NXP USA Inc. v. MediaTek Inc. et al

Filing 196

CLAIM CONSTRUCTION MEMORANDUM OPINION AND ORDER. Signed by Magistrate Judge Roy S. Payne on 5/9/2022. (nkl, )

Case 2:21-cv-00318-JRG Document 196 Filed 05/09/22 Page 1 of 14 PageID #: 3131

IN THE UNITED STATES DISTRICT COURT
FOR THE EASTERN DISTRICT OF TEXAS
MARSHALL DIVISION
NXP USA, INC.,
Plaintiff,
v.
MEDIATEK INC., MEDIATEK USA, INC.,
AMAZON.COM INC., and
BEST BUY CO., INC.,
Defendants.

§
§
§
§
§
§
§
§
§
§
§

Case No. 2:21-CV-00318-JRG

CLAIM CONSTRUCTION MEMORANDUM OPINION AND ORDER
In this patent case, Plaintiff NXP USA, Inc., asserts claims from two wirelesscommunications patents against Defendants Mediatek, Inc., Mediatek USA, Inc., Amazon.com,
Inc., and Best Buy Co., Inc. U.S. Patent 10,742,780 (the “’780 Patent”) relates “to parsing and
encoding methods in wireless communications systems.” ’780 Patent at 1:29–31. U.S. Patent
10,560,158 (the “’158 Patent”) concerns “wireless local area networks that utilize orthogonal
frequency division multiple access (OFDMA),” ’158 Patent at 1:21–24. OFDMA is a digital
modulation scheme that allows simultaneous transmission from multiple clients to an access
point. Id. at 3:2–11.
The parties dispute the scope of one term from each patent. From the ’780 Patent,
Defendants challenge the phrase “minimum number of encoders” as indefinite. Plaintiff counters
that Defendants have “plucked” the term from the proper context “to create a false appearance of
‘indefiniteness.’” Dkt. No. 115 at 1. From the ’158 Patent, Defendants urge a particular
construction for “trigger information portion,” which refers to a portion of a data unit transmitted
from a network access point to clients. Plaintiff, however, asserts the phrase need not be given a

1

Case 2:21-cv-00318-JRG Document 196 Filed 05/09/22 Page 2 of 14 PageID #: 3132

specific construction—that is, “plain and ordinary meaning” will suffice.
Having considered the parties’ briefing, along with arguments of counsel during an
April 14, 2022 hearing, the Court resolves the disputes as follows.
I.

LEGAL STANDARDS
A.

Generally

“‘[T]he claims of a patent define the invention to which the patentee is entitled the right
to exclude.’” Phillips v. AWH Corp., 415 F.3d 1303, 1312 (Fed. Cir. 2005) (en banc) (quoting
Innova/Pure-Water, Inc. v. Safari Water Filtration Sys., Inc., 381 F.3d 1111, 1115 (Fed. Cir.
2004)). As such, if the parties dispute the scope of the claims, the court must determine their
meaning. See, e.g., Verizon Servs. Corp. v. Vonage Holdings Corp., 503 F.3d 1295, 1317 (Fed.
Cir. 2007); see also Markman v. Westview Instruments, Inc., 517 U.S. 370, 390 (1996), aff’g, 52
F.3d 967, 976 (Fed. Cir. 1995) (en banc).
Claim construction, however, “is not an obligatory exercise in redundancy.” U.S. Surgical
Corp. v. Ethicon, Inc., 103 F.3d 1554, 1568 (Fed. Cir. 1997). Rather, “[c]laim construction is a
matter of [resolving] disputed meanings and technical scope, to clarify and when necessary to
explain what the patentee covered by the claims . . . .” Id. A court need not “repeat or restate
every claim term in order to comply with the ruling that claim construction is for the court.” Id.
When construing claims, “[t]here is a heavy presumption that claim terms are to be given
their ordinary and customary meaning.” Aventis Pharm. Inc. v. Amino Chems. Ltd., 715 F.3d
1363, 1373 (Fed. Cir. 2013) (citing Phillips, 415 F.3d at 1312–13). Courts must therefore “look
to the words of the claims themselves . . . to define the scope of the patented invention.” Id.
(citations omitted). “[T]he ordinary and customary meaning of a claim term is the meaning that
the term would have to a person of ordinary skill in the art in question at the time of the

