On the other end of
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`the spectrum, classification 6 represents the highest quality channel for which the
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`selected modulation and coding parameters produce a throughput performance of
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`4
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`U.S. Patent No. 7,848,439
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`4.
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`
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`In addition to the coding parameters illustrated in Table 2 above, the ’439
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`Patent teaches two methods for determining an appropriate coding parameter. In a
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`first method, the channel quality for each subband within a subband group is
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`measured, total possible throughput for the group is calculated based on the
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`channel qualities, and a coding parameter is selected based on this total throughput.
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`Id. at 11:19-34. Accordingly, the system calculates a total number of bits that can
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`be communicated over the subband group and calculates a coding parameter from
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`that value. In a second method, the system performs the same steps of the first
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`method, but assigns a discounting weight to the throughput of the subband group.
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`Id. at 11:35-46. The specific example described in the ’439 Patent calculates a total
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`bit throughput and discounts it by 10% (i.e., multiplies the throughput by 0.9)
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`before using the value to calculate a coding parameter. Id. A POSITA in the
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`technical field of the ’439 Patent would recognize that discounting the throughput
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`before calculating a common coding parameter for multiple subbands helps
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`prevent overloading the lower quality subbands in the group. Singer Decl. (Ex.
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`1003) at ¶ 48.
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`B.
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`Summary of the prosecution history of the ’439 Patent
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`The PCT application that resulted in the ’439 Patent was filed on November
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`18, 2005 as PCT/JP2005/021246, and the ‘439 Patent claims priority to a Chinese
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`U.S. Patent No. 7,848,439
`patent application, CN 2004-1-0094967, dated November 19, 2004. ’439 Patent
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`(Ex. 1001). For purposes of this proceeding, Petitioner assumes the priority date
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`for the Challenged Claims is November 19, 2004.
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`The Examiner issued a Non-Final Rejection on February 2, 2010, rejecting
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`proposed claims 1, 6, 7, and 9-11 as anticipated under § 102 by the Applicant
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`Admitted Prior Art (AAPA) discussed in the ‘439 Application at ¶¶ 0002-0025,
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`0035-0038, and depicted in Figs. 3A-B. ’439 Patent File History (Ex. 1002), Office
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`Action at 254-58. Finding claims 2-5, 8, and 12 allowable if written in independent
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`form, the Examiner noted the following:
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`The prior art of record, AAPA et al. does not teach or suggest a
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`pattern storage section that stores patterns for selecting subbands
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`constituting the subband groups in advance . . .
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`The prior art of record, AAPA et al. also does not teach or suggest
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`wherein the parameter deciding section decides the coding parameters
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`in such a manner that the number of information bits obtained by
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`assigning a weight to the sum of the number of information bits
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`that are able to be assigned to all of the subbands within the
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`subband group, is assigned to the subband group.
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`Id. at 258 (emphasis added) (describing limitations in claims 2 and 8).
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`In response, the Applicant amended the claims such that all claims include
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`U.S. Patent No. 7,848,439
`either (1) the pattern storage limitation of original claim 2 or (2) the weight per
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`subband group limitation of original claim 8. Id. at 277-85.
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`The Examiner then allowed the claims and the ’439 Patent issued on May
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`17, 2011. ’439 patent (Ex. 1001).
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`C.
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`Level of skill of a person having ordinary skill in the art
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`A person of ordinary skill in the art (POSITA) at the filing of the ’439 Patent
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`would have been a person having a Bachelor’s degree in electrical engineering or
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`the equivalent plus three years of experience working with digital communication
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`systems or in network engineering or a Master’s degree in electrical engineering
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`with an emphasis on communication systems or the equivalent plus one year of
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`experience working with digital communication systems or
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`in network
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`engineering. Singer Decl. (Ex. 1003) at ¶33.
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`III. REQUIREMENTS FOR INTER PARTES REVIEW UNDER 37 C.F.R.
