Terminal, base station and wireless communication method

Abstract

To appropriately control the monitoring of a repeatedly transmitted downlink control channel.SOLUTION: A terminal comprises: a reception unit that receives search space information on a search space associated with a control resource set; and a control unit that controls the monitoring of a downlink control channel using the search space within a time period of a predetermined cycle on the basis of the search space information. The control unit controls the monitoring of the downlink control channel repeatedly transmitted between different slots within the time period and / or in the same slot on the basis of repetition information on the repetition of the downlink control channel included in the search space information.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present disclosure relates to a terminal, a base station, and a wireless communication method. [Background technology]

[0002] The Third Generation Partnership Project (3GPP), an international standardization organization, has specified Release 15 of New Radio (NR), a fifth-generation (5G) RAT, as the successor to Long Term Evolution (LTE), a 3.9th-generation radio access technology (RAT), and LTE-Advanced, a fourth-generation RAT (see, for example, Non-Patent Document 1).

[0003] In Release 15, a control resource set (CORESET) is provided in at least a portion of the band available to a terminal (e.g., User Equipment (UE)), thereby improving frequency utilization efficiency compared to LTE, in which a control region is provided across the entire band available to the terminal. [Prior art documents] [Non-patent literature]

[0004] [Non-Patent Document 1] 3GPP TS 38.300 V15.9.0 (2020-03) Summary of the Invention [Problem to be solved by the invention]

[0005] Currently, 3GPP has begun studying functions for Internet of Things (IoT) terminals that use NR for wireless access. It is expected that the available bandwidth for IoT terminals will be narrower than that of terminals introduced in Release 15. To compensate for the reduced coverage caused by such narrow bandwidth, repeated transmission of the downlink control channel is also being considered.

[0006] The present disclosure has been made in consideration of the above circumstances, and one of its objectives is to provide a terminal, a base station, and a wireless communication method that can appropriately control monitoring of a repeatedly transmitted downlink control channel. [Means for solving the problem]

[0007] A terminal according to one aspect of the present disclosure includes a receiving unit that receives search space information regarding a search space associated with a control resource set, and a control unit that controls monitoring of a downlink control channel using the search space within a predetermined period based on the search space information, and the control unit may control monitoring of the downlink control channel that is repeatedly transmitted between different slots and / or within the same slot within the period based on repetition information regarding repetition of the downlink control channel included in the search space information. [Effects of the Invention]

[0008] According to one aspect of the present disclosure, monitoring of repeatedly transmitted downlink control channels can be appropriately controlled. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a diagram illustrating an example of an overview of a wireless communication system according to an embodiment of the present invention. [Figure 2] FIG. 1 is a diagram illustrating an example of PDCCH monitoring in NR. [Figure 3] FIG. 10 is a diagram illustrating another example of PDCCH monitoring in NR. [Figure 4] FIG. 10 is a diagram illustrating a first example of inter-slot repetition according to the present embodiment. [Figure 5] FIG. 10 is a diagram illustrating a second example of inter-slot repetition according to the present embodiment. [Figure 6] FIG. 10 is a diagram illustrating a third example of inter-slot repetition according to the present embodiment. [Figure 7] FIG. 10 is a diagram illustrating a first example of intra-slot repetition according to the present embodiment. [Figure 8] 10A and 10B are diagrams illustrating an example of a combination of inter-slot repetition and intra-slot repetition according to the present embodiment. [Figure 9] FIG. 10 is a diagram showing an example of search space information according to the present embodiment. [Figure 10] FIG. 10 is a diagram illustrating an example of derivation of the number of repetitions according to the present embodiment. [Figure 11] FIG. 2 is a diagram illustrating a first example of determining frequency domain resources for repetition according to the present embodiment. [Figure 12] FIG. 10 is a diagram showing a first example of CORESET information according to the present embodiment. [Figure 13] FIG. 10 is a diagram illustrating a second example of determining frequency domain resources for repetition according to the present embodiment. [Figure 14] FIG. 10 is a diagram showing a second example of CORESET information according to the present embodiment. [Figure 15] FIG. 10 is a diagram illustrating a second example of determining frequency domain resources for repetition according to the present embodiment. [Figure 16] FIG. 10 is a diagram showing a third example of CORESET information according to the present embodiment. [Figure 17] FIG. 10 is a diagram illustrating a fourth example of determining frequency domain resources for repetition according to the present embodiment. [Figure 18] FIG. 10 is a diagram illustrating a fifth example of determining frequency domain resources for repetition according to the present embodiment. [Figure 19] FIG. 10 is a diagram showing an example of search space information according to the present embodiment. [Figure 20] FIG. 10 is a diagram illustrating an example of PDCCH information according to the present embodiment. [Figure 21] FIG. 10 is a diagram illustrating an example of repeated transmission of a PDCCH to which frequency hopping according to the present embodiment is applied. [Figure 22] FIG. 10 is a diagram illustrating an example of switching search space groups according to the present embodiment. [Figure 23] A figure showing an example of DCI used for search space group switching control in this embodiment. [Figure 24] FIG. 10 is a diagram showing an example of values ​​in a search group switching field according to the present embodiment. [Figure 25] FIG. 2 is a diagram illustrating an example of the hardware configuration of each device in the wireless communication system according to the present embodiment. [Figure 26] FIG. 2 is a diagram illustrating an example of a functional block configuration of a terminal according to the present embodiment. [Figure 27] FIG. 2 is a diagram illustrating an example of a functional block configuration of a base station according to the present embodiment. [Figure 28] FIG. 10 is a diagram illustrating an example of a PDCCH monitoring operation in the wireless communication system according to the present embodiment. [Figure 29] A figure showing an example of the operation of switching search space groups in the wireless communication system of this embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] Embodiments of the present disclosure will be described with reference to the accompanying drawings. In the drawings, components with the same reference numerals may have the same or similar configurations.

[0011] Fig. 1 is a diagram showing an example of an overview of a wireless communication system according to this embodiment. As shown in Fig. 1, the wireless communication system 1 may include terminals 10, base stations 20, and a core network 30. Note that the numbers of terminals 10 and base stations 20 shown in Fig. 1 are merely examples and are not limited to the numbers shown in the figure.

[0012] The radio access technology (RAT) of the radio communication system 1 is assumed to be, for example, NR, but is not limited to this, and various RATs such as RATs of the sixth generation and later can be used.

[0013] The terminal 10 is a predetermined terminal or device such as a smartphone, a personal computer, an in-vehicle terminal, an in-vehicle device, a stationary device, a telematics control unit (TCU), etc. The terminal 10 may also be called a user equipment (UE), a mobile station (MS), a user terminal, a radio apparatus, a subscriber terminal, an access terminal, etc. The terminal 10 may be either mobile or fixed. The terminal 10 is configured to be able to communicate using, for example, NR as a RAT.

[0014] The base station 20 forms one or more cells C and communicates with the terminal 10 using the cells C. The cell C may be interchangeably referred to as a serving cell, a carrier, a component carrier (CC), or the like. The base station 20 may also be called a gNodeB (gNB), en-gNB, a Next Generation-Radio Access Network (NG-RAN) node, a low-power node, a Central Unit (CU), a Distributed Unit (DU), a gNB-DU, a Remote Radio Head (RRH), an Integrated Access and Backhaul / Backhauling (IAB) node, or the like. The base station 20 is not limited to a single node, and may be configured with multiple nodes (for example, a combination of a lower node such as a DU and an upper node such as a CU).

[0015] The core network 30 is, for example, a core network compatible with NR (5G Core Network: 5GC), but is not limited to this. An apparatus on the core network 30 (hereinafter also referred to as a "core network apparatus") performs mobility management such as paging and location registration of the terminal 10. The core network apparatus may be connected to the base station 20 via a predetermined interface (for example, an S1 or NG interface).

[0016] The core network device may include, for example, at least one of an Access and Mobility Management Function (AMF) that manages C-plane information (e.g., information related to access and mobility management, etc.) and a User Plane Function (UPF) that controls the transmission of U-plane information (e.g., user data).

[0017] In the wireless communication system 1, a terminal 10 receives a downlink (DL) signal and / or transmits an uplink (UL) signal from a base station 20. One or more carriers may be configured in the terminal 10. The bandwidth of each carrier is, for example, 5 MHz to 400 MHz. One or more bandwidth parts (BWPs) may be configured in one carrier. One BWP has at least a portion of the bandwidth of the carrier.

[0018] One or more control resource sets (CORESETs) may be configured in one BWP. A CORESET is a resource in the time domain and frequency domain used for transmitting downlink control channels. For example, a CORESET is composed of a predetermined number of symbols (e.g., 1 to 3 symbols) and a predetermined number of resource blocks (RBs) (e.g., 6n (n≧1) RBs).

[0019] In the following, a physical downlink control channel (PDCCH) will be described as an example of a downlink control channel, but the downlink control channel may be any channel used to transmit downlink control information (Downlink Control Channel: DCI), and its name is not limited to PDCCH.

[0020] A CORESET includes multiple control channel elements (CCEs). One CCE is composed of a predetermined number of resource element groups (REGs). For example, one REG may be composed of one RB (i.e., one symbol and 12 subcarriers), and one CCE may be composed of six REGs (i.e., six RBs).

