UNITED STATES PATENT AND TRADEMARK OFFICE
`__________________
`
`BEFORE THE PATENT TRIAL AND APPEAL BOARD
`___________________
`
`ERICSSON INC. AND TELEFONAKTIEBOLAGET
`LM ERICSSON,
`Petitioner
`
`v.
`
`INTELLECTUAL VENTURES II LLC,
`Patent Owner
`___________________
`
`Patent 7,269,127
`
`Title: PREAMBLE STRUCTURES FOR SINGLE-INPUT, SINGLE-
`OUTPUT (SISO) AND MULTI-INPUT, MULTI-OUTPUT (MIMO)
`COMMUNICATION SYSTEMS
`_____________________
`
`PETITION FOR INTER PARTES REVIEW
`
`
`
`Pursuant to the provisions of 35 U.S.C. §§ 311-319, Petitioner Ericsson Inc.
`
`and Telefonaktiebolaget LM Ericsson (collectively, “Ericsson”) hereby petitions the
`
`Patent Trial and Appeal Board to institute an inter partes review of claims 1-10, 17,
`
`20, 21, 23, and 24 of United States Patent No. 7,269,127 (“the ’127 patent,” ERIC-
`
`1001) that issued on September 11, 2007, to Mody et al. According to USPTO
`
`records, the ’127 patent is currently assigned to Intellectual Ventures II LLC (“IV”).
`
`
`
`
`
`

`

`Petition for Inter Partes Review of U.S. 7,269,127
`
`
`TABLE OF CONTENTS
`
`I.  Mandatory Notices ............................................................................................... 1 
`
`A.  Real Party-in-Interest ................................................................................. 1 
`
`B.  Related Matters .......................................................................................... 1 
`
`C.  Lead and Back-up Counsel and Service Information ............................... 1 
`
`II.  Grounds for Standing ........................................................................................... 2 
`
`III.  Relief Requested .................................................................................................. 2 
`
`IV. The Reasons for the Requested Relief ................................................................. 2 
`
`A.  Summary of the ’127 Patent and Comparison with Primary
`Reference ................................................................................................... 2 
`
`B.  The Prosecution History ........................................................................... 10 
`
`C.  The Prior Art of the Present Petition ......................................................... 10 
`
`V.  Identification of Challenges and Claim Construction .......................................... 19 
`
`A.  Challenged Claims .................................................................................... 19 
`
`B.  Claim Construction ................................................................................... 19 
`
`
`
` Frame Structure ....................................................................................... 19 1.
`
`
`
` Preamble Structure .................................................................................. 20 2.
`
`
`
` Data Structure .......................................................................................... 22 3.
`
`
`
` Pilot Symbol ............................................................................................ 23 4.
`
`
`
` Training Symbol ...................................................................................... 23 5.
`
`
`
` Enhanced Training Symbol ..................................................................... 24 6.
`
`C.  Statutory Grounds for Challenges ............................................................. 26 
`
`
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`i
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`

`

`Petition for Inter Partes Review of U.S. 7,269,127
`
` Challenge #1: Claims 1-3 and 5 are unpatentable under 35 U.S.C. § 1.
`
`103(a) over Schmidl and Arslan .................................................................. 27 
`
` Challenge #2: Claims 4 and 6-10 are unpatentable under 35 U.S.C. § 2.
`
`103(a) over Schmidl, Arslan, and Kim ........................................................ 40 
`
` Challenge #3: Claim 17 is unpatentable under 35 U.S.C. § 103(a) over 3.
`
`Schmidl, Arslan, Kim, and Heiskala. .......................................................... 46 
`
` Challenge #4: Claims 20 and 21 are unpatentable under 35 U.S.C. § 4.
`
`103(a) over Schmidl and Kim ..................................................................... 48 
`
` Challenge #5: Claims 23 and 24 are unpatentable under 35 U.S.C. § 5.
`
`103(a) over Schmidl, Kim, and Heiskala .................................................... 57 
`
`VI.  Conclusion .......................................................................................................... 59 
`
`
`
`ii
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`

