UNITED STATES PATENT AND TRADEMARK OFFICE
`_________________
`BEFORE THE PATENT TRIAL AND APPEAL BOARD
`_________________
`APPLE INC.,
`Petitioner
`
`v.
`
`TELEFONAKTIEBOLAGET LM ERICSSON
`Patent Owner
`__________________
`
`Case No. IPR2022-00464
`Patent No. 10,193,600
`__________________
`
`PATENT OWNER’S PRELIMINARY RESPONSE
`
`

`

`Case No. IPR2022-00464
`Patent No. 10,193,600
`
`TABLE OF CONTENTS
`LIST OF EXHIBITS ................................................................................................. ii
`I.
`INTRODUCTION ........................................................................................... 1
`II.
`SUMMARY OF ARGUMENT ....................................................................... 1
`III. OVERVIEW OF THE ’600 PATENT ............................................................ 3
`A.
`Background of the Technology of the ’600 Patent ............................... 4
`Systems with multiple antennas .................................................. 4
`Precoding ..................................................................................11
`Rank ..........................................................................................13
`Codebooks, Codebook Subset Restriction (CSR), and
`Bitmaps .....................................................................................15
`The ’600 Patent and “Rank-Agnostic” Signaling that Restricts
`Precoders “Without Regard to the Precoders’ Transmission
`Rank” ...................................................................................................17
`Summary of the Prosecution History of the ’600 Patent ....................20
`The Examiner Rejects the Claims over Jing and Novlan .........21
`Patent Applicants Amend the Claims on July 11, 2018 ...........22
`LEVEL OF ORDINARY SKILL IN THE ART ...........................................22
`CLAIM CONSTRUCTION ..........................................................................22
`THE BOARD SHOULD EXERCISE ITS DISCRETION TO DENY
`INSTITUTION ..............................................................................................23
`A.
`Novlan Was Cited During Prosecution to Reject the Claims .............25
`B.
`TS 36.213 v12.3.0 Is Cumulative of Art Before the Examiner ..........27
`VII. SCOPE AND CONTENT OF THE ASSERTED PRIOR ART
`REFERENCES ..............................................................................................30
`
`IV.
`V.
`VI.
`
`B.
`
`C.
`
`i
`
`

`

`B.
`
`A.
`
`Case No. IPR2022-00464
`Patent No. 10,193,600
`Novlan (Ex. 1005) Does Not Teach That the “Codebook Subset
`Restriction Signaling Is Rank-Agnostic Signaling That Jointly
`Restricts the Precoders in a Group without Regard to the
`Precoders’ Transmission Rank.” .........................................................30
`Novlan’s General Subset Restrictions ......................................32
`Novlan’s Sampling Based Subset Restriction ..........................33
`Signaling the Restriction in Novlan ..........................................36
`Novlan’s Bitmap Signaling .......................................................37
`TS 36.213 v12.3.0 (Ex. 1006) Does Not Teach That the
`“Codebook Subset Restriction Signaling Is Rank-Agnostic
`Signaling That Jointly Restricts the Precoders in a Group
`without Regard to the Precoders’ Transmission Rank.” .....................40
`VIII. PETITIONER HAS NOT DEMONSTRATED A REASONABLE
`LIKELIHOOD THAT ANY OF THE CHALLENGED CLAIMS
`ARE UNPATENTABLE ...............................................................................43
`A.
`Petitioner Mistakenly Assumes That Restriction Based On
`Spatial Domain Is Necessarily Rank-Agnostic. ..................................45
`Petitioner Mistakenly Assumes That Restriction Based On
`Transmission Mode Is Necessarily Rank-Agnostic. ...........................49
`Petitioner Mistakenly Assumes That The Mere Existence Of
`“Rank-2” Precoders Discloses Rank-Agnostic Restriction. ...............55
`IX. CONCLUSION ..............................................................................................59
`CERTIFICATE OF COMPLIANCE ......................................................................... 1
`CERTIFICATE OF SERVICE .................................................................................. 2
`
`B.
`
`C.
`
`ii
`
`