`§ 42.104
`A. Grounds for standing under 37 C.F.R. § 42.104(a)
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`Petitioners certify that the ’439 Patent is available for IPR and that the
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`Petitioners are not barred or estopped from requesting IPR challenging the claims
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`of the ’439 Patent.
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`B.
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`Identification of challenge under 37 C.F.R. § 42.104(b) and relief
`requested
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`In view of the prior art and evidence presented, claims 1-8 of the ’439 Patent
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`are unpatentable and should be cancelled. 37 C.F.R. § 42.104(b)(1). Further, based
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`U.S. Patent No. 7,848,439
`on the prior art references identified below, IPR of the Challenged Claims should
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`be granted. 37 C.F.R. § 42.104(b)(2).
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`Proposed Grounds of Unpatentability
`Ground 1: Claims 1, 3, 5-11 are obvious under § 103(a) over U.S.
`Patent No. 6,904,283 to Xiaodong Li, et al. (“Li”) in view of U.S.
`Patent No. 7,885,228 to Jay Rod Walton, et al. (“Walton”)
`Ground 2: Claims 2, 4 are obvious under § 103(a) over Li in view
`of Walton and in further view of U.S. Patent No. 7,221,680 to Rajiv
`Vijayan, et al. (“Vijayan”)
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`Exhibits
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`1004, 1005
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`1004, 1005,
`1006
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`Section IV identifies where each element of the Challenged Claims is found
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`in the prior art. 37 C.F.R. § 42.104(b)(4). The exhibit numbers of the supporting
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`evidence relied upon to support the challenges are provided above and the
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`relevance of the evidence to the challenges raised are provided in Section IV. 37
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`C.F.R. § 42.104(b)(5). Exhibits 1001–1013 are also attached.
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`C. Claim construction under 37 C.F.R. § 42.104(b)(3)
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`In this proceeding, claim terms of an unexpired patent should be given their
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`“broadest reasonable construction in light of the specification.” 37 C.F.R.
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`§ 42.100(b); Cuozzo Speed Techs., LLC v. Lee, 136 S. Ct. 2131, 2144-46 (2016).
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`Petitioner understands that the Patent Trial and Appeal Board (“PTAB”) may soon
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`apply the standard applied by Article III courts (i.e., the Phillips standard).
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`Petitioner has applied the plain and ordinary meaning of all claim terms below and
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`does not believe any claim terms require express construction to resolve the
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`U.S. Patent No. 7,848,439
`proposed grounds of rejection presented herein. Petitioner does not, however,
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`waive any argument in any litigation that claim terms in the ’439 Patent are
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`indefinite or otherwise invalid nor does Petitioner waive its right to raise specific
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`issues of claim construction in any litigation.
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`IV. THERE
`IS A REASONABLE LIKELIHOOD THAT THE
`CHALLENGED CLAIMS OF THE
`’439 PATENT ARE
`UNPATENTABLE
`A. Ground 1: Li in view of Walton renders claims 1, 3, 5-11 obvious
`Li was filed on April 17, 2001 and therefore qualifies as prior art with regard
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`to the ’439 Patent under 35 U.S.C. § 102(e) (pre-AIA). Li (Ex. 1004). Li discloses
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`an OFDMA cellular communication system in which subcarriers are partitioned
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`into groups and one or more groups are allocated to a cellular subscriber. Id. at
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`Abstract, 11:46-67. Li also describes an adaptive modulation and coding (AMC)
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`technique for measuring the downlink channel quality and selecting modulation
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`and coding parameters accordingly. Id. at 3:17-53.
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`Like the ’439 Patent, Li explains that channel quality in an OFDM system is
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`measured by a cellular handset, coding and modulation parameters are selected
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`based on these measurements, and the result is reported back to the base station.
