NOKIA TECHNOLOGIES OY

Patent Trials and Appeals Board

Jun 9, 2021

2020001458 (P.T.A.B. Jun. 9, 2021)

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.
15/815,106 11/16/2017 Esa TIIROLA 059864.02604 6683
11051 7590 06/09/2021
SQUIRE PB (Nokia)
Nokia Technologies Oy
ATTN: IP Department
2550 M Street, NW
Washington, DC 20037
EXAMINER
AREVALO, JOSEPH
ART UNIT PAPER NUMBER
2642
NOTIFICATION DATE DELIVERY MODE
06/09/2021 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):
IP-Squire@SquirePB.com
sonia.whitney@squirepb.com
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
____________

BEFORE THE PATENT TRIAL AND APPEAL BOARD
____________

Ex parte ESA TIIROLA,
VOLKER BRAUN,
and KAROL SCHOBER
____________

Appeal 2020–001458
Application 15/815,106
Technology Center 2600
____________

Before ANTON W. FETTING, DEBRA K. STEPHENS, and
JAMES P. CALVE, Administrative Patent Judges.

FETTING, Administrative Patent Judge.

DECISION ON APPEAL

Appeal 2020-001458
Application 15/815,106

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STATEMENT OF THE CASE1
Esa Tiirola, Volker Braun, And Karol Schober (Appellant2) seeks
review under 35 U.S.C. § 134 of a final rejection of claims 1–5, 9–14, and
20. Claims 6–8 and 15–19 are not rejected.3 We have jurisdiction over the
appeal pursuant to 35 U.S.C. § 6(b).
This invention is in the context of wireless communications with Long
Term Evolution (LTE) technology. Part of the communication protocol has
control information being included in the signal in a physical downlink
control channel (PDCCH), for which the receiver must search. The portions
of the signal subject to such search are referred to as a search space. The
search process includes signal decoding and is referred to as blind decoding.
This process as such has been in place since at least the advent of LTE 3G
communications. The invention however recites solving a problem in a
more current LTE technology context described in the Specification.
In LTE 5G New Radio communications protocols, monitoring
occasions can be once a slot, once per multiple slots or multiple times in a
slot. In an embodiment, physical downlink control channel (PDCCH) blind
search may be arranged by means of parallel search spaces or search space
sets mapped to one or multiple control resource sets (CORESETs). During a

1 Our decision will make reference to the Appellant’s Appeal Brief (“Appeal
Br.,” filed August 9, 2019) and Reply Brief (“Reply Br.,” filed December
16, 2019), and the Examiner’s Answer (“Ans.,” mailed November 25, 2019),
and Final Action (“Final Act.,” mailed March 27, 2019).
2 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 Nokia
Technologies Oy (Appeal Br. 3).
3 Claims 7 and 18 were not rejected. Final Act. 10. The rejection of claims
6, 8, 15–17, and 19 were withdrawn. Ans. 3.
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Application 15/815,106

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PDCCH blind search, a user equipment (UE) may be monitoring predefined
control channel elements (CCEs), aggregated CCEs and/or downlink control
information (DCI) sizes in predefined time instants, corresponding to
configured monitoring occasions. Spec. para. 24.
Certain working assumptions and agreements have been made in
3GPP RANI working group meetings with respect to control channel blind
search. For example, in the case when only CORESET(s) for slot-based
scheduling is configured for a UE, the maximum number of PDCCH blind
decodes per slot per carrier is X, where the value of X does not exceed 44.
Spec. para. 26.
Generally, it may be desirable to allow over-booking of the blind
decodings (BDs) for some time instances, since, for a majority of time
instances, the BDs would be below the maximum allowed. This would
allow dimensioning the BDs on different search spaces and/or sets of search
spaces according to typical number of BDs, instead of the maximum number
of BDs. Spec. para. 32.
LTE supports PDCCH candidate reduction, but the reduction is
configured in a semi-static manner per serving cell, by means of direct
scaling of PDCCH candidates on different aggregation level. It does not
take into account the scenario where overbooking occurs in a dynamic
manner. One solution would be to restrict a NR gNB to configure at most X
blind decodes (e.g., X=44BDs) across all time instances. However, this
solution may be too restrictive, as the BD peaks would only seldom occur.
A consequence of this approach would be that a UE’s BD capacity would be
underutilized for most of the time. This would create additional PDCCH
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Application 15/815,106