`

`Petition for Inter Partes Review of U.S. 7,269,127
`
`
` I. Mandatory Notices
`A. Real Party-in-Interest
`The real party-in-interest is Ericsson.
`
`B. Related Matters
`As of the filing date of this petition and to the best knowledge of Ericsson,
`
`the ’127 patent is involved in the following litigations:
`
` IV I LLC et al. v. AT&T Mobility LLC et al., 1-13-cv-01668 (D. Del. 2013).
`
` IV I LLC et al. v. Leap Wireless Int’l et al., 1-13-cv-01669 (D. Del. 2013).
`
` IV I LLC et al. v. Nextel Operations et al., 1-13-cv-01670 (D. Del. 2013).
`
` IV I LLC et al. v. T-Mobile USA Inc. et al., 1-13-cv-01671 (D. Del. 2013).
`
` IV I LLC et al. v. U.S. Cellular Corp., 1-13-cv-01672 (D. Del. 2013).
`
`C. Lead and Back-up Counsel and Service Information
`
`Lead Counsel
`
`Back-up Counsel
`
`J. Andrew Lowes
`HAYNES AND BOONE, LLP
`2323 Victory Ave. Suite 700
`Dallas, TX 75219
`
`Phone: (972) 680-7557
`Fax: (214) 200-0853
`andrew.lowes.ipr@haynesboone.com
`USPTO Customer No. 27683
`USPTO Reg. No. 40,706
`
`Please address all correspondence to lead and back-up counsel. Ericsson
`
`David M. O’Dell
`HAYNES AND BOONE, LLP
`2323 Victory Ave. Suite 700
`Dallas, TX 75219
`
`Phone: (972) 739-8635
`Fax: (214) 200-0853
`david.odell.ipr@haynesboone.com
`USPTO Customer No. 27683
`USPTO Reg. No. 42,044
`
`also consents to electronic service by email.
`
`
`
`1
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`

`

`II. Grounds for Standing
`
`Petition for Inter Partes Review of U.S. 7,269,127
`
`
`Ericsson certifies that the ’127 patent for which review is sought is available
`
`for inter partes review and that Ericsson is not barred or estopped from requesting
`
`inter partes review challenging the patent claims on grounds stated in the petition.
`
`III. Relief Requested
`
`Ericsson asks that the Board review the accompanying prior art and analysis,
`
`institute a trial for inter partes review of claims 1-10, 17, 20, 21, 23, and 24 of the
`
`’127 patent, and cancel those claims as unpatentable.
`
`IV. The Reasons for the Requested Relief
`
`The full statement of the reasons for the relief requested is as follows:
`
`A.
`
`Summary of the ’127 Patent and Comparison with Primary
`Reference
`
`The
`
`’127 patent
`
`is directed
`
`to
`
`the use of
`
`frame structures
`
`in
`
`telecommunications. A frame structure includes a preamble structure and a data
`
`structure, and the ‘127 patent alleges various shortcomings in existing preamble
`
`structures, including that existing structures include “considerable redundancy” which
`
`“reduces system throughput.” ERIC-1001, 2:66-3:12. According to the ‘127 patent
`
`“there is a need for an efficient preamble structure that provides time and frequency
`
`synchronization, estimation of parameters such as noise variance and channel
`
`parameters, and low PAPR [(peak-to-average power ratio)] when used with SISO
`
`
`
`2
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`

`

`[(single-input,
`
`single-output)]
`
`Petition for Inter Partes Review of U.S. 7,269,127
`
`[(multi-input, multi-output)]
`
`and MIMO
`
`communication systems.” Id. 3:13-17. To that end, the ’127 patent is directed to “a
`
`system for providing efficient preamble structures for use in single-input, single-
`
`output (SISO) and multi-input, multi-output (MIMO) communication systems.” Id.
`
`3:21-24. In an effort to meet the stated goal, the ’127 patent discloses a preamble
`
`structure including two training symbols, with one being considered an enhanced
`
`training symbol. See id. 10:50-11: 26. Claim 1 is representative and in relevant part
`
`recites “each modulator outputting a frame structure comprising a preamble structure
`
`and a data structure, the preamble structure comprising at least one training symbol
`
`and an enhanced training symbol; […] wherein the enhanced training symbol is a
`
`single symbol” (emphasis added). FIG. 6 of the ’127 patent, a portion of which is
`
`reproduced below, illustrates the disclosed frame structure.
`
`As shown above, the ’127 patent’s frame structure 68 includes a preamble
`
`structure 70 followed by a data structure 72. The preamble structure 70 includes an
`
`enhanced training symbol 79 and a training symbol 74, both including a cyclic prefix
`
`
`
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`3
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`