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`Compare id. at 3:5-23 (“The techniques disclosed herein are described using
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`OFDMA” wherein “each subscriber
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`first measures
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`the channel and
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`interference information for all the subcarriers and then selects multiple
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`U.S. Patent No. 7,848,439
`subcarriers with good performance (e.g., a high signal-to-interference plus noise
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`ratio (SINR)) and feeds back the information on these candidate subcarriers to
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`the base station.”) and id. at 8:1-3 (“The estimated SINR values are also used to
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`choose the appropriate coding/modulation rate for each cluster as discussed above.
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`By using an appropriate SINR indexing scheme, an SINR index may also indicate
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`a particular coding and modulation rate that a subscriber desires to use.”)
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`with ’439 Patent (Ex. 1001) at 4:32-46 (“[T]he receiving side first needs to select
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`AMC parameters for use in the data blocks that the transmission side transmits In
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`the procedure where the receiving side selects parameters first, channel estimation
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`is carried out using the received signal. A method based on a pilot or blind
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`channel estimation etc. may be given as a method of channel estimation. After this,
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`channel estimation section 319 transmits channel characteristics of the
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`obtained OFDM subcarriers
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`to subband AMC parameter selecting
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`section 318. Subband AMC parameter selecting section 318 first carries out
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`analysis of the performance of the subbands in OFDM in this way, and selects
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`AMC parameters appropriate for the respective subbands from the selected set of
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`AMC parameters. AMC parameters obtained in this way are then transmitted
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`back to the transmission side via a feedback channel.”) (emphases added).
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`Additionally, in both Li and the ’439 Patent, OFDM subbands/clusters of
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`subcarriers are grouped prior to allocation in order to decrease control signaling
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`overhead. Compare Li (Ex. 1004) at 11:61-67 (“The clusters may be allocated in
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`groups. Goals of group-based cluster allocation include reducing the data bits
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`for cluster indexing, thereby reducing the bandwidth requirements of the
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`feedback channel (information) and control channel (information) for cluster
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`allocation.”) with ’439 Patent (Ex. 1001) at (“The object of the present invention
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`is . . . reducing the feedback overhead compared with subband adaptive methods
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`of the related art by combining all of the subbands on a frequency domain of a
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`subcarrier communication system based on a fixed rule to as to give several
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`subband groups.”) (emphases added).
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`Because both Li and the ‘439 Patent teach OFDM communication systems in
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`which channel quality measurements are used to select modulation and coding
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`parameters and to allocate subcarriers in groups as a means of reducing feedback
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`overhead, Li is in the same field of endeavor and is reasonably pertinent to the
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`claims in the ’439 Patent. Singer Decl. (Ex. 1003) at ¶¶ 36-37. Therefore, Li is also
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`analogous to the claimed invention in the ’439 Patent.
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`Li was not cited or considered during prosecution of the ’439 Patent and, as
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`shown in this petition, raises new invalidity issues of the challenged claims that
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`have not been before the Patent Office.
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`Although Li teaches that subcarrier clusters can be grouped and that the
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`SINR (which may indicate particular modulation and coding parameters) is
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`reported on the clusters within the group, it does not expressly describe choosing
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`the same parameters for all clusters within the group as required by the Challenged
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`Claims. As discussed in detail below, it was well known at the filing of the ’439
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`Patent invention to perform AMC such that the entire group of subcarriers
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`allocated to a subscriber use the same modulation and coding parameters.