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blocking, and would reduce the quality of experience (data rate, latency).
Spec. para. 37.
The claims are directed to managing and/or controlling PDCCH blind
decodings (BDs) between multiple search spaces or sets of search spaces, or
CORESETs. The managing of the BDs may include, when a UE reaches the
predefined maximum number of BDs/reference time unit (such as 44
BDs/slot), predefined rules being provided for how to reduce the number of
BDs down to an allowed level. Spec. para. 38.
An understanding of the invention can be derived from a reading of
exemplary claim 1, which is reproduced below (bracketed matter and some
paragraphing added).
1. A method, comprising:
[1] configuring, by a network node,
multiple search spaces, sets of search spaces, and/or
control resource sets, to a user equipment, that results in
monitoring occasions where more blind decodings are
required than allowed by capability of the user
equipment;
[2] identifying the monitoring occasions for which an allowed
number of blind decodings is exceeded;
[3] determining a reduced set of blind decodings and/or
candidates,
wherein the reduced set of blind decodings and/or
candidates are determined by predefined search space
priorities or rules;
[4] transmitting physical downlink control channel(s) to the
user equipment given the reduced set.

The Examiner relies upon the following prior art:
Name Reference Date
Appeal 2020-001458
Application 15/815,106

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Kim US 2014/0133427 A1 May 15, 2014
Lee US 2015/0271790 A1 Sept. 24, 2015