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`Petition for Inter Partes Review of U.S. 7,269,127
`
`76 and a training block 78. Finally, the data structure 72 comprises data symbols 80,
`
`each data symbol including a cyclic prefix 76 and a data block 82.
`
`The above disclosed and claimed frame structure was well known in the art
`
`prior to the earliest priority date of the ’127 patent. For example, U.S. Patent No.
`
`5,732,113 (“Schmidl”)1 discloses a data frame that corresponds to the disclosed frame
`
`structure in the ’127 patent. Schmidl, ERIC-1002, 11:60-13:65; see also ERIC-1009,
`
`¶¶ 41-51. Schmidl illustrates the data frame 130 in FIG. 6, which is annotated and
`
`reproduced below. See also, ERIC-1009, ¶ 41.
`
`
`
`Just like the ’127 patent, Schmidl discloses that the “data frame 130 includes
`
`an OFDM training sequence 132 [corresponding to the claimed ‘preamble
`
`structure’] that is composed of two successive OFDM symbols, a first OFDM
`
`1 Schmidl is cited on the face of the ’127 patent, although it was not used during
`
`prosecution to substantively reject the claims. See ERIC-1008.
`
`
`
`4
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`Petition for Inter Partes Review of U.S. 7,269,127
`
`training symbol 134 [corresponding to the claimed ‘enhanced training symbol’]
`
`and a second OFDM training symbol 136 [corresponding to the claimed ‘at least
`
`one training symbol’].” ERIC-1002, 12:1-4. Further, like the ’127 patent,
`
`Schmidl’s data frame includes a data structure, comprising OFDM data symbols
`
`138a . . . 138(M-2), combined with and following the OFDM training sequence
`
`132. See id. FIG. 6. Therefore, Schmidl’s data frame discloses the frame structure
`
`of the ’127 patent.
`
`In addition to the correspondence between frame structures, Schmidl’s
`
`training symbol and transmitter correspond to ’127 patent’s “enhanced training
`
`symbol” and transmitter, respectively, as discussed further below.
`
`The ’127 patent describes the enhanced training symbol as a symbol that has a
`
`time-domain length equal to a single symbol (e.g., a single OFDM symbol), includes
`
`a cyclic prefix and a training block, and can be subdivided into a number of sections.
`
`ERIC-1001, FIG. 7 (reproduced below); see also ERIC-1009, ¶ 26. Specifically, the
`
`’127 patent states that “[t]he entire length of the enhanced training symbol 84 is Ts,”
`
`which “is equal to the length of only one symbol period in an OFDM or other space-
`
`time communication system.” ERIC-1001, 13:1-6, 13:39-40, and 13:16-19. The
`
`combination of a cyclic prefix 76 and a training block 78 forms the enhanced training
`
`symbol. See id. FIG. 6. Finally, the ’127 patent states that “[t]he enhanced training
`
`symbol 79 of length G+NI can be further subdivided into smaller sections . . ..” Id.
`
`
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`5
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`Petition for Inter Partes Review of U.S. 7,269,127
`
`11:63-66. The sections of an enhanced training symbol are illustrated in the below-
`
`annotated FIG. 7 of the ’127 patent. In the embodiment of FIG. 7, all of the sections
`
`are the same. See ERIC-1001, 13:48-49.
`
`
`
`Schmidl also teaches an enhanced training symbol with equal sections. For
`
`example, Schmidl discloses that the first OFDM training symbol (corresponding to
`
`the claimed “enhanced training symbol”) is a single OFDM symbol that includes two
`
`halves (which are “sections”), each half including the same data. ERIC-1002, FIG. 7,
`
`12:49-13:4 and 14:16-30. Schmidl further discloses that the first OFDM training
`
`symbol is “a time-domain OFDM symbol that has two identical halves . . .” where
`
`“the first half of the symbol is identical to the second half of the symbol.” Id. 12:49-
`
`13:4 (emphasis added).
`
`Further, Schmidl discloses that the first OFDM training symbol includes a
`
`cyclic prefix and a training interval (corresponding to the “training block”), just like in
`
`the embodiments of the ‘127 patent. See ERIC-1002, FIGs. 4 and 6, 2:38-43 and
`
`
`
`6
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`