`

`Case No. IPR2022-00464
`Patent No. 10,193,600
`
`TABLE OF AUTHORITIES
`
` Page(s)
`
`Cases
`Advanced Bionics, LLC v. MED-EL Elektromedizinische Geräte
`GmbH,
`IPR2019-01469, Paper 6 (P.T.A.B. Feb. 13, 2020) (precedential) .............. 23, 24
`Arendi SARL v. Apple Inc.,
`832 F.3d 1355 (Fed. Cir. 2016) .......................................................................... 43
`Becton, Dickinson and Co. v. B. Braun Melsungen AG,
`IPR2017-01586, Paper 8 (P.T.A.B. Dec. 15, 2017) (precedential) .............. 23, 24
`Nidec Motor Corp. v. Zhongshan Broad Ocean Motor Co.,
`868 F.3d 1013 (Fed. Cir. 2017) .......................................................................... 22
`Vivid Techs., Inc. v. Am. Sci. & Eng'g, Inc.,
`200 F.3d 795 (Fed. Cir. 1999) ............................................................................ 22
`Federal Statutes
`35 U.S.C. §314(a) .............................................................................................. 1, 2, 3
`35 U.S.C. § 325(d) ......................................................................................... 1, 20, 23
`Other Authorities
`H.R. Rep. No. 112–98, pt. 1 (2011) ....................................................................... 2, 3
`
`i
`
`

`

`Case No. IPR2022-00464
`Patent No. 10,193,600
`
`LIST OF EXHIBITS
`Description
`U.S. Patent No. 10,193,600 (“the ’600 Patent”)
`Certified File History of U.S. Patent No. 10,193,600
`Declaration of Dr. Apostolos K. Kakaes for Inter Partes Review of
`U.S. Patent No. 10,193,600
`Curriculum Vitae of Dr. Apostolos K. Kakaes
`U.S. Patent Application Publication No. 2014/0016549 (“Novlan”)
`3GPP TS 36.213, v12.3.0 (“36.213”)
`3GPP TS 36.213, v10.1.0
`U.S. Patent No. 8,891,676
`Declaration of Friedhelm Rodermund in Support of Petition for Inter
`Partes Review of U.S. Patent No. 10,193,600
`U.S. Provisional Patent Application No. 62/103,101 (“the ’600
`Patent Provisional”)
`U.S. Patent Application Publication No. 2013/0163687 (“Jing”)
`U.S. Provisional Patent Application No. 61/670,936 (the “Novlan
`Provisional”)
`Dahlman et al., 4G – LTE / LTE-Advanced for Mobile Broadband
`(Academic Press 2011) (“Dahlman”)
`Declaration of James L. Mullins in Support of Petition for Inter Partes
`Review of U.S. Patent No. 10,193,600
`U.S. Patent Application Publication No. 2008/0051091
`Sesia, et al., LTE - The UMTS Long Term Evolution From Theory
`to Practice (Wiley 2d. ed. 2011) (“Sesia”)
`Declaration of Jacob Robert Munford in Support of Petition for Inter
`Partes Review of U.S. Patent No. 10,193,600
`Declaration Of Dr. Muriel Médard, Sc.D In Support Of Patent Owner’s
`Preliminary Response
`Curriculum Vitae of Dr. Muriel Médard
`
`Exhibit
`1001
`1002
`1003
`
`1004
`1005
`1006
`1007
`1008
`1009
`
`1010
`
`1011
`1012
`
`1013
`
`1014
`
`1015
`1016
`
`1017
`
`2001
`
`2002
`
`ii
`
`

`

`Case No. IPR2022-00464
`Patent No. 10,193,600
`
`I.
`
`INTRODUCTION
`
`Patent Owner Telefonaktiebolaget LM Ericsson (“Ericsson”) submits this
`
`Preliminary Response to the Petition for Inter Partes Review (“Petition” or “Pet.”)
`
`of claims 1-28 (“Challenged Claims”) of U.S. Patent No. 10,193,600 (“the ’600
`
`Patent”) (Ex. 1001). Ericsson respectfully requests that the Board deny institution,
`
`because there is not a reasonable likelihood that Petitioner would prevail with respect
`
`to any claim challenged in the petition. 35 U.S.C. §314(a).
`
`II.
`
`SUMMARY OF ARGUMENT
`
`The Petition raises a single ground, arguing that all Challenged Claims would
`
`be obvious over “Novlan, or alternatively Novlan in view of 36.213.” Pet. at 2.
`
`Institution should be denied, because the Petition rehashes arguments already
`
`rejected by the Examiner during prosecution, using references that still fail to
`
`disclose or suggest the limitation used to achieve allowance.
`
`The Board should exercise its discretion to deny institution. 35 U.S.C. §
`
`325(d). Novlan (Ex. 1005) was used by the Examiner to reject claims during
`
`prosecution, and TS 36.213 v12.3.0 (Ex. 1006) is cumulative of TS 36.213 v10.1.0
`
`(Ex. 1007) that was discussed extensively within the specification of Novlan. Fully
`
`aware of Novlan and the teachings of 36.213, the Examiner issued the ’600 Patent
`
`after the independent claims were amended to recite “the codebook subset restriction
`
`signaling is rank-agnostic signaling that jointly restricts the precoders in a group
`
`-1-
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`

