`
`
`
`UNITED STATES PATENT AND TRADEMARK OFFICE
`
`
`
`BEFORE THE PATENT TRIAL AND APPEAL BOARD
`
`
`
`Ericsson Inc.
`
`Petitioner
`
`v.
`
`Electronics and Telecommunications Research Institute
`
`Patent Owner
`
`
`Patent No. 9,496,976
`Filing Date: July 7, 2015
`Issue Date: November 15, 2016
`
`Title: CELL SEARCH METHOD, FORWARD LINK FRAME TRANSMISSION
`METHOD, APPARATUS, USING THE SAME AND FORWARD LINK FRAME
`STRUCTURE
`
`Inter Partes Review No. IPR2019- 00240
`
`
`PETITION FOR INTER PARTES REVIEW
`UNDER 35 U.S.C. §§ 311-319 AND 37 C.F.R. § 42.100 ET SEQ.
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`

`

`
`
`Table of Contents
`
`I.
`
`II.
`
`Preliminary Statement .................................................................................. 1
`
`Standards Background .................................................................................. 2
`
`III. Technological Background ........................................................................... 3
`
`A.
`
`B.
`
`The location of the P-SCH and S-SCH in prior art 3G frames ............. 6
`
`The location of the P-SCH and S-SCH in prior art 4G frames ............. 7
`
`1.
`
`2.
`
`3.
`
`4G proposals disclosed sending the P-SCH and S-SCH
`multiple times per frame, similar to 3G ...................................... 8
`
`4G proposals disclosed sending the P-SCH and S-SCH in
`consecutive OFDM symbols within the subframe ...................... 9
`
`Prior art cellular devices also used the P-SCH and S-SCH
`to determine the base station’s Cell ID .....................................11
`
`IV. The ’976 Patent ............................................................................................12
`
`A.
`
`B.
`
`Challenged Claims ..............................................................................14
`
`Priority Date and Prosecution History ................................................15
`
`V.
`
`Prior Art .......................................................................................................18
`
`A. U.S. Patent No. 8,031,745 (“TI Patent”) .............................................18
`
`1.
`
`2.
`
`3.
`
`The TI Patent is Prior Art Under 35 U.S.C. 102(e) ..................18
`
`The Teachings of the TI Patent .................................................23
`
`The Teachings of the TI Provisional .........................................24
`
`a.
`
`b.
`
`The text of the TI Provisional discloses the frame
`structure of the ’976 Patent .............................................25
`
`Figure 6 of the TI Provisional discloses multiple
`embodiments of the frame structure of the ’976
`Patent ..............................................................................25
`
`
`
`1
`
`

`

`
`
`B.
`
`R1-060812 (“Samsung”) .....................................................................31
`
`1.
`
`2.
`
`Samsung is Prior Art Under 35 U.S.C. § 102(a) ......................31
`
`The Teachings of Samsung .......................................................32
`
`C.
`
`R1-061144 (“CHTTL”) .......................................................................33
`
`1.
`
`2.
`
`CHTTL is Prior Art Under 35 U.S.C. § 102(a) ........................33
`
`The Teachings of CHTTL .........................................................34
`
`VI. Statement of Precise Relief Requested ......................................................36
`
`A.
`
`B.
`
`C.
`
`D.
`
`Claims for Which Review is Requested ..............................................36
`
`Statutory Grounds of Challenge ..........................................................36
`
`Level of Ordinary Skill .......................................................................36
`
`Claim Construction..............................................................................37
`
`VII. Claims 9, 10, and 16 are Unpatentable ......................................................38
`
`A. Ground #1: Claims 9, 10, and 16 are anticipated under 35
`U.S.C. § 102(a) by the TI Patent, or in the alternative, are
`obvious under 35 U.S.C. § 103 over the TI Patent .............................38
`
`1.
`
`Claim 9 ......................................................................................38
`
`a.
`
`b.
`
`c.
`
`d.
`
`[9.1] A method of generating and transmitting
`downlink transmission by a base station in a
`wireless communication system, the method
`comprising: .....................................................................38
`
`[9.2] generating a first primary synchronization
`sequence: .........................................................................39
`
`[9.3] generating a second primary synchronization
`sequence: .........................................................................40
`
`[9.4] generating a first secondary synchronization
`sequence: .........................................................................42
`
`
`
`2
`
`