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`Petition for Inter Partes Review of U.S. 7,269,127
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`4:55-62. The combined teachings of FIGs. 4 and 6 of Schmidl are annotated and
`
`reproduced below for convenience. See ERIC-1009, ¶ 43. Therefore, Schmidl’s
`
`first OFDM training symbol discloses the enhanced training symbol of the ’127
`
`patent. See id.; see also ERIC-1009, ¶¶ 43-45.
`
`
`
`The ’127 patent discloses utilizing known OFDM system components to insert
`
`the enhanced training symbol into the data structure discussed above. ERIC-1001,
`
`FIGs. 1-3. FIGs. 1 and 3 of the ‘127 patent are annotated and reproduced below along
`
`with annotated FIG. 1 of Schmidl (a few blocks with similar functions are colored
`
`similarly to highlight the similarities).
`
`
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`7
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`

`

`Petition for Inter Partes Review of U.S. 7,269,127
`
`
`Transmitter/Modulator of the ’127 Patent:
`
`Transmitter/Modulator of Schmidl:
`
`
`
`
`
`
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`8
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`

`Petition for Inter Partes Review of U.S. 7,269,127
`
`In addition to the frame structure, the ’127 patent describes and claims a
`
`transmitter. The ‘127 transmitter (illustrated in FIG. 1) includes several components
`
`such as an encoder, a modulator, and an antenna. See id. Further, the ’127 patent
`
`illustrates details of a modulator 24 in FIG. 3. As evident from FIG. 3, the ’127
`
`modulator includes an inverse discrete Fourier transform (IDFT) stage that
`
`converts training blocks and data blocks from the frequency domain to the time
`
`domain to produce time domain samples, and a cyclic prefix inserter that inserts
`
`guard intervals into each of the time domain samples. See id. FIG. 3 and 8:1-18.
`
`The output of the inserter is further processed by a digital-to-analog converter
`
`(DAC), a mixer, a local oscillator, and an amplifier prior to being transmitted by
`
`the antenna over the channel. See id. 8:19-34.
`
`Schmidl also teaches a transmitter, just like the ’127 patent. ERIC-1002, 1:39-
`
`3:33 and FIG. 1 (annotated and reproduced above). Also like the ’127 patent,
`
`Schmidl’s transmitter comprises an encoder, modulator, and an antenna. See id.
`
`Further, like the ’127 patent, Schmidl’s modulator components include an inverse
`
`Fourier transform stage, a digital signal processor (DSP), digital-to-analog
`
`converters (DACs), mixers, a local oscillator, and an amplifier. See id.
`
`
`
`Thus, and as explained further below, the features set forth in the challenged
`
`claims were well known in the art at the time the ’127 patent was filed.
`
`
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`9
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`

`Petition for Inter Partes Review of U.S. 7,269,127
`
`
`B. The Prosecution History
`
`The ’127 patent was filed October 4, 2002 and claims priority to U.S.
`
`Provisional Application No. 60/327,145 filed October 4, 2001. During prosecution,
`
`the independent claims of the ’127 patent were substantively rejected under 35 U.S.C.
`
`§ 102(e) as being anticipated by U.S. Application Publication No. 2002/0122382 to
`
`Ma et al., and some dependent claims were indicated as including allowable subject
`
`matter. See ERIC-1008, pp. 71-72. In response, the patentee amended the
`
`independent claims to include the allowable subject matter to place the application in
`
`condition for allowance. See id. 58. Claim 1, for example, was amended to include
`
`“wherein the enhanced training symbol is a single symbol.” Id., p. 59.
`
`C. The Prior Art of the Present Petition
`
`Schmidl. The primary reference of the present petition is U.S. Patent No.
`
`5,732,113 (“Schmidl”) issued on March 24, 1998. ERIC-1002. Therefore, Schmidl is
`
`prior art to the ’127 patent under pre-AIA 35 U.S.C. § 102(b). Schmidl relates to
`
`“timing and frequency synchronization of an OFDM receiver to an OFDM signal
`
`[…].” ERIC-1002, 1:8-12; see also ERIC-1009, ¶¶ 41-51. Regarding transmission,
`
`Schmidl states that “[t]he present invention provides a method . . . for frame/symbol
`
`timing estimation and
`
`synchronization,
`
`frequency offset estimation and
`
`correction/synchronization,
`
`and
`
`sampling
`
`rate
`
`offset
`
`estimation
`
`and
`
`correction/synchronization.” ERIC-1002, 11:23-31. “The method of the present
`
`
`
`10
`
`