2

Case 2:21-cv-00318-JRG Document 196 Filed 05/09/22 Page 3 of 14 PageID #: 3133

invention, i.e., as of the effective filing date of the patent application.” Phillips, 415 F.3d at 1313.
This “person of ordinary skill in the art is deemed to read the claim term not only in the context
of the particular claim in which the disputed term appears, but in the context of the entire patent,
including the specification.” Id.
Intrinsic evidence is the primary resource for claim construction. See Power-One, Inc. v.
Artesyn Techs., Inc., 599 F.3d 1343, 1348 (Fed. Cir. 2010) (citing Phillips, 415 F.3d at 1312). For
certain claim terms, “the ordinary meaning of claim language as understood by a person of skill
in the art may be readily apparent even to lay judges, and claim construction in such cases
involves little more than the application of the widely accepted meaning of commonly
understood words.” Phillips, 415 F.3d at 1314; see also Medrad, Inc. v. MRI Devices Corp., 401
F.3d 1313, 1319 (Fed. Cir. 2005) (“We cannot look at the ordinary meaning of the term . . . in a
vacuum. Rather, we must look at the ordinary meaning in the context of the written description
and the prosecution history.”). But for claim terms with less-apparent meanings, courts consider
“‘those sources available to the public that show what a person of skill in the art would have
understood disputed claim language to mean[,] [including] the words of the claims themselves,
the remainder of the specification, the prosecution history, and extrinsic evidence concerning
relevant scientific principles, the meaning of technical terms, and the state of the art.’” Phillips,
415 F.3d at 1314 (quoting Innova, 381 F.3d at 1116).
B.

Indefiniteness

“[A] patent is invalid for indefiniteness if its claims, read in light of the specification
delineating the patent, and the prosecution history, fail to inform, with reasonable certainty, those
skilled in the art about the scope of the invention.” Nautilus, Inc. v. Biosig Instruments, Inc., 572
U.S. 898, 901 (2014). “A patent must be precise enough to afford clear notice of what is

3

Case 2:21-cv-00318-JRG Document 196 Filed 05/09/22 Page 4 of 14 PageID #: 3134

claimed,” but that consideration must be made while accounting for the inherent limitations of
language. Id. at 908–09. “Indefiniteness must be proven by clear and convincing evidence.”
Sonix Tech. Co. v. Publ’ns Int’l, Ltd., 844 F.3d 1370, 1377 (Fed. Cir. 2017).
II.

THE LEVEL OF ORDINARY SKILL IN THE ART
The level of ordinary skill in the art is the skill level of a hypothetical person who is

presumed to have known the relevant art at the time of the invention. In re GPAC, 57 F.3d 1573,
1579 (Fed. Cir. 1995). In resolving the appropriate level of ordinary skill, courts consider the
types of and solutions to problems encountered in the art, the speed of innovation, the
sophistication of the technology, and the education of workers active in the field. Id. Importantly,
“[a] person of ordinary skill in the art is also a person of ordinary creativity, not an automaton.”
KSR Int’l Co. v. Teleflex Inc., 550 U.S. 398, 421 (2007).
The parties generally agree on the level of ordinary skill in the art at the time of
invention. 1 Plaintiff’s expert asserts a skilled artisan would have had “an undergraduate degree in
electrical engineering, computer science, or an equivalent field, and . . . at least 3 years of
experience in the field of wireless communications.” Ding Decl., Dkt. No. 115-4 ¶ 19.
Defendants’ expert opines a skilled artisan “would have had a bachelor’s degree in electrical
engineering or a similar field and two or more years of experience with wireless communication
networks, such as local area networks.” Bims Decl., Dkt. No. 133-1 ¶ 19. Neither party suggests
the Court must resolve the differences between these proffered skill levels to arrive at the correct
constructions.
1

The ’780 Patent stems from an application claiming the benefit of provisional application nos.
61/678,531 (filed Aug. 1, 2012) and 61/390,971 (filed Oct. 7, 2010). ’780 Patent at [63]. The Office granted the ’158 Patent from an application claiming priority to application no. 15/380,795
(filed Dec. 15, 2016). ’158 Patent at [63].