`Case No. IPR2022-00464
`Patent No. 10,193,600
`without regard to the precoders’ transmission rank.” Novlan and the later version of
`
`36.213 relied upon by Petitioner still fail to disclose or suggest this limitation, either
`
`alone or in combination.
`
`The Board should also deny institution under 35 U.S.C. § 314(a), because
`
`Petitioner has not shown a likelihood of unpatentability for any claim. After the
`
`amendment during prosecution, every Challenged Claim now requires that “the
`
`codebook subset restriction signaling is rank-agnostic signaling that jointly restricts
`
`the precoders in a group without regard to the precoders’ transmission rank.” Novlan
`
`and TS 36.213 fail to disclose this limitation, and they expressly teach the opposite.
`
`Novlan and TS 36.213, whether alone or in combination with one another, do not
`
`teach rank-agnostic signaling, and the codebook subset restrictions do not restrict
`
`precoders in a group without regard to the precoders’ transmission rank. Ex. 2001
`
`(Médard Decl.) ¶19.
`
`Apple’s Petition is nothing more than a cut-and-paste of a prior petition filed
`
`by Samsung challenging the same claims of the ’600 Patent. See IPR2021-00730
`
`(filed on Mar. 26, 2021). The ’600 Patent is not currently asserted against Apple in
`
`any pending litigation, so Apple’s Petition is not a means for “providing a quick and
`
`cost-effective alternative[] to litigation,” which is the purpose of inter partes review
`
`as outlined in the legislative history. H.R. Rep. No. 112–98, pt. 1, at 40 (2011). The
`
`use of inter partes review in this manner, particularly where Petitioner has failed to
`
`-2-
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`

`

`Case No. IPR2022-00464
`Patent No. 10,193,600
`show that it has a reasonable likelihood of prevailing as to any Challenged Claim
`
`pursuant to Section 314(a), “frustrate[s] the purpose of the section as providing quick
`
`and cost-effective alternatives to litigation” and “divert[s] resources from the
`
`research and development of inventions.” See, e.g., id. at 40 (2011) (Legislative
`
`history establishing inter partes review).1 Here, as Apple admits, it “largely
`
`repurposes the Samsung IPR” (Pet. at 63) at little or no cost to Apple, relying on the
`
`same expert retained by Samsung and presenting the same weak arguments
`
`challenging the claims of the ’600 Patent.
`
`III. OVERVIEW OF THE ’600 PATENT
`
`The ’600 Patent describes a novel system and method for codebook subset
`
`restriction (CSR) for multiple input multiple output (MIMO) systems. Ex. 1001. For
`
`purposes of this Preliminary Response, the limitation that distinguishes both Novlan
`
`(Ex. 1005) and 36.213 (Ex. 1006) from all of the Challenged Claims is, “wherein the
`
`codebook subset restriction signaling is rank-agnostic signaling that jointly restricts
`
`the precoders in a group without regard to the precoders’ transmission rank.” Ex.
`
`2001 ¶¶33-34.
`
`Patent Owner’s expert, Dr. Muriel Médard, an MIT Professor who has
`
`extensively researched wireless communications, provides a background of rank and
`
`1 Unless otherwise noted, all emphasis is added by Patent Owner.
`
`-3-
`
`