`

`Petition for Inter Partes Review of U.S. 7,269,127
`
`invention for timing and frequency synchronization of a receiver to an OFDM signal
`
`relies on the detection and analysis of a special OFDM training sequence that is
`
`included in the OFDM signal and preferably transmitted within a data frame.” Id.
`
`11:60-64. “The format of this OFDM training sequence is an important aspect of the
`
`present invention, and an illustration of such an OFDM training sequence within a
`
`data frame is shown in FIG. 6.” which is annotated and reproduced above. Id. 11:64-
`
`67.
`
`As discussed above, just like the ’127 patent, Schmidl discloses that a
`
`transmitted data frame (corresponding to the claimed “frame structure”) comprises
`
`an OFDM data sequence (corresponding to a “data structure”) including data
`
`symbols and a training sequence (corresponding to a “preamble structure”), which
`
`includes a plurality of training symbols and is needed by the receiver “to acquire
`
`and synchronize to the OFDM signal.” See id. FIG. 6 and 12:34-35. Each of the
`
`training symbols includes a cyclic prefix and a training interval (corresponding to a
`
`“training block”), and each of the data symbols includes a cyclic prefix and a data
`
`interval (corresponding to a “data block”). See id. FIGs. 4 and 6. For example,
`
`Schmidl discloses that “DSP 18 . . . adds a cyclic prefix or guard interval of length
`
`Tg to each symbol.” Id. 2:38-43. In Schmidl, “a data frame 100 includes M
`
`consecutive symbols 112a, 112b, . . . , 112M, each of which includes a guard
`
`interval, Tg, as well as the OFDM symbol interval, Ts,” and “[t]herefore, each
`
`
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`11
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`

`

`Petition for Inter Partes Review of U.S. 7,269,127
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`symbol has a total duration of Tg +Ts seconds.” Id. FIG. 4 and 4:55-63. The
`
`combined teachings of FIGs. 4 and 6 of Schmidl are annotated and reproduced
`
`below for convenience. See ERIC-1009, ¶ 43.
`
`
`
`As discussed above, Schmidl’s training sequence (corresponding to a
`
`“preamble structure”) includes a first OFDM training symbol 134 (corresponding
`
`to the “enhanced training symbol”) and a second OFDM training symbol 136
`
`(corresponding to “at least one training symbol”). See ERIC-1002 11:67-12:4.
`
`“Training symbols 134 and 136 are preferably placed at the beginning of the data
`
`frame 130.” Id. 12:16-17.
`
`Regarding the first OFDM training symbol, Schmidl discloses that, “[t]o
`
`estimate symbol/frame timing in order to synchronize the receiver to the OFDM
`
`
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`12
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`

`Petition for Inter Partes Review of U.S. 7,269,127
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`signal, the method . . . utilizes the time-domain symmetry properties of first OFDM
`
`training symbol 134.” Id. 14:16-20. “One of the key advantages . . . is that it
`
`enables a receiver to accurately synchronize to the symbol/frame timing of an
`
`OFDM signal with the reception of just one symbol, first OFDM training symbol
`
`134.” Id. 14:26-30. Further, Schmidl discloses that the training interval of the first
`
`OFDM training symbol is divided into two identical halves (corresponding to “a
`
`number of sections”) having the same data. See id. 12:49-13:4. For example,
`
`Schmidl discloses that the first OFDM training symbol is “a time-domain OFDM
`
`symbol that has two identical halves . . .” where “the first half of the symbol is
`
`identical to the second half .” Id. FIG. 7 (reproduced below).
`
`
`
`Therefore, in Schmidl, the first training symbol is a single symbol that
`
`includes at least two sections (i.e., a number of sections), and is used for the
`
`purpose of synchronization. See id. 12:49-13:4 and 14:16-31.
`
`Regarding the second OFDM training symbol, Schmidl discloses that “[t]he
`
`preferred embodiment also comprises a second OFDM training symbol 136, which
`
`in the preferred embodiment directly follows first OFDM training symbol 134.”
`
`
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`13
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`