[0021] Candidate resources in which PDCCHs are allocated (hereinafter referred to as "PDCCH candidates") are composed of a predetermined number of CCEs according to an aggregation level (AL). For example, when AL=1, one PDCCH candidate is composed of one CCE, and when AL=2, one PDCCH candidate is composed of two CCEs.

[0022] A search space includes PDCCH candidates each consisting of one or more CCEs in a CORESET associated with the search space. Therefore, it can be said that the search space is composed of at least a portion of the CORESET associated with the search space. Terminal 10 monitors each PDCCH candidate included in the search space to detect DCI.

[0023] Here, monitoring refers to decoding DCI for each PDCCH candidate in a search space according to a predetermined format, and is called "blind decoding." Furthermore, the search space may include a common search space (CSS) that is a search space common to one or more terminals 10, and a UE-specific search space (USS) that is a search space specific to a terminal 10. Such a search space may be provided for each AL, and a set of search spaces for one or more ALs may be called a search space set. In this specification, a "search space" may be a search space for a specific AL or a search space set.

[0024] Information about each CORESET (hereinafter referred to as "CORESET information") is provided to the terminal 10 from the base station 20. The CORESET information may be, for example, an information item (Information Element: IE) "ControlResourceSet" of Radio Resource Control (RRC). Here, the IE may be referred to as a parameter. The CORESET information may include, for example, at least one of the following: CORESET identification information (e.g., RRC IE "controlResourceSetId") Duration information (e.g., RRC IE "duration") indicating the duration of the CORESET (hereinafter referred to as "CORESET duration"). Frequency domain resource information indicating the frequency domain resources that make up the CORESET (e.g., RRC IE "frequencyDomainResources")

[0025] Furthermore, information regarding each search space (hereinafter referred to as "search space information") is provided to terminal 10 from base station 20. The search space information may be, for example, an RRC IE "SearchSpace." The search space information may include, for example, at least one of the following: Search space identification information (e.g., RRC IE "searchSpaceId") Identification of the CORESET associated with the search space (e.g., RRC IE "controlResourceSetId") Period / offset information (for example, RRC IE “monitoringSlotPeriodicityAndOffset”) indicating the period k and offset o for monitoring the PDCCH. Hereinafter, the period k and offset o will be referred to as the monitoring period k and monitoring offset o, respectively. Monitoring period information (for example, RRC IE “duration”) indicating the period T for monitoring the PDCCH; hereinafter, this period T is referred to as the monitoring period T. Monitoring symbol information indicating the first symbol for monitoring the PDCCH within a slot (e.g., RRC IE "monitoringSymbolsWithinSlot") Search space group information (e.g., RRC IE "searchSpaceGroupIdList") indicating one or more groups (hereinafter "search space groups") to which the search space is associated.

[0026] Terminal 10 controls PDCCH monitoring based on the CORESET information and search space information. Figure 2 is a diagram showing an example of PDCCH monitoring in NR. For example, Figure 2 shows an example of PDCCH monitoring using search space #1 associated with CORESET #1.

[0027] 2, for example, the monitoring cycle k is 10 slots, and the monitoring period T is 4 slots. Also, the CORESET period for CORESET#1 associated with search space#1 is 2 symbols, and the frequency domain resource for CORESET#1 is 6n (n≧1) RBs.

[0028] The terminal 10 receives radio frame number n f , the radio frame #n f Slot number n in s,f , the number of slots in the radio frame N s,f , the monitoring period k, and the monitoring offset o, the start slot of the monitoring period is determined. For example, the terminal 10 determines the slot having the slot number that satisfies the following equation (1) (slot #0 in FIG. 2) as the start slot of the monitoring period. (Formula 1) (n f N s,f +n s,f -o) mod k=0

[0029] Note that FIG. 2 is merely an example, and the radio frame number n f , the radio frame #n f Slot number n in s,f , the number of slots in the radio frame N s,f , the monitoring period k, and the monitoring offset o are not limited to those shown in the figures. For example, in the examples shown in FIG. 2 and subsequent figures, the subcarrier spacing (SCS) is 15 kHz, so the number of slots N in the radio frame is s,f = 10, but is not limited to this. When using an SCS greater than 15 kHz (for example, 30 kHz, 60 kHz, 120 kHz, etc.), the number of slots in a radio frame N s,f increases.

[0030] 2, among the bits corresponding to symbols #0 to #13, the bit corresponding to symbol #0 is "1". Therefore, in each slot within the monitoring period (hereinafter referred to as "monitoring slot"), CORESET #1 associated with search space #1 is arranged in two symbols, starting from symbol #0. As described above, search space #1 is at least a part of CORESET #1 associated with search space #1.

[0031] Terminal 10 monitors each PDCCH candidate in search space #1, using T consecutive slots from start slot #0 determined as described above as monitoring slots. Terminal 10 detects a PDCCH for terminal 10 by monitoring each PDCCH candidate in search space #1. In other words, detecting the PDCCH may be said to be detecting DCI in a predetermined format in which a cyclic redundancy check (CRC) is scrambled by a predetermined Radio Network Temporary Identifier (RNTI).

[0032] The DCI format may include a DCI format used for scheduling the downlink shared channel (e.g., DCI format 1_X), a DCI format used for scheduling the uplink shared channel (e.g., DCI format 0_X), a DCI format used for purposes other than scheduling (e.g., DCI format 2_X), etc., where X is a positive integer.

[0033] Figure 3 is a diagram showing another example of PDCCH monitoring in NR. For example, Figure 3 shows an example of PDCCH monitoring using search space #2 associated with CORESET #2. Figure 3 differs from Figure 2 in that multiple search spaces are set in each slot within a monitoring period. The differences between Figure 3 and Figure 2 will be mainly described below.

[0034] 3, the CORESET period for CORESET#2 is one symbol. In the monitoring symbol information, among the bits corresponding to symbols #0 to #13, the bits corresponding to symbols #0 and #7 are "1". Therefore, in each slot within the monitoring period, CORESET#2 associated with search space #2 is allocated to one symbol starting from symbol #0 or #7.

[0035] Terminal 10 monitors each PDCCH candidate in search space #2 for each of symbols #0 and #7 in each slot within the monitoring period. In Fig. 3, terminal 10 does not detect a PDCCH in search space #2 for symbol #0, but detects a PDCCH in search space #2 for symbol #7.

[0036] In this way, in NR, terminal 10 monitors the PDCCH within a monitoring period that is set at a predetermined cycle. Furthermore, one or more search spaces can be set in each slot within the monitoring period, and terminal 10 may monitor one or more search spaces within each slot.

[0037] Meanwhile, NR Release 17 is considering supporting functions for terminals with lower performance and price range than terminals for enhanced Mobile Broadband (eMBB) and Ultra-reliable and Low Latency Communications (URLLC) introduced in Releases 15 and 16. Such terminals are also called reduced capability (RedCap) terminals or devices, and may be used, for example, in industrial wireless sensors, video surveillance cameras, wearable devices, etc.

[0038] RedCap terminals are expected to have higher performance than terminals for low-power wide-area (LPWA) communications, and the carriers used by RedCap terminals may have bandwidths of, for example, 20 MHz, 50 MHz, or 100 MHz. LPWA includes, for example, Category 1, Long Term Evolution for Machine-type communication (LTE-M), which operates on an LTE-based RAT, and Narrow Band IoT (NB-IoT). The maximum bandwidth of Category 1 is 20 MHz, the maximum bandwidth of LTE-M is 1.4 MHz (6 RB), and the maximum bandwidth of NB-IoT is 180 kHz (1 RB). In this way, RedCap terminals may be used as a mid-range terminal between eMBB, URLLC, and LPWA.

[0039] When a RedCap terminal is assumed as the terminal 10, repeated transmission of the PDCCH is being considered to compensate for the reduction in coverage caused by a narrower carrier bandwidth. Specifically, it is assumed that the base station 20 repeatedly transmits the PDCCH in the time domain and / or the frequency domain.

[0040] However, the terminal 10 performs reception processing (e.g., demodulation, decoding, etc.) of the PDCCH on the assumption that the PDCCH for the first transmission will be transmitted in each search space set within a monitoring period of a predetermined cycle. Therefore, when the PDCCH is repeatedly transmitted, the terminal 10 may not be able to appropriately monitor the repeatedly transmitted PDCCH using an existing monitoring method.

[0041] Therefore, in this embodiment, (1) monitoring of PDCCHs repeatedly transmitted using different time domain resources (hereinafter referred to as "first PDCCH monitoring"), (2) monitoring of PDCCHs transmitted using different frequency domain resources (hereinafter referred to as "second PDCCH monitoring"), and (3) a combination of the first and second PDCCH monitoring will be described. Also, in this embodiment, (4) control related to a switch of search space groups (hereinafter referred to as "switching control") will be described.

[0042] (1) First PDCCH monitoring In the first PDCCH monitoring, monitoring of the PDCCH that is repeatedly transmitted in the time domain will be described. Terminal 10 controls monitoring of the PDCCH that is repeatedly transmitted using different time domain resources within a predetermined monitoring period T, based on information related to PDCCH repetition included in search space information (hereinafter referred to as "repetition information").

