Massachusetts Institute of Technology

Patent Trials and Appeals Board

May 21, 2020

14579365 - (D) (P.T.A.B. May. 21, 2020)

UNITED STATES PATENT AND TRADEMARK OFFICE
UNITED STATES DEPARTMENT OF COMMERCE
United States Patent and Trademark Office
Address: COMMISSIONER FOR PATENTS
P.O. Box 1450
Alexandria, Virginia 22313-1450
www.uspto.gov
APPLICATION NO. FILING DATE FIRST NAMED INVENTOR ATTORNEY DOCKET NO. CONFIRMATION NO.
14/579,365 12/22/2014 Swarun Suresh Kumar 70009-D37001 2285
164831 7590 05/21/2020
OCCHIUTI & ROHLICEK LLP
50 Congress Street
Suite 1000
Boston, MA 02109
EXAMINER
WINDRICH, MARCUS E
ART UNIT PAPER NUMBER
3646
NOTIFICATION DATE DELIVERY MODE
05/21/2020 ELECTRONIC
Please find below and/or attached an Office communication concerning this application or proceeding.
The time period for reply, if any, is set in the attached communication.
Notice of the Office communication was sent electronically on above-indicated "Notification Date" to the
following e-mail address(es):
INFO@ORPATENT.COM
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
BEFORE THE PATENT TRIAL AND APPEAL BOARD
Ex parte SWARUN SURESH KUMAR and DINA KATABI
Appeal 2019-001637
Application 14/579,365
Technology Center 3600
Before JENNIFER D. BAHR, JOHN C. KERINS, and
ARTHUR M. PESLAK, Administrative Patent Judges.
BAHR, Administrative Patent Judge.
DECISION ON APPEAL
STATEMENT OF THE CASE
Pursuant to 35 U.S.C. § 134(a), Appellant1 appeals from the
Examiner’s decision to reject claims 1–18. We have jurisdiction under
35 U.S.C. § 6(b).
We AFFIRM IN PART and enter a NEW GROUND OF
REJECTION.

1 We use the word “Appellant” to refer to “applicant” as defined in
37 C.F.R. § 1.42. Appellant identifies the real party in interest as
Massachusetts Institute of Technology. Appeal Br. 2.
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Application 14/579,365

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CLAIMED SUBJECT MATTER
Appellant’s invention is directed to “radio frequency localization,” for
example, “using synthetic aperture techniques, and in particular . . .
techniques in which emissions from targeted objects are not necessarily
synchronous with the receiver and/or emissions from a targeted object to the
receiver follow multiple discrete paths, such as direct path and one or more
reflected paths.” Spec. ¶ 4. Claim 1, reproduced below, is illustrative of the
claimed subject matter.
1. A method comprising:
receiving a plurality of radio transmissions from a target
device, each radio transmission of the plurality of radio
transmissions being received at a plurality of antennas at known
locations, wherein each radio transmission comprises a plurality
of components at different transmission frequencies;
processing the received radio transmissions to determine,
for each of a plurality of directions of arrival of the radio
transmissions, a characterization of a channel from the target
device, the characterization of the channel including
characterizations of the channel at the different
transmission frequencies of the components of the radio
transmissions, wherein at least one of the directions of arrival
corresponds to a reflected path from the target device to the
locations of the antenna; and
determining a most direct direction of arrival from the
plurality of directions of arrival, including computing for each
direction of arrival a quantity representing a path length from
the target using the characterization of the channel for the
direction of arrival at the different transmission frequencies,
and comparing said computed quantities to determine the most
direct direction.
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REFERENCES
The prior art relied upon by the Examiner is:
Name Reference Date
Sugar US 2012/0320787 A1 Dec. 20, 2012
Schatzberg US 2014/0094200 A1 Apr. 3, 2014
Jamieson US 2015/0234033 A1 Aug. 20, 2015
REJECTIONS
Claims 1–7, 10, 11, and 15–182 stand rejected under 35 U.S.C.
§ 102(a)(2) as anticipated by Jamieson.
Claims 8 and 9 stand rejected under 35 U.S.C. § 103 as unpatentable
over Jamieson and Sugar.
Claims 12–14 stand rejected under 35 U.S.C. § 103 as unpatentable
over Jamieson and Schatzberg.
OPINION
Anticipation—Jamieson
The Examiner finds that Jamieson discloses all of the elements of
independent claims 1 and 16. Final Act. 4–5, 7–8. Appellant argues that
Jamieson does not disclose determining a characterization of the channel for
each of a plurality of directions of arrival, the characterization “including
characterizations of the channel at the different transmission frequencies of
the components of the radio transmissions” as required in claims 1 and 16,
as well as claims 2–7, 10, 11, 15, 17, and 18, which depend from, or
incorporate all of the limitations of, claim 1. Appeal Br. 20–21.

