`
`
`
`UNITED STATES PATENT AND TRADEMARK OFFICE
`
`
`
`BEFORE THE PATENT TRIAL AND APPEAL BOARD
`
`
`
`Ericsson Inc., Nokia of America Corporation
`
`Petitioners
`
`v.
`
`Godo Kaisha IP Bridge 1
`
`Patent Owner
`
`
`Patent No. 8,077,594 B2
`Filing Date: August 10, 2010
`Issue Date: December 13, 2011
`
`Title: Radio Communication Base Station Device and Correlation Setting Method
`
`Inter Partes Review No. IPR2022-00726
`
`
`PETITION FOR INTER PARTES REVIEW
`UNDER 35 U.S.C. §§ 311-319 AND 37 C.F.R. § 42.100 ET SEQ.
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`

`

`Table of Contents
`
`Preliminary Statement .................................................................................. 1
`I.
`Payment of Fees ............................................................................................. 3
`II.
`III. Grounds for Standing .................................................................................... 3
`IV.
`Identification of Challenge and Relief Requested ...................................... 4
`V.
`Technological Background ........................................................................... 4
`A.
`The 3GPP Organization ........................................................................ 4
`B.
`Frame Structure in LTE ......................................................................... 5
`C.
`Random Access in LTE ......................................................................... 6
`D. Uplink Reference Signals in LTE .......................................................11
`VI. The ’594 Patent ............................................................................................14
`A. Alleged Problem Addressed by ’594 Patent .......................................14
`B.
`The ’594 Patent’s Alleged Solution ....................................................14
`C.
`Prosecution History .............................................................................15
`D.
`Level of Ordinary Skill .......................................................................15
`E.
`Claim Construction..............................................................................16
`1.
`“a position of a guard time in a subframe” (Claims 1 and
`13): “a position of a guard time in a subframe as received
`at the base station” ....................................................................16
`“the guard time is of a given time length” (claims 1, 13):
`“the guard time is of a predetermined time length” ..................17
`“the guard time during which nothing is transmitted”
`(Claims 1 and 13): “the guard time during which nothing
`except the SRS is transmitted” ..................................................18
`
`2.
`
`3.
`
`i
`
`

`

`4.
`
`c.
`
`“subframe” (claims 1, 2, 7, 9, 10, 13): “a 1 millisecond
`time period in a frame” .............................................................22
`Claimed Priority Date ..........................................................................23
`F.
`VII. Prior Art .......................................................................................................24
`A.
`R1-073172 (“36.211 v1.2.0”) (EX-1012) ...........................................24
`B.
`R1-072296 (“the Nokia SRS Contribution”) (EX-1004) ....................24
`C.
`36.300 v8.0.0 (EX-1005) .....................................................................25
`VIII. Claims 1-13 are Unpatentable ....................................................................25
`A. Ground #1: 36.211 v1.2.0 Combined with 36.300 v8.0.0 and
`R1-072296 (“the Nokia SRS Contribution”) Renders the
`Challenged Claims Obvious ................................................................25
`1. Motivation to Combine .............................................................25
`2.
`Claim 1 ......................................................................................28
`a.
`[1.pre]: “A base station comprising” ..............................28
`b.
`[1.a]: “a receiving unit configured to receive a
`Sounding Reference Signal (SRS) that is mapped
`to a position of a guard time in a subframe, in
`which a random access preamble is transmitted,
`and that is transmitted from a mobile station
`apparatus, the guard time during which nothing is
`transmitted being added to the last of the random
`access preamble, and a cyclic prefix being added
`to the beginning of the random access preamble;
`and” .................................................................................30
`[1.b]: “a demodulating unit configured to
`demodulate the received SRS,” ......................................40
`[1.c]: “wherein the random access preamble is a
`preamble sequence selected from a set of preamble
`sequences, and”...............................................................42
`
`d.
`
`ii
`
`