[0043] Here, the different time domain resources may be, for example, different slots within a predetermined periodic monitoring period T, or different symbols within the same slot within the monitoring period T. In this way, the PDCCH may be repeated between different slots within one or more monitoring periods (hereinafter referred to as "inter-slot repetition"), or may be repeated within the same slot within the monitoring period (hereinafter referred to as "intra-slot repetition").

[0044] Furthermore, the repetition information may include information indicating the repetition number R of the PDCCH, or may include information indicating the maximum value of the repetition number R. In the latter case, terminal 10 may determine the repetition number R based on the maximum value and a predetermined field value in the DCI. Note that the repetition number R may also be called a repetition level, etc.

[0045] The repetition information may include information indicating the start slot of PDCCH repetition (hereinafter referred to as "start slot information"). In addition, in the case of intra-slot repetition, the repetition information may include information indicating the symbol in which the PDCCH is repeated (hereinafter referred to as "repetition symbol information").

[0046] Based on the repetition information described above, the terminal 10 may set a search space used to monitor a PDCCH transmitted by inter-slot repetition and / or intra-slot repetition. The terminal 10 may detect the PDCCH by monitoring PDCCH candidates in the set search space.

[0047] In this way, when the PDCCH is repeatedly transmitted, the search space for monitoring the PDCCH is also repeatedly set, so that the repetition of the PDCCH may be rephrased as the repetition of the search space. Hereinafter, the search space is also referred to as the "repetition search space."

[0048] (1.1) Inter-slot repetition Inter-slot repetition may be applied to multiple slots within one monitoring period T among the monitoring periods T of a predetermined cycle, or may be applied to multiple slots spanning multiple monitoring periods T among the monitoring periods T of a predetermined cycle.

[0049] In the inter-slot repetition, the monitoring slot #k in which the 1st to Rth PDCCHs are transmitted within a predetermined monitoring period T is determined based on the number of repetitions R of the PDCCH. i Specifically, the terminal 10 determines the repetition number R, the start slot #k0 of the repetition, the radio frame number n f , the radio frame #n f Slot number n in s,f , the number of slots in the radio frame N s,f, monitoring period k, monitoring interval T, and monitoring offset o, based on at least one of the monitoring slot #k. i For example, the terminal 10 may determine k (i=0,...,R-1) starting from k0 having slot numbers that satisfy the following equation (2): R-1 Monitoring slots up to and including slot #k i It may be determined as (i=0,...,R-1).

number

[0050] The start slot #k0 of the repetition may be explicitly notified to the terminal 10 by the base station 20 using the start slot information. Alternatively, the start slot #k0 may be derived by the terminal 10 itself based on implicit information, without explicit notification of the start slot information. For example, the terminal 10 may regard the start slot of the monitoring period T as the start slot #k0 of the repetition.

[0051] Fig. 4 is a diagram showing a first example of inter-slot repetition according to this embodiment. In Fig. 4, as described in Fig. 2, based on the search space information of search space #1, the monitoring period T of search space #1 is set to slots #0 to #3 of each radio frame. Also, based on the CORESET information of CORESET #1 associated with search space #1, CORESET #1 is allocated to symbols #0 to #2 of each slot within the monitoring period T. This search space #1 is used as a repetitive search space.

[0052] For example, in Fig. 4, the number of repetitions R of the PDCCH is 2, and the start slot #k0 of the repetition is the same as the start slot #0 of the predetermined cycle monitoring period T. Terminal 10 assumes that the PDCCH with the repetition number R is transmitted in R consecutive slots starting from the start slot #k0 of the repetition. Since R = 2 in Fig. 4, terminal 10 assumes that the first and second PDCCHs are mapped within search space #1 of slots #k0 and #k1, respectively, and monitors search space #1 of slots #k0 and #k1.

[0053] For example, in FIG. 4, the terminal 10 detects the first PDCCH by monitoring search space #1 in slot #k0, and detects the second PDCCH by monitoring search space #1 in slot #k1. i If the (i+1)th PDCCH is successfully decoded in (0≦i≦R-1), slot #k i+1 The terminal 10 may stop monitoring search space #1 thereafter, or may continue monitoring for the number of repetitions R. Furthermore, the terminal 10 may combine the first PDCCH to the (i+1)th PDCCH to decode the (i+1)th PDCCH.

[0054] 5 is a diagram showing a second example of inter-slot repetition according to this embodiment. The prerequisites for FIG. 5 are the same as those for FIG. 4, and differences from FIG. 4 will be mainly described below. In FIG. 5, the terminal 10 determines the start slot #k0 of the repetition based on start slot information from the base station 20. The start slot information may be, for example, the period and offset of the start slot of the repetition, or may be an offset from the start slot of the monitoring period T.

[0055] For example, in FIG. 5, the start slot information indicates an offset (here, 2) from the start slot #0 of the monitoring period T. Based on the start slot #0 of the monitoring period T determined by the above equation (1) and the offset "2" indicated by the start slot information, terminal 10 determines the start slot #k0 of the repetition to be slot #2. In FIG. 5, the number of repetitions R=4, and slot #3 in which search space #1 for the second PDCCH is provided is the final slot of the monitoring period T. Therefore, search spaces #1 for the third and fourth PDCCHs are provided in slots #0 and #1 of the next monitoring period T.

[0056] In this way, the terminal 10 counts up the slot number by one from the start slot #k0 of the repetition (here, slot #2 of radio frame #0) to the monitoring slot #k. i (0≦i≦R-1) and monitor slot #k i+1 If the monitoring slot #k is a slot other than the monitoring period T (here, slot #4 of radio frame #0), i+1 may be determined as the start slot of the next monitoring period (here, slot #0 of radio frame #1 kT slots after slot #4 of radio frame #0). The terminal 10 may repeat the above process by counting up i by 1 until i becomes equal to the number of repetitions R-1. In this way, R monitoring slots #k0 to #k R-1 may span multiple monitoring periods.

[0057] Fig. 6 is a diagram showing a third example of inter-slot repetition according to this embodiment. In Fig. 6, as described in Fig. 3, based on the search space information of search space #2, the monitoring period T of search space #2 is set to slots #0 to #3 of each radio frame. Also, based on the CORESET information of CORESET #2 associated with search space #2, CORESET #2 is allocated to symbols #0 and #7 of each slot within the monitoring period T. This search space #2 is used as a repetitive search space.

[0058] In Figure 6, for each monitoring slot #k i 4 and 5 in that multiple search spaces are provided for (i=0,...,R-1). As shown in FIG. 6, each monitoring slot #k i Different PDCCHs may be transmitted within the plurality of search spaces. Note that the different PDCCHs may be PDCCHs that transmit different DCIs.

[0059] 6, for example, the first PDCCH #1 is mapped into search space #2 of symbol #0 of monitoring slot #k0, and the first PDCCH #2 is mapped into search space #2 of symbol #7 of monitoring slot #k1. Furthermore, the second PDCCH #1 is mapped into search space #2 of symbol #0 of the next monitoring slot #k1, and the second PDCCH #2 is mapped into search space #2 of symbol #7 of monitoring slot #k1.

[0060] In this way, in the inter-slot repetition, R monitoring slots #k are used for repetition. i When multiple search spaces are provided for each of (i=0, . . . , R−1), multiple PDCCHs can be repeated between monitoring slots by mapping different PDCCHs to the multiple search spaces.

[0061] (1.2) In-slot repetition Intra-slot repetition may be applied to different symbols in the same slot during a predetermined period of monitoring time T. The following mainly describes the differences from (1.1) above.

[0062] For intra-slot repetition, the base station 20 transmits repetition symbol information indicating the symbols at which the PDCCH is repeated within one slot (i.e., the symbols at which the second and subsequent PDCCHs are transmitted) to the terminal 10. Based on the monitoring symbol information and repetition symbol information, the terminal 10 controls monitoring of the PDCCH that is repeatedly transmitted using multiple symbols within the same slot.

[0063] Fig. 7 is a diagram showing a first example of intra-slot repetition according to this embodiment. In Fig. 7, based on search space information of search space #3, a monitoring period T of search space #3 is set to slots #0 to #3 of each radio frame. Also, based on CORESET information of CORESET #3 associated with search space #3, CORESET #3 is allocated to symbols #0, #4, #8, and #12 of each monitoring slot. This search space #3 is used as a repetitive search space.

[0064] In FIG. 7, the monitoring symbol information in the search space information indicates the first symbols #0, #4, #8, and #12 in which search space #3 is arranged. Furthermore, the repetition symbol information in the search space information indicates the first symbols #4 and #12 in which search space #3 for monitoring the second and subsequent PDCCHs is arranged. For example, in FIG. 7, the repetition symbol information is a 14-bit bitmap corresponding to each of symbols #0 to #13, and the bits corresponding to symbols #4 and #12 are "1". Therefore, terminal 10 assumes that the first PDCCH is mapped in search space #3 of symbol #0, and the second PDCCH is mapped in search space #3 of symbol #4. The same applies to symbols #8 and #12 as to symbols #0 and #4.