Claims 1, 2, and 10–12 stand rejected under 35 U.S.C. § 102(a)(1) as
anticipated by Lee.
Claims 3–5, 9, 13, 14, and 20 stand rejected under 35 U.S.C. § 103(a)
as unpatentable over Lee and Kim.
ISSUES
The issues of anticipation and obviousness turn primarily on whether
the references describe the claim limitations.
FACTS PERTINENT TO THE ISSUES
The following enumerated Findings of Fact (FF) are believed to be
supported by a preponderance of the evidence.
Facts Related to Claim Construction
01. Blind search or blind decoding may refer to the process by which
a UE finds its physical downlink control channel (PDCCH) by
monitoring a set of PDCCH candidates in every monitoring
occasion. Spec. para. 24.
Facts Related to the Prior Art
Lee
02. Lee is directed to receiving control information in a wireless
communication system. Lee para. 1.
03. Lee describes LTE defining a control channel element (CCE) set
where PDCCH is able to be positioned for each of the user
equipment. The CCE set for which a user equipment is able to
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search its own PDCCH is called a PDCCH search space, or simply
a search space (SS). An individual resource to which PDCCH is
able to be transmitted within the SS is called a PDCCH candidate.
One PDCCH candidate corresponds to 1, 2, 4, or 8 CCEs
according to a CCE aggregation level. A base station transmits an
actual PDCCH (DCI) via an arbitrary PDCCH candidate within
the SS and a user equipment monitors the SS to find out the
PDCCH (DCI). Specifically, the user equipment attempts a blind
decoding (BD) for PDCCH candidates within the SS. Lee para.
41.
04. Lee additionally describes a search space (SS) having a different
size in accordance with each PDCCH format in an LTE system. A
USS (UE-specific search space) and a CSS (common search
space) are separately defined. The USS is also called a dedicated
search space. The UE-specific search space may be individually
set for each user equipment.A range of the common search space
is known to all user equipment. The UE-specific and the common
search space can be overlapped for a given user equipment. If all
control channel elements (CCEs) are already allocated to different
user equipment in the USS, which is configured for a specific UE,
because there is no remaining CCE, a base station may not find
enough CCE resources to transmit PDCCH to the specific user
equipment in a given subframe. In order to minimize this
blocking that may be kept in a next subframe, a start point of the
UE-specific search space is modified by a UE-specific hopping
sequence in every subframe. Lee para. 42.
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05. Lee further describes user equipment not performing searches in
accordance with all the defined downlink control information
(DCI) formats at the same time, in order to reduce a calculation
load of a user equipment due to a blind decoding (BD) attempt
count. Lee para. 43.
06. Lee still further describes a plurality of PDCCHs for a plurality
of user equipment being transmitted within a control region of an
identical subframe. A base station does not provide information
on where a corresponding PDCCH is situated within the control
region to the user equipment. Hence, the user equipment (UE)
searches the subframe for PDCCH for its own in a manner of
monitoring a set of PDCCH candidates. In this case, the verb
`monitor` means that the user equipment attempts to decode each
of the received PDCCH candidates in accordance with each of the
PDCCH formats and each of the CCE aggregation levels. This is
called a blind decoding (blind detection). By using the blind
decoding, the user equipment simultaneously performs an
identification of the PDCCH transmitted to the user equipment
and a decoding of the control information transmitted on a
corresponding PDCCH. Lee para. 67.
ANALYSIS
Claims 1, 2, and 10–12 rejected under 35 U.S.C. § 102(a)(1) as anticipated
by Lee
As Appellant puts into perspective, the claims recite limitations in a
different technological context than Lee. The claims
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relate to new radio (NR) PDCCH search space. However, Lee is
directed to LTE PDCCH search spaces, which defines the
numbers in the specifications for CSS and USS, and the UEs
had to support those for the blind decoding. In LTE, CSS and
USS are monitored in every slot since the number of blind
decodings was not time-variant, as it is in new radio (NR). For
example, the current invention describes the frequency of a
monitoring occasion in paragraph [0024] of the pre grant
publication for the current application, "A monitoring occasion
can be once a slot, once per multiple slots or multiple times in a
slot." However, because Lee refers to LTE, the UE has
capability to continuously monitor or theoretically an infinite
number of monitoring occasions.
Appeal Br. 10–11.
We are persuaded the Examiner has not shown that “Lee discloses
monitoring occasions where more blind decodings are required than allowed
by the capability of the user equipment.” Appeal Br. 11; see also Reply Br.
4–5.
In particular, the Examiner does not show where Lee describes
“monitoring occasions where more blind decodings are required than
allowed by capability of the user equipment,” but instead transcribes part of
Lee paragraph 41. The Examiner goes on to determine that in Lee,
the user equipment is able to search its own PDCCH Control
Channel Element (CCE) setting the candidates, also monitoring
the slot of the sub frame corresponding to the control channels
that are assigned. In general, a plurality of PDCCHs can be
transmitted in a sub frame. The PDCCH carries a message
known as a DCI (downlink control information) and the DCI
includes resource allocation information for a UE or a UE
group and different control information. In general, a plurality
of PDCCHs can be transmitted in a subframe. Each of a
plurality of the PDCCHs is transmitted using one or more CCEs
(control channel element).
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Ans. 4–5. See also Final Action 2. Although this fairly characterizes some
aspects of LTE technology, this contains no determinations as to how Lee
describes the limitation at issue. As Appellant contends, the Examiner has
not shown Lee describes this problem and so has not shown Lee describes
the claimed solution.

Claims 3–5, 9, 13, 14, and 20 rejected under 35 U.S.C. § 103(a) as
unpatentable over Lee and Kim
We are persuaded by Appellant's arguments that the Examiner has not
shown Kim overcomes the deficiencies of Lee. Appeal Br. 20–25.

CONCLUSIONS OF LAW
The rejection of claims 1, 2, and 10–12 under 35 U.S.C. § 102(a)(1) as
anticipated by Lee is improper.
The rejection of claims 3–5, 9, 13, 14, and 20 under 35 U.S.C.
§ 103(a) as unpatentable over Lee and Kim is improper.

Appeal 2020-001458
Application 15/815,106

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CONCLUSION
The rejection of claims 1–5, 9–14, and 20 is reversed.
Claims 6–8 and 15–19 are not rejected.

In summary:
Claims
Rejected
35 U.S.C.
§
Reference(s)/Basis  Affirmed Reversed
1, 2, 10–12 102(a)(1) Lee 1, 2, 10–12
3–5, 9, 13,
14, 20
103 Lee, Kim 3–5, 9, 13,
14, 20
Overall Outcome 1–5, 9–14,
20

REVERSED