`Petition for Inter Partes Review of U.S. 7,269,127
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`Id. 13:44-46. “Although the two symbols need not be placed next to each other,
`
`doing so minimizes the effect of time variation of the channel over the duration of
`
`the training sequence.” Id. 13:47-49. In this way, Schmidl’s training sequence
`
`including the first OFDM training symbol and the second OFDM training symbol
`
`allows timing and frequency synchronization between the receiver and the
`
`transmitter. See id. 11:27-30, 60-64.
`
`Also as discussed above, Schmidl discloses a transmitter for transmitting the
`
`data frame. See id. FIG. 1. Like the ’127 patent, Schmidl’s transmitter comprises
`
`several components including an encoder, an inverse Fourier transform stage, a
`
`digital signal processor (DSP), and an antenna. See id. FIG. 1 of Schmidl
`
`illustrates a
`
`transmitter, and
`
`is annotated and compared against
`
`the
`
`transmitter/modulator of the ’127 patent to show the similarities.
`
`As discussed above, Schmidl discloses combining training symbols, which
`
`are used for synchronization, with data symbols in the data frame. See id. FIG. 6.
`
`In addition, it was known at the time of the invention of the ’127 patent to insert
`
`pilot symbols, which are also used for synchronization between a receiver and
`
`transmitter, into (between) data symbols of a data frame. ERIC-1009, ¶ 51. For
`
`example, Arslan discloses a frame structure having pilot symbols inserted into data
`
`symbols for synchronization purposes. Id.; ERIC-1003, FIG. 4 and 6:7-21.
`
`
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`14
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`

`

`Petition for Inter Partes Review of U.S. 7,269,127
`
`Arslan. U.S. Patent No. 6,411,649 (“Arslan”) was filed October 20, 1998 and
`
`issued on June 25, 2002. ERIC-1003. Therefore, Arslan is prior art to the ’127 patent
`
`under pre-AIA 35 U.S.C. § 102(e). Arslan “compensates for variations in the channel
`
`including channel fade . . . by utilizing pilots in an information sequence to
`
`periodically retrain a channel estimator.” ERIC-1003, 2:64-3:3 and ERIC-1009, ¶¶
`
`52-54. Arslan discloses that “a channel tracker may be synchronized using a
`
`synchronization sequence and then periodically retrained using known pilot symbols.”
`
`ERIC-1003, 3:3-6. For example, Arslan discloses that, “in wireless mobile radio
`
`systems, known data sequences are inserted periodically into the transmitted
`
`information sequences.” Id. 1:54-57. To that end, in FIG. 4, Arslan illustrates “a
`
`frame structure which . . . includes a synchronizing portion 0-A using training
`
`symbols, information portions B-C, F-G and J-K and pilot portions D-E, H-I and Y-
`
`Z.” Id. FIG. 4 and 6:7-11.
`
`As evident from FIG. 4, in Arslan, “the pilot portions are interspersed
`
`between information portions so as to allow retraining of the adaptive channel
`
`estimator 30 during the frame.” Id. 6:11-14.
`
`
`
`
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`15
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`