[0065] 7, the bit of the repetition symbol information corresponding to the first symbol in which the second or subsequent PDCCH may be arranged within one slot is set to "1," and the bit corresponding to the first symbol in which the initially transmitted PDCCH may be arranged is set to "0," but is not limited to this. The repetition symbol information may be any information that can identify whether the initially transmitted PDCCH or the second or subsequent PDCCH is arranged in the symbol, and for example, the bit corresponding to the first symbol in which the second or subsequent PDCCH may be arranged within one slot may be set to "0," and the bit corresponding to the first symbol in which the initially transmitted PDCCH may be arranged may be set to "1."

[0066] (1.3) Combination of inter-slot and intra-slot repetition The inter-slot repetition and intra-slot repetition described above may be combined. Specifically, the terminal 10 may monitor one or more PDCCHs that are repeatedly transmitted using multiple symbols across multiple monitoring slots.

[0067] Fig. 8 is a diagram showing an example of a combination of inter-slot repetition and intra-slot repetition according to this embodiment. In Fig. 8, search space #3 and CORESET #3 are set as in Fig. 7, but it differs from Fig. 7 in that the number of repetitions R is 7. The following mainly describes the differences from Fig. 7. In Fig. 8, the repetition symbol information indicates the first symbols #4, #8 and #12 in which search space #3 for monitoring the PDCCH for the second and subsequent times is placed.

[0068] As shown in FIG. 8, the symbol pattern for transmitting the second and subsequent PDCCHs indicated by the repetition symbol information is a pattern of symbols for multiple monitoring slots #k i (0≦i≦R s -1), where R is the number of monitoring slots for the PDCCH with the repetition number R. s is the number of repetitions R and the number of search spaces n where the second and subsequent PDCCHs in one slot can be mapped. ssBased on this, for example, ceil{(R-1) / n ss In FIG. 8, the number of repetitions R is 7, and the number of search spaces n ss is 3, so R s is ceil{(7-1) / 3}=2.

[0069] In FIG. 8, monitoring slots #k0 and #k1 are included in different monitoring periods, but they may of course be included in the same monitoring period.

[0070] (1.4) Signaling of repetitive information Next, signaling of repetition information used for the first PDCCH monitoring will be described. As described above, the repetition information may include at least one of information indicating the number of PDCCH repetitions R, information indicating the maximum value of the number of repetitions R, start slot information, and repetition symbol information.

[0071] The repetition information may be transmitted from the base station 20 to the terminal 10 using a higher layer parameter. The higher layer parameter may be a parameter of the RRC layer (e.g., an RRC IE) or a parameter of the Medium Access Control (MAC) layer (e.g., a MAC Control Element (MAC CE)).

[0072] Fig. 9 is a diagram showing an example of search space information according to this embodiment. Fig. 9 shows an example in which the RRC IE "SearchSpace" as search space information includes the repetition information. Here, the repetition information includes information indicating the number of repetitions R (e.g., RRC IE "numRepetition-r17") and repetition symbol information (e.g., RRC IE "repetitionSymbolsWithinSlot-r17").

[0073] 9, the number of repetitions R may be, for example, 1, 2, 4, 8, 16, 32, 64, 128, or 256. Furthermore, the RRC IE "repetitionSymbolsWithinSlot-r17" as repetition symbol information may be a 14-bit bitmap.

[0074] 9 is merely an example, and the RRC IE "SearchSpace" may include, as repetition information, information indicating the maximum value of the number of repetitions R of PDCCH instead of information indicating the number of repetitions R. Furthermore, the RRC IE "SearchSpace" may include start slot information.

[0075] Fig. 10 is a diagram showing an example of derivation of the number of repetitions according to this embodiment. Fig. 10 shows an example of derivation of the number of repetitions R when search space information (for example, RRC IE "SearchSpace") includes information indicating the maximum value of the number of repetitions R of PDCCH.

[0076] Terminal 10 may determine the number of repetitions R of PDCCH based on the value of a predetermined field in DCI and the above-mentioned maximum value rep_max. For example, in Fig. 10, the value of a predetermined field in DCI is associated with parameters r1 to r4 for deriving the number of repetitions R. Terminal 10 determines the number of repetitions R based on the above-mentioned maximum value rep_max and these parameters.

[0077] For example, in Fig. 10, when the maximum value rep_max of the number of repetitions R of PDCCH is 8, if the value of a predetermined field in DCI is "00", the number of repetitions R = rep_max / 8 = 1. Similarly, if the value of a predetermined field in DCI is "01", "10", or "11", the number of repetitions R = 2, 4, or 8.

[0078] As shown in FIG. 10, by dynamically specifying the number of repetitions R of PDCCH based on DCI, the coverage extension range can be controlled more flexibly.

[0079] As described above, in the first PDCCH monitoring, the repetition search space is set based on the repetition information included in the search space information, so that monitoring of the PDCCH that is repeatedly transmitted using different time domain resources within a monitoring period with a predetermined cycle can be appropriately controlled.

[0080] (2) Second PDCCH monitoring In the second PDCCH monitoring, monitoring of the PDCCH repeatedly transmitted in the frequency domain will be described. The terminal 10 controls monitoring of the PDCCH repeatedly transmitted among a plurality of frequency domain resources corresponding to one or more CORESETs.

[0081] The repeating search space used for monitoring the PDCCH may be associated with a single CORESET (see 2.1 below) or with multiple CORESETs (see 2.2 below).

[0082] (2.1) Iterative search space associated with a single CORESET When a repetitive search space is associated with a single CORESET, the multiple frequency domain resources on which the PDCCH is repeatedly transmitted may correspond to the single CORESET.

[0083] The CORESET information for the CORESET may include a plurality of frequency domain resource information indicating the plurality of frequency domain resources respectively (see 2.1.1 below), may include frequency domain resource information indicating one of the plurality of frequency domain resources and repetition number information indicating the number of PDCCH repetitions (see 2.1.2 below), or may include frequency domain resource information indicating one of the plurality of frequency domain resources and offset information indicating the offset (see 2.1.3 below).

[0084] (2.1.1) First Example of Determining Frequency Domain Resources for Repetition In a first determination example, the terminal 10 determines a plurality of frequency domain resources for a single CORESET based on a plurality of frequency domain resource information included in CORESET information related to the CORESET.

[0085] 11 is a diagram showing a first example of determining frequency domain resources for repetition according to this embodiment. For example, in FIG. 11, CORESET#1 is associated with search space #1 used as a repetition search space. The CORESET information for CORESET#1 includes frequency domain resource information indicating frequency domain resource #0 for CORESET#1, as well as frequency domain resource information 1 and 2 indicating frequency domain resources #1 and #2 for CORESET#1, respectively.

[0086] The frequency domain resource information, frequency domain resource information 1, and frequency domain resource information 2 may each be a bitmap including bits corresponding to a group of a predetermined number of RBs (hereinafter referred to as an "RB group"). The length of the bitmap may be determined based on the number of RBs constituting the BWP and the number of RBs constituting one RB group. In FIG. 11, one RB group is assumed to be composed of six consecutive RBs, but this is not limited thereto, and one RB group may be composed of one or more RBs.

[0087] In the frequency domain resource information, frequency domain resource information 1 and 2, bits corresponding to RB groups constituting frequency domain resources #0, #1 and #2 may be set to "1", and bits corresponding to other RB groups may be set to "0". Note that frequency domain resources #0, #1 and #2 for the same CORESET #1 may be configured with different RB groups, and may not be allowed to include overlapping RB groups.

[0088] 11, terminal 10 may assume that search space #1 is arranged in each of frequency domain resources #0, #1, and #2 for CORESET #1. Terminal 10 may use search space #1 to control monitoring of the (i+1)th PDCCH transmitted in frequency domain resource #i (here, 0≦i≦2).

[0089] 11, the CORESET period of CORESET#1, which is composed of different frequency domain resources #0, #1, and #2, is the same, but this is not limited thereto and may be different. In this way, the CORESET period of CORESET#1 may be common to multiple frequency domain resources for CORESET#1, or may be set for each frequency domain resource for CORESET#1.

[0090] Fig. 12 is a diagram showing a first example of CORESET information according to this embodiment. For example, Fig. 12 shows an example in which the RRC IE "ControlResourceSet" as the CORESET information includes a plurality of pieces of frequency domain resource information each indicating a plurality of frequency domain resources for the CORESET identified by the RRC IE "controlResourceSetId".

[0091] For example, in the RRC IE "ControlResourceSet" shown in Fig. 12, the frequency domain resources for the initial transmission (first transmission) may be indicated by the RRC IE "frequencyDomainResources." On the other hand, the frequency domain resources for the second and subsequent transmissions may be indicated by the RRC IE "frequencyDomainResourcesRepetition-r17."

[0092] In this way, the CORESET information may include a list of frequency domain resource information for the second or subsequent transmissions (e.g., RRC IE "frequencyDomainResourcesRepetition-r17") in addition to frequency domain resource information for the initial transmission (e.g., RRC IE "frequencyDomainResourcesRepetition-r17"). The number of entries in the list may be equal to the number of repetitions R-1, for example. Each piece of frequency domain resource information for the second or subsequent transmissions may indicate an RB group that does not overlap with the frequency domain resource information for the initial transmission.

