UNITED STATES PATENT AND TRADEMARK OFFICE
`__________________
`
`BEFORE THE PATENT TRIAL AND APPEAL BOARD
`___________________
`
`ERICSSON INC. AND TELEFONAKTIEBOLAGET
`LM ERICSSON,
`Petitioner
`
`v.
`
`INTELLECTUAL VENTURES II LLC,
`Patent Owner
`___________________
`
`Patent 7,787,431
`
`Title: METHODS AND APPARATUS FOR MULTI-CARRIER
`COMMUNICATIONS WITH VARIABLE CHANNEL
`BANDWIDTH
`_____________________
`
`PETITION FOR INTER PARTES REVIEW
`
`
`
`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, 2, 8-12,
`
`and 18-22 of United States Patent No. 7,787,431 (“the ’431 patent,” ERIC-1001)
`
`that issued on August 31, 2010, to Xiaodong Li, et al. According to USPTO
`
`records, the ’431 patent is currently assigned to Intellectual Ventures II LLC (“IV”).
`
`
`
`
`
`

`

`Petition for Inter Partes Review of U.S. 7,787,431
`
`
`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 Related Technology and the ’431 Patent ............................ 2 
`
`B.  The Prosecution History .............................................................................. 7 
`
`C.  The Prior Art of the Present Petition ............................................................ 8 
`
`V.  Reasons That Challenges Are Not Cumulative ..................................................... 15 
`
`VI.  Identification of Challenges and Claim Construction............................................ 15 
`
`A.  Challenged Claims .................................................................................... 15 
`
`B.  Claim Construction ................................................................................... 16 
`
`1.  Bandwidth ................................................................................................. 16 
`
`2.  Core-Band ................................................................................................ 17 
`
`3.  Primary Preamble ..................................................................................... 17 
`
`4.  Peak-to-Average Ratio .............................................................................. 18 
`
`C.  Statutory Grounds for Challenges .............................................................. 19 
`
`1.  Challenge #1: Claims 8-11 and 18-21 are unpatentable under 35 U.S.C. §
`103(a) over Li, Yamaura, and Zhuang ........................................................... 20 
`
`
`
`i
`
`

`

`Petition for Inter Partes Review of U.S. 7,787,431
`
`2.  Challenge #2: Claims 1, 2, 12, and 22 are unpatentable under 35 U.S.C. §
`103(a) over Li, Yamaura, Zhuang, and Beta .................................................. 39 
`
`3.  Challenge #3: Claims 8-11 and 18-21 are unpatentable under 35 U.S.C. §
`103(a) over Li, Yamaura, Mody, Nobilet, and Popovic .................................. 47 
`
`4.  Challenge #4: Claims 1, 2, 12, and 22 are unpatentable under 35 U.S.C. §
`103(a) over Li, Yamaura, Mody, Nobilet, Popovic, and Beta ......................... 56 
`
`VII. Conclusion .......................................................................................................... 60 
`
`
`
`ii
`
`

`

`Petition for Inter Partes Review of U.S. 7,787,431
`
`
` 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
`
`’431 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. United States Cellular Corp., 1-13-cv-01672 (D. Del. 2013).
`
`C. Lead and Back-up Counsel and Service Information
`
`Lead 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
`
`Back-up Counsel
`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
`
`Please address all correspondence to lead and back-up counsel. Ericsson also
`
`consents to electronic service by email.
`
`
`
`1
`
`