`Petition for Inter Partes Review of U.S. 7,269,127
`
`Based on the above discussion, Schmidl is directed at synchronization
`
`between wireless transmitters and receivers, and discloses that a transmitter
`
`transmits a signal having a frame structure comprising training symbols and data
`
`symbols. See ERIC-1002, 1:5-12. Also, Arslan is directed at utilizing pilot
`
`symbols inserted into the data symbols to maintain synchronization between
`
`wireless transmitters and receivers. See ERIC-1003, 3:1-6. Further, Arslan
`
`discloses a frame structure having training symbols combined with data symbols
`
`and pilot symbols inserted into the data symbols. See id. FIG. 4. Therefore, both
`
`Schmidl and Arslan are directed at improving synchronization between a wireless
`
`transmitter and a wireless receiver, and disclose frame structures including
`
`information for the same. Accordingly, it would have been obvious for one of
`
`ordinary skill in the art to apply the known technique of inserting pilot symbols
`
`into data symbols, as taught by Arslan, to the known frame structure of Schmidl to
`
`yield predictable results. ERIC-1009, ¶¶ 52-54.
`
`Kim. U.S. Patent No. 7,012,881 (“Kim”) was filed December 29, 2000 and
`
`issued on March 14, 2006. ERIC-1004. Therefore, Kim is prior art to the ’127 patent
`
`under pre-AIA under 35 U.S.C. § 102(e). Kim “relates to . . . using an analytic tone
`
`to calculate the timing offset and frequency offset estimations in an orthogonal
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`frequency division multiplexing
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`(OFDM)
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`system,”
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`thereby
`
`improving
`
`synchronization in the OFDM system. ERIC-1004, 1:7-10 and ERIC-1009, ¶¶ 55-
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`Petition for Inter Partes Review of U.S. 7,269,127
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`59. Kim illustrates “a signal architecture for a wireless local area network
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`(WLAN) according to the prior art OFDM system.” Id. FIG. 8 and 2:22-24.
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`
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`As evident from annotated FIG. 8, Kim discloses that a training symbol (R1)
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`is provided with a cyclic prefix or guard interval (G1) followed by a training
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`interval (corresponding to “training block”) that includes four sections. See id.
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`FIG. 8. In other words, Kim discloses that a training symbol may include five
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`sections. See id. Further, in Kim, each section includes a number of samples. See
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`id. 2:32-34. For example, Kim discloses that, “in each of the symbols, the guard
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`interval is N/4, where N = 64, such that the length of the guard symbol is 16.” Id.
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`Regarding samples in a section, the training interval of an OFDM training
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`symbol is 3.2 µs, which corresponds to a number of samples determined by 3.2 µs x
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`20 Msamples/sec = 64, which is consistent with “N = 64” provided in Kim. ERIC-
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`1009, ¶¶ 57-58. Also, it is well known that a sampling rate multiplied by a time
`
`interval yields a number of samples in the time interval. See id.
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`Petition for Inter Partes Review of U.S. 7,269,127
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`Regarding the combination of Schmidl and Kim, Schmidl is directed at
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`improving synchronization between an OFDM transmitter and an OFDM receiver,
`
`and discloses that training symbols include training intervals having a number of
`
`sections. ERIC-1002, FIGs. 4 and 6, and 4:55-62; see also ERIC-1009, ¶ 59. Further,
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`Kim, which is also directed to improving synchronization between an OFDM
`
`transmitter and an OFDM receiver, discloses that (i) intervals in data symbols and
`
`training symbols include respective number of sections, and that (ii) each section
`
`includes a number of samples. ERIC-1004, FIG. 8 and 2:32-34; see also ERIC-1009,
`
`¶ 59. Therefore, both Schmidl and Kim are directed at improving synchronization in
`
`an OFDM system and discuss training symbols including a number of sections for
`
`improving synchronization. Accordingly, it would have been obvious for one of
`
`ordinary skill in the art to apply the known techniques of dividing the training
`
`symbols into a number of sections with each section including a number of samples,
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`as taught by Kim, to the known training symbols of Schmidl to yield predictable
`
`results. ERIC-1009, ¶ 59.
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`Other prior art references disclose even more techniques related to enhanced
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`training symbols and a wireless transmitter. See id. ¶¶ 60-61. These include:
`
` U.S. Patent No. 6,298,035 (“Heiskala”) was filed on December 21, 1999,
