George Jöngren et al.

Patent Trials and Appeals Board

Aug 2, 2019

14925418 - (D) (P.T.A.B. Aug. 2, 2019)

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.
14/925,418 10/28/2015 George Jöngren 1009-1588 / P33784 US3 5138
102721 7590 08/02/2019
Murphy, Bilak & Homiller/Ericsson
1255 Crescent Green
Suite 200
Cary, NC 27518
EXAMINER
LY, ANH VU H
ART UNIT PAPER NUMBER
2472
NOTIFICATION DATE DELIVERY MODE
08/02/2019 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):
official@mbhiplaw.com
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
________________

BEFORE THE PATENT TRIAL AND APPEAL BOARD
________________

Ex parte GEORGE JÖNGREN, LARS LINDBOM, and
STEFAN PARKVALL
________________

Appeal 2017-010634
Application 14/925,418
Technology Center 2400
________________

Before ALLEN R. MacDONALD, JEREMY J. CURCURI, and
KERRY BEGLEY, Administrative Patent Judges.

CURCURI, Administrative Patent Judge.

DECISION ON APPEAL
Appellants appeal under 35 U.S.C. § 134(a) from the Examiner’s
rejection of claims 1–12. Final Act. 1. We have jurisdiction under 35 U.S.C.
§ 6(b).
Claims 1–10 and 12 are rejected under pre-AIA 35 U.S.C. § 103(a) as
obvious over Yoo (US 2012/0087261 A1; published Apr. 12, 2012), Cai (US
2010/0323684 A1; published Dec. 23, 2010), and Liu (US 2010/0173660
A1; published July 8, 2010). Final Act. 4–7.
Claim 11 is rejected under pre-AIA 35 U.S.C. § 103(a) as obvious
over Yoo, Cai, Liu, and Barbieri (US 2012/0076025 A1; published Mar. 29,
2012). Final Act. 7–8.
We reverse.
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STATEMENT OF THE CASE
Appellants’ invention relates to “techniques for allocating reference
signals to carrier resources in [wireless communication] networks.” Spec.
¶ 2. Claim 1 is illustrative and reproduced below:
1. A method for transmitting data to a mobile station,
the method comprising
transmitting cell-specific reference symbol (CRS) signals
from a primary, high-power, transmitting node having a first
coverage area;
transmitting the same CRS signals from each of two or
more secondary, low-power, transmitting nodes, each of the
secondary transmitting nodes having a coverage area that is
within or substantially within the first coverage area; and
simultaneously transmitting a physical downlink data
channel to a mobile station from the primary, high-power,
transmitting node and from at least one of but fewer than all of
the two or more secondary, low-power, transmitting nodes,
wherein said at least one but fewer than all of the two or more
secondary, low-power, transmitting nodes is selected based on a
determination of whether the physical downlink data channel
transmissions from each secondary transmitting node could be
received by the mobile station with adequate signal strength.

PRINCIPLES OF LAW
We review the appealed rejections for error based upon the issues
identified by Appellants, and in light of the arguments and evidence
produced thereon. Ex parte Frye, 94 USPQ2d 1072, 1075 (BPAI 2010)
(precedential).