`

`II. Grounds for Standing
`
`Petition for Inter Partes Review of U.S. 7,787,431
`
`
`Ericsson certifies that the ’431 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 the grounds identified 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, 2, 8-12, and 18-22 of the ’431 patent,
`
`and cancel those claims as unpatentable.
`
`IV. The Reasons for the Requested Relief
`
`A. Summary of the Related Technology and the ’431 Patent
`
`The ’431 patent relates generally to multi-carrier communication systems, such
`
`as systems that employ orthogonal frequency division multiplexing (OFDM). See
`
`ERIC-1001, 1:43-47 and 2:36-38; See also, ERIC-1012, ¶ 19. “A basic structure of a
`
`multi-carrier signal in the frequency domain is made up of subcarriers and, illustrated in
`
`FIG. 3, which shows three types of subcarriers” – data subcarriers, pilot subcarriers, and
`
`silent subcarriers. ERIC-1001, 3:23-32. Fig. 3 is reproduced below:
`
`
`
`2
`
`

`

`Petition for Inter Partes Review of U.S. 7,787,431
`
`
`
`
`Note that in Fig. 3, which is admitted prior art, subcarriers are grouped as various
`
`subchannels. The ’431 patent describes a rationale for the subcarrier groupings that
`
`“[t]he data subcarriers can be arranged into groups called subchannels to support
`
`scalability and multiple-access.” Id., 3:33-34.
`
`The claims of the ’431 patent conceptually relate to and can be divided into three
`
`aspects of communication technology:
`
`(1) variable bandwidth multi-carrier systems;
`
`(2) characteristics of a core-band; and
`
`(3) properties of a primary preamble, which is transmitted in the core-band.
`
`
`
`3
`
`

`

`Petition for Inter Partes Review of U.S. 7,787,431
`
`For the sake of example, claim 1 is reproduced below, annotated to show the three
`
`aspects identified above.
`
` These aspects form a conceptual framework for
`
`understanding the claims. See, ERIC-1012, ¶¶ 24-25.
`
`1. In a variable bandwidth wireless communication system
`communicating under multiple different communication schemes that
`each have a different bandwidth, a process performed by a base station
`of generating an information bearing signal for wireless transmission,
`the process comprising:
`[Aspect (1):]
`utilizing by the base station a number of subcarriers to construct a
`variable bandwidth wireless channel;
`utilizing by the base station groups of subcarriers, wherein each
`group includes a plurality of subcarriers;
`maintaining a fixed spacing between adjacent subcarriers;
`adding or subtracting, by the base station, groups of subcarriers to
`scale the variable bandwidth wireless channel and achieve an operating
`channel bandwidth; and
`[Aspect (2):]
`wherein a core-band, including a plurality of subcarrier groups,
`substantially centered at an operating center frequency of the different
`communication schemes, is utilized by the base station as a broadcast
`channel carrying radio control and operation signalling, where the core-
`band is substantially not wider than a smallest possible operating
`channel bandwidth of the system; and
`[Aspect (3):]
`wherein the information bearing signal has a primary preamble
`
`
`
`4
`
`

`

`Petition for Inter Partes Review of U.S. 7,787,431
`
`
`sufficient for basic radio operation and wherein:
`the primary preamble is a direct sequence in the time domain
`with a frequency content confined within the core-band, or is an
`orthogonal frequency-divisional multiplexing (OFDM) symbol
`corresponding to a particular frequency pattern within the core-
`band; and
`wherein properties of the primary preamble comprise:
`an autocorrelation having a large correlation peak with respect
`to sidelobes;
`a cross-correlation with other primary preambles having a
`small cross-correlation coefficient with respect to power of other
`primary preambles; and
`a small peak-to-average ratio; and wherein a large number of
`primary preamble sequences exhibit the properties.
`
`As explained later in the prosecution history section below, the first two aspects
`
`were conceded during prosecution as being in the prior art, and it was the third aspect
`
`relating to the specific properties of the preamble that resulted in claim allowance. We
`
`agree with the Examiner that (1) variable bandwidth multi-carrier systems, and (2)
`
`characteristics of a core-band were well known in the art. Furthermore, additional
`
`references provided herein, which were not considered by the Examiner, disclose claim
`
`aspect (3) – properties of a primary preamble, which is transmitted in the core-band.
`
`More specifically, and referring to aspect (1), the ’431 patent states: “In some
`
`embodiments, the variable channel bandwidth is realized by adjusting the number of
`
`
`
`5
`
`