`

`e.
`
`f.
`
`g.
`
`h.
`
`i.
`
`
`
`[9.5] generating a second secondary
`synchronization sequence: ..............................................42
`
`[9.6a] transmitting the downlink transmission
`including the first and second primary
`synchronization sequences and the first and second
`secondary synchronization sequences, wherein the
`downlink transmission comprises a plurality of
`subframes sequentially arranged in time domain,
`each of the plurality of subframes containing a
`plurality of symbols sequentially arranged in time
`domain, ...........................................................................44
`
`[9.6b] wherein a first subframe in the downlink
`transmission includes a first symbol representing
`the first primary synchronization sequence, and
`wherein a second subframe in the downlink
`transmission includes a second symbol
`representing the first secondary synchronization
`sequence: .........................................................................47
`
`[9.7] wherein a first indicator is identified based on
`the first primary synchronization sequence, a
`second indicator is identified based on the first
`secondary synchronization sequence, and a cell
`identifier is identified based on the first indicator
`and the second indicator: ................................................49
`
`[9.8] wherein the first subframe includes a third
`symbol representing a second secondary
`synchronization sequence, the third symbol being
`directly adjacent to the first symbol, and wherein
`the second subframe includes a fourth symbol
`representing a second primary synchronization
`sequence, the fourth symbol being directly
`adjacent to the second symbol ........................................50
`
`2.
`
`Claim 10 ....................................................................................55
`
`a.
`
`[10.1] The method of claim 9, wherein the first
`primary synchronization sequence is the same as
`
`
`
`3
`
`

`

`
`
`the second primary synchronization sequence, and
`the first secondary synchronization sequence is
`different from the second secondary
`synchronization sequence. ..............................................55
`
`3.
`
`Claim 16 ....................................................................................57
`
`a.
`
`[16.1] The method of claim 9, wherein the
`downlink transmission comprises a frame, and the
`first and second primary synchronization
`sequences and the first and second secondary
`synchronization sequences are contained in the
`frame. ..............................................................................57
`
`The TI Patent discloses this limitation. For example, in
`Figure 8, the first and second P-SCHs and first and
`second S-SCHs are in the first and sixth
`subframes, all within the same frame: ............................58
`
`B. Ground #2: Claims 9, 10, and 16 are anticipated under 35
`U.S.C. § 102(a) by Samsung, or in the alternative, are obvious
`under 35 U.S.C. § 103 over Samsung .................................................59
`
`1.
`
`Claim 9 ......................................................................................59
`
`a.
`
`b.
`
`c.
`
`d.
`
`e.
`
`[9.1] A method of generating and transmitting
`downlink transmission by a base station in a
`wireless communication system, the method
`comprising: .....................................................................59
`
`[9.2] generating a first primary synchronization
`sequence: .........................................................................59
`
`[9.3] generating a second primary synchronization
`sequence: .........................................................................61
`
`[9.4] generating a first secondary synchronization
`sequence: .........................................................................62
`
`[9.5] generating a second secondary
`synchronization sequence: ..............................................63
`
`
`
`4
`
`

`

`f.
`
`g.
`
`h.
`
`i.
`
`
`
`[9.6a] transmitting the downlink transmission
`including the first and second primary
`synchronization sequences and the first and second
`secondary synchronization sequences, wherein the
`downlink transmission comprises a plurality of
`subframes sequentially arranged in time domain,
`each of the plurality of subframes containing a
`plurality of symbols sequentially arranged in time
`domain, ...........................................................................65
`
`[9.6b] wherein a first subframe in the downlink
`transmission includes a first symbol representing
`the first primary synchronization sequence, and
`wherein a second subframe in the downlink
`transmission includes a second symbol
`representing the first secondary synchronization
`sequence: .........................................................................67
`
`[9.7] wherein a first indicator is identified based on
`the first primary synchronization sequence, a
`second indicator is identified based on the first
`secondary synchronization sequence, and a cell
`identifier is identified based on the first indicator
`and the second indicator: ................................................68
`
`[9.8] wherein the first subframe includes a third
`symbol representing a second secondary
`synchronization sequence, the third symbol being
`directly adjacent to the first symbol, and wherein
`the second subframe includes a fourth symbol
`representing a second primary synchronization
`sequence, the fourth symbol being directly
`adjacent to the second symbol ........................................69
`
`2.
`
`Claim 10 ....................................................................................70
`
`a.
`
`[10.1] The method of claim 9, wherein the first
`primary synchronization sequence is the same as
`the second primary synchronization sequence, and
`the first secondary synchronization sequence is
`
`
`
`5
`
`