[0093] In FIG. 12, the RRC IEs "frequencyDomainResources" and "frequencyDomainResourcesRepetition-r17" are bitmaps containing bits corresponding to each RB group in the BWP and have 45 bits, but are not limited to these as long as they are information indicating frequency domain resources.

[0094] (2.1.2) Second Example of Determining Frequency Domain Resources for Repetition In the second determination example, the terminal 10 determines a plurality of frequency domain resources for a single CORESET based on frequency domain resource information and repetition number information included in CORESET information related to the CORESET. The second configuration example will be described focusing on differences from the first configuration example.

[0095] Fig. 13 is a diagram showing a second example of determining frequency domain resources for repetition according to the present embodiment. In Fig. 13, the CORESET information for CORESET#1 differs from Fig. 11 in that it includes repetition number information indicating the number of PDCCH repetitions R (here, R=3) instead of a plurality of frequency domain resource information 1 and 2 indicating frequency domain resources #1 and #2 for CORESET#1, respectively.

[0096] 13, terminal 10 assumes that frequency domain resources #0, #1, and #2, which are equal to the number of repetitions R, are allocated for CORESET #1 consecutively from frequency domain resource #0. Terminal 10 also assumes that the number of RBs in frequency domain resources #1 and #2 is equal to the number of RBs in frequency domain resource #0 (here, 6 RBs).

[0097] As described above, terminal 10 may assume that search space #1 is placed in each of frequency domain resources #0, #1, and #2 determined based on the RBs (more specifically, the positions and number of RBs) allocated to frequency domain resource #0 indicated by the frequency domain resource information and the number of repetitions R.

[0098] Fig. 14 is a diagram showing a second example of CORESET information according to this embodiment. For example, in Fig. 14, the RRC IE "ControlResourceSet" as the CORESET information includes an RRC IE "numRepetition-r17" indicating the number of repetitions R of PDCCH (or CORESET) instead of the RRC IE "frequencyDomainResourcesRepetition-r17" in Fig. 12. As shown in Fig. 14, the number of repetitions R may be set to, for example, any one of 1, 2, 4, 8, 16, or 32.

[0099] In this way, the CORESET information may include repetition number information (e.g., RRC IE "numRepetition-r17") in addition to frequency domain resource information for the initial transmission (e.g., RRC IE "frequencyDomainResources"). The repetition number information has a smaller number of bits than each piece of frequency domain resource information from the second time onwards shown in Fig. 12, so in the second configuration example, it is possible to reduce overhead due to the CORESET information compared to the first configuration example.

[0100] (2.1.3) Third Example of Determining Frequency Domain Resources for Repetition In the third determination example, the terminal 10 determines a plurality of frequency domain resources for a single CORESET based on frequency domain resource information and offset information included in CORESET information related to the CORESET. The third configuration example will be described focusing on differences from the first or second configuration example.

[0101] Fig. 15 is a diagram showing a second example of determining frequency domain resources for repetition according to the present embodiment. Fig. 15 differs from Fig. 13 in that the CORESET information for CORESET #1 includes offset information indicating offsets for frequency domain resources #1 and #2, instead of repetition number information.

[0102] For example, in FIG. 15, the offset information is offset n f1 and n f2 The offset value may indicate the number of RB groups to be shifted. In FIG. 15, the offset n f1 =2, and frequency domain resource #1 is shifted by 2 RB groups from the starting RB group of frequency domain resource #0. In this way, the amount of shift indicated by the offset value may be an integer multiple of the number of RBs constituting one RB group (e.g., 6 RBs), but is not limited to this and may be any predetermined number of RBs.

[0103] Terminal 10 receives frequency domain resource #0 indicated by the frequency domain resource information, and receives the RB group offset n from the starting RB group of frequency domain resource #0. f1 and n f2 It is assumed that frequency domain resources #1 and #2 shifted by 1 are allocated for CORESET #1. It is also assumed that terminal 10 has the same number of RBs in frequency domain resources #1 and #2 as the number of RBs in frequency domain resource #0 (here, 6 RBs).

[0104] In FIG. 15, the offset n for frequency domain resource #i (i≧1) fiis the offset for the starting RB group of frequency domain resource #0, but is not limited to this. fi may be the offset to the last RB group of frequency domain resource #0.

[0105] Also, the offset n of the frequency domain resource #i (i≧1) fi may be the offset relative to the starting RB group of frequency domain resource #i-1, or the offset n fi may be the offset to the last RB group of frequency domain resource #i-1.

[0106] Fig. 16 is a diagram showing a third example of CORESET information according to this embodiment. For example, in Fig. 16, the RRC IE "ControlResourceSet" as the CORESET information may include an RRC IE "rbg-ShiftList-r17" indicating the offset of each frequency domain resource for the second and subsequent repetitions, instead of the RRC IE "frequencyDomainResourcesRepetition-r17" in Fig. 12. The RRC IE "rbg-ShiftList-r17" is a list of RRC IEs "RBG-Shift-r17" indicating the offset of each frequency domain resource, and the RRC IE "RBG-Shift-r17" may be able to specify an offset value of 1 to 32, for example. Furthermore, the RRC IE "ControlResourceSet" may include an RRC IE "numRepetition-r17" indicating the number of repetitions R of PDCCH.

[0107] Thus, in addition to the frequency domain resource information for the first transmission (e.g., RRC IE "frequencyDomainResources"), the CORESET information may include offset information (e.g., RRC IE "rbg-ShiftList-r17") indicating the offset of each frequency domain resource for subsequent repetitions. Since the offset information has fewer bits compared to the frequency domain resource information for each subsequent repetition shown in FIG. 12, in the third setting example, the overhead due to the CORESET information can be reduced compared to the first setting example. Also, since the frequency domain resource #i can be distributed and arranged within the BWP, the frequency diversity gain can be improved compared to the second setting example.

[0108] Note that in the above, the offset n fi for each frequency domain resource #i (0 < i < R) for subsequent repetitions is specified by the base station 20, but it is not limited to this. An offset n f common to the frequency domain resources #i (0 < i < R) for subsequent repetitions may be specified by the base station 20. The above CORESET information may include offset information indicating the common offset n f .

[0109] FIG. 17 is a diagram showing a fourth determination example of the frequency domain resources for repetitions according to the present embodiment. In FIG. 17, it is different from FIG. 15 in that an offset n f common to the frequency domain resources #i (0 < i < R) for subsequent repetitions is used. As shown in FIG. 17, the common offset n f may be the offset of the frequency domain resource #i with respect to the start RB group of the frequency domain resource #i - 1 (i > 0). Although not shown, the common offset n f may be the offset of the frequency domain resource #i with respect to the last RB group of the frequency domain resource #i - 1 (i > 0).

[0110] 17, the CORESET information may include offset information indicating an offset common to each frequency domain resource for the second and subsequent repetitions, and repetition information indicating the number of repetitions R of the PDCCH (or CORESET). Terminal 10 uses frequency domain resource #0 indicated by the frequency domain resource information, the starting RB group of frequency domain resource #0, and the common offset n f frequency domain resource #1 shifted by a common offset n from the starting RB group of frequency domain resource #1 f It is assumed that frequency domain resource #2 shifted by 1 is allocated for CORESET #1. Furthermore, it is assumed that terminal 10 has the same number of RBs in frequency domain resources #1 and #2 as the number of RBs in frequency domain resource #0 (here, 6 RBs).

[0111] As described above, when a repetition search space is associated with a single CORESET, by configuring a plurality of frequency domain resources for the single CORESET, it is possible to repeat the PDCCH among a plurality of frequency domain resources. In this case, by changing the CORESET information, it is possible to realize the repetition of the PDCCH among a plurality of frequency domain resources without changing the search space information.

[0112] (2.2) Iterative search space associated with multiple CORESETs When a repeating search space is associated with multiple CORESETs, multiple frequency domain resources on which the PDCCH is repeatedly transmitted may correspond to each of the multiple CORESETs. Search space information regarding the repeating search space may include identification information of each of the multiple CORESETs.

[0113] The terminal 10 determines the frequency domain resource of each of the plurality of CORESETs based on the plurality of CORESET information of each of the plurality of CORESETs. Specifically, the terminal 10 determines the frequency domain resource of each of the plurality of CORESETs based on the frequency domain resource information included in each of the plurality of CORESET information.

[0114] Fig. 18 is a diagram showing a fifth example of determining frequency domain resources for repetition according to this embodiment. For example, in Fig. 18, CORESETs #1, #2, and #3 are associated with search space #1 used as a repetition search space, and the CORESET information of each of CORESETs #1, #2, and #3 includes frequency domain resource information indicating frequency domain resources #0, #1, and #2, respectively. Each piece of frequency domain resource information is as described in Fig. 11.

[0115] 18, terminal 10 may assume that search space #1 is arranged in frequency domain resources #0, #1, and #2 for CORESETs #1, #2, and #3 associated with search space #1, respectively. Furthermore, terminal 10 may monitor search space #1 associated with CORESET #i, for example, assuming that the ith repetition of PDCCH is transmitted using frequency domain resources for CORESET #i (here, i≧1).