4

Case 2:21-cv-00318-JRG Document 196 Filed 05/09/22 Page 5 of 14 PageID #: 3135

III.

THE DISPUTED TERMS
A.

“minimum number of encoders” (’780 Patent, Claims 1, 7–9, 12, 15–17)
Plaintiff’s Construction

Defendants’ Construction

Not indefinite.

Indefinite.
1.

The ’780 Patent

The ’780 Patent teaches enabling the use of certain modulation and coding schemes
(MCSs) with system configurations not otherwise intended to be used with such schemes. If an
MCS violates a particular system’s constraints on parsing or coding techniques, that MCS cannot
be used with the system. See ’780 Patent at 3:39–43. The patent teaches altering otherwise
invalid parsing rules and/or coding techniques of the MSC to accommodate these system
configurations. See id. at 3:47–50.
For example, the patent describes one constraint—“the integer NDBPS/NES constraint”—
that requires equal encoder parsing. This means the number of data bits per OFDM symbol 2
(NDBPS) divided by the number of encoders used by the system (NES) must be an integer. An
MCS that violates this constraint, if required by a particular system configuration, will be
excluded. See generally ’780 Patent at 8:34–47.
The Summary describes four embodiments—two methods and two devices—concerning
this constraint. Each summarized method describes generating a data unit with coded bits and
then, if necessary, padding the data unit to ensure it corresponds to the encoding parameters of
the system. ’780 Patent at 1:56–2:3; see also id. at 2:19–32. Each summarized apparatus has a
network interface that implements an embodiment of the method. Id. at 2:4–18; id. at 2:33–46.
2

An OFDM symbol is essentially an electromagnetic waveform that can be deconstructed into
information.

5

Case 2:21-cv-00318-JRG Document 196 Filed 05/09/22 Page 6 of 14 PageID #: 3136

The ’780 Patent has two independent claims directed to “the integer NDBPS/NES
constraint.” Claim 1 recites a network interface configured to:
receive a plurality of information bits to be included in a physical
layer (PHY) data unit for transmission via a communication
channel,
determine a number NES of encoders for encoding the plurality of
information bits for transmission at a particular data rate using
frequency division multiplexing (OFDM), [and]
prior to encoding the information bits, add a number of padding
bits to the information bits, wherein the number of padding bits
is determined based on the determined number NES of
encoders[.]
’780 Patent at 23:20–40. Later in the “determining” step, the claim ensures “the integer
NDBPS/NES constraint” will be satisfied by requiring that
[if the] number NDBPS of information bits per OFDM
symbol . . . divided by a minimum number of encoders, operating
at a particular coding rate, required for encoding the plurality of
information bits . . . is a non-integer value, the number NES of
encoders is selected as a number that i) is greater than the
minimum number of encoders and ii) satisfies a constraint that
NDBPS/NES is an integer value[.]
Id. at 23:26–36 (emphasis added). Method Claim 12 recites (1) performing these same three
steps, (2) adding padding bits to the information bits based on the determined number of
encoders (NES), and (3) encoding the information bits. Id. at 24:33–57.
2.

The Dispute: Definiteness of “Minimum Number of Encoders”

Defendants allege a skilled artisan would not know how to determine the required
“minimum number of encoders.” For one, they base their challenge on the lack of any
information about this term in the specification. Dkt. No. 133 at 6–7. They also cite an excerpt
suggesting the number of encoders can be decremented, stressing “[i]f the number of encoders
can be decremented, the network interface did not have a ‘minimum’ number of encoders to