`

`
`
`different from the second secondary
`synchronization sequence. ..............................................70
`
`3.
`
`Claim 16 ....................................................................................72
`
`a.
`
`[16.1] The method of claim 9, wherein the
`downlink transmission comprises a frame, and the
`first and second primary synchronization
`sequences and the first and second secondary
`synchronization sequences are contained in the
`frame. ..............................................................................72
`
`C. Ground #3: Claim 16 is obvious under 35 U.S.C. § 103(a) over
`the TI Patent in view of CHTTL .........................................................73
`
`1.
`
`2.
`
`A POSITA would have been motivated to combine TI
`with CHTTL ..............................................................................73
`
`Claim 16 ....................................................................................75
`
`a.
`
`[16.1] The method of claim 9, wherein the
`downlink transmission comprises a frame, and the
`first and second primary synchronization
`sequences and the first and second secondary
`synchronization sequences are contained in the
`frame ...............................................................................75
`
`D. Ground #4: Claim 16 is obvious under 35 U.S.C. § 103(a) over
`Samsung in view of CHTTL ...............................................................73
`
`1.
`
`2.
`
`A POSITA would have been motivated to combine
`Samsung with CHTTL ..............................................................73
`
`Claim 16 ....................................................................................75
`
`a.
`
`[16.1] The method of claim 9, wherein the
`downlink transmission comprises a frame, and the
`first and second primary synchronization
`sequences and the first and second secondary
`synchronization sequences are contained in the
`frame ...............................................................................75
`
`
`
`
`
`6
`
`

`

`
`
`VIII. Conclusion ....................................................................................................80
`IX. Mandatory Notices Under 37 C.F.R. §42.8 .............................................810
`
`A.
`
`B.
`
`C.
`
`D.
`
`Real Parties-In-Interest ........................................................................80
`
`Related Matters ....................................................................................80
`
`Lead and Back-Up Counsel .................................................................80
`
`Service Information .............................................................................80
`
`X. Certification Under 37 C.F.R. §42.24(d) ...................................................81
`
`XI. Payment of Fees ...........................................................................................81
`
`XII. Time for Filing Petition ...............................................................................81
`
`XIII. Grounds for Standing ..................................................................................81
`
`
`
`
`
`
`
`
`7
`
`

`

`
`Exhibit #
`
`
`
`Table of Exhibits
`
`Description
`
`1001
`
`1002
`
`1003
`
`1004
`
`1005
`
`1006
`
`1007
`
`1008
`
`1009
`
`1010
`
`1011
`
`1012
`
`1013
`
`1014
`
`1015
`
`1016
`
`1017
`
`1018
`
`1019
`
`Declaration of Dr. Alexander Haimovich
`
`Curriculum Vitae of Dr. Alexander Haimovich
`
`Declaration of Craig Bishop
`
`United States Patent No. 9,496,976
`
`File History of U.S. Patent No. 9,496,976
`
`English Translation of Korean Patent Application No. 10-2006-
`0069800
`
`English Translation of Korean Patent Application 10-2007-0006230
`
`English Translation of Korean Patent Application 10-2007-0074705
`
`United States Patent No. 8,031,745
`
`United States Provisional Application No. 60/745,250
`
`R1-060812
`
`R1-050707
`
`R1-060860
`
`R1-062990
`
`R1-070650
`
`R1-061144
`
`R1-051357
`
`R1-060072
`
`TR 25.814 v0.5
`
`
`
`8
`
`

`

`
`
`TR 25.814 v1.0.3
`
`TR 25.814 v1.2.2
`
`TS 125 211 v6.7.0 (2005-12)
`
`TS 125 214 v6.7.1 (2005-12)
`
`Cell Searching in WCDMA by Sanat Kamal Bahl
`
`1020
`
`1021
`
`1022
`
`1023
`
`1024
`
`
`
`
`
`9
`
`