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`and is prior art to the ’127 patent under pre-AIA 35 U.S.C. § 102(e). ERIC-1006.
`
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`Petition for Inter Partes Review of U.S. 7,269,127
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`As shown below in the present petition, and discussed in detail in the
`
`accompanying Expert Declaration (ERIC-1009), each element in the challenged
`
`claims of the ’127 patent was well known to one of ordinary skill in the art at the time
`
`of the invention, and the cited combinations would have been obvious to the person of
`
`ordinary skill. Thus, combinations of Schmidl, Arslan, Kim, and Heiskala render
`
`claims 1-10, 17, 20, 21, 23, and 24 of the ’127 patent obvious under 35 U.S.C § 103.
`
`V.
`
`Identification of Challenges and Claim Construction
`
`A. Challenged Claims
`Claims 1-10, 17, 20, 21, 23, and 24 of the ’127 patent are hereby challenged.
`
`B. Claim Construction
`This petition presents claim analysis in a manner that is consistent with the
`
`broadest reasonable interpretation in light of the specification. See 37 C.F.R.
`
`§ 42.100(b). For the sake of reference, claim terms will be identified in bold italics:
`
`
`1.
`
`Frame Structure
`
`The ’127 patent uses the terms “frame structure” in the claims and detailed
`
`description. The ’127 patent does not set forth a special meaning for the above terms.
`
`However, both the specification and the claims of the ’127 patent describe frame
`
`structures as having preamble structures and data structures. See ERIC-1001, 1:60-
`
`64; 16:60-62 and ERIC-1009, ¶ 34. In particular, the ’127 patent states that “[o]ne
`
`such technique, known as space-time processing (STP), processes and combines
`
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`19
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`Petition for Inter Partes Review of U.S. 7,269,127
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`‘preamble structures’ and ‘data structures’ into groups referred to herein as ‘frame
`
`structures.’” ERIC-1001, 1:60-64. The ’127 patent also states that “[e]ach frame
`
`structure generally includes a preamble structure followed by a data structure.” Id.
`
`2:7-9. Finally, the ’127 patent illustrates a frame structure in FIG. 6, partially
`
`reproduced below to show frame structure 68.
`
`
`
`Therefore, these terms should be given their broadest reasonable interpretation
`
`to one of ordinary skill in the art in view of the specification and the ordinary and
`
`accustomed meaning of the terms. Thus, based on the above discussion, one of
`
`ordinary skill in the art would understand the terms “frame structure” to mean a unit
`
`of transmission comprising a preamble structure followed by a data structure. See
`
`ERIC-1009, ¶ 34.
`
`
`2.
`
`Preamble Structure
`
`The ’127 patent uses the terms “preamble structure” in the claims and the
`
`detailed description. The ’127 patent does not set forth a special meaning for the above
`
`terms. However, the ’127 patent describes the above terms as structures containing “an
`
`overhead for providing synchronization and parameter estimation, allowing a receiver
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`Petition for Inter Partes Review of U.S. 7,269,127
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`to decode signals received from a transmitter.” ERIC-1001, 2:1-3. The ’127 patent
`
`also states that “[e]ach frame structure generally includes a preamble structure
`
`followed by a data structure.” Id. 2:7-9. Further, the ’127 patent states that
`
`“[t]raining symbols are typically added as prefixes to the data structures (e.g., at
`
`the beginning of frame structure) to enable training (i.e., time and frequency
`
`synchronization) between the transmitter and receiver . . ..” and that “[t]hese
`
`training symbols can be referred to as preambles and are part of the preamble
`
`structures.” Id. 2:10-15. Finally, the ’127 patent illustrates a frame structure in
`
`FIG. 6, partially reproduced below to highlight preamble structure 70.
`
`
`
`Therefore, these terms should be given their broadest reasonable interpretation to
`
`one of ordinary skill in the art in view of the specification and the ordinary and
`
`accustomed meaning of the terms. Thus, based on the above discussion and the
`
`ordinary meaning of the word “preamble,” one of ordinary skill in the art would
`
`understand the terms “preamble structure” to mean a portion of the frame structure
`
`located near the beginning of the frame structure, before the data structure, and
`
`comprising at least two training symbols. See ERIC-1009, ¶ 35.
`
`
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`21
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`Petition for Inter Partes Review of U.S. 7,269,127
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`
`Data Structure
`
`
`3.
`
`The ’127 patent uses the terms “data structure” in the claims and the detailed
`
`description. The ’127 patent does not set forth a special meaning for the above terms.
`
`However, the ’127 patent describes that “data structures” follow the preamble structures
`
`within the frame structure, and include transmit data or information organized as data
`
`symbols. See ERIC-1001, 1:64-2:1. In particular, the ’127 patent states that
`
`“[w]ireless communication systems typically transmit data, or information . . . as
`
`formatted data symbols . . . which are typically organized into groups referred to herein
`
`as data structures.” Id. Finally, the ’127 patent illustrates a frame structure in FIG. 6,
`
`partially reproduced below to highlight data structure 72.
`
`
`
`Therefore, these terms sho