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ANALYSIS
THE OBVIOUSNESS REJECTION OF CLAIMS 1–10 AND 12 OVER YOO, CAI, AND
LIU
Contentions
The Examiner finds Yoo, Cai, and Liu teach all limitations of
independent claims 1, 4, 7, and 12. Final Act. 4–6. In particular, the
Examiner finds:
Yoo fails to explicitly disclose transmitting the same CRS signals
from each of two or more secondary, transmitting nodes, and also
fails to disclose . . . simultaneously transmitting a physical
downlink data channel to a mobile station from the primary,
high-power, transmitting node and from at least one of but fewer
than all of the two or more secondary, low-power, transmitting
nodes.
Final Act. 5 (emphasis added). In turn, the Examiner further finds:
Cai discloses transmitting the same CRS signals from one or
more secondary, transmitting nodes (relay node [(RN)]) (45th
paragraph, Type-II RN can transmit a CRS that is identical to the
CRS transmitted from an access node), and also discloses
simultaneously transmitting a physical downlink data channel to
a mobile station from the primary, high-power, transmitting node
(access node) and from at least one of the one or more secondary,
low-power, transmitting nodes (relay node) (40th paragraph,
when the RN 120 transmits a CRS, the access node 110 and the
RN 120 may simultaneously transmit data using transmit
diversity. The access node 110 and RN 120 may simultaneously
transmit a plurality of control signaling transmissions, including
broadcast channel (BCH), paging channel (PCH), PDCCH,
PRICH, and PCFICH, which may be based on transmit
diversity).
Final Act. 5.
Regarding the combination of Yoo and Cai, the Examiner reasons:
It would have been obvious for one of ordinary skill[] in the art
at the time the invention was made to combine the teachings of
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Yoo and Cai in order to modify Yoo’s system to be able to
transmit the same CRS[]s from all the neighboring cells so the
system [would have been] able to detect any interference
happening from the macro cell when the pico cell is also
transmitting information to the user and also it would have been
obvious to simultaneously transmit control signals (PDCCH)
from both nodes to have the UE receive information in
synchronous manner.
Final Act. 5.
Among other arguments, Appellants present the following principal
arguments:
i. “[M]odifying Yoo’s system as suggested by the Final Office
Action would result in an invention that is both unsatisfactory for its
intended purpose and that changes the operational principles of Yoo’s
system.” App. Br. 9.
ii. “Cai’s transmission of the same CRS from secondary cells is
purposeful, and is done to provide transmit diversity; Cai’s CRS
transmissions are not interference, so there is no CRS interference to
detect as suggested by the Office’s above-quoted reasoning.” App. Br. 10.
“The transmissions from Cai’s secondary cells contribute to the desired
signal reception at Cai’s user agent (mobile station), and thereby improve
the signal quality at such a user agent (mobile station). In direct contrast to
this, the transmissions from Yoo’s non-serving nodes[] degrade the desired
signal reception at Yoo’s UE (mobile station).” App. Br. 11. “One would not
[have found] it obvious to modify Yoo’s system to replace Yoo’s
non-serving (interfering) nodes with Cai’s secondary (contributing) cells, as
these nodes and cells serve nearly opposite purposes.” App. Br. 11.
iii. Yoo teaches away from simultaneous transmission of a physical
downlink data channel from a primary node and from at least one secondary
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node because “Yoo clearly describes interference coordination techniques
wherein simultaneous transmission of data to a UE from a serving
[evolved Node B (eNB)] and an ‘interfering eNB’ is avoided.” App. Br. 11
(citing Yoo ¶ 46). “It would not [have been] obvious to one skilled in the art
to modify Yoo’s system to do the opposite of this.” App. Br. 12.
iv. Modifying Yoo’s system to transmit the same CRS signal from
a primary node and two or more secondary nodes would frustrate Yoo’s
interference cancellation because “it would make no sense to use Yoo’s
interference cancellation techniques to cancel a simultaneously transmitted
signal from a neighboring cell when that signal is intentionally transmitted to
improve signal reception, as taught by Cai.” App. Br. 13.
In response, the Examiner explains that “[t]he combination of Yoo
and Cai only helps Yoo’s system to increase its reception quality and
eliminate interference from the desired transmission. The combination of
Yoo and Cai does not modify Yoo’s primary goals and its intended use of
avoiding and canceling interference.” Ans. 7.
The Examiner further explains that “Cai discloses that CRSs and data
transmitted from access node and relay node to the UE can be performed
simultaneously using different antenna configurations and/or different
frequencies.” Ans. 7.
In the Reply Brief, in what we see as the most pertinent part,
Appellants further argue the following:
The Appeal Brief, at pages 11-14, explains that Yoo’s
system seeks: (1) to avoid interference by coordinating
transmissions among transmitting nodes so that interfering nodes
do not transmit when a serving cell is transmitting; and (2) to
cancel any interference (e.g., due to required common reference
symbol (CRS) transmissions) that is nevertheless present. In a
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different context, Cai teaches that the same signals (e.g., CRS,
user data) may be transmitted from multiple nodes in order to
improve signal reception at a user agent (UA, Cai’s term for UE).
This is accomplished by receiving, at the UA, a combined signal
representing a composite of the signals transmitted from multiple
nodes. As discussed in detail in the Appeal Brief, avoiding or
canceling an unwanted interfering signal (as described in Yoo) is
nearly an opposite technique from purposefully
transmitting/receiving the same signal (as described in Cai).
Reply Br. 2.