`

`e.
`
`4.
`
`5.
`
`6.
`
`3.
`
`[1.d]: “wherein the guard time is of a given time
`length.” ............................................................................42
`Claim 2: “The base station apparatus according to claim
`1, wherein the guard time is added to the last of the
`random access preamble, and the SRS is mapped in the
`last of the subframe.” ................................................................43
`Claim 3: “The base station apparatus according to claim
`1, wherein the SRS is mapped such that a time gap
`between the SRS and the random access preamble is
`maximized.” ..............................................................................44
`Claim 4: “The base station apparatus according to claim
`1, wherein said receiving unit receives the random access
`preamble transmitted from a mobile station apparatus,
`which is non-synchronized in an uplink.” ................................45
`Claim 5: “The base station apparatus according to claim
`1, wherein said receiving unit receives the random access
`preamble transmitted from another mobile station
`apparatus.” .................................................................................45
`Claim 6: “The base station apparatus according to claim
`1, wherein said receiving unit receives the SRS at a
`constant period.” .......................................................................46
`Claim 7: “The base station apparatus according to claim
`6, wherein the period is defined by a number of
`subframes.” ...............................................................................47
`Claim 8: “The base station apparatus according to claim
`1, wherein said receiving unit receives the SRS at a
`period, which is m/n times of a period at which a random
`access preamble is transmitted, wherein m and n are
`positive integers.”......................................................................48
`10. Claim 9: “The base station apparatus according to claim
`1, wherein said receiving unit receives the SRS at a
`constant period in at least part of subframes in which
`random access preambles are transmitted.” ..............................50
`
`7.
`
`8.
`
`9.
`
`iii
`
`

`

`11. Claim 10: “The base station apparatus according to claim
`1, wherein said receiving unit receives the SRS at a
`constant period in subframes including a subframe, in
`which a random access preamble is transmitted.” ....................50
`12. Claim 11: “The base station apparatus according to claim
`1, wherein said receiving unit receives the SRS using
`frequency hopping.” ..................................................................51
`13. Claim 12: “The base station apparatus according to claim
`1 further comprising a transmitting unit configured to
`transmit control information related to a time resource of
`the SRS.” ...................................................................................52
`14. Claim 13 ....................................................................................54
`a.
`[13.pre]: “A receiving method comprising” ...................54
`b.
`[13.a]: “receiving a Sounding Reference Signal
`(SRS) mapped to a position of a guard time in a
`subframe, in which a random access preamble is
`transmitted, the guard time during which nothing is
`transmitted being added to the last of the random
`access preamble, and a cyclic prefix being added
`to the beginning of the random access preamble;
`and” .................................................................................54
`[13.b]: “demodulating the received SRS,” .....................55
`[13.c]: “wherein the random access preamble is a
`preamble sequence selected from a set of preamble
`sequences, and”...............................................................55
`[13.d]: “wherein the guard time is of a given time
`length.” ............................................................................55
`IX. The Board Should Reach the Merits of This Petition ..............................56
`A.
`Institution is Proper Under § 325(a) ....................................................56
`B.
`Institution is Proper Under § 314(a) ....................................................56
`X. Conclusion ....................................................................................................58
`
`c.
`d.
`
`e.
`
`iv
`
`

`

`XI. Mandatory Notices Under 37 C.F.R. §42.8 ...............................................58
`A.
`Real Parties-In-Interest ........................................................................58
`B.
`Related Matters ....................................................................................58
`C.
`Lead and Back-Up Counsel .................................................................59
`D.
`Service Information .............................................................................60
`XII. Certification Under 37 C.F.R. §42.24(d) ...................................................60
`
`
`
`
`
`
`
`v
`
`