`

`Petition for Inter Partes Review of U.S. 7,787,431
`
`usable subcarriers.” ERIC-1001, 4:25-26. In one embodiment, “[t]he variable channel
`
`bandwidth is realized by adjusting the number of usable subcarriers, whose spacing is
`
`set constant.” Id., 4:41-42. According to the equations in Fig. 2, which is admitted prior
`
`art, bandwidth is proportional to the number of subcarriers. See id., Fig. 2 and ERIC-
`
`1012, ¶ 21. The same concepts are disclosed in U.S. Patent No. 6,904,283 (“Li”)
`
`utilized below to illustrate these prior art features.
`
`Referring to aspect (2), the ’431 patent states: “To facilitate the user terminals to
`
`operate in a variable bandwidth (VB) environment, specific signaling and control
`
`methods are required. Radio control and operation signaling is realized through the use
`
`of a core-band (CB).” ERIC-1001, 4:64-67. The core-band is used to transmit control
`
`signals and control channels: “[i]n one embodiment relevant or essential radio control
`
`signals such as preambles, ranging signals, bandwidth request, and/or bandwidth
`
`allocation are transmitted within the CB.” Id., 5:8-13 (emphasis added). An example of
`
`a narrow band to transmit control signals in an OFDM system is disclosed in U.S.
`
`Patent No. 7,782,750 (“Yamaura”). The control signals in Yamaura are transmitted in a
`
`broadcast preamble using subcarriers centered at an operating frequency.
`
`Referring to aspect (3), which was added during prosecution to gain allowance
`
`of the claims, claim 1 recites certain properties for the preamble sequences, including
`
`autocorrelation, cross-correlation, and peak-to-average ratio properties. However, the
`
`’431 patent specification does not disclose any examples of preamble structures
`
`
`
`6
`
`

`

`Petition for Inter Partes Review of U.S. 7,787,431
`
`achieving the desired properties. Even though no examples are disclosed in the ’431
`
`patent, it was well known to utilize preamble sequences with the claimed properties.
`
`For example, as explained herein, U.S. Patent No. 7,426,175 (“Zhuang”) discloses a
`
`large number of preamble sequences with the requisite autocorrelation, cross-
`
`correlation, and peak-to-average ratio properties. Additionally, as explained herein,
`
`Exhibit ERIC-1006 (“Nobilet”) also discloses a large number of sequences with the
`
`requisite properties.
`
`Accordingly, as demonstrated herein, features of the claims of the ’431 patent
`
`related to these three aspects – (1) variable bandwidth multi-carrier systems; (2)
`
`characteristics of a core-band; and (3) properties of a primary preamble, which is
`
`transmitted in the core-band – were well-known in the art at the time the ’431 patent
`
`was filed.
`
`B. The Prosecution History
`
`Original claim 1 of the ’431 patent was rejected as being unpatentable over U.S.
`
`Patent No. 6,175,550 (Van Nee) and another U.S. patent in an office action dated April
`
`28, 2009. ERIC-1010, pp. 191-193. Among other claims, claim 3, a claim directed to
`
`properties of a primary preamble, was indicated as allowable. See id., p. 207. After a
`
`final rejection, the Applicants authorized an Examiner’s Amendment for claim 1 (see
`
`id., p. 53), which included the subject matter of claim 3. Specifically, the Examiner’s
`
`Amendment added the entirety of aspect (3), described above with reference to claim 1.
`
`
`
`7
`
`