`

`
`
`Table of Authorities
`
`
`CASES
`
`In re Giacomini,
`612 F.3d 1380 (Fed. Cir. 2010)................................................................................................16
`
`Dynamic Drinkware, LLC v. Nat’l Graphics, Inc.,
`800 F.3d 1375 (Fed. Cir. 2015)................................................................................................17
`
`Dow Chem. Co. v. Sumitomo Chem. Co.,
`257 F.3d 1364 (Fed. Cir. 2001)................................................................................................35
`
`Phillips v. AWH Corp.,
`415 F.3d 1303 (Fed. Cir. 2005) (en banc)................................................................................35
`
`
`STATUTES
`
`35 U.S.C. §102 ....................................................................................................................... passim
`
`35 U.S.C. § 103 ...................................................................................................................... passim
`
`35 U.S.C. §§ 311-319 ......................................................................................................................1
`
`35 U.S.C. §§ 311 ............................................................................................................................34
`
`
`OTHER AUTHORITIES
`
`37 C.F.R. § 42.100(b) ................................................................................................................1, 35
`
`37 C.F.R. § 42.100 et seq. ................................................................................................................1
`
`37 C.F.R. §42.101(b) .....................................................................................................................35
`
`37 C.F.R. §42.8 ..............................................................................................................................76
`
`37 C.F.R. §42.24(d) .......................................................................................................................77
`
`37 C.F.R. §42.102(a)(1) .................................................................................................................77
`
`37 C.F.R. §42.104(a)......................................................................................................................77
`
`
`
`10
`
`

`

`I.
`
`Preliminary Statement
`
`
`
`Petitioner Ericsson Inc. (“Ericsson”) respectfully requests inter partes
`
`review and cancellation of claims 9, 10, and 16 of U.S. Patent No. 9,496,976 (“the
`
`’976 Patent”) under 35 U.S.C. §§ 311-319 and 37 C.F.R. § 42.100 et seq.
`
`The ’976 Patent relates to the wireless communication between cellular
`
`devices and base stations and, in particular, a concept called cell search. The patent
`
`explains that cell search is the process by which cellular devices search nearby
`
`base stations to find the base station with the strongest signal and synchronize with
`
`that base station. See, e.g., Ex. 1004 at 40:10-14. All of the concepts claimed in the
`
`’976 Patent were developed during the 4G LTE standard-setting process by Texas
`
`Instruments (“TI”), Samsung, Chunghwa Telecom Laboratories (“CHTTL”), and
`
`others, and included in printed publications that were submitted to the standard-
`
`setting body, emailed to a listserv of participants and, in the case of TI, patented.
`
`Electronics and Telecommunications Research Institute (“ETRI”), the entity that
`
`filed the application that issued as the ’976 Patent, did not contribute any of this
`
`technology to the 4G standard, but participated in conversations on the listserv in
`
`which these contributions were distributed.1 Shortly thereafter, ETRI filed a patent
`
`
`1 See, e.g., https://list.etsi.org/scripts/wa.exe?A2=ind0603C&L=3GPP_
`
`TSG_RAN_WG1&O=D&P=173320
`
`1
`
`

`

`
`
`application on these ideas in South Korea. Ex. 1006. As shown below, the TI
`
`Patent and Samsung contribution taught all aspects of the challenged claims before
`
`ETRI filed its patent application.
`
`This Petition, supported by the Declaration of Dr. Alexander Haimovich
`
`(“Haimovich” or “Ex. 1001”), explains why there is a reasonable likelihood that
`
`claims 9, 10, and 16 of the ’976 Patent are unpatentable as anticipated by or
`
`obvious to a person of ordinary skill in the art (“POSITA”) in view of the prior art
`
`cited herein, the knowledge and understanding of a POSITA, and the ’976 Patent
`
`itself. Accordingly, claims 9, 10, and 16 of the ’976 Patent should be cancelled.
`
`II.
`
`Standards Background
`
`The technology at issue in this petition was developed by members of the
`
`Third Generation Partnership Project (“3GPP”) during the 4G standard setting
`
`process. 3GPP is the standard setting organization responsible for creating and
`
`maintaining the 4G cellular standard. Many of the most innovative cellular
`
`companies in the world are members of 3GPP and participated in this process.
`
`To create the 4G standard, 3GPP held standard setting meetings at which
`
`3GPP members proposed technology to include in the standard. These proposals
`
`were typically submitted in documents called “contributions.” The 3GPP members
`
`emailed their contributions to a 3GPP email list and posted them to the publicly
`
`available 3GPP FTP site before each meeting.
`
`2
`
`