[0116] 18, the CORESET periods of CORESETs #1, #2, and #3 associated with repetition search space #1 are the same, but this is not limited to this and they may be different. In this way, when multiple CORESETs are associated with repetition search space #1, the CORESET period, frequency domain resources, etc. can be flexibly set for each repetition.

[0117] Fig. 19 is a diagram showing an example of search space information according to the present embodiment. For example, Fig. 19 shows an example in which the RRC IE "SearchSpace" as search space information includes identification information of multiple CORESETs associated with the repetitive search space.

[0118] For example, in the RRC IE "SearchSpace" shown in Fig. 19, a CORESET in which a repetition search space for monitoring a PDCCH for an initial transmission (first time) is arranged may be indicated by the RRC IE "controlResourceSetId". On the other hand, a CORESET in which a repetition search space for monitoring a PDCCH for the second or subsequent time is arranged may be indicated by the RRC IE "controlResourceSetRepetition-r17".

[0119] In this way, the search space information may include a list (e.g., RRC IE "controlResourceSetRepetition-r17") of identification information of CORESET for second or subsequent transmissions (e.g., RRC IE "ControlResourceSetId") in addition to identification information of CORESET for initial transmission (e.g., RRC IE "controlResourceSetId"). The number of entries in the list may be equal to the repetition count R-1, for example.

[0120] The CORESET information related to the above-described repetitive CORESET may be distinguished from the CORESET for initial transmission and notified from the base station 20 to the terminal 10. Specifically, the list of CORESET information may be included in information related to the PDCCH (hereinafter referred to as "PDCCH information"). The PDCCH information may include PDCCH information individual to the terminal 10 (hereinafter referred to as "individual PDCCH information") and / or PDCCH information common to one or more terminals 10 (hereinafter referred to as "common PDCCH information").

[0121] Fig. 20 is a diagram showing an example of PDCCH information according to the present embodiment. Fig. 20 shows an example in which the RRC IE "PDCCH-Config" as individual PDCCH information and the RRC IE "PDCCH-ConfigCommon" as common PDCCH information include CORESET information and identification information of multiple CORESETs associated with a repetitive search space.

[0122] For example, the RRC IE "PDCCH-Config" shown in FIG. 20 includes the RRC IE "repetitionControlResourceSetToAddModList-r17", and the RRC IE "repetitionControlResourceSetToAddModList-r17" may be a list of RRC IEs "ControlResourceSet" as CORESET information of a CORESET in which a repetition search space for monitoring the second and subsequent PDCCHs is arranged. Furthermore, the RRC IE "PDCCH-Config" may include the RRC IE "repetitionControlResourceSetToReleaseList-r17", which is a list of RRC IEs "ControlResourceSetId" as identification information of the CORESET. Furthermore, the RRC IE "PDCCH-ConfigCommon" shown in FIG. 20 may include the above-mentioned RRC IE "repetitionControlResourceSetToAddModList-r17".

[0123] In this way, by including the individual PDCCH information and the common PDCCH information CORESET information (e.g., RRC IE "repetitionControlResourceSetToAddModList-r17") of the CORESET in which the repetition search space is placed, it is possible to repeatedly transmit both a PDCCH individual to a terminal 10 and a PDCCH common to one or more terminals 10 using multiple CORESETs.

[0124] As described above, when a repetition search space is associated with a plurality of CORESETs, by configuring a plurality of frequency domain resources corresponding to each of the plurality of CORESETs, it is possible to repeat the PDCCH among a plurality of frequency domain resources. In this case, by changing the search space information and / or PDCCH information, it is possible to realize the repetition of the PDCCH among a plurality of frequency domain resources without changing the CORESET information.

[0125] (3) Combination of Primary and Secondary PDCCH Monitoring In the above-mentioned first PDCCH monitoring, it is assumed that the terminal 10 controls the monitoring of the PDCCH that is repeatedly transmitted using the same frequency domain resource between different time domain resources (e.g., between slots and / or between symbols in the same slot), but this is not limited to this.

[0126] In the first PDCCH monitoring, the terminal 10 may control monitoring of PDCCHs repeatedly transmitted using different frequency domain resources between different time domain resources (e.g., between slots and / or between symbols in the same slot), i.e., the first PDCCH monitoring can be combined with the second PDCCH monitoring.

[0127] In addition, in the above-mentioned second PDCCH monitoring, it is assumed that terminal 10 controls the monitoring of PDCCHs that are repeatedly transmitted between multiple frequency domain resources corresponding to one or more CORESETs in the same time domain resource within a monitoring period of a predetermined cycle, but this is not limited to this.

[0128] In the second PDCCH monitoring, the terminal 10 may control monitoring of PDCCHs repeatedly transmitted among multiple frequency domain resources corresponding to one or more CORESETs in different time domain resources within a predetermined periodic monitoring period, i.e., the second PDCCH monitoring can be combined with the first PDCCH monitoring.

[0129] In this way, repeating the PDCCH using different frequency domain resources for each time domain resource within a predetermined periodic monitoring period by combining the first and second PDCCH monitoring may be called "frequency hopping."

[0130] Fig. 21 is a diagram showing an example of repeated transmission of PDCCH to which frequency hopping according to this embodiment is applied. For example, Fig. 21 shows, as an example, a combination of inter-slot repetition shown in Fig. 2 and a first determination example of frequency domain resources for repetition shown in Fig. 11. Although not shown, it goes without saying that any of the aspects described in the first and second PDCCH monitoring may be combined.

[0131] As shown in Fig. 21, different frequency domain resources #0 and #1 corresponding to CORESET #1 are used between repeated monitoring slots #0 and #1. Terminal 10 may control monitoring of search space #1 on the assumption that the first PDCCH is transmitted using frequency domain resource #0 in monitoring slot #0, whereas the second PDCCH is transmitted using frequency domain resource #1 in monitoring slot #1.

[0132] In FIG. 21, it is assumed that the number of frequency domain resources #0 and #1 configured for CORESET #1 associated with the repetition search space #1 is equal to the number of PDCCH repetitions R (for example, R=2 in FIG. 21), but this is not limited to this. The number N of frequency domain resources configured for CORESET #1 FR may be smaller or larger than the number of repetitions R. The number of repetitions R > the number of frequency domain resources N FR In this case, the repetition search space may be arranged in the same frequency domain resource for each predetermined number of repetitions. For example, frequency domain resource #0 may be used for odd-numbered repetitions, and frequency domain resource #1 may be used for even-numbered repetitions.

[0133] (4) Search space group switching control Next, the control of switching between search space groups will be described. In this embodiment, the repeating search spaces described in (1) to (3) above may be associated with one or more search space groups. For example, search space information (e.g., RRC IE "SearchSpace") may include search space group information (e.g., RRC IE "searchSpaceGroupIdList") indicating one or more search space groups to which the repeating search space is associated.

[0134] Terminal 10 controls the switching of search space groups based on the value of a predetermined field of DCI. Figure 22 is a diagram showing an example of switching of search space groups according to this embodiment. Figure 22 shows an example in which terminal 10 switches the search space group used for monitoring the repeatedly transmitted PDCCH from search space group #1 to #2.

[0135] For example, in Figure 22, the monitoring period k2 of the repeating search space associated with search space group #2 is longer than the monitoring period k1 of the repeating search space associated with search space group #1. Note that in Figure 22, the monitoring periods T1 and T2 of the search spaces associated with search space groups #1 and #2, respectively, are assumed to be the same, but this is not limited to this. The configuration of the search space associated with each search space group (e.g., monitoring period k, monitoring period T, start slot of monitoring period T, number of PDCCH candidates per aggregation level, symbol in which the search space is placed within the monitoring slot, etc.) can be freely set using search space information for the search space.

[0136] 22, terminal 10 controls switching of search space groups based on the value of a predetermined field in DCI. Furthermore, terminal 10 controls monitoring of PDCCH using a repeating search space associated with the search space group based on the value of the predetermined field in the DCI.

[0137] Fig. 23 is a diagram showing an example of DCI used for search space group switching control according to this embodiment. As shown in Fig. 23, the DCI may be a DCI format (e.g., DCI format 1_X) used for scheduling a downlink shared channel or a DCI format (e.g., DCI format 0_X) used for scheduling an uplink shared channel. Here, X is an arbitrary integer.

[0138] In the following, a physical downlink shared channel (PDSCH) and a physical uplink shared channel (PUSCH) will be described as examples of a downlink shared channel and an uplink shared channel. However, the names of the downlink shared channel and the uplink shared channel are not limited to PDSCH and PUSCH as long as they are channels used to transmit user data and / or higher layer parameters.

[0139] As shown in FIG. 23, DCI format 1_X or 0_X may include a search space group switching field used to switch search space groups, a resource allocation field indicating resources allocated to PDSCH or PUSCH, and the like.