2 Although the Examiner omits claim 15 from the statement of the rejection
on page 4 of the Final Action, the Examiner discusses claim 15 on page 7 of
the Final Action in the detailed explanation of the rejection.
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The Examiner points out that Jamieson discloses “using an
Orthogonal Frequency Division Multiplexing (OFDM) scheme,” which
“contains different frequencies and phase data.” Ans. 4 (citing Jamieson
¶¶ 17, 49). Thus, according to the Examiner, “[o]nce Jamieson receives and
processes the [OFDM] signal in paragraphs 50–51, the multiple frequencies
have been characterized.” Id.
Jamieson discloses using the repeated long training signals S0 and S1
of the 802.11 OFDM preamble to perform the angle of arrival (AoA)
spectrum computation. Jamieson ¶¶ 52–53, 55. Jamieson’s “system detects
the preamble of the packet and records a small part of it.” Id. ¶ 53
(disclosing using 10 samples, which is less than 1.5% of the duration of the
preamble). Long training signal S0 is received at antenna set 52A, and long
training signal S1 is received at antenna set 52B. Id. ¶ 55. Signals S0 and
S1 fall well within the coherence time of the wireless channel (i.e., the span
of time over which the channel, based on the RF carrier frequency and speed
of motion of transmitters, receivers, and nearby objects, can be considered
stationary). Id. Thus, “the information obtained from each set of antennas
52A, 52B can be treated as if the two respective sets of information [were]
obtained simultaneously from different radios at the AP” (i.e., access point).
Id. Jamieson generates an AoA spectrum, which “is an estimate of incoming
power of the signal as a function of angle of arrival, as shown in” Figure 3.
Id. ¶ 56.
Jamieson does not expressly indicate that training signals S0 and S1of
the OFDM preamble are obtained over different carrier frequencies, rather
than a common carrier frequency, for the preamble. Nevertheless, even
assuming that samples of signals S0 and S1 are obtained at different
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frequencies to produce an AoA spectrum, thereby hypothetically generating
incoming power values for different angles of arrival in the spectrum at
different frequencies, the Examiner does not point to any disclosure in
Jamieson that indicates that Jamieson’s system determines, for each of a
plurality of directions of arrival, a characterization which itself includes
characterizations at different transmission frequencies.
For the above reasons, we do not sustain the rejection of claims 1–7,
10, 11, and 15–18 as anticipated by Jamieson.
Obviousness—Jamieson and Sugar
Claim 8
Claim 8, which depends indirectly from claim 1, recites that
“determining the quantity representing the path length includes determining
a quantity characterizing a relationship between the phase response and the
frequency at each of the different transmission frequencies.” Appeal Br. 38
(Claims App.). The Examiner finds that Jamieson “does not expressly
disclose a relationship between phase response and frequency at each
transmission frequency,” but finds that “Sugar teaches angle of arrival
calculations using relationships between phase and frequency differences.”
Final Act. 9 (citing Sugar, Abstract, Fig. 8). The Examiner determines it
would have been obvious “to use frequency and phase relationships in order
to gain the benefit of improving the analysis, including when the device is
moving as taught by Jamieson.” Id. (citing Jamieson ¶ 11).
Sugar teaches receiving two or more data packets from two or more
sequential transmissions at different center frequencies and estimating time
differences and/or carrier differences among the two or more transmissions.
Sugar, Abstract, Fig. 8.
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Appellant does not specifically contest the Examiner’s combination of
Jamieson and Sugar. Rather, Appellant acknowledges that “Sugar discusses
estimating time differences and/or carrier phase differences among two or
more transmissions (with different carrier frequencies),” but contends that
“such time or carrier-phase difference is not the same as determining a phase
response of a channel (much less the phase response as at each of different
frequencies).” Appeal Br. 27; see also Reply Br. 11–12. However, it is not
immediately apparent, and Appellant does not explain with sufficient clarity
and specificity, why a phase difference is not a “phase response,” even as
defined in footnote 2 on pages 27–28 of the Appeal Brief. Further, Sugar
estimates a phase difference for each of the one or more transmissions,
which have different carrier frequencies.
For the above reasons, Appellant does not apprise us of error in the
rejection of claim 8 as unpatentable over Jamieson and Sugar, which we,
thus, sustain.
Claims 1, 5, and 7—New Ground of Rejection
A determination of obviousness of the subject matter of a dependent
claim also inherently subsumes therewithin a determination of obviousness
of the subject matter of any broader claim from which the dependent claim
depends or otherwise incorporates all limitations. See Ormco Corp. v. Align
Tech. Inc., 498 F.3d 1307, 1319 (Fed. Cir. 2007) (when a dependent claim is
“found to have been obvious, the broader claims . . . must also have been
obvious”). Thus, the determination of obviousness of the subject matter of
claim 8 also inherently subsumes a determination that the subject matter of
claims 1, 5, and 7, all of the limitations of which claim 8 incorporates by its
dependence, would have been obvious. See Appeal Br. 38 (Claims App.).
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Accordingly, pursuant to the principle of Ormco, and our authority under
37 C.F.R. § 41.50(b), we enter a new ground of rejection of claims 1, 5, and
7 under 35 U.S.C. § 103 as unpatentable over Jamieson and Sugar.
Claim 9
The Examiner finds that Jamieson as modified in view of Sugar, as
discussed above, satisfies the limitation “wherein the quantity characterizing
a relationship between the phase response and the frequency comprises a
quantity characterizing rate of change of phase response as a function of