`

`Case No. IPR2022-00464
`Patent No. 10,193,600
`other technology related to the ’600 Patent. The technology includes: systems with
`
`multiple antennas, and how signals transmitted from one antenna affects signals
`
`transmitted from other antennas; precoding as a mathematical technique to focus
`
`antenna signals; how matrix “rank” is used to characterize and understand the
`
`multiple antennas; and codebooks and restricting the available precoders. Ex. 2001
`
`¶¶33-65.
`
`A.
`
`Background of the Technology of the ’600 Patent
`
`Systems with multiple antennas
`
`The ’600 Patent in the “Background” section explains that multiple antennas
`
`have been used in various communications protocols (such as 3G / 4G Long Term
`
`Evolution, or LTE). Such systems have been referred to as MIMO (Multiple In,
`
`Multiple Out) and used to boost capacity and coverage of the wireless system. See,
`
`e.g., Ex. 1001 at 1:22-29. In MIMO systems, data to be sent is divided into multiple
`
`data streams, the data streams are then transmitted in parallel over the air, and signal
`
`processing at the receiver is used to recover the data. Id. at 1:25-29. The ’600 Patent
`
`teaches methods for “adapting the transmission to the current channel conditions” in
`
`order to improve signal quality and bandwidth. Id. at 1:29-31; Ex. 2001 ¶35.
`
`Transmit antennas have regions of propagation of the electromagnetic energy
`
`they transmit, generally termed lobes. Figure A below is a modified version of
`
`Figure 4 of Novlan (Ex. 1005), modified to show a receiving antenna and to draw
`
`-4-
`
`

`

`Case No. IPR2022-00464
`Patent No. 10,193,600
`exemplary lobes from one antenna in a two-dimensional transmit array. The primary
`
`lobe is oriented toward the receiver, and a smaller lobe can be seen at the back of the
`
`antenna, pointing away from the receiver.
`
`FIGURE A
`
`Ex. 1005 at Fig. 4 (modified). The shapes of the lobes are dictated by the shape of
`
`the antennas and the electromagnetic properties of the frequencies at which they
`
`operate. Ex. 2001 ¶¶35-37.
`
`As shown in Figure A, a transmit signal from one transmit antenna is received
`
`at multiple receive antennas. Likewise, a given antenna at the receiver will receive
`
`signals from multiple transmit antennas. The signals from different transmit
`
`antennas overlap, as show in Figure B, which can create interference that affects
`
`performance of the wireless network.
`
`-5-
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`

`

`Case No. IPR2022-00464
`Patent No. 10,193,600
`
`FIGURE B
`
`.
`
`Ex. 1005 at Fig. 4 (modified); Ex. 2001 ¶38.
`
`The effect of interference can be represented schematically in the figure
`
`below, in which transmit-side antennas are presented on the left (X) and receive-side
`
`antennas are presented on the right (Y).
`
`-6-
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`

`

`Case No. IPR2022-00464
`Patent No. 10,193,600
`
`Figure C
`
`Each antenna i at the transmitter sends an input signal Xi. Each receive antenna j at
`
`the receiver receives an output signal Yj. At the receiver, the antenna j receives the
`
`combined, additive effect of the transmissions from the total number of transmit
`
`antennas (X1 + X2 + … Xi + … + XNT). The signals overlap, which can create
`
`interference and can reduce performance of the wireless network. Ex. 2001 ¶39.
`
`In an actual system, the signals from the multiple transmit antennas will not
`
`be received identically for a given receive antenna. There will be different weighting
`
`coefficients, depending on the relative positions of transmit and receive antennas,
`
`and the characteristics of the medium over which the electromagnetic propagation
`
`from the sender to the receiver is taking place (e.g., channel conditions).
`
`-7-
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`

`Case No. IPR2022-00464
`Patent No. 10,193,600
`
`Ex. 2001 ¶40.
`
`Figure D
`
`The channel conditions are not the same between all paths. For example, the
`
`distance may be different between the antenna pairs, or there could be obstructions.
`
`As a result, the effect of the signal Xi transmitted by antenna i at receiver j is
`
`weighted by a factor hi,j. Given that there can be multiple transmit antennas,
`
`mathematically, the formula for any one particular receive antenna (j) would read:
`
`𝑌𝑗=𝑋1 ℎ1,𝑗+𝑋2 ℎ2,𝑗+⋯+𝑋𝑖 ℎ𝑖,𝑗+⋯+ 𝑋𝑁𝑇 ℎ𝑁𝑇,𝑗.
`
`The above equation is for one particular receive antenna (j), but in a system there
`
`can be NR total number of receive antennas. Thus, there would be a set of equations,
`
`one for Y1, one for Y2, one for Yj, and one for YNR; Ex. 2001 ¶40.
`
`-8-
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`