[0140] Alternatively, as shown in FIG. 23, the DCI may be a DCI format (for example, DCI format 2_X) used for purposes other than scheduling of PDSCH or PUSCH. Here, X is an arbitrary integer. As shown in FIG. 23, DCI format 2_X may include M (M≧1) search space group switching fields #1 to #M. Here, M may be, for example, the number of cells C configured in terminal 10. Note that DCI format 2_X is not limited to the one shown in the figure, and may, of course, include a single search space group switching field.

[0141] Figure 24 is a diagram showing an example of the value of the search group switching field according to this embodiment. Note that the search group switching field in Figures 23 and 24 may be a predetermined field in the DCI, and the name is not limited to this. Also, in Figure 24, the search group switching field is assumed to be 2 bits, but it is not limited to this and may be 1 bit or more.

[0142] As shown in Fig. 24, each value in the search group switching field may indicate a search space group to which switching is to be performed. In Fig. 24, the search space group to which switching is to be performed, indicated by each value in the search group switching field, is set in terminal 10 by a higher layer parameter, but is not limited to this and may be determined in advance in specifications.

[0143] Furthermore, terminal 10 may use a value in the search group switching field to indicate information related to the number of repetitions R of PDCCH monitored in a search space associated with the search space group indicated by the value. For example, in FIG. 24, the information related to the number of repetitions R is parameter values ​​r1 to r4, but is not limited to this and may be the number of repetitions R itself. Terminal 10 receives information indicating the maximum value rep_max of the number of repetitions R separately from the DCI.

[0144] As shown in Fig. 24, the terminal 10 may determine the number of repetitions R based on the maximum value rep_max and the parameter value indicated by the value of the search group switching field. Note that Fig. 24 is merely an example, and it goes without saying that the number of repetitions R associated with each value of the search group switching field may be defined in the specifications.

[0145] Furthermore, when the DCI including the search group switching field is a DCI format (for example, DCI format 1_X or 0_X) used for scheduling the PDSCH or PUSCH, terminal 10 may determine the number of repetitions R of the PDSCH or PUSCH based on the value of the search group switching field. In this way, the number of repetitions R derived based on the value of the search space group switching field of DCI format 1_X or 0_X in FIG. 23 may be the number of repetitions R of the PDSCH or PUSCH. Note that the number of repetitions R of the PDSCH or PUSCH can be derived in the same way as the number of repetitions R of the PDCCH.

[0146] Furthermore, a DCI format (for example, DCI format 1_X or 0_X) used for scheduling a PDSCH or a PUSCH may include, in addition to the value of the search group switching field, a predetermined field value used to derive the number of repetitions R of a PDSCH or a PUSCH. In this case, terminal 10 may determine the number of repetitions R of a PDCCH based on the value of the search space group switching field, and may determine the number of repetitions R of a PDSCH or a PUSCH based on the predetermined field value.

[0147] Furthermore, terminal 10 may use a value of a search space group switching field in a DCI format (for example, DCI format 2_X) used for purposes other than scheduling the PDSCH or PUSCH to derive the number of repetitions R of the PDSCH and / or PUSCH. Alternatively, the value of the search space group switching field in the DCI format may be used to derive the number of repetitions R of the PDCCH, and other field values ​​in the DCI format may be used to derive the number of repetitions R of the PDSCH or PUSCH.

[0148] As described above, when a search space group is dynamically switched using DCI, it is possible to dynamically control the number of repetitions R of PDCCH monitored in a search space associated with the search space group. Therefore, it is possible to appropriately control the monitoring of the PDCCH. In addition, it is possible to dynamically control the number of repetitions of PDSCH or PUSCH scheduled by the DCI.

[0149] (Wireless communication system configuration) Next, we will explain the configuration of each device in the above-described wireless communication system 1. Note that the following configuration is intended to show the configuration necessary for explaining this embodiment, and does not exclude each device from having a functional block other than that shown.

[0150] <Hardware configuration> 25 is a diagram showing an example of the hardware configuration of each device in the wireless communication system according to this embodiment. Each device in the wireless communication system 1 (for example, a terminal 10, a base station 20, a CN 30, etc.) includes a processor 11, a storage device 12, a communication device 13 for performing wired or wireless communication, and an input device 14 for accepting various input operations and outputting various information.

[0151] The processor 11 is, for example, a CPU (Central Processing Unit) and controls each device in the wireless communication system 1. The processor 11 may execute various processes described in this embodiment by reading and executing a program from the storage device 12. Each device in the wireless communication system 1 may be configured with one or more processors 11. Furthermore, each device may be called a computer.

[0152] The storage device 12 is configured by, for example, storage such as a memory, a hard disk drive (HDD), and / or a solid state drive (SSD), etc. The storage device 12 may store various information necessary for the processor 11 to execute processing (for example, a program executed by the processor 11, etc.).

[0153] The communication device 13 is a device that communicates via a wired and / or wireless network, and may include, for example, a network card, a communication module, a chip, an antenna, etc. The communication device 13 may also include an amplifier, an RF (Radio Frequency) device that performs processing related to wireless signals, and a BB (BaseBand) device that performs baseband signal processing.

[0154] The RF device performs, for example, D / A conversion, modulation, frequency conversion, power amplification, etc. on the digital baseband signal received from the BB device to generate a radio signal to be transmitted from antenna A. The RF device also performs frequency conversion, demodulation, A / D conversion, etc. on the radio signal received from the antenna to generate a digital baseband signal and transmit it to the BB device. The BB device performs processing to convert the digital baseband signal into packets, and processing to convert the packets into digital baseband signals.

[0155] The input / output device 14 includes, for example, input devices such as a keyboard, a touch panel, a mouse, and / or a microphone, and output devices such as a display and / or a speaker.

[0156] The hardware configuration described above is merely an example. Each device in the wireless communication system 1 may omit some of the hardware shown in Fig. 25, or may include hardware not shown in Fig. 25. Furthermore, the hardware shown in Fig. 4 may be configured using one or more chips.

[0157] <Function block configuration> Terminal 26 is a diagram showing an example of a functional block configuration of a terminal according to this embodiment. As shown in FIG. 26, the terminal 10 includes a receiving unit 101, a transmitting unit 102, and a control unit 103.

[0158] All or part of the functions realized by the receiving unit 101 and the transmitting unit 102 can be realized using the communication device 13. All or part of the functions realized by the receiving unit 101 and the transmitting unit 102 and the control unit 103 can be realized by the processor 11 executing a program stored in the storage device 12. The program can be stored in a storage medium. The storage medium storing the program may be a non-transitory computer-readable medium. The non-transitory storage medium is not particularly limited, and may be, for example, a storage medium such as a USB memory or a CD-ROM.

[0159] The receiving unit 101 receives a downlink signal. The receiving unit 101 may also receive information and / or data transmitted via the downlink signal. Here, "receiving" may include performing reception-related processing such as at least one of receiving, demapping, demodulating, decoding, monitoring, and measuring a radio signal.

[0160] The downlink signal may include, for example, at least one of the PDCCH, PDSCH, downlink reference signal, synchronization signal, broadcast channel, etc. The downlink reference signal may include, for example, a demodulation reference signal (DMRS) of the PDCCH or PDSCH.

[0161] Furthermore, the receiving unit 101 receives DCI. Specifically, the receiving unit 101 may detect a PDCCH by monitoring a search space and receive DCI transmitted via the PDCCH. The receiving unit 101 may receive a PDSCH based on the DCI and receive user data and / or higher layer parameters transmitted via the PDSCH. The receiving unit 101 may also transmit DCI including a value of a predetermined field used for switching search space groups (for example, FIG. 23).

[0162] The receiver 101 may receive search space information (e.g., FIGS. 9 and 19) regarding a search space associated with a control resource set (CORESET). The receiver 101 may also receive CORESET information (e.g., FIGS. 12, 14, and 16) regarding one or more CORESETs associated with the search space.

[0163] Furthermore, the receiving unit 101 may receive the PDCCH information (for example, FIG. 20). The PDCCH information may be for each predetermined bandwidth (for example, BWP or cell C) set in the terminal 10, and may include CORESET information related to one or more CORESETs used within the predetermined bandwidth, and search space information related to one or more search spaces.

[0164] Furthermore, the receiving unit 101 may receive information indicating the maximum value of the number of repetitions R (for example, FIG. 24). This information may be included in the search space information.

[0165] Furthermore, the receiving unit 101 may combine the repeatedly transmitted PDCCHs and decode the DCI based on the combination result, or the receiving unit 101 may decode the DCI based on each PDCCH without combining the repeatedly transmitted PDCCHs.

[0166] The transmitting unit 102 transmits an uplink signal. The transmitting unit 102 may also transmit information and / or data transmitted via the uplink signal. Here, "transmitting" may include performing transmission-related processing such as at least one of encoding, modulation, mapping, and transmission of a radio signal. The uplink signal may include at least one of the above-mentioned PUSCH, an uplink reference signal, etc. The uplink reference signal may include, for example, a DMRS of a PUSCH, etc.

[0167] The control unit 103 performs various controls in the terminal 10. Specifically, the control unit 103 may control monitoring of the downlink control channel using the search space within a predetermined cycle of monitoring period T, based on the search space information and / or the CORESET information.