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`One example is Walton, which was filed March 20, 2003 and therefore
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`qualifies as prior art with regard to the ’439 Patent under 35 U.S.C. § 102(e) (pre-
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`AIA). Walton (Ex. 1005). The subject matter in Walton is in the same technical
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`field as Li and is analogous to Li with respect to transmission techniques applicable
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`to an OFDM system. Walton describes “[t]echniques . . . to select the proper
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`transmission mode for a data transmission in a multi-channel communication
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`system with multiple transmission channels having varying SNRs. A suitable
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`transmission mode may be determined for each data stream to be independently
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`processed (e.g., coded and modulated) and transmitted on a designated group of
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`transmission channels.” Id. at 2:21-27. Walton notes that its techniques are
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`applicable in OFDMA systems and notes, like Li and the ‘439 Patent, that
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`performing AMC on individual subcarriers/channels requires “a high feedback rate
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`. . . to send back information (e.g., the SNR or transmission mode) for each
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`transmission channel, which is needed by the transmitter to code and modulate data
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`on a channel-by-channel basis.” Id. at 1:17-25, 1:50-67. To decrease the required
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`feedback overhead, Walton describes a group-based AMC method in which “an
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`SNR estimate [] is initially obtained for each of the multiple transmission
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`channels,” “an average SNR [] is then computer,” and “an operating SNR” is then
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`calculated, considering both aspects of the system and variance between the
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`individual channel SNRs. Id. at 2:28-67. From the operating SNR, a transmission
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`mode is selected and “utilized for all of the multiple transmission channels.” Id.
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`Because Walton, like Li and the ’439 Patent, discloses an OFDM
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`communication system directed to minimizing AMC feedback overhead by
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`selecting modulation and coding parameters for an entire group of subcarriers, it is
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`in the same field of endeavor and is reasonably pertinent to the claims of the ’439
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`Patent. Singer Decl. (Ex. 1003) at ¶ 38. Therefore, Walton and Li are not only
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`analogous art with respect to each other and they are also analogous to the claimed
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`invention in the ’439 Patent.
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`Walton was not cited or considered during prosecution of the ’439 Patent
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`and as shown in this petition, raises new invalidity issues of the challenged claims
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`that have not been before the Patent Office.
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`i. Claim 1
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`1. A communication apparatus comprising:
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`
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` To the extent the preamble is limiting, Li discloses a communication
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`apparatus in form of an OFDMA cellular system comprised of multiple subscribers
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`communicating with a base station within a cell. Li (Ex. 1004) at 3:5-17. Although
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`Li refers to the communication apparatus (i.e., cellular handset) as a “subscriber”
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`throughout its disclosure, a POSITA would understand that descriptions of
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`functionality attributed to “subscribers” are in fact functionalities in the
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`subscriber’s cellular handset, or communication apparatus. Singer Decl. (Ex. 1003)
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`at ¶ 41 (noting, at 3:12-17, Li expressly equates “subscribers” to “mobiles,” which
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`a POSITA would understand is a reference to mobile handsets, and which a
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`POSITA would consider a “communication apparatus” as required by this claim).
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` [1(a)] a channel estimating section that carries out a channel estimation per
`subband;
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`Li teaches channel estimation across the full frequency bandwidth:
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`For downlink channels, each subscriber first measures the channel and
`interference information for all the subcarriers . . . The feedback
`may comprise channel and interference information (e.g., signal-to-
`interference-plus-noise-ratio information) on all subcarriers or just a
`portion of subcarriers.
`Li (Ex. 1004) at 3:18-25 (emphasis added).
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`Li also teaches that AMC can be performed on clusters of subcarriers:
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`A cluster can contain consecutive or disjoint subcarriers. The
`mapping between a cluster and its subcarriers can be fixed or
`reconfigurable. In the latter case, the base station informs the
`subscribers when the clusters are redefined. In one embodiment, the
`frequency spectrum includes 512 subcarriers and each cluster
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`includes four consecutive subcarriers, thereby resulting in 128
`clusters.
`Id. at 5:18-27 (emphasis added); see also id. at Fig. 1A. This is consistent
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`with the ’439 Patent’s teaching that “a subband indicates a subcarrier group
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`comprised of subcarriers in neighboring positions on the frequency domain.”
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`‘439 Patent (Ex. 1001) at 2:19-21 (emphasis added). Accordingly, Li’s subcarrier
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`“cluster” is the same as the ’439 Patent’s subcarrier “subband.” Singer Decl. (Ex.