`

`Case No. IPR2022-00464
`Patent No. 10,193,600
`In a generalized system with NR receive antennas and NT transmit antennas,
`
`the values of hi,j in a system can be expressed in matrix form, as in the generalized
`
`equation below:
`
`[𝑋1… 𝑋𝑁𝑇]𝐻=[𝑌1… 𝑌𝑁𝑅]
`[𝑋1… 𝑋𝑁𝑇] represents a vector X that corresponds to the transmitted signals across
`particular transmit antenna. [𝑌1… 𝑌𝑁𝑅] represents a vector Y that corresponds to the
`
`all transmit antennas in the system, with Xi denoting the signal transmitted by one
`
`received signals across all receive antennas in the system, and Yj denotes the signal
`
`received by one particular receive antenna (j). H represents a matrix that contains
`
`each of the hi,j values, as follows:
`
`𝐻= [ℎ1,1 ⋯ ℎ1,𝑁𝑅
`⋮
`⋱
`⋮
`ℎ𝑁𝑇,1 ⋯ ℎ𝑁𝑇,𝑁𝑅]
`
`The above matrix H (also referred to as a “transfer matrix”) represents the collective
`
`effect of: all transmit antennas in the system; all receive antennas; and the
`
`communications medium between them. Each particular value of hi,j can be a
`
`complex quantity and can also account for the polarization of antennas and channel
`
`conditions. See, e.g., Ex. 1001 (’600 Patent) at 9:20-37. Ex. 2001 ¶¶40-41.
`
`-9-
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`

`Case No. IPR2022-00464
`Patent No. 10,193,600
`An advantageous system in terms of reducing interference would be one in
`
`which the lobes of the transmit antennas are narrow and focused on specific receive
`
`antennas, such as pictured below.
`
`FIGURE E
`
`Ex. 1005 at Fig. 4 (modified). This effect can be visualized by the figure below,
`
`where the transmit side antennas are on the left and the receive antennas are on the
`
`right.
`
`-10-
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`

`

`Case No. IPR2022-00464
`Patent No. 10,193,600
`
`Figure F
`
`In the hypothetical case above, there would be no interference at receive antennas
`
`among the transmissions of transmit antennas, because a receive antenna would
`
`receive a signal from a single transmit antenna. Obtaining such narrow lobes is,
`
`however, expensive in terms of antenna hardware. Moreover, in terms of operational
`
`flexibility, it is advantageous to be able to provide multiple configurations of the
`
`type shown in Figures A-D. To achieve such configurations, utilization of
`
`mechanical steering of beams is possible, but can be expensive and onerous. Ex.
`
`2001 ¶¶42-43.
`
`Precoding
`
`To increase channel throughput and achieve transmission in a similar manner
`
`to what is shown schematically above in Figure E and Figure F (e.g., where one
`
`-11-
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`

`

`Case No. IPR2022-00464
`Patent No. 10,193,600
`receive antenna receives signals from one transmit antenna), the channel conditions
`
`would be such that for every Yj antenna, one ℎ𝑖,𝑗 would ideally be of large amplitude
`
`and the others would be approximately 0. However, to achieve this result through
`
`antenna hardware alone can be expensive and would reduce the ability of the system
`
`to adapt to changed conditions. Ex. 2001 ¶44.
`
`Precoding is a technique that, using mathematical manipulation, allows for
`
`focusing a signal from a transmit antenna to one particular receive antenna, and
`
`adapting that signal as channel conditions change. As explained in the ’600 Patent,
`
`“precoding” refers to the processing of signals before transmission to provide
`
`flexibility to a system that translates into performance gains. See, e.g., Ex. 1001 at
`
`1:35-38 (“Precoding is another form of adaptation where the phases and amplitudes
`
`of the aforementioned signals are adjusted to better fit the channel properties.”); see
`
`also 1:29-31; Ex. 2001 ¶45.
`
`As the ’600 Patent explains, “[p]recoding may be interpreted as multiplying
`
`the signal with different beamforming weights for each antenna prior to
`
`transmission.” See Ex. 1001 at 9:39-41; see 14:1-20 (describing how a precoder can
`
`include “one or more beamforming vectors”). Mathematically, precoding involves
`
`multiplying [𝑋1… 𝑋𝑁𝑇] by a “precoder matrix” (W) in order to obtain a desired
`[𝑌1… 𝑌𝑁𝑅] . A “precoder matrix” is sometimes simply referred to as a “precoder.”
`
`Ex. 2001 ¶46.
`
`-12-
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`