`

`Petitioners’ Exhibit List
`
`
`Exhibit No.
`EX-1001
`
`Description
`U.S. Patent No. 8,077,594 (“the ’594 Patent”)
`
`EX-1002
`
`EX-1003
`
`EX-1004
`
`EX-1005
`
`EX-1006
`EX-1007
`EX-1008
`EX-1009
`EX-1010
`
`EX-1011
`
`EX-1012
`
`EX-1013
`
`File History of U.S. Patent No. 8,077,594 (U.S. Patent
`Application No. 12/853,582 (“the ’582 Application”))
`3GPP TR 25.814 V7.1.0 (2006-09) Technical Report, 3rd
`Generation Partnership Project; Technical Specification
`Group Radio Access Network; Physical Layer Aspects for
`Evolved Universal Terrestrial Radio Access (UTRA)
`(Release 7) (“3GPP TR 25.814”)
`R1-072296, TSG-RAN Working Group 1 Meeting #49;
`Agenda Item 7.11.2: UL Sounding (“the Nokia SRS
`Contribution”)
`3GPP TS 36.300 V8.0.0 (2007-03) Technical Specification,
`3rd Generation Partnership Project; Technical Specification
`Group Radio Access Network; Evolved Universal Terrestrial
`Radio Access (E-UTRA) and Evolved Universal Terrestrial
`Radio Access Network (E-UTRAN); Overall Description;
`Stage 2 (Release 8) (“36.300 v8.0.0”)
`3GPP TR 25.814 archive directory listing
`3GPP TS 36.213 archive directory listing
`3GPP TS 36.300 archive directory listing
`3GPP TS 36.211 archive directory listing
`3GPP TR 21.905 v8.1.0, “Vocabulary for 3GPP
`Specifications (Release 8)” dated June 2007
`Appendix 7.1 – ’594 Patent LTE from Patent Owner’s
`infringement contentions, served September 15, 2021.
`R1-073172, 3rd Generation Partnership Project; Technical
`Specification Group Radio Access Network; Evolved
`Universal Terrestrial Radio Access (E-UTRA); Physical
`Channels and Modulation (Release 8), 3GPP TS 36.211
`v1.2.0 (2007-06) (“36.211 v1.2.0”)
`3rd Generation Partnership Project; Technical Specification
`Group Radio Access Network; Physical layer procedures
`(Release 8), 3GPP TS 36.213 v1.2.0 (2007-05) (“36.213
`v1.2.0”)
`
`vi
`
`

`

`Exhibit No.
`EX-1014
`
`EX-1015
`EX-1016
`
`EX-1017
`
`EX-1018
`
`EX-1019
`
`EX-1020
`
`EX-1021
`
`EX-1022
`
`EX-1023
`EX-1024
`EX-1025
`EX-1026
`EX-1027
`
`EX-1028
`
`EX-1029
`
`EX-1030
`
`Description
`Draft Report of 3GPP TSG RAN WG1 #49b v0.1.0 (“49b
`v010”)
`Listserve record of July 5, 2007 e-mail attaching 49b v010
`3rd Generation Partnership Project; Technical Specification
`Group Radio Access Network; Evolved Universal Terrestrial
`Radio Access (E-UTRA); Physical Channels and
`Modulation (Release 8), 3GPP TS 36.211 v1.2.0 (2007-06)
`(Republication of EX-1012)
`Joint Claim Construction Chart from co-pending district
`court litigation (March 15, 2022)
`IP Bridge’s Opening Markman Brief from co-pending
`district court litigation (Feb. 15, 2022)
`IP Bridge’s Unopposed Motion to Continue Claim
`Construction Hearing from co-pending district court
`litigation
`Order granting IP Bridge’s Unopposed Motion to Continue
`Claim Construction Hearing and resetting claim construction
`hearing from co-pending district court litigation
`Docket Control Order from Stingray IP Solutions, LLC v.
`Legrand et al., pending in the Eastern District of Texas
`First Amended Docket Control Order from Island
`Intellectual Property LLC v. TD Ameritrade, Inc. et al.,
`pending in the Eastern District of Texas
`INTENTIONALLY OMITTED
`INTENTIONALLY OMITTED
`INTENTIONALLY OMITTED
`INTENTIONALLY OMITTED
`“About 3GPP,” available at https://www.3gpp.org/about-
`3gpp
`“LTE Overview,” available at
`http://www.3gpp.org/technologies/keywords-acronyms/98-
`lte
`
`Declaration of Craig Bishop
`
`Declaration of Antti Toskala
`
`vii
`
`