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`1003) at ¶ 35.
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`Li describes a process by which pilot symbols are transmitted from the base
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`station to subscriber device from which the subscriber device can calculate quality
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`(i.e., signal-to-interference plus noise ration (SINR)) on a subcarrier cluster basis:
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`[E]ach base station transmits pilot symbols simultaneously, and
`each pilot symbol occupies
`the entire OFDM
`frequency
`bandwidth, as shown in FIGS. 2A-C. Referring to FIGS. 2A-C, pilot
`symbols 201 are shown traversing the entire OFDM frequency
`bandwidth for cells A, B and C, respectively.
`. . .
`A subscriber estimates the SINR for each cluster from the pilot
`symbols. In one embodiment, the subscriber first estimates the
`channel response, including the amplitude and phase, as if there is no
`interference or noise. Once the channel is estimated, the subscriber
`calculates the interference/noise from the received signal.
`Id. at 7:37-55 (emphasis added); see also id. at Figs. 2A-C.
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`IPR2018-01477
`U.S. Patent No. 7,848,439
`[1(b)] a parameter deciding section that decides modulation parameters and
`coding parameters per subband group comprised of a plurality of the subbands,
`based on a result of the channel estimation per subband;
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`Li
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`teaches
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`that subbands/clusters can be allocated
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`in groups of
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`subbands/clusters and that a parameter deciding section decides modulation and
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`coding parameters on a subband/cluster basis, based on the result of the channel
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`estimation discussed with reference to the preceding limitation. As described in
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`detail below, it would have been obvious to modify Li to decide a single set of
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`modulation and coding parameters for the entire subband/cluster group in
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`accordance with the teachings of Walton.
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`As discussed with reference to the preceding limitation, Li teaches that a
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`subscriber’s handset measures channel quality—SINR—and
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`reports
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`this
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`measurement back to the base station. Li also teaches that coding/modulation
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`parameters are decided based on the channel estimation and that these parameters
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`are indicated in the feedback to the base station:
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` [E]ach subscriber selects one or more clusters with good
`performance (e.g., high SINR and low traffic loading) relative to each
`other and feeds back the information on these candidate clusters to
`the base station through predefined uplink access channels . . . the
`feedback of information from each subscriber to the base station
`contains a SINR value for each cluster and also indicates the
`coding/modulation rate that the subscriber desires to use.
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`IPR2018-01477
`U.S. Patent No. 7,848,439
`Id. at 5:50-6:10 (emphasis added). Alternatively, Li teaches that an index
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`corresponding to the SINR value can be transmitted that indicates the selected
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`modulation and coding parameters. Id. at 11:5-9 (“Typically, an index to the
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`SINR level, instead of the SINR itself is sufficient to indicate the appropriate
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`coding/modulation for the cluster. For example, a 3-bit field can be used for
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`SINR indexing to indicate 8 different rates of adaptive coding/modulation.”)
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`(emphasis added); see also id. at 8:1-3 (“By using an appropriate SINR indexing
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`scheme, an SINR index may also indicate a particular coding and modulation rate
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`that a subscriber desires to use.”).
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`Further, Li teaches that the pilot symbols (sent for channel estimation) may
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`indicate which clusters are available to be allocated:
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`In another embodiment, the pilot signal sent from the base station to
`the subscriber also indicates the availability of each cluster, e.g., the
`pilot signal shows which clusters have already been allocated for other
`subscribers and which clusters are available for new allocations.
`Id. at 12:44-48 (emphasis added). To the extent this limitation requires the handset,
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`rather than the base station, make a final decision regarding which group of
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`subbands to use, one of skill in the art would understand that the base station
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`indicating available groups of subbands via pilot symbols would result in the
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`handset selecting and reporting modulation and coding parameters only for
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`IPR2018-01477
`U.S. Patent No. 7,848,439
`available subbands, thereby making the final decision. Singer Decl. (Ex. 1003) at ¶
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`42.