`

`
`
`III. Technological Background2
`The concepts claimed in the ’976 Patent were well known before its alleged
`
`priority date. In prior art cellular systems, each base station was assigned one or
`
`more geographical coverage areas called a “cell,” represented by the hexagons in
`
`the figure below.3
`
`
`
`The collection of base station cells made up the cellular network. Each cell was
`
`assigned a cell identifier (“Cell ID”) that the base station used to scramble its
`
`2 This Technological Background section is supported by the Declaration of Dr.
`
`Alexander Haimovich Ex. 1001 at ¶¶ 30-52.
`
`3 Base station cells are often not in a hexagonal layout, but are shown that way here
`
`for ease of understanding.
`
`3
`
`

`

`
`
`messages. Thus phones needed to learn the base station’s cell identifier to decode
`
`signals from that base station. Phones also needed to synchronize with the base
`
`station in time and frequency . This process is called “cell search.”
`
`Prior art designers recognized that they could make the cell search procedure
`
`easier for cellular devices by dividing the Cell IDs into groups. For example, in the
`
`table below, the 512 Cell IDs 4 are divided into 16 “Cell Groups,” each group
`
`consisting of 32 “Cell IDs within the Group.”
`
`Cell Groups
`Cell Group 1 =
`Cell Group 2 =
`Cell Group 3 =
`. . .
`Cell Group 16 =
`
`Cell ID within the Group
`(0, 1, 2, 3, 4, . . . 31, 32)
`(0, 1, 2, 3, 4, . . . 31, 32)
`(0, 1, 2, 3, 4, . . . 31, 32)
`. . .
`(0, 1, 2, 3, 4, . . . 31, 32)
`
`Cell ID
`(0, 1, 2, 3, 4, . . . 31, 32)
`(33, 34, 35, . . ., 63, 64)
`(65, 66, 67, . . ., 95, 96)
`. . .
`(481, 482, . . ., 511, 512)
`
`
`
`If a cellphone received a signal indicating a cell was in “Cell Group 3” and had a
`
`“Cell ID within the Group” of “31,” then the cellphone could determine that the
`
`“Cell ID” for that cell was “95.”
`
`
`4 In prior art 3G networks, each base station cell was assigned one of 512 different
`
`Cell IDs. Designers determined 512 Cell IDs was enough Cell IDs to minimize the
`
`risk that two base station cells in the same geographic area would have the same
`
`Cell ID.
`
`4
`
`

`

`
`
`
`
`If Cell IDs are not divided into cell groups, then when cellular devices
`
`received a Cell ID signal, they would have to compare the received signal to a list
`
`of every possible Cell ID in the system (512 in the example above) to find the best
`
`match. By separating the cell IDs into 16 groups of 32 cell IDs within the group, a
`
`cellular device could first determine the cell ID group (one of only 16 possibilities)
`
`and then determine the cell ID within the group (one of only 32 possibilities). This
`
`allowed cellular devices to perform two simple correlations instead of one difficult
`
`correlation.
`
`Prior art designers accomplished cell search through the use of two repeating
`
`signals broadcast in each base station cell: the Primary Synchronization Signal
`
`(commonly referred to as “P-SCH”) and Secondary Synchronization Signal
`
`(commonly referred to as “S-SCH”). The P-SCH enabled cellular devices to detect
`
`the base station and begin the process of synchronizing their time and frequency
`
`with the base station. The S-SCH allowed the devices to complete the
`
`synchronization process.
`
`5
`
`

`

`
`
`A. The location of the P-SCH and S-SCH in prior art 3G frames
`
`A frame is a logical structure that can be used to organize data for
`
`transmission in a wireless communication system. The figure below, excerpted
`
`from a 2003 IEEE journal article, depicts a 3G5 frame:
`
`
`
`Ex. 1024 at 18. The text below the figure discloses that the frame spans 10 msec
`
`and is divided into 15 equal parts called “slots.” Each slot spans 0.67 msec. The
`
`
`5 3G used wideband code division multiple access (“WCDMA”) technology, as
`
`indicated in the figure.
`
`6
`
`