`

`Exhibit No.
`EX-1031
`EX-1032
`
`Description
`Declaration of Mark Mahon, PHD
`CV of Mark Mahon, PHD
`
`
`
`
`
`
`viii
`
`

`

`TABLE OF AUTHORITIES
`
`Page(s)
`
`
`CASES
`Apple Inc. v. Fintiv, Inc.,
`IPR2020-00019, Paper 11 (P.T.A.B. Mar. 20, 2020) ................................... 56, 57
`Apple Inc. v. Maxell, Ltd.,
`IPR2020-00204, Paper 11 (PTAB June 19, 2020) ............................................. 58
`Baxalta Inc. v. Genentech, Inc.,
`972 F.3d 1341 (Fed. Cir. 2020) .......................................................................... 21
`Becton, Dickinson & Co. v. B. Braun Melsungen AG,
`IPR2017-01586, Paper 8 (P.T.A.B. Dec. 15, 2017) ........................................... 56
`Curtiss-Wright Flow Control Corp. v. Velan, Inc.,
`438 F.3d 1374 (Fed. Cir. 2006) .......................................................................... 21
`Dow Chem. Co. v. Sumitomo Chem. Co.,
`257 F.3d 1364 (Fed. Cir. 2001) .......................................................................... 16
`Edwards Lifesciences LLC v. Cook Inc.,
`582 F.3d 1322 (Fed. Cir. 2009) .......................................................................... 22
`General Plastic Industrial Co., Ltd. v. Canon Kabushiki Kaisha,
`IPR2016-01357, Paper 19 (P.T.A.B. Sept. 6, 2017)........................................... 56
`HP Inc. v. Slingshot Printing LLC,
`IPR2020-01084, Paper 13 (P.T.A.B. Jan. 14, 2021) .......................................... 57
`Immunex Corp. v. Sanofi-Aventis U.S. LLC,
`977 F.3d 1212 (Fed. Cir. 2020) .......................................................................... 20
`Norian Corp. v. Stryker Corp.,
`363 F.3d 1321 (Fed. Cir. 2004) .......................................................................... 26
`Ortho-McNeil Pharm., Inc. v. Mylan Labs., Inc.,
`520 F.3d 1358 (Fed. Cir. 2008) .......................................................................... 22
`Phillips v. AWH Corp.,
`415 F.3d 1303 (Fed. Cir. 2005) (en banc) .................................................... 16, 22
`
`ix
`
`

`

`Sand Revolution II, LLC v. Cont’l Intermodal Grp.-Trucking LLC,
`IPR2019-01393, Paper 24 (PTAB June 16, 2020) ....................................... 57, 58
`Sinorgchem Co., Shandong v. Int’l Trade Comm’n,
`511 F.3d 1132 (Fed. Cir. 2007) .......................................................................... 23
`STATUTES
`35 U.S.C. §§102(a) and (b) ................................................................................ 24, 25
`35 U.S.C. § 311 ...................................................................................................... 1, 4
`35 U.S.C. § 325(d) ................................................................................................... 56
`
`
`
`
`
`
`x
`
`

`

`Listing of Claims
`
`
`
`1
`
`1a
`
`Claim Text
`Cl. No. Lim.
`1pre A base station comprising:
`a receiving unit configured to receive a Sounding Reference
`Signal (SRS) that is mapped to a position of a guard time in a
`subframe, in which a random access preamble is transmitted,
`and that is transmitted from a mobile station apparatus, the
`guard time during which nothing is transmitted being added to
`the last of the random access preamble, and a cyclic prefix
`being added to the beginning of the random access preamble;
`and
`a demodulating unit configured to demodulate the received
`1b
`SRS,
`1c wherein the random access preamble is a preamble sequence
`selected from a set of preamble sequences, and
`1d wherein the guard time is of a given time length.
`The base station apparatus according to claim 1, wherein the
`guard time is added to the last of the random access preamble,
`and the SRS is mapped in the last of the subframe.
`The base station apparatus according to claim 1, wherein the
`SRS is mapped such that a time gap between the SRS and the
`random access preamble is maximized.
`The base station apparatus according to claim 1, wherein said
`receiving unit receives the random access preamble
`transmitted from a mobile station apparatus, which is non-
`synchronized in an uplink.
`The base station apparatus according to claim 1, wherein said
`receiving unit receives the random access preamble
`transmitted from another mobile station apparatus.
`The base station apparatus according to claim 1, wherein said
`receiving unit receives the SRS at a constant period.
`The base station apparatus according to claim 6, wherein the
`period is defined by a number of subframes.
`The base station apparatus according to claim 1, wherein said
`receiving unit receives the SRS at a period, which is m/n times
`of a period at which a random access preamble is transmitted,
`wherein m and n are positive integers.
`
`2
`
`3
`
`4
`
`5
`
`6
`
`7
`
`8
`
`2
`
`3
`
`4
`
`5
`
`6
`
`7
`
`8
`
`xi
`
`