frequency” in claim 9. Final Act. 10 (citing Jamieson ¶ 11; Sugar, Abstract,
Fig. 8). We agree with Appellant that the cited portions of Jamieson and
Sugar do not discuss “a quantity characterizing rate of change of phase
response as a function of frequency.” Appeal Br. 29–30. Thus, we do not
sustain the rejection of claim 9 as unpatentable over Jamieson and Sugar.
Obviousness—Jamieson and Schatzberg
Claim 12
Claim 12 depends from claim 1 and further recites that “receiving and
processing the plurality of radio transmissions from a target device at the
plurality of antennas at known locations includes applying a Synthetic
Aperture Radar (SAR) approach.” Appeal Br. 39 (Claims App.). The
Examiner finds that Jamieson fails to disclose using an SAR technique.
Final Act. 10. The Examiner finds that “Schatzberg teaches location
determination including a moving antenna,” and determines it would have
been obvious “to use a moving antenna in order to gain the benefit of
improving multipath detection as taught by Jamieson wherein there is
movement of the receiver.” Id. (citing Schatzberg ¶¶ 16–17; Jamieson ¶ 73).
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Appellant argues that Schatzberg “does not discuss or even mention
the SAR approach.” Appeal Br. 31.
The Examiner responds by explaining that, according to a “broadest
reasonable interpretation” of “Synthetic Aperture Radar (SAR) approach,”
“[a]ccounting for antenna movement when receiving [and] analyzing signals
is a synthetic aperture radar approach.” Ans. 8. Appellant argues, and we
agree, that this is an “overly broad” interpretation of “Synthetic Aperture
Radar (SAR) approach” in light of Appellant’s Specification. Reply Br. 12.
Appellant disputes the Examiner’s finding that Schatzberg discloses a
moving antenna. Id. at 13. Nevertheless, even assuming Schatzberg does
disclose a moving antenna, Appellant contends that disclosure of “a moving
antenna does not mean that Schatzberg discloses an SAR approach.” Id. at
13.
Appellant’s Specification provides insight as to what is meant by
“applying a Synthetic Aperture Radar (SAR) approach” within the context
of Appellant’s invention. See Spec. ¶¶ 5, 47, 52, 59, 64, 68. An SAR
approach uses an antenna that moves relative to the target as it receives
signals from the target, thereby receiving the transmissions at different
locations and creating a synthetic aperture with the movement. Id. ¶¶ 5, 47.
In conventional SAR, the radio signal is transmitted from the antenna toward
the target and then reflected from the target and received at the antenna. Id.
The radio signal that is transmitted is generated by a clock signal that is also
used in processing the received reflected signal, thereby affording the
advantage that the relative phase of the transmitted signal and the received
signal can be used to provide range information. Id. ¶ 47. “In the
application of localization of independent transmitting devices (e.g., LTE or
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WiFi devices), the receiver of the [signal emitted] from the transmitting
devices does not share a common clock or oscillator” with the transmitting
device. Id. “[T]herefore the reception of the signal does not provide range
information in the same manner as is available in conventional SAR
techniques.” Id. However, Appellant’s invention uses the moving antenna,
as in conventional SAR, in combination with a fixed antenna, to determine
the most direct direction of arrival of the emitted signal, using computation
analogous to that used in SAR receivers, as disclosed in paragraphs 52, 59,
64, and 68 of the Specification. Thus, in light of Appellant’s Specification,
we construe “receiving and processing the plurality of radio transmissions
. . . applying a Synthetic Aperture Radar (SAR) approach” to mean using at
least a moving antenna and the computations discussed in paragraphs 52, 59,
64, and 68.
The Examiner’s conclusion of obviousness is flawed because it is
predicated on an unreasonable and overly broad interpretation of “receiving
and processing the plurality of radio transmissions . . . applying a Synthetic
Aperture Radar (SAR) approach.” The portions of Schatzberg and Jamieson
cited by the Examiner do not mention using an SAR approach as described
in Appellant’s Specification. Schatzberg uses movement sensors,
orientation sensors, and directional sensors fixed or strapped to a user’s body
to assist in tracking the location of the user. Schatzberg ¶¶ 4, 16–17.
Paragraph 73 of Jamieson, cited by the Examiner, mentions leveraging
movements of the transmitter or nearby objects by making use of the
observation that the direct-path peak on the AoA spectrum is usually stable
when there are small movements of the transmitter, the receiver, or objects
between the two, while the reflection-path peaks usually change
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significantly with such movements. It is not apparent, and the Examiner
makes no attempt to explain, why these teachings, whether taken together or
in combination, would have prompted one of ordinary skill in the art to
apply an SAR approach as construed in accordance with Appellant’s
Specification.
Moreover, the Examiner’s application of Schatzberg in rejecting claim
12 does not appear to cure the aforementioned deficiency of the rejection of
claim 1 as anticipated by Jamieson.
Accordingly, for both of these reasons, we do not sustain the rejection
of claim 12 as unpatentable over Jamieson and Schatzberg.
Claims 13 and 14
The Examiner’s application of Schatzberg in rejecting claims 13 and
14, which depend from claim 1, does not cure the aforementioned deficiency
of the rejection of claim 1 as anticipated by Jamieson. See Final Act. 10–11
(proposing to modify Jamieson by using a moving antenna, as taught by
Schatzberg, and concluding that this combination would render obvious the
subject matter of claims 13 and 14). Accordingly, we do not sustain the
rejection of claims 13 and 14 as unpatentable over Jamieson and Schatzberg.
DECISION SUMMARY
In summary:
Claims
Rejected
35
U.S.C. §
Reference(s)/Basis Affirmed Reversed New
Ground
1–7, 10,
11, 15–18
102(a)(2) Jamieson 1–7, 10,
11, 15–18