`

`
`
`top two rows of the figure are labeled “P-SCH” and “S-SCH” and indicate that the
`
`P-SCH and S-SCH were sent at the beginning of each slot. Each of the P-SCH
`
`blocks in the figure is light blue, indicating that the P-SCH was the same in every
`
`slot. The S-SCH blocks in the figure change colors from slot to slot, indicating that
`
`the S-SCH changed from slot to slot. The S-SCH changed from slot to slot to
`
`enable cellular devices to synchronize in time with the base station. Cellular
`
`devices could determine a base station’s timing by figuring out which S-SCH they
`
`received. For example, if a cellular device received the green S-SCH in the figure
`
`above, it could determine when the second slot in the frame began and use that
`
`information to determine the base station’s “frame timing.”6
`
`B.
`
`The location of the P-SCH and S-SCH in prior art 4G frames
`
`In 2005, about a year before ETRI filed its provisional patent application,
`
`the industry began specifying cell search for the new 4G cellular system. 3G used a
`
`technology called “Wideband Code Division Multiple Access” (“WCDMA”),
`
`which allowed multiple cellular devices to send data at the same time and
`
`frequency. Thus, as described above, in 3G, the P-SCH and S-SCH were sent at the
`
`
`6 Though the figure shows colors repeating within the frame, e.g., a green S-SCH
`
`in slots 2 and 14, the S-SCH in WCDMA was different in every slot. See Ex. 1001
`
`at ¶ 45.
`
`7
`
`

`

`
`
`same time and frequency. The 4G cellular system used a different technology
`
`called orthogonal frequency division multiplexing (“OFDM”), in which the P-SCH
`
`and S-SCH would be sent at different times and/or frequencies.
`
`1.
`
`4G proposals disclosed sending the P-SCH and S-SCH
`multiple times per frame, similar to 3G
`
`An LTE frame, similar to the 3G frame, spans 10 msec. In 3G, the 10 msec
`
`frame was divided into 15 equal parts called “slots.” In 4G, the 10 msec frame was
`
`divided into equal parts called “subframes.” In 3G, the P-SCH and S-SCH were
`
`sent 15 times per frame, at the beginning of each slot. In early 4G prior art
`
`proposals, companies proposed sending the P-SCH and S-SCH less frequently than
`
`in 3G. For example, in R1-050707, NTT Docomo, NEC, and Sharp proposed
`
`sending the P-SCH and S-SCH two or four times per frame, rather than 15 times
`
`per frame like 3G:
`
`See Ex. 1012 at 12. This figure represents two different proposals for a 10
`
`millisecond LTE frame. Each red line represents a “synchronization channel.” In
`
`the top proposal, the synchronization channel was sent two times per frame. In the
`
`
`
`8
`
`

