NOKIA TECHNOLOGIES OYDownload PDFPatent Trials and Appeals BoardJun 9, 20212020001458 (P.T.A.B. Jun. 9, 2021) Copy Citation 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 2 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. Appeal 2020-001458 Application 15/815,106 3 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 Appeal 2020-001458 Application 15/815,106 4 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 5 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 Appeal 2020-001458 Application 15/815,106 6 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. Appeal 2020-001458 Application 15/815,106 7 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 Appeal 2020-001458 Application 15/815,106 8 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). Appeal 2020-001458 Application 15/815,106 9 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 10 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 Copy with citationCopy as parenthetical citation