`

`Petition for Inter Partes Review of U.S. 7,787,431
`
`See id., p. 277. In explaining the allowable subject matter, the Examiner stated that the
`
`prior art “discloses a variable bandwidth system by adjusting the number of
`
`subcarriers”, and “discloses a primary channel with a central channel in which dynamic
`
`link assignment is constrained in the central channel to maintain synchronization,”
`
`which correspond to aspects (1) and (2), above. ERIC-1010, pp. 53-54. As explained
`
`in further detail below, references provided herein, which were not before the
`
`Examiner, teach the features of aspect (3).
`
`C. The Prior Art of the Present Petition
`
`Li. U.S. Patent No. 6,904,283 (“Li”), having a priority date of April 17, 2001,
`
`qualifies as prior art under 35 U.S.C. § 102(e)(pre-AIA). Li “relates to the field of
`
`wireless communications; more particularly, the invention relates to multi-cell, multi-
`
`subscriber wireless systems using orthogonal frequency division multiplexing
`
`(OFDM).” ERIC-1002, 1:11-14. Li explains that “[i]n OFDM, a wide bandwidth is
`
`divided into multiple narrow-band subcarriers, which are arranged to be orthogonal
`
`with each other.” Id., 1:19-21. The subcarriers are divided into clusters. See ERIC-
`
`1012, ¶ 34. For example, “FIG. 1A illustrates multiple subcarriers, such as subcarrier
`
`101, and cluster 102. A cluster, such as cluster 102, is defined as a logical unit that
`
`contains at least one physical subcarrier, as shown in FIG. 1A. 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
`
`
`
`8
`
`

`

`Petition for Inter Partes Review of U.S. 7,787,431
`
`when the clusters are redefined. In one embodiment, the frequency spectrum includes
`
`512 subcarriers and each cluster includes four consecutive subcarriers, thereby resulting
`
`in 128 clusters.” Id., 5:18-27. That is, in Li’s Fig. 1A, for example, four consecutive
`
`subcarriers form a cluster.
`
`A base station can assign a subscriber one or more clusters of subcarriers. See
`
`ERIC-1012, ¶ 35. At a later time, a number of clusters can be increased, thereby
`
`increasing bandwidth (i.e., the bandwidth is variable). See id. For example, “the base
`
`station first allocates multiple clusters, referred to herein as the basic clusters, to
`
`establish a data link between the base station and the subscriber. The base station then
`
`subsequently allocates more clusters, referred to herein as the auxiliary clusters, to
`
`the subscriber to increase the communication bandwidth.” ERIC-1002, 6:43-48
`
`(emphasis added).
`
`Yamaura. U.S. Patent No. 7,782,750 (“Yamaura”), having a priority date of
`
`February 20, 2003, qualifies as prior art under 35 U.S.C. § 102(e)(pre-AIA). Yamaura
`
`“relates to a radio communication method, a radio communication system, [and] a radio
`
`communication base station … particularly suitable for radio transmission based on
`
`OFDM modulation (Orthogonal Frequency Division Multiplexing).” ERIC-1003,
`
`1:10-18. Furthermore, “[t]he present invention was completed to reduce loads in a base
`
`station or a terminal station when control signals are transmitted from a base station to a
`
`
`
`9
`
`

`

`Petition for Inter Partes Review of U.S. 7,787,431
`
`terminal station in the radio communication system of the type mentioned above.” Id.,
`
`5:64-67.
`
`Yamaura points out that in conventional OFDM systems “the signal to call a
`
`terminal station from a base station is transmitted, with all information placed on
`
`subcarriers in the transmission band, and the called terminal station receives all the
`
`subcarriers to receive the calling signal. This means that the terminal station has to
`
`receive and decode the band signal (corresponding to 20 MHz) every 2 ms regardless of
`
`presence or absence of data being transmitted and received. It follows, therefore, that
`
`large quantities of signals have to be processed even when no information data is
`
`transmitted and received.” Id., 5:39-46. In order to address this issue, Yamaura
`
`discloses a system in which “part of control signals addressed to a terminal station from
`
`a base station is transmitted by means of a carrier whose band is narrower than that
`
`for said multi-carrier signals […]” Id., 6:5-8. An example of control signals narrower
`
`than that for a multi-carrier signal is presented in Fig. 16, reproduced below. In the
`
`figure, subcarriers SC1 and SC2 carry control signals. See, e.g., id., 21:11-15.
`
`The control signals in Yamaura are transmitted in a broadcast preamble using the
`
`subcarriers centered at an operating frequency. See ERIC-1012, ¶ 40-41. For example,
`
`referring to Fig. 17, “[t]he broadcast burst consists of BCH for the multiple addressing
`
`of broadcast preamble and base station information, FCH to inform each terminal
`
`station of the traffic channel allocation in the same frame, and ACH for reply to RCH
`
`
`
`10
`
`