`

`
`
`bottom proposal, the synchronization channel was sent four times per frame. The
`
`contribution further proposed that the synchronization channels can include a P-
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`SCH and S-SCH:
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`Id. at 11-12.
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`2.
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`4G proposals disclosed sending the P-SCH and S-SCH in
`consecutive OFDM symbols within the subframe
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`In LTE, each 10 msec frame consisted of 10 subframes, each subframe
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`consisted of two slots, and each slot consisted of seven OFDM symbols.7 ETRI
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`claims that it invented the idea of placing the P-SCH and S-SCH in consecutive
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`OFDM symbols within the subframe, but, as shown below, this was disclosed in
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`multiple printed publications before ETRI filed its patent.
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`For example, in March 2006, approximately four months before ETRI filed
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`its application, Samsung proposed placing
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`the primary and secondary
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`synchronization signals in consecutive OFDM symbols in R1-060812, Figure 4:
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`7 Under a special condition known as “extended cyclic prefix,” each subframe
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`consisted of six OFDM symbols instead of seven OFDM symbols.
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`9
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`Similarly in May 2006, two months before ETRI filed its application,
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`Chunghwa Telecom Laboratories (“CHTTL”) proposed placing the P-SCH and S-
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`SCH in consecutive OFDM symbols in R1-061144. Figure 1 shows the placement
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`of the P-SCH and S-SCH in consecutive OFDM symbols at the end of the
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`subframe (red circles added):
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`10
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`ETRI received the Samsung and CHTTL contributions by email, but did not
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`disclose them to the USPTO during prosecution of the ’976 Patent.
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`And, as will be explained in detail below, TI filed a patent application three
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`months before ETRI filed its application disclosing the concept of placing the P-
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`SCH and S-SCH in consecutive OFDM symbols.
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`3.
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`Prior art cellular devices also used the P-SCH and S-SCH to
`determine the base station’s Cell ID
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`In 3G prior art systems, cellular devices looked to the S-SCH and another set
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`of signals called “pilot signals” to determine a base station’s Cell ID. The S-SCH
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`contained the base station’s Cell Group ID and the pilot signals contained the base
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`station’s Cell ID within the Group. The cellular devices could use the Cell Group
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`11
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`
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`ID and Cell ID within the Group to determine the base station’s Cell ID, as shown
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`in Section III above. Ex. 1001 at ¶¶ 34-38.
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`For 4G prior art systems, Texas Instruments (“TI”) and Samsung proposed
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`moving the Cell ID information from the pilot signals to the P-SCH. That is, Cell
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`ID information was to be included in the P-SCH and S-SCH, rather than the S-
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`SCH and pilot signals. See, e.g., TI contribution R1-061434 (disclosing that “P-
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`SCH and S-SCH are used jointly to obtain the full cell ID”); Samsung contribution
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`R1-060812 (disclosing that “cell code group sequence may possibly be carried in
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`P-SCH. S-SCH (Secondary SCH) would carry cell specific code.”).
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`IV. The ’976 Patent
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`The ’976 Patent is titled “Cell Search Method, Forward Link Frame
`
`Transmission Method, Apparatus Using the Same and Forward Link Frame
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`Structure” and claims priority to a South Korean Provisional Application filed on
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`July 25, 2006. Similar to 3G and the 4G proposals above, the ’976 Patent describes
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`sending the P-SCH multiple times per frame, as shown in Figure 10 (red circles
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`added).
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`12
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`Each red circle includes a P-SCH, labeled 160, and an S-SCH, labeled 170.
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`As shown here, the P-SCH and S-SCH are in consecutive OFDM symbols, like the
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`Samsung and CHTTL 4G proposals above. The ’976 Patent also discloses using
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`the P-SCH and S-SCH to determine the Cell ID, similar to the Samsung and TI
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`proposals above. See, e.g., ’976 Patent at 10:48-52 (“[I]nformation about the cell
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`groups . . . is sent through the primary synchronization channel and information
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`about the cell sub-groups 30 is sent through the secondary synchronization
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`channel.”).
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`As disclosed by the ’976 Patent, the multiple S-SCHs in a frame together
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`form a single “hopping code” that cellular devices use to determine a base station’s
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`Cell ID within the Group. Ex. 1004 at 7:36-38. A cellular device could not
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`determine the Cell ID within the Group by decoding one of multiple S-SCHs in a
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`13
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`frame, but rather had to decode all S-SCHs in the frame to determine the Cell ID
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`
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`within the Group. Ex. 1001 at ¶¶ 53-59.
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`A. Challenged Claims
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`The Challenged Claims are claims 9, 10, and 16 of the ’976 Patent. Claim 9,
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`the only challenged independent claim, discloses:
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`9. [9.1] A method of generating and
`transmitting downlink
`transmission by a base station in a wireless communication system,
`the method comprising;
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`[9.2] generating a first primary synchronization sequence;
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`[9.3] generating a second primary synchronization sequence;
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`[9.4] generating a first secondary synchronization sequence;
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`[9.5] generating a second secondary synchronization sequence; and
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`[9.6] transmitting the downlink transmission including the first and
`second primary synchronization sequences and the first and second
`secondary
`synchronization
`sequences, wherein
`the downlink
`transmission comprises a plurality of subframes sequentially arranged
`in time domain, each of the plurality of subframes containing a
`plurality of symbols sequentially arranged in time domain, wherein a
`first subframe in the downlink transmission includes a first symbol
`representing the first primary synchronization sequence, and wherein
`a second subframe in the downlink transmission includes a second
`symbol representing the first secondary synchronization sequence,
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`[9.7] wherein a first indicator is identified based on the first primary
`synchronization sequence, a second indicator is identified based on
`the first secondary synchronization sequence, and a cell identifier is
`identified based on the first indicator and the second indicator,
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`[9.8] wherein the first subframe includes a third symbol representing a
`second secondary synchronization sequence, the third symbol being
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`14
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`direct