Our Review
Appellants’ arguments persuade us that the Examiner’s reasoning to
combine the teachings of Cai with the teachings of Yoo lacks a rational
underpinning. See KSR Int’l Co. v. Teleflex Inc., 550 U.S. 398, 418 (2007)
(“[R]ejections on obviousness grounds cannot be sustained by mere
conclusory statements; instead, there must be some articulated reasoning
with some rational underpinning to support the legal conclusion of
obviousness.” (quoting In re Kahn, 441 F.3d 977, 988 (Fed. Cir. 2006))).
Cai discloses “a Type-II RN can transmit a CRS that is identical to the
CRS transmitted from an access node on the same antenna port.” Cai ¶ 45.
Thus, we agree with the Examiner that Cai describes transmitting the same
CRS signals from each secondary transmitting node. See Final Act. 5 (citing
Cai ¶¶ 40, 45).
Now turning to the primary reference, Yoo, Yoo discloses:
Communication in a dominant interference scenario may
be supported by performing inter-cell interference coordination
(ICIC). According to certain aspects of ICIC, resource
coordination/partitioning may be performed to allocate resources
to an eNB located near the vicinity of a strong interfering eNB.
The interfering eNB may avoid transmitting on the
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allocated/protected resources, possibly except for a CRS. A UE
can then communicate with the eNB on the protected resources
in the presence of the interfering eNB and may observe no
interference (possibly except for the CRS) from the interfering
eNB.
Yoo ¶ 46 (emphases added); see also Yoo, Abstract (“When CRS tones of
an interferer may collide with control/data tones of a serving cell, CRS
interference cancellation (CRS IC) or puncturing of interfered resource
elements (REs) may be appropriate.”).
Yoo further discloses:
Performing CRS IC generally includes subtracting CRS
transmissions of one or more non-serving Node Bs from the
transmissions of the serving Node B and the one or more
non-serving Node Bs. For example, a UE may receive signals
from a plurality of access points. The access points may be
ordered in decreasing signal strength. Using an interference
cancellation technique, the UE may estimate channel from the
cell with the strongest received signal, reconstruct the common
reference signal of the cell with the strongest received signal, and
subtract the reconstructed signal from the received signal to
cancel the interference caused by the cell with the strongest
received signal. The process may be repeated on the received
signal to cancel the interference from the other cells.
Yoo ¶ 55.
Thus, Yoo describes CRS transmissions from a non-serving Node B
that interfere with CRS transmissions from a serving Node B. Yoo Abstract,
¶¶ 46, 55. Yoo also describes an interference cancellation technique for this
situation. Yoo ¶ 55.
Put another way, the CRS transmissions of Yoo are not transmitting
the same CRS using transmit diversity. See Yoo, Abstract, ¶¶ 46, 55; see
also Final Act. 5. That said, we do not see any rational reason on the record
explaining why one of ordinary skill in the art would have modified Yoo, in
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light of Cai, to transmit the same CRS using transmit diversity. Although
Cai does disclose using transmit diversity, we agree with Appellants
(arguments (ii) and (iv) above) that Yoo and Cai are using nearly opposite
techniques. See App. Br. 10–11, 13; see also Reply Br. 2.
According to the Examiner, the reason to modify Yoo “to transmit the
same CRS[]s from all the neighboring cells” is “so the system will be able to
detect any interference happening from the macro cell when the pico cell is
also transmitting information to the user.” Final Act. 5; see also Ans. 7.
First, the Examiner’s rejection lacks sufficient explanation and support as to
how using transmit diversity for the CRS signals in Yoo would make the
system able to detect interference, as stated in the Examiner’s reasoning, and
we do not readily discern how this modification would do so.
Further, at best, we read the Examiner’s reasoning as saying a skilled
artisan would eliminate the interfering CRS transmission from a non-serving
Node B in Yoo by simply replacing it with a non-interfering (same) CRS (as
claimed). Yet, Yoo’s title is “DYNAMIC SWITCHING BETWEEN
COMMON REFERENCE SIGNAL INTERFERENCE CANCELATION
AND RESOURCE ELEMENT PUNCTURING IN A CO-CHANNEL
HETEROGENEOUS NETWORK.” Yoo, Title. Moreover, Yoo’s Abstract
explains that “[w]hen CRS tones of an interferer may collide with
control/data tones of a serving cell, CRS interference cancellation (CRS IC)
or puncturing of interfered resource elements (REs) may be appropriate.”
Yoo, Abstract. Thus, it appears that the entire purpose of Yoo is to handle
interference from CRS transmission from a non-serving Node B.
Accordingly, the Examiner’s rejection lacks persuasive reasoning regarding,
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and we do not readily discern, why a skilled artisan would have modified
Yoo to use transmit diversity for CRS signals.
In short, Yoo’s non-serving (but still interfering) node serves a nearly
opposite purpose of Cai’s secondary, contributing cell. On the record before
us, the reasoning provided to modify Yoo to transmit a same CRS lacks a
rational underpinning for reasons explained above.
We, therefore, do not sustain the Examiner’s rejection of independent
claims 1, 4, 7, and 12.
We also do not sustain the Examiner’s rejection of claims 2, 3, 5, 6,
and 8–10, which variously depend from claims 1, 4, and 7.

THE OBVIOUSNESS REJECTION OF CLAIM 11 OVER YOO, CAI, LIU, AND
BARBIERI
Claim 11 depends from claim 7. The Examiner’s rejection of claim 11
does not cure the deficiency discussed above in the Examiner’s rejection of
claim 7. See Final Act. 7–8.
We, therefore, do not sustain the Examiner’s rejection of claim 11.

ORDER
The Examiner’s decision rejecting claims 1–12 is reversed.

REVERSED