`

`Petition for Inter Partes Review of U.S. 7,787,431
`
`used for calling from the terminal station. In the case of this embodiment, the two
`
`subcarriers SC1 and SC2 shown in FIG. 16 are used for transmission of specific
`
`control signals in the sections of broadcast preamble, BCH, and FCH in the broadcast
`
`burst.” ERIC-1003, 21:7-15 (emphasis added). Fig. 17 is reproduced below (color
`
`annotations added). See ERIC-1012, ¶ 43.
`
`
`
`In Yamaura, the narrowband control signals, such as those transmitted using
`
`SC1, and SC2 above, are used to provide a call signal to a terminal station so that the
`
`terminal station can judge whether the terminal station is being called. See ERIC-1012,
`
`¶ 49. “Part of the control signals to be transmitted from the base station to the terminal
`
`station by means of the narrow-band carrier is, for example, a call signal to call terminal
`
`stations individually or as a group. Upon reception of this call signal, the terminal
`
`station can judge that there is a call from the base station.” ERIC-1003, 10:58-63.
`
`Cross correlation detection is used to detect the narrowband control signal.
`
`ERIC-1012, ¶ 47. For example, “FIG. 15 shows the constitution of the control signal
`
`
`
`11
`
`

`

`Petition for Inter Partes Review of U.S. 7,787,431
`
`receiving unit 242 in the terminal station shown in FIG. 6. It is so constructed as to
`
`receive the control signal by means of simple cross correlation detection.” ERIC-
`
`1003, 19:64-67 (emphasis added). Thus, Yamaura recognizes the transmission of
`
`preambles in a core-band as well as using cross correlation to detect the presence of the
`
`control signals in the preamble.
`
`Zhuang. U.S. Patent No. 7,426,175 (“Zhuang”), having a priority date of March
`
`30, 2004, qualifies as prior art under 35 U.S.C. § 102(e)(pre-AIA). Zhuang addresses a
`
`“need [that] exists for a method and apparatus for pilot signal or preamble transmission
`
`that optimizes both the cross correlation between pilot signals, as well as optimizing
`
`each pilot signal’s auto correlation.” ERIC-1004, 2:7-10. To address the need, “pilot
`
`sequences are constructed from distinct ‘classes’ of chirp sequences that have an
`
`optimal cyclic cross correlation property while satisfying the ideal cyclic auto-
`
`correlation requirement. Utilization of chirp sequences for pilot sequences results in
`
`pilot channels that have good cross correlation as well as having good auto-correlation.”
`
`Id., 2:22-29.
`
`“A pilot signal (or preamble) is commonly used for communication systems to
`
`enable the receiver to perform a number of critical functions, including but not limited
`
`to, the acquisition and tracking of timing and frequency synchronization, the estimation
`
`and tracking of desired channels for subsequent demodulation and decoding of the
`
`information data, the estimation and monitoring of the characteristics of other channels
`
`
`
`12
`
`