`

`Cl. No. Lim.
`
`9
`
`10
`
`Claim Text
`The base station apparatus according to claim 1, wherein said
`receiving unit receives the SRS at a constant period in at least
`part of subframes in which random access preambles are
`transmitted.
`The base station apparatus according to claim 1, wherein said
`receiving unit receives the SRS at a constant period in
`subframes including a subframe, in which a random access
`preamble is transmitted.
`The base station apparatus according to claim 1, wherein said
`receiving unit receives the SRS using frequency hopping.
`The base station apparatus according to claim 1 further
`comprising a transmitting unit configured to transmit control
`information related to a time resource of the SRS.
`13pre A receiving method comprising:
`receiving a Sounding Reference Signal (SRS) mapped to a
`position of a guard time in a subframe, in which a random
`access preamble is transmitted, the guard time during which
`nothing is transmitted being added to the last of the random
`access preamble, and a cyclic prefix being added to the
`beginning of the random access preamble; and
`demodulating the received SRS,
`13b
`13c wherein the random access preamble is a preamble sequence
`selected from a set of preamble sequences, and
`13d wherein the guard time is of a given time length.
`
`9
`
`10
`
`11
`
`12
`
`13
`
`
`
`
`
`
`
`11
`
`12
`
`13a
`
`
`
`xii
`
`

`

`I.
`
`Preliminary Statement
`
`On behalf of Nokia of America Corporation and Ericsson Inc. (collectively,
`
`“Petitioners”) and in accordance with 35 U.S.C. § 311 and 37 C.F.R. § 42.100, inter
`
`partes review (“IPR”) is respectfully requested for claims 1-13 (“Challenged
`
`Claims”)1 of U.S. Patent No. 8,077,594 (“the ’594 Patent”).
`
`The ’594 Patent relates to the transmission of two signals in a cellular radio
`
`access network’s uplink, which consists of transmissions from user equipment (UE)
`
`to a base station. EX-1001 1:12-20; EX-1031 at ¶¶ 37, 67-70. Specifically, the ’594
`
`Patent’s claims are directed to transmission of a random access preamble and a
`
`sounding reference signal (SRS) in the same uplink radio subframe. EX-1001 14:6-
`
`18; EX-1031 at ¶¶ 67-70. The ’594 Patent claims an arrangement in which (among
`
`other requirements) a base station is configured to receive an “SRS at the tail end of
`
`the subframe” during what is referred to as the “guard time.” EX-1001 6:64-7:2;
`
`EX-1031 at ¶¶ 67-70.
`
`Figure 5 from the ’594 Patent has been reproduced below with color coding
`
`to show a random access preamble (red), the cyclic prefix of the random access
`
`
`1 The limitations of the Challenged Claims are listed and identified in the claim
`
`listing included on x-xi.
`
`1
`
`