`

`Case No. IPR2022-00464
`Patent No. 10,193,600
`The precoder matrix facilitates the system adapting the channel properties to
`
`current channel conditions. The ’600 Patent further explains precoding:
`
`Precoding is another form of adaptation where the phases and
`amplitudes of the aforementioned signals are adjusted to better fit the
`current channel properties. The signals form a vector-valued signal and
`the adjustment can be thought of as multiplication by a precoder matrix.
`
`Ex. 1001 at 1:35-40. The “precoding” adapts the signals provided to the transmit
`
`antennas. The effect of the precoder matrix can include forming narrow, focused
`
`beams from input antennas to selected output antennas. In effect, precoding can
`
`transform the system from Figure A-D into a system that virtually operates like
`
`Figure E-F. Multiple precoder matrices are typically available, so one aspect of
`
`precoding involves selecting the appropriate precoder matrix (W) to use. Ex. 2001
`
`¶¶47-49. This ability of MIMO systems to mimic multiple systems relates to the
`
`concept of layers, or streams. The number of layers, or streams, is the number of
`
`separate transmitter/receiver pairs that the MIMO system can mimic, and it is limited
`
`by the rank of the matrix. The notion of layers is related to that of virtual
`
`beamforming. Ex. 2001 ¶50.
`
`Rank
`
`A core aspect of MIMO systems includes the rank of the transfer matrix and
`
`the rank of the precoding matrix. The term “rank” relates to the dimension of a
`
`matrix. The rank of a matrix is upper bounded by the minimum of the number of
`
`rows (e.g., number of transmit antennas) and the number of columns (e.g., the
`
`-13-
`
`

`

`Case No. IPR2022-00464
`Patent No. 10,193,600
`number of receive antennas). Ex. 2001 ¶¶51-55 (explaining the math behind matrices
`
`and rank).
`
`The above concepts of rank also apply to the precoder matrix W. For example,
`
`the ’600 Patent provides an example of a precoder matrix with rank = 1:
`
`Ex. 1001 at 18:5-6. There is a single column and two rows. The ’600 Patent also
`
`provides an example of a set of multiple precoder matrices, with each individual
`
`precoder matrix having rank = 1:
`
`Id. at 18:5-6. The ’600 Patent provides an example of a precoder matrix with L
`
`columns:
`
`-14-
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`

`Case No. IPR2022-00464
`Patent No. 10,193,600
`Id. at 14:31-44. Ex. 2001 ¶56. Pre-multiplying H by another matrix (e.g., the
`
`precoding matrix W) has the effect of producing a different matrix. The pre-
`
`multiplication cannot increase rank, but it can maintain rank. Pre-multiplying H by
`
`another matrix underlies the notion of precoding that is discussed above. Ex. 2001
`
`¶57.
`
`Codebooks, Codebook Subset Restriction (CSR), and
`Bitmaps
`
`The ’600 Patent discusses that there can be more than one precoder in a
`
`system, such as the set of rank-1 precoders shown below:
`
`Ex. 1001 at 18:3-6. Accordingly, the patent explains that one “common approach
`
`[for precoding] is to select the precoder matrix from a finite and indexed set, a so-
`
`called codebook.” Id. at 1:40-42. The codebook can be thought of as a collection
`
`of possible precoder matrices (W) that can be selected in order to best adapt the
`
`system to the current channel conditions. The receiver searches the codebook to
`
`select the best precoder, and the “receiver recommend[s] a suitable precoder matrix
`
`to the transmitter by signaling the precoder matrix indicator (PMI) over a feedback
`
`link.” Ex. 1001 at 1:45-49; Ex. 2001 ¶58.
`
`-15-
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`Case No. IPR2022-00464
`Patent No. 10,193,600
`The ’600 Patent explains that a “larger codebook” allows the receiver to
`
`“better match the current channel conditions” because the precoding can be more
`
`finely tuned to the channel conditions. Ex. 1001 at 1:49-54. In certain systems, such
`
`as multi-user MIMO (MU-MIMO), the “operation could benefit more from having
`
`a larger number of elements than a codebook used in a single-user multiple input
`
`multiple output (SU-MIMO) operation.” Id. at 2:9-15. For large antenna arrays or
`
`for situations where a large amount of equipment is located within an area, “the
`
`effective beams become narrow and a codebook containing many precoders is
`
`required for the intended coverage area.” Ex. 1001 at 2:41-43. The codebook
`
`becomes even larger when a two-dimensional array is used. Ex. 1001 at 2:44-49;
`
`Ex. 2001 ¶59.
`
`Though a larger codebook can provide advantages in system flexibility, a
`
`drawback is that identification of a precoder from the large codebook imposes
`
`transmission overhead, which could be an issue “if the feedback link has a limited
`
`capacity.” Ex. 1001 at 1:49-54. Large codebooks also impose search overhead if
`
`the receiver has to select among more precoders. Ex. 2001 ¶60. One other
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`consideration is that describing the precoder matrix W may create excessive
`
`overhead in terms of cost of description. The information needed to convey the
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`precoder W may compete for resources such as bandwidth and transmit energy with
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`the information that the system seeks to transmit (payload). Ex. 2001 ¶61.
`
`-16-
`
`