`

`Petition for Inter Partes Review of U.S. 7,787,431
`
`for handoff, interference suppression, etc.” Zhuang, 1:12-19 (emphasis added). Thus,
`
`Zhuang discloses that preambles and pilot signals are commonly used for
`
`synchronization and channel estimation. Id.
`
`Zhuang describes properties of “Generalized Chirp-Like” sequences, which are
`
`used as preambles in an OFDM system and include good autocorrelation and
`
`crosscorrelation, and low PAPR. See ERIC-1004 2:55-58, 5:9-15, and 6:5-6; See also,
`
`ERIC-1012, ¶ 56.
`
`Beta. TR101146v3.0.0, “Universal Mobile Telecommunications System
`
`(UMTS); UMTS Terrestrial Radio Access (UTRA); Concept evaluation (UMTS 30.06
`
`version 3.0.0)”, December 1997 (“Beta”), qualifies as prior art under 35 U.S.C. §
`
`102(b)(pre-AIA). As shown in the table from Beta below, Beta discloses variable
`
`bandwidth in units of 100 kHz (24 subcarriers) within an available bandwidth of 100
`
`kHz, 200 kHz, 400 kHz, 800 kHz, or 1.6 MHz, which allows for “flexible” deployment
`
`according to the table.
`
`
`ERIC-1007, p. 176 and ERIC-1012 ¶ 70 (color annotation added). Each set of 24
`
`
`
`subcarriers constituting 100 kHz is a “group” of subcarriers as the term is used in the
`
`claims of the ’431 patent. See ERIC-1012, ¶ 70.
`
`Beta also discloses allocating a variable number of bandslots (and therefore
`
`
`
`13
`
`

`

`Petition for Inter Partes Review of U.S. 7,787,431
`
`variable bandwidth). See ERIC-1007, p. 198 and ERIC-1012, ¶ 70. “The resources
`
`(time and frequency) are allocated based on the type of services, operational
`
`environment/scenarios) (i.e., give more flexibility).” ERIC-1007, p. 198. The modes of
`
`“resource allocations” include n time slots + n band slots. EERIC-1007, p. 198. That
`
`is, variable number of time slots and a variable number of bandslots (variable
`
`bandwidth) can be used for resource allocation. See ERIC-1012, ¶ 70. Thus, a
`
`variable number of bandslots may be allocated, each of which is 100 kHz, which allows
`
`the bandwidth to vary in any of the available bandwidths of 200 kHz, 400 kHz, 800
`
`kHz, and 1.6 MHz. See id.
`
`Other prior art references described in detail in the challenges below disclose
`
`properties of preamble sequences, that include good autocorrelation, crosscorrelation,
`
`and low peak-to-average power ratio. These include:
`
` U.S. Patent Publication No. 2002/0181509 (“Mody”) having a priority date of April
`
`24, 2001 and a publication date of December 5, 2002, qualifies as prior art under 35
`
`U.S.C. § 102(b)(pre-AIA).
`
` S. Nobilet, et al., “Spreading Sequences for Uplink and Downlink MC-CDMA
`
`Systems:
`
` PAPR and MAI Minimization”, European Transactions on
`
`Communications, pp. 465-473, vol. 13, no. 5, September-October 2002 (“Nobilet”)
`
`qualifies as prior art under 35 U.S.C. § 102(b)(pre-AIA); and
`
` B. Popovic, “Spreading Sequences for Multicarrier CDMA Systems”, IEEE Trans.
`
`
`
`14
`
`