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`As noted above, Li teaches that subbands/clusters can be further joined into
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`cluster groups:
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`In another embodiment, for the downlink, the clusters are
`partitioned into groups. Each group can include multiple clusters.
`FIG. 6 illustrates an exemplary partitioning. Refer ring to FIG. 6,
`groups 1-4 are shown with arrows pointing to clusters that are in each
`group as a result of the partitioning.
`Li (Ex. 1004) at 11:47-52. The following annotated FIG. 6 highlights the clusters
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`of “Group 1” in blue and the clusters of “Group 2” in green to illustrate one
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`grouping embodiment described by Li:
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`Li teaches that the handset knows which clusters are included in a group and
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`that both a group index and SINR values for each cluster within a selected group
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`are communicated to the base station:
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`IPR2018-01477
`U.S. Patent No. 7,848,439
`In one embodiment, a subscriber first selects the group with the best
`overall performance and then feedbacks the SINR information for
`the clusters in that group. . . . By transmitting the SINR of all the
`clusters in the group sequentially, only the group index, instead of all
`the cluster indices, needs to be transmitted. Thus, the feedback for
`each group generally contains two types of information: the group
`index and the SINR value of each cluster within the group.
`Id. at 12:9-19 (emphasis added).
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`Although Li decided modulation and coding parameters on a per-
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`subband/cluster basis, it would have been obvious, to modify Li such that a single
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`pair of modulation and coding parameters were decided for the whole group in
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`accordance with the teachings of Walton. Walton teaches a method for selecting a
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`single set of modulation and coding parameters (i.e., transmission mode) that is
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`applied to a group of transmission channels of varying SNRs (signal-to-noise
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`ratio):
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`Techniques are provided herein to select the proper transmission
`mode for a data transmission in a multi-channel communication
`system with multiple transmission channels having varying SNRs. A
`suitable transmission mode may be determined for each data stream to
`be
`independently processed (e.g., coded and modulated) and
`transmitted on a designated group of transmission channels.
`Walton (Ex. 1005) at 2:21-27.
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`IPR2018-01477
`U.S. Patent No. 7,848,439
`Specifically, Walton teaches that individual SNRs are calculated for the
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`channels, an average is then calculated, and certain adjustments are made to arrive
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`at an “operating SNR” that is used to select a transmission mode (modulation and
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`coding parameters) for all channels within the group:
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`In one specific method of determining a suitable transmission mode
`for a data stream sent on multiple transmission channels, an SNR
`estimate (for example, in units of dB) is initially obtained for each
`of the multiple transmission channels used to transmit that data
`stream. An average SNR [] is then computed for the SNR estimates
`for the multiple transmission channels . . . The variance of the SNR
`estimates . . . is also computed . . . A back-off factor, γbo, is then
`determined, for example, based on a function [] of the average SNR
`and the SNR variance. . . . An operating SNR [] for the transmission
`channels is next computed based on the average SNR and the back-
`off factor . . . . The transmission mode for the data stream is then
`selected based on the operating SNR, for example, using a look-up
`table of supported transmission modes and their required SNRs. The
`selected transmission mode is utilized for all of the multiple
`transmission channels used to transmit the data stream.
`Id. at 2:28-67 (emphasis added).
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`The motivations to modify Li in light of Walton are many, including from
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`the references themselves. As discussed above, Li teaches that a significant benefit
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`of grouping subbands/clusters of subcarriers is reducing the required feedback
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`channel bandwidth between the handset and base station. Li (Ex. 1004) at 11:62-
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`IPR2018-01477
`U.S. Patent No. 7,848,439
`67. But because Li proposes reporting a separate SINR and transmission mode for
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`each subband/cluster within a chosen group, the required feedback channel
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`bandwidth must accommodate control data corresponding to each individual
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