`

`Case No. IPR2022-00464
`Patent No. 10,193,600
`The ’600 Patent teaches that one way to allow flexibility in precoder matrix
`
`selection while also coping with large codebook sizes is to use codebook subset
`
`restriction (also abbreviated as “CSR” or “restriction”). Using this technique, a
`
`larger codebook can contain a relatively large number of precoder matrices (also
`
`referred to as “precoders”), but “a subset of the precoders in the codebook is
`
`restricted so that the UE has a smaller set of possible precoders to choose from.” Ex.
`
`1001 at 2:18-25; see also id. at 6:20-31; Ex. 2001 ¶62.
`
`The ’600 Patent clarifies that existing CSR approaches restrict the codebook
`
`by signaling a bitmap containing one bit for each precoder in the codebook. In such
`
`a bitmap, a single bit is used “for each precoder in the codebook, where a ‘1’ would
`
`indicate that the precoder is restricted (meaning that the UE is not allowed to choose
`
`and report said precoder).” Ex. 1001 at 2:32-35. However, this approach can also
`
`consume excessive overhead. Ex. 2001 ¶63.
`
`B.
`
`The ’600 Patent and “Rank-Agnostic” Signaling that Restricts
`Precoders “Without Regard to the Precoders’ Transmission Rank”
`
`The ’600 Patent discusses that signaling of the CSR can become prohibitive
`
`(e.g., requiring too many bits in the bitmap) for large codebooks or many users
`
`requiring frequent updates.
`
`Signaling a codebook subset restriction in the conventional way by
`means of a bitmap with one bit for every precoder can thus impose a
`large overhead, especially if the codebook subset restriction (CSR) is
`frequently updated or if there are many users served by the cell which
`each has to receive the CSR.
`
`-17-
`
`

`

`Case No. IPR2022-00464
`Patent No. 10,193,600
`Ex. 1001 at 2:41-54. The ’600 Patent provides a more efficient way to communicate
`
`the CSR, especially in cases where the CSR is large and needs to be frequently
`
`updated. Ex. 2001 ¶64.
`
`The ’600 Patent proposes “jointly restricting” a group of precoders by
`
`“restricting a certain component that the precoders have in common.” Ex. 1001 at
`
`2:63-65. The ’600 Patent explains how the joint restriction of a group of precoders
`
`can be “rank-agnostic,” by restricting precoders “irrespective of their transmission
`
`rank.” Ex. 1001 at 13:27-32. The ’600 Patent also explains that rank-agnostic
`
`restriction occurs when “the signaling jointly restricts the group of precoders
`
`regardless of the precoders’ transmission rank (i.e., regardless of which rank-specific
`
`codebook they belong to).” Id. at 17:9-15; see also 23:1-2. Among other examples,
`
`the ’600 Patent provides that uses rank-agnostic signaling to jointly restrict
`
`precoders across all ranks when a restricted component (such as beam precoders b0)
`
`are restricted. Id.at 17:9-21; Ex. 2001 ¶65.
`
`When “signaling CSR based on beam precoders,” an advantage of the ’600
`
`Patent is reducing signal overhead because “one does not need to signal a separate
`
`CSR for precoders with different rank (precoders with different rank are restricted
`
`with the same CSR).” Ex. 1001 at 17:21-25; see id. at 18:46-54 (further examples
`
`of rank-agnostic signaling). The independent claims of the ’600 Patent further
`
`-18-
`
`