`

`preamble (orange), the guard time of the random access preamble (green), and the
`
`SRS (yellow). EX-1031 at ¶ 70.
`
`
`
`The ’594 Patent admits that almost all elements of the Challenged Claims—
`
`including the transmitted SRS and preamble signals—were already known in the art.
`
`EX-1001 1:12-2:3; EX-1031 at ¶ 67. It was known that an SRS and a random access
`
`preamble were transmitted from mobile stations to a base station. EX-1001 1:12-21,
`
`1:39-50; EX-1031 at ¶ 67. It was further known that an SRS and a random access
`
`preamble could be transmitted in the same subframe. EX-1001 1:25-27, 1:54-57;
`
`EX-1031 at ¶ 67. Demodulating the SRS and using it for channel quality estimation,
`
`frequency scheduling, timing detection, and transmission power control was also
`
`known. EX-1001 1:12-21, 1:35-38; EX-1031 at ¶ 67. And the structure of a random
`
`access preamble in a subframe was known, i.e., it was known that the preamble was
`
`preceded by a cyclic prefix and followed by a guard time. EX-1001 1:50-54, 1:67-
`
`2:3; EX-1031 at ¶ 67. It was also known that a mobile station would generate random
`
`2
`
`

`

`access preambles using sequences selected from a set of sequences. EX-1001 1:44-
`
`50; EX-1031 at ¶ 67.
`
`The only remaining aspects of the Challenged Claims that are not expressly
`
`admitted by the ’594 Patent as well-known in the art relates to reception of an SRS
`
`at the tail end of the subframe, during the guard time of a transmitted random access
`
`preamble. EX-1031 at ¶ 67. However, transmitting the SRS in the last symbol of a
`
`subframe is expressly taught by the prior art. EX-1004; EX-1031 at ¶¶ 62-65.
`
`Accordingly, the Challenged Claims should be cancelled as unpatentable.
`
`II.
`
`Payment of Fees
`
`The Office may charge any additional fees to Deposit Account No. 50-5723.
`
`III. Grounds for Standing
`Petitioners hereby certify that the ’594 Patent is available for IPR and that the
`
`Petitioners are not barred or estopped from requesting IPR challenging the claims of
`
`the ’594 patent on the grounds identified herein. Neither Petitioners, nor any party
`
`in privity with Petitioners: (i) have filed a civil action challenging the validity of the
`
`Challenged Claims; (ii) have been served a complaint alleging infringement of the
`
`’594 Patent more than one year prior to the present date; or (iii) are estopped from
`
`challenging the claims on the grounds identified in the petition. The Challenged
`
`Claims also have not been the subject of a prior IPR or a finally concluded district
`
`court litigation.
`
`3
`
`

`

`IV.
`
`Identification of Challenge and Relief Requested
`
`Petitioners request that the Board institute an IPR under 35 U.S.C. § 311 of
`
`Challenged Claims 1-13 of the ’594 Patent, and that the Board cancel the same as
`
`being unpatentable in view of the cited prior art and the Grounds described below.
`
`Ground 1: 36.211 v1.2.0 combined with 36.300 v8.0.0 and R1-072296 (“the
`
`Nokia SRS Contribution”) renders claims 1-13 obvious (§ 103).
`
`V. Technological Background
`The ’594 Patent relates to two LTE uplink signals: random access preambles
`
`and sounding reference signals. EX-1001 1:12-62; EX-1031 at ¶ 37. Both random
`
`access preambles and sounding reference signals were part of the proposed uplink
`
`model for LTE long before the alleged invention. EX-1003 at 75-77; 82-87; EX-
`
`1031 at ¶ 37. This section provides a brief overview of each uplink signal, as well as
`
`an overview of 3GPP, the standards-setting organization responsible for developing
`
`LTE.
`
`A. The 3GPP Organization
`The Third Generation Partnership Project (3GPP) is a standards-setting
`
`organization that began in 1998 as a joint partnership between several
`
`telecommunications companies to develop and standardize various aspects of mobile
`
`network operator systems. EX-1027; EX-1031 at ¶¶ 38-39. The development of
`
`specifications by 3GPP is an ongoing, collaborative effort involving hundreds of
`
`4
`
`