6

Case 2:21-cv-00318-JRG Document 196 Filed 05/09/22 Page 7 of 14 PageID #: 3137

begin with.” Id. at 7 (citing ’780 Patent at 19:57–60). And “[t]o make things more difficult,”
claim Defendants, “[t]he different encoding rates and other parameters, such as the number of
spatial streams, affect the number of encoders in a network interface,” so a skilled artisan could
not know the minimum number of encoders without additional information not specified in the
claims. Id.
According to Plaintiff, Defendants’ position “ignores considerable evidence to the
contrary” from the intrinsic record. Dkt. No. 115 at 5. Plaintiff notes the disputed phrase “is
surrounded by descriptive language that infuses the term with meaning,” and argues Defendants
have ignored that context. Id. at 5. Specifically, Plaintiff stresses the claims’ recitation of a
“particular coding rate” removes any ambiguity inherent in the term. Id. at 5–6. Plaintiff also
cites language from the specification, dependent claims, and the related provisional application
as showing “examples of specific calculations” for the “minimum number of encoders.” Id. at 6–
8.
Contrary to Defendants’ assertion, a skilled artisan would understand the scope of this
term with reasonable certainty. Starting with the claim language, Defendants’ position ignores
that the minimum number of encoders depends on a “particular coding rate.” That encoders
might have many different “coding rates” is immaterial, because the claims differentiate between
embodiments based on “particular coding rates.” The excerpt on which Defendants rely simply
explains that the number of encoders can be decremented relative to other embodiments
of the invention.
Concerning Defendants’ contention that a skilled artisan would need to know additional
information, such as the number of spatial streams or constellation size, to determine the
minimum number of encoders, the claim language suggests otherwise. The claims recite only

7

Case 2:21-cv-00318-JRG Document 196 Filed 05/09/22 Page 8 of 14 PageID #: 3138

that the “minimum number of encoders” is the number required for “encoding the information
bits.” They do not, for example, recite “the minimum number of encoders required for encoding
the plurality of information bits into X spatial streams.” Although Defendants correctly suggest
the number of coded bits in an OFDM symbol might depend on the constellation size or number
of spatial streams, Dkt. No. 133 at 7 (citing Bims Decl., Dkt. No. 133-1 ¶ 67), the claims already
account for those parameters because the number of information bits per symbol (NDBPS) is a
given in the “determining” step. See id. at 23:26–27.
Defendants’ criticisms of Plaintiff’s position are based on two allegedly incorrect
assumptions by Plaintiff. First, say Defendants, Plaintiff wrongly assumes “coding rate,” as used
in the claims at issue, refers to the speed (i.e., throughput) of encoders. They note, correctly, the
specification describes the “coding rate” as the ratio of information bits to total encoded bits per
symbol. Dkt. No. 133 at 9 (citing ’780 Patent at 8:18–47, 9:22–12:58, fig.3). According
to Defendants, a skilled artisan would have understood that meaning of “coding rate” and at
least “been confused by the inconsistency” of using that term in the claims. Id. at 10.
But this is not a persuasive critique. A skilled artisan would understand “coding rate” in
the claims in the context of the surrounding language. That context shows the encoder “operates”
at a “coding rate” and is “for encoding the plurality of information bits for transmission.” ’780
Patent at 23:29–31. From this language alone, the meaning of “coding rate” in the claims is clear,
and it pertains to throughput. See id. at 24:11–14 (limiting, in Claim 9, the “coding rate” of
each encoder to a throughput of 600 Mbps). Moreover, a skilled artisan would understand that
“coding rate” as used in the specification—that is, the ratio of information bits to total
encoded bits—has no applicability to this claim language.
Second, Defendants criticize Plaintiff’s position as assuming all encoders have the same

8

Case 2:21-cv-00318-JRG Document 196 Filed 05/09/22 Page 9 of 14 PageID #: 3139

speed of 600 Mbps. Dkt. No. 133 at 9. Plaintiff replies that it makes no such assumptions, and
that its brief simply cites examples from the specification. Dkt. No. 142 at 5. The Court agrees
with Plaintiff: Nothing in Plaintiff’s opening brief assumes all encoders operate at the same
speed. See Dkt. No. 115 at 6 (noting “[e]xamples of how to compute this minimum quantity are
provided in the specification”).
Given the context of the surrounding language, Defendants have not carried their burden
of showing a skilled artisan would not understand the scope of this term with reasonable
certainty. Accordingly, the term is not indefinite.
B.

“trigger information portion” (’158 Patent, Claims 1, 2, 4, 12, 13, 15)

Plaintiff’s Construction
Plain and ordinary meaning.