8, 9 103 Jamieson, Sugar 8 9 1, 5, 7
12–14 103 Jamieson,
Schatzberg
12–14
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Overall
Outcome
8 1–7, 9–18 1, 5, 7

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FINALITY OF DECISION
This decision contains a new ground of rejection pursuant to
37 C.F.R. § 41.50(b). 37 C.F.R. § 41.50(b) provides “[a] new ground of
rejection pursuant to this paragraph shall not be considered final for judicial
review.” 37 C.F.R. § 41.50(b) also provides:
When the Board enters such a non-final decision, the appellant,
within two months from the date of the decision, must exercise
one of the following two options with respect to the new ground
of rejection to avoid termination of the appeal as to the rejected
claims:
(1) Reopen prosecution. Submit an appropriate
amendment of the claims so rejected or new Evidence relating
to the claims so rejected, or both, and have the matter
reconsidered by the examiner, in which event the prosecution
will be remanded to the examiner. The new ground of rejection
is binding upon the examiner unless an amendment or new
Evidence not previously of Record is made which, in the
opinion of the examiner, overcomes the new ground of rejection
designated in the decision. Should the examiner reject the
claims, appellant may again appeal to the Board pursuant to this
subpart.
(2) Request rehearing. Request that the proceeding be
reheard under § 41.52 by the Board upon the same Record. The
request for rehearing must address any new ground of rejection
and state with particularity the points believed to have been
misapprehended or overlooked in entering the new ground of
rejection and also state all other grounds upon which rehearing
is sought.
Further guidance on responding to a new ground of rejection can be
found in the Manual of Patent Examining Procedure § 1214.01.
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TIME PERIOD FOR RESPONSE
No time period for taking any subsequent action in connection with
this appeal may be extended under 37 C.F.R. § 1.136(a). See 37 C.F.R.
§ 1.136(a)(1)(iv).
AFFIRMED IN PART; 37 C.F.R. § 41.50(b)