`

`engineers from many companies. EX-1031 at ¶ 39. Members of the various 3GPP
`
`working groups submit written contributions and discussion documents, ultimately
`
`capturing accepted proposals and changes in Technical Reports and Technical
`
`Specifications. EX-1031 at ¶ 39. 3GPP stores and controls all of these documents
`
`electronically and retains them on the public 3GPP server indefinitely. EX-1031 at
`
`¶ 39; EX-1029 at ¶¶ 28-34; EX-1030 at ¶¶ 19-22, 27-30, 40-46.
`
`Major changes to the 3GPP standards are introduced as “Releases,” which
`
`comprise several Technical Specifications. EX-1031 at ¶ 39. As of the ’594 Patent’s
`
`earliest claimed priority date, 3GPP was in the process of standardizing and drafting
`
`the technical specifications that would together form 3GPP Release 8, which
`
`included the fourth generation (4G) cellular network, also known as the evolved
`
`universal terrestrial radio access network (EUTRAN) or Long-Term Evolution
`
`(LTE). EX-1031 at ¶ 41.
`
`Frame Structure in LTE
`
`B.
`The LTE frame structure would have been familiar to a POSITA. EX-1031 at
`
`¶ 48. By the ’594 Patent’s earliest claimed priority date, 3GPP had developed a
`
`“frame structure type 1” for use in frequency division duplexed and time division
`
`duplexed transmissions. EX-1012 at § 4.1; EX-1031 at ¶ 48. Frame structure type 1
`
`was well developed, and its format was written into the draft technical specifications
`
`for LTE’s physical layer signals. EX-1012 at § 4.1; EX-1031 at ¶ 48. As shown
`
`5
`
`

`

`below, in frame structure type 1 a radio frame was divided into 10 subframes, with
`
`each subframe having a duration of 1 millisecond. EX-1012 at § 4.1; EX-1031 at ¶
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`48.
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`
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`C. Random Access in LTE
`Random access was used in prior-generation cellular networks, and the
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`concept would have been familiar to a POSITA. EX-1031 at ¶ 49. The random access
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`procedure in LTE, generally, allows a UE2 to contact an eNB3 to request network
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`access without a prior connection. EX-1031 at ¶ 49 From the early stages of LTE
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`standardization, it was known that this random access procedure would require the
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`UE to send a signal called a “random access preamble” during a scheduled random
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`access slot in an uplink frame. EX-1003 at 82-87; EX-1031 at ¶¶ 49-51. The figure
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`below is from a proposal under consideration in September 2006, and it illustrates
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`2 A mobile station is also called user equipment, or UE, in the context of LTE.
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`3 A base station is also called an evolved NodeB, or eNB, in the context of LTE.
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`6
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`