1.

Defendants’ Construction
“fields that include information for one or more of the second
communication devices to receive the trigger frame and that
include the length or duration of one or more of those fields”

U.S. Patent 10,560,158

The ’158 Patent relates to wireless communication networks that allow simultaneous
uplink transmissions from multiple clients to an access point. ’158 Patent at [57]. To facilitate
this communication, the access point broadcasts a data unit that includes a “trigger frame” to
trigger the simultaneous uplink transmissions. Id. The method teaches generating a trigger frame
that includes a “padded portion” of a length that depends on the time-duration requirements of
the clients. Id. at 1:50–55. Padding the trigger frame helps ensure sufficient time for the client
stations to prepare for the uplink transmissions. Id. at 11:63–12:5.
FIG. 10 (below) shows an exemplary trigger frame 1000, which includes a frame control
field 1002, a duration/ID 1004, receiver and transmitter addresses, 1006, 1008, a frame body
1020, and a frame check field 1022. The frame body 1020 includes a trigger length 1048,

9

Case 2:21-cv-00318-JRG Document 196 Filed 05/09/22 Page 10 of 14 PageID #: 3140

common information 1050, per-user/group subfields 1052, and a padding portion 1054. The
trigger length 1048 indicates the length or duration of the common information 1050 and the peruser/group subfields 1052. See generally ’158 Patent at 17:20–43.

FIG. 10 of the ’158 Patent
Like the ’780 Patent, the ’158 Patent includes two independent claims—a method claim
and an apparatus configured to implement similar steps. Claim 1 recites:
1. A method for communicating in a wireless communication
network, the method comprising:
determining, at a first communication device, respective time
duration requirements for preparing uplink transmissions
by multiple second communication devices as part of an
uplink multi-user (MU) transmission;
generating, at the first communication device, a physical layer
(PHY) data unit that includes a trigger frame, wherein the
trigger frame is for triggering simultaneous uplink
transmissions by multiple second communication devices
as part of the uplink MU transmission, wherein the trigger
frame includes a trigger information portion, and wherein
the PHY data unit is generated such that a duration between
transmission of an end of the trigger information portion
and transmission of an end of the PHY data unit is
sufficient to satisfy the respective time duration

10

Case 2:21-cv-00318-JRG Document 196 Filed 05/09/22 Page 11 of 14 PageID #: 3141

requirements of the multiple second communication
devices;
transmitting, with the first communication device, the PHY
data unit; and
receiving, at the first communication device, the simultaneous
uplink transmissions, triggered by the trigger frame, from
the multiple second communication devices.
’158 Patent at 24:56–25:12 (emphasis added). Independent Claim 12 recites a “wireless network
interface” configured to implement similar steps. Id. at 26:20–44.
2.

The Dispute

The parties dispute the scope of “trigger information portion.” Defendants claim the term
is coined, and the specification provides its meaning when describing FIGS. 10 and 11. Dkt. No.
133 at 12, 15–19. Plaintiff, however, suggests “plain and ordinary meaning” will suffice. Dkt.
No. 115 at 12–15.
The parties’ dispute became more focused at the hearing. Before the hearing, the Court
proposed a preliminary construction of “portion of a trigger frame containing information that
can trigger a simultaneous uplink transmission by the second communication device.”
Defendants generally accepted that preliminary construction, but suggested it should contemplate
both “preparing and triggering” the simultaneous transmissions. 3 Moreover, Defendants
suggested that a trigger length, such as the trigger length 1048 in FIGS. 10 and 11, are
encompassed within the concept of “preparing.” This is consistent with their proposed
construction from the briefing, which requires “the length or duration” of other fields. Plaintiff
countered that “preparing” was redundant to “triggering,” and criticized Defendants’ attempt to
expressly include a length or duration in the construction as unnecessary. In short, Plaintiff
3

Specifically, Defendants suggested, as the proper construction, “portion of a trigger frame containing information for preparing and triggering a simultaneous uplink transmission by the second communication device.”