`

`Petition for Inter Partes Review of U.S. 7,787,431
`
`Comm., pp. 918-926, vol. 47, no. 6, June 1999 (“Popovic”) qualifies as prior art
`
`under 35 U.S.C. § 102(b)(pre-AIA).
`
`V. Reasons That Challenges Are Not Cumulative
`
`Challenges #1 and #2 are based on a first set of references including Zhuang, and
`
`Challenges #3 and #4 are based on a second set of references that replaces Zhuang with
`
`the combination of Mody, Nobilet, and Popovic. Petitioner respectfully submits that
`
`these respective sets of challenges are not cumulative. Zhuang provides all the claimed
`
`features of the preamble in a single reference but is prior art under 35 U.S.C. § 102(e)
`
`that may be subject to a challenge from the patent owner. The second set of references,
`
`on the other hand, replaces Zhuang with the combination of Mody, Nobilet, and
`
`Popovic, each of which is prior art under 35 U.S.C. § 102(b) that cannot be sworn
`
`behind. Therefore, Challenges #1 and #2, based on the first set of references including
`
`Zhuang, and Challenges #3 and #4, based on the second set of references including
`
`references Mody, Nobilet, and Popovic, are not cumulative. Thus, each set of
`
`challenges should be included in the review of claims 1, 2, 8-12, and 18-22 of the ’431
`
`patent.
`
`VI.
`
`Identification of Challenges and Claim Construction
`
`A. Challenged Claims
`
`Claims 1, 2, 8-12, and 18-22 of the ’431 patent are challenged in this petition.
`
`15
`
`
`
`
`
`

`

`Petition for Inter Partes Review of U.S. 7,787,431
`
`
`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.
`
`Bandwidth
`
`The ‘431 patent uses the term “bandwidth” in the abstract, the claims, and the
`
`detailed description. However, the ‘431 patent does not set forth a special meaning for
`
`the above term. As such, this term should be given its broadest reasonable
`
`interpretation to one of ordinary skill in the art in view of the specification and the
`
`term’s ordinary and accustomed meaning. See, e.g., ERIC-1012, ¶ 28. The ‘431 patent
`
`uses the term “bandwidth” to refer to a frequency range a system occupies or uses. For
`
`example, Fig. 6 of the ‘431 patent “illustrates the signal structure in the frequency
`
`domain” for a specific embodiment. ERIC-1001, 4:36-37. “The variable channel
`
`bandwidth is realized by adjusting the number of usable subcarriers, whose spacing is
`
`set constant.” Id., 4:41-42. Fig. 6 illustrates various bandwidths (measured as a
`
`frequency range, e.g., 5 MHz or 10 MHz) and numbers of subcarriers corresponding to
`
`the bandwidth. See also, ERIC-1012, ¶ 28. Thus, under the broadest reasonable
`
`interpretation in view of the ‘431 patent specification and the ordinary and accustomed
`
`meaning, one of ordinary skill in the art would understand that “bandwidth” means a
`
`frequency range that a component, circuit, or system passes or uses. ERIC-1013, p. 6
`
`
`
`16
`
`

`

`Petition for Inter Partes Review of U.S. 7,787,431
`
`
`and ERIC-1012, ¶ 28.
`
`2.
`
`Core-Band
`
`The ‘431 patent uses the term “core-band” in the claims and the detailed
`
`description. The ‘431 patent sets forth a special meaning for core-band as follows: “[a]
`
`core-band, substantially centered at the operating center frequency, is defined as a
`
`frequency segment that is not greater than the smallest operating channel bandwidth
`
`among all the possible spectral bands that the receiver is designed to operate with.”
`
`ERIC-1001, 4:67-5:4 (emphasis added). Under the broadest reasonable interpretation
`
`in view of the ‘431 patent specification one of ordinary skill in the art would understand
`
`that “core-band” means a frequency segment that is not greater than the smallest
`
`operating channel bandwidth among all the possible spectral bands that a receiver is
`
`designed to operate with. ERIC-1012, ¶ 29.
`
`3.
`
`Primary Preamble
`
`The ‘431 patent uses the term “primary preamble” in the claims and the detailed
`
`description. Although the term “preamble” is a common term, the term “primary
`
`preamble” is not known as a term of art in the field. See ERIC-1012, ¶ 30. Rather, the
`
`‘431 patent uses the term in a special way. The term “preamble” denotes transmission
`
`near the beginning of a transmission, such as a frame or slot. Id. For example, “[t]he
`
`downlink transmission in each frame begins with a downlink preamble”, and
`
`“[s]imilarly, uplink transmission can begin with an uplink preamble, which can be the
`
`
`
`17
`
`