`

`Case No. IPR2022-00464
`Patent No. 10,193,600
`clarify that the CSR signaling “jointly restricts the precoders in a group without
`
`regard to the precoders’ transmission rank.” Ex. 2001 ¶65.
`
`The ’600 Patent reduces the overhead of restriction signaling by using rank-
`
`agnostic signaling, which makes use of assumptions and predictions about which
`
`precoders are more likely to be restricted in order to communicate the codebook
`
`subset restrictions. Ex. 1001 at 6:49-57; see also id. at 6:58-64 (identifying a
`
`reference configuration and based on that, communicating codebook subset
`
`restrictions by estimating or predicting future conditions); 7:58-8:6 (based on
`
`assumption of which configuration will “have the highest probability of being
`
`signaled”). Ex. 2001 ¶66.
`
`The ’600 Patent teaches using such predictability to reduce the overhead
`
`needed to communicate CSRs, such as by separating precoders (W) into groups
`
`according to likelihood of use. More likely precoders are assigned shorter
`
`descriptions, while less likely precoders are assigned longer descriptions. Ex. 1001
`
`at 7:9-27. Some bits may be used to announce whether or not a new precoder (W)
`
`is likely, given the current state of the system. This approach is akin to compression
`
`techniques for communicating codebook subset restrictions. Ex. 1001 at 7:27-39;
`
`Ex. 2001 ¶66.
`
`-19-
`
`

`

`Case No. IPR2022-00464
`Patent No. 10,193,600
`Summary of the Prosecution History of the ’600 Patent
`
`C.
`
`The ’600 Patent was filed on June 17, 2016 as Application No. 15/105,648.
`
`Also on June 17, 2016, applicants filed a preliminary amendment that canceled
`
`claims 1-38 and introduced claims 39-70. Ex. 1002 at 75-82. As they are relevant
`
`to the Section 325(d) inquiry, Claims 39-44 are copied below:
`
`39. (New) A method implemented by a network node for signaling to a
`wireless communication device which precoders in a codebook are
`restricted from being used, the method characterized by:
`
`generating codebook subset restriction signaling that, for each of one
`or more groups of precoders, jointly restricts the precoders in the group
`by restricting a certain component that the precoders in the group have
`in common; and
`
`sending the generated signaling from the network node to the wireless
`communication device.
`
`40. (New) The method of claim 39, wherein the codebook subset
`restriction signaling is rank-agnostic signaling that jointly restricts the
`precoders in a group without regard to the precoders’ transmission rank.
`
`41 . (New) The method of claim 39, wherein a precoder comprising one
`or more beam precoders is restricted if at least one of its one or more
`beam precoders is restricted.
`
`42. (New) The method of claim 39, wherein the certain component
`comprises a beam precoder.
`
`43. (New) The method of claim 42, wherein a beam precoder is a
`Kronecker product of different beamforming vectors associated with
`different dimensions of a multi-dimensional antenna array.
`
`44. (New) The method of claim 43, wherein the different beamforming
`vectors comprise Discrete Fourier Transform (OFT) vectors.
`
`-20-
`
`

`

`Case No. IPR2022-00464
`Patent No. 10,193,600
`Ex. 1002 at 75-77 (6/17/2016 Claims). Similar dependent claims were used in other
`
`sets of claims.
`
`The Examiner Rejects the Claims over Jing and Novlan
`
`On April 13, 2018, the USPTO Examiner rejected application claims 39, 41-
`
`42, and other claims as anticipated by U.S. Patent Publication No. 2013/0163687 to
`
`Jing (Ex. 1011). Ex. 1002 (’600 Patent File History, 4/13/2018 Office Action) at
`
`310-315. Notably, the Examiner held that Jing discloses “jointly restricts the
`
`precoders in the group by restricting a certain component that the precoders in the
`
`group have in common.” Ex. 1002 (’600 Patent File History, 4/13/2018 Office
`
`Action) at 312.
`
`The Examiner also found that claims 43 and 44 (and other similar dependent
`
`claims) would have been obvious over Jing (Ex. 1011) in view of Novlan (Ex. 1005).
`
`The Examiner found that Novlan supplies disclosure for a “beam precoder” (claim
`
`43) and for “beamforming” (claim 44). Ex. 10