11

Case 2:21-cv-00318-JRG Document 196 Filed 05/09/22 Page 12 of 14 PageID #: 3142

contends “trigger information portion” includes the information that triggers the stations’
simultaneous transmission, whereas Defendants suggest it includes any trigger-related
information. See Dkt. No. 133 at 18 (suggesting a skilled artisan “would also have understood
‘Effective Trigger Length’ field 1048 to be part of the ‘trigger information portion’ because it is
also an information field related to the trigger of the client stations” (emphasis added)); see also
id. (“In that way it provides trigger-related information about the common and per-user/group
information fields 1050 and 1052.” (emphasis added)).
Although neither “trigger information” nor “trigger information portion” appear in the
specification outside of the claims, the specification refers to “trigger frame” ubiquitously. The
Abstract, for example, explains the patent is directed to “[a] method for communicating in a
wireless communication network” in which
a trigger frame is generated to trigger simultaneous uplink transmissions by
multiple communication devices. The trigger frame includes a padding portion
having a length determined based on respective time duration requirements of the
multiple communication devices, the respective time duration requirements for
preparing uplink transmission by the corresponding second communication
devices. The trigger frame is transmitted to the multiple communication devices.
The simultaneous uplink transmissions, triggered by the trigger frame, are
received from the multiple communication devices.
’158 Patent at [57] (emphasis added). With reference to FIGS. 3A–3C, which show exemplary
data units, the patent explains
the data portion 304 includes a trigger frame that triggers uplink OFDMA
transmission by a plurality of client stations 25. In an embodiment, the trigger
frame includes information that indicates allocation of subchannels to be used for
uplink OFDMA transmission, in an embodiment. The trigger frame further
indicates other transmission parameters to the multiple client stations 25, such as
which modulation and coding scheme (MCS) each of the multiple client stations
25 should use, the OFDM numerology (e.g., guard interval, tone spacing, etc.)
that each of the multiple client stations should use, transmit power that each of the
multiple client stations 25 should use, etc.

12

Case 2:21-cv-00318-JRG Document 196 Filed 05/09/22 Page 13 of 14 PageID #: 3143

’158 Patent at 8:48–59 (emphasis added).
Based on these excerpts, Defendants’ construction is too narrow. For one, they arrive at
their construction from FIGS. 10–11, which are each “a block diagram of a [trigger]
frame . . . according to an embodiment.” Id. at 2:36–37 (emphasis added); see also id. at 2:38–39
(same). Moreover, initiating simultaneous transmissions is different than “preparing” for those
transmissions and does not inherently require a field length or duration. In embodiments with
predetermined frame lengths, for example, there may be no need to communicate lengths or
durations of the trigger frame, but the client stations will nonetheless be “triggered.” The Court
finds no reason to exclude such embodiments from the scope of the claims, as Defendants’
construction would do.
The point of the invention is not what makes up the “trigger information,” but the clients’
“decision” to simultaneously transmit based on information received from the access point.
While the “trigger information” could also be “preparation information” (e.g., the allocation of
subchannels or the modulation and coding scheme), the claims do not require that. Accordingly,
the Court construes “trigger information portion” as “portion of a trigger frame containing
information that can trigger simultaneous uplink transmissions by the second communication
devices.”

13

Case 2:21-cv-00318-JRG Document 196 Filed 05/09/22 Page 14 of 14 PageID #: 3144

IV.

CONCLUSION
Term

The Court’s Construction

“minimum number of encoders”

Not indefinite.

“trigger information portion”

“portion of a trigger frame containing information
that can trigger simultaneous uplink transmissions
by the second communication devices”

.

The Court ORDERS each party not to refer, directly or indirectly, to its own or any other
party’s claim-construction positions in the presence of the jury. Likewise, the Court ORDERS
the parties to refrain from mentioning any part of this opinion, other than the actual positions
adopted by the Court, in the presence of the jury. Neither party may take a position before the
jury that contradicts the Court’s reasoning in this opinion. Any reference to claim construction
proceedings is limited to informing the jury of the positions adopted by the Court.
SIGNED this 3rd day of January, 2012.
SIGNED this 9th day of May, 2022.

____________________________________
ROY S. PAYNE
UNITED STATES MAGISTRATE JUDGE

14