`

`Petition for Inter Partes Review of U.S. 7,787,431
`
`first or more of the OFDM symbols in the first uplink (UL) slot.” ERIC-1001, 3:51-52
`
`and 56-58.
`
`According to the ‘431 patent, the term “primary preamble” describes “a
`
`preamble … designed to only occupy the CB [core band].” Id., 5:19-20. This feature
`
`of the core-band also appears in various independent claims. For example, claim 1
`
`states: “the primary preamble is a direct sequence in the time domain with a frequency
`
`content confined within the core-band, or is an orthogonal frequency-divisional
`
`multiplexing (OFDM) symbol corresponding to a particular frequency pattern within
`
`the core-band” (emphasis added). Under the broadest reasonable interpretation in view
`
`of the ‘431 patent specification one of ordinary skill in the art would understand that
`
`“primary preamble” means a signal transmitted near the beginning of a transmission,
`
`such as a frame or a time slot, and occupying only the core band. ERIC-1012, ¶ 31.
`
`4.
`
`Peak-to-Average Ratio
`
`The ‘431 patent uses the term “peak-to-average ratio” in the claims and the
`
`detailed description. The term “peak-to-average ratio,” without further clarification,
`
`does not identify the metric or signal characteristic used to form the ratio. See ERIC-
`
`1012, ¶ 32. This term, however, is understood as referring to a metric that is of general
`
`concern in OFDM systems– that is, the peak to average power ratio. See id. A large
`
`ratio of peak power to average power has disadvantages, such as “an increased
`
`complexity of digital-to-analog converters and a reduced efficiency of the RF [radio
`
`
`
`18
`
`

`

`Petition for Inter Partes Review of U.S. 7,787,431
`
`frequency] power amplifier.” See ERIC-1009, p. 3 and ERIC-1012, ¶ 32. Thus,
`
`reduction of peak-to-average power has been studied extensively for OFDM systems.
`
`See ERIC-1009, pp. 4-38 and ERIC-1012, ¶ 32. The term for the metric is shortened in
`
`the ’431 patent from the more typical peak-to-average power ratio (see, e.g., id., p. 3;
`
`See also, ERIC-1005, ¶ 47) to “peak-to-average ratio.” Under the broadest reasonable
`
`interpretation in view of the ’431 patent specification and the ordinary and accustomed
`
`meaning, one of ordinary skill in the art would understand that “peak-to-average ratio”
`
`means peak-to-average power ratio. ERIC-1012, ¶ 32.
`
`C. Statutory Grounds for Challenges
`
`Challenge #1:
`
`
`
`Claims 8-11 and 18-21 are unpatentable under 35 U.S.C. § 103(a) over Li,
`
`Yamaura, and Zhuang.
`
`Challenge # 2
`
`
`
`Claims 1, 2, 12, and 22 are unpatentable under 35 U.S.C. § 103(a) over Li,
`
`Yamaura, Zhuang, and Beta.
`
`Challenge # 3
`
`
`
`Claims 8-11 and 18-21 are unpatentable under 35 U.S.C. § 103(a) over Li,
`
`Yamaura, Mody, Nobilet, and Popovic.
`
`Challenge # 4
`
`Claims 1, 2, 12, and 22 are unpatentable under 35 U.S.C. § 103(a) over Li,
`
`
`
`19
`
`

`

`Yamaura, Mody, Nobilet, Popovic, and Beta.
`
`Petition for Inter Partes Review of U.S. 7,787,431
`
`
`For the sake of cross-reference, the following analysis assigns reference
`
`numbers, such as “8.0,” to refer to specific portions of the claims. The following
`
`analysis explains how each claim limitation is met by the combined references.
`
`Detailed factual support is provided in the included Expert Declaration, ERIC-1012
`
`beginning at page 50.
`
`1.
`Challenge #1: Claims 8-11 and 18-21 are unpatentable under
`3