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`which slot could be reserved for the random access preamble transmission (shown
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`in green). Id.
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`
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`EX-1003 Fig. 9.1.2.1.1.1-1 (p. 83) (annotation in original)
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`It was also generally known that an eNB could receive a random access
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`preamble from a UE, and that the eNB could respond with a resource allocation that
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`allowed the UE to access the network. EX-1003 at 86; EX-1031 at ¶ 50. This is
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`illustrated in the figure below, which shows one of the proposed random access
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`procedures under consideration in September 2006. Id.
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`7
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`EX-1003 Fig. 9.1.2.1.1.3-2 (p. 86)
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`Another concept that would have been familiar to a POSITA was the
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`difference between synchronized and non-synchronized transmissions. EX-1031 at
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`¶¶ 52-56. The principal difference between these transmissions was time alignment.
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`EX-1031 at ¶¶ 52-53. Specifically, synchronized transmissions from UEs were
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`scheduled to arrive at the eNB at the same time, whereas non-synchronized
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`transmissions could arrive at different times. EX-1031 at ¶¶ 52-56.
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`The following figure illustrates synchronized transmissions. EX-1031 at ¶ 53:
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`8
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`As shown above on the left, the synchronized transmissions (blue and orange)
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`both arrive at the eNB at the same time, and in line with the end of a subframe (the
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`dotted line). EX-1031 at ¶¶ 53-54. To achieve this synchronization, UE1 must begin
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`its transmission (orange) before the end of the subframe. EX-1031 at ¶¶ 53-54. This
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`“lead” time is necessary because the transmission takes time to arrive at the eNB.
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`EX-1031 at ¶¶ 53-54. And UE2 must begin its transmission (blue) even earlier
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`because UE2 is further away from the eNB, so its transmission will take longer to
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`arrive. EX-1031 at ¶¶ 53-54. In this example, both UE1 and UE2 know how much
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`“lead” time—also called “timing advance”—to add in order to ensure that their
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`transmissions arrive at the same time, and in line with the end of a subframe. EX-
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`1031 at ¶¶ 53-54. Consequently, both UEs are considered “synchronized” in the
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`uplink.
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`In contrast non-synchronized UEs do not yet know the appropriate timing
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`advance to apply and instead know only when downlink transmissions arrive from
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`the eNB. EX-1003 at 82-86; EX-1031 at ¶ 55. Downlink transmissions take longer
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`to arrive at UEs that are farther away from the eNB. EX-1031 at ¶ 55. Similarly, the
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`farther away a UE is, the longer it takes for its uplink transmissions to reach the eNB.
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`Id. As a result, a non-synchronized UE’s uplink transmissions arrive later the farther
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`away the UE is from the eNB. Id. Non-synchronized UE uplink transmissions, such
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`as a random access preamble, therefore arrive at the eNB subject to some variable
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`and uncertain delay, and could potentially interfere with later scheduled uplink
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`transmissions. Id.
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`Early in LTE’s standardization process, contributors considered this problem
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`and designed the non-synchronized random access scheme accordingly. EX-1003 at
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`82-87; EX-1031 at ¶ 56. To prevent a non-synchronized random access preamble
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`from interfering with later scheduled signals using the same frequency resources,
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`3GPP contributors added “guard times” for the non-synchronized random access
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`window. EX-1003 at 83; EX-1031 at ¶ 56. These guard times could allow random
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`access preambles to arrive early or late without interfering with other transmissions.
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`Id.
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`By the ’594 Patent’s earliest claimed priority date, 3GPP had adopted a non-
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`synchronized random access scheme. EX-1031 at ¶ 57. In that scheme, the random
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`10
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`access preamble was well developed, and its format was written into the draft
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`technical specifications for LTE’s physical layer signals. EX-1012 at § 6.7.1; EX-
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`1031 at ¶ 57. The figure below, taken from a prior art draft technical specification,
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`shows the agreed format for the random access preamble, including a cyclic prefix
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`(orange), the random access preamble (red), and a guard time (green). EX-1012 at §
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`6.7.1 (annotated); EX-1031 at ¶ 57.
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`
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`D. Uplink Reference Signals in LTE
`In parallel with development of random access procedures, 3GPP contributors
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`were also developing a signal often called the Sounding Reference Signal (SRS).
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`The signal could be used by the base station to “sound” a channel to help estimate
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`its quality. EX-1003 at 75-77; EX-1031 at ¶ 58. At the time, it was well known that,
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`in LTE, data could be transmitted in parallel along different frequency subcarriers.
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`Id. An eNB could use an SRS to measure the received uplink signal power for many
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`frequency subcarriers. Id. This measurement could allow the eNB to optimally
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`assign subcarriers for each UE to use in uplink transmissions. Id. This process of
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`assigning subcarriers was called “frequency-selective scheduling.” Id.
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`The same draft technical specification that specified the agreed random access
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`preamble parameters also specified an SRS in the uplink channel. EX-1012 at §
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`6.5.2.2; EX-1031 at ¶ 59. 3GPP also decided which sequences to use for the SRS
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`and established numerous signaled SRS parameters (transmission bandwidth,
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`period, cyclic shift, and sub-frame). EX-1014 at 32-33; EX-1031 at ¶ 60. One of the
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`remaining decisions prior to the ’594 Patent’s earliest claimed priority date was
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`where, within the subframe, to position the SRS. EX-1014 at 32-33; EX-1031 at ¶
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`61. Although a final decision had not been made, 3GPP contributors had already
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`proposed placing the SRS at the end of a subframe and during the guard time of a
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`random acces