[0168] The control unit 103 may control the monitoring of the PDCCH that is repeatedly transmitted between different slots and / or within the same slot within the monitoring period T based on repetition information regarding the repetition of the PDCCH included in the above search space information (see (1) above).

[0169] Here, the repetition information may include information indicating the number of repetitions R of the PDCCH. The control unit 103 may determine the different slots based on the number of repetitions R (for example, FIGS. 4 to 6, 8 and 9).

[0170] Furthermore, the repetition information may include information indicating the maximum value of the number of repetitions R of the PDCCH. The control unit 103 may determine the different slots based on the number of repetitions R determined based on the maximum value and a predetermined field value in the DCI (for example, FIGS. 4 to 6, 8 and 10).

[0171] Furthermore, the repetition information may include information indicating the start slot #k0 of the PDCCH repetition. Control section 103 may determine the different slots based on the start slot #k0 (for example, FIGS. 4 to 8).

[0172] The different slots may be multiple slots within one monitoring period T of a predetermined cycle (e.g., FIG. 4), or multiple slots spanning multiple periods of a predetermined cycle of monitoring period T (e.g., FIGS. 5, 6, and 8).

[0173] Furthermore, the repetition information may include repetition symbol information indicating the symbols on which the PDCCH is repeated. The control unit 103 may determine the plurality of symbols for monitoring the PDCCH in the same slot based on the repetition symbol information and monitoring symbol information indicating the symbols for monitoring the PDCCH (for example, FIGS. 7 and 8).

[0174] The control unit 103 may control monitoring of PDCCHs that are repeatedly transmitted using the same frequency domain resource between the different slots and / or within the same slot (see (1) above). Also, the control unit 103 may control monitoring of PDCCHs that are repeatedly transmitted using different frequency domain resources between the different slots and / or within the same slot (see (3) above, for example, FIG. 21).

[0175] The control unit 103 may control monitoring of the PDCCH, which is repeatedly transmitted among a plurality of frequency domain resources corresponding to the one or more CORESETs (see (2) above).

[0176] Here, the search space may be associated with a single CORESET, and the plurality of frequency domain resources may correspond to the single CORESET (see (2.1) above).

[0177] The CORESET information for the single CORESET may include a plurality of pieces of frequency domain resource information indicating the plurality of frequency domain resources, respectively. The control unit 103 may determine the plurality of frequency domain resources based on the plurality of pieces of frequency domain resource information (for example, FIGS. 11 and 12).

[0178] Furthermore, the CORESET information for the single CORESET may include frequency domain resource information indicating one of the frequency domain resources and repetition number information indicating the number of PDCCH repetitions R. The control unit 103 may determine the plurality of frequency domain resources based on the frequency domain resource information and the repetition number information (e.g., FIGS. 13 and 14).

[0179] Furthermore, the CORESET information for the single CORESET may include frequency domain resource information indicating one of the plurality of frequency domain resources and offset information indicating offsets for other frequency domain resources of the plurality of frequency domain resources. The control unit 103 may determine the plurality of frequency domain resources based on the frequency domain resource information and the offset information (for example, FIGS. 15 to 17).

[0180] Furthermore, the search space may be associated with multiple CORESETs, and the multiple frequency domain resources may correspond to the multiple CORESETs, respectively (see (2.2) above).

[0181] The control unit 103 may determine the plurality of frequency domain resources based on a plurality of pieces of CORESET information relating to the plurality of CORESETs (for example, FIGS. 18 to 20).

[0182] The control unit 103 may determine a monitoring period T of a predetermined cycle for monitoring the PDCCH using a search space based on the search space information. Furthermore, the control unit 103 may determine the plurality of frequency domain resources corresponding to the same time domain resource within the monitoring period T (see (2) above). Alternatively, the control unit 103 may determine a plurality of frequency domain resources corresponding to different time domain resources within the monitoring period T (see (3) above, for example, FIG. 21).

[0183] Further, when the receiving unit 101 successfully decodes the (i + 1)-th (0 ≤ i < R - 1) PDCCH, the control unit 103 may stop monitoring the PDCCH after the (i + 2)-th time. For example, when the control unit 103 successfully decodes the (i + 1)-th PDCCH in slot #k i it may stop monitoring the repetition search space provided after slot #k i+1 or may continue monitoring for R times. Similarly, when the control unit 103 successfully decodes the (i + 1)-th PDCCH in frequency resource #i, it may stop monitoring the repetition search space provided after frequency resource #i + 1 or may continue monitoring for R times.

[0184] In addition, the control unit 103 may control the switching of the search space group based on the value of a predetermined field in the DCI. The control unit 103 may determine the repetition number R of the PDCCH to be monitored using the search space associated with the search space group based on the value of the predetermined field (see (4) above).

[0185] Further, the control unit 103 may determine the repetition number R of the PDCCH to be monitored using the search space associated with the search space group after switching based on the maximum value of the repetition number R of the PDCCH and the value of the predetermined field in the DCI (for example, FIG. 24).

[0186] In addition, when the control unit 103 controls the switching of the search space group based on the value of the predetermined field in the DCI, it may determine the repetition number of the PDSCH or PUSCH scheduled by the DCI.

[0187] ≪Base Station≫ FIG. 27 is a diagram showing an example of the functional block configuration of the base station according to the present embodiment. As shown in FIG. 27, the base station 20 includes a receiving unit 201, a transmitting unit 202, and a control unit 203.

[0188] All or part of the functions realized by the receiving unit 201 and the transmitting unit 202 can be realized using the communication device 13. All or part of the functions realized by the receiving unit 201 and the transmitting unit 202 and the control unit 203 can be realized by the processor 11 executing a program stored in the storage device 12. The program can be stored in a storage medium. The storage medium storing the program may be a computer-readable non-transitory storage medium. The non-transitory storage medium is not particularly limited, and may be, for example, a storage medium such as a USB memory or a CD-ROM.

[0189] The receiving unit 201 receives the uplink signal. The receiving unit 201 may also receive information and / or data transmitted via the uplink signal.

[0190] The transmitting unit 202 transmits the downlink signal. The transmitting unit 202 may also transmit information and / or data transmitted via the downlink signal.

[0191] Furthermore, the transmitting unit 202 transmits the DCI. Specifically, the transmitting unit 202 may transmit the DCI via a PDCCH. The transmitting unit 202 may transmit a PDSCH scheduled by the DCI.

[0192] Furthermore, the transmitter 202 may transmit DCI including a value of a predetermined field used for switching search space groups (for example, FIG. 23). The value of the predetermined field may indicate information regarding the number of repetitions of a downlink control channel monitored using a search space associated with the search space group. The value of the predetermined field may indicate information regarding the number of repetitions of a downlink shared channel or an uplink shared channel scheduled by the downlink control information.

[0193] The transmitter 202 may transmit search space information (e.g., FIGS. 9 and 19) related to a search space associated with a control resource set (CORESET). Furthermore, the receiver 101 may transmit CORESET information (e.g., FIGS. 12, 14, and 16) related to one or more CORESETs associated with the search space. Furthermore, the transmitter 202 may transmit the PDCCH information (e.g., FIG. 20). Furthermore, the transmitter 202 may transmit information indicating the maximum value of the number of repetitions R (e.g., FIG. 24).

[0194] The control unit 203 performs various controls in the base station 20. Specifically, the control unit 203 may control transmission of a downlink control channel using a search space within a predetermined period of monitoring time T, based on the search space information and / or the CORESET information.

[0195] The control unit 203 may control repeated transmission of the PDCCH between different slots and / or within the same slot within the monitoring period T based on repetition information regarding the repetition of the PDCCH included in the above search space information (see (1) above).

[0196] Here, the repetition information may include information indicating the number of repetitions R of the PDCCH. The control unit 203 may determine the different slots based on the number of repetitions R (for example, FIGS. 4 to 6 and 9).

[0197] Furthermore, the repetition information may include information indicating the maximum value of the number of repetitions R of the PDCCH. Control section 203 may determine the different slots based on the number of repetitions R determined based on the maximum value and a predetermined field value in the DCI (for example, FIGS. 4 to 6 and 10).

[0198] Furthermore, the repetition information may include information indicating the start slot #k0 of the PDCCH repetition. Control section 203 may determine the different slots based on the start slot #k0 (for example, FIGS. 4 to 8).

[0199] The different slots may be multiple slots within one monitoring period T of a predetermined cycle of monitoring periods T (e.g., FIG. 4), or multiple slots spanning multiple periods of a predetermined cycle of monitoring periods T (e.g., FIGS. 5 and 6).

[0200] Furthermore, the repetition information may include repetition symbol information indicating symbols for repeating the PDCCH. The control unit 203 may determine multiple symbols for repeatedly transmitting the PDCCH within the same slot based on the repetition symbol information and monitoring symbol information indicating symbols for monitoring the PDCCH (e.g., FIGS. 7 and 8).

[0201] The control unit 203 may control repeated transmission of the PDCCH using the same frequency domain resource between the different slots and / or within the same slot (see (1) above). Also, the control unit 203 may control repeated transmission of the PDCCH using different frequency domain resources between the different slots and / or within the same slot (see (3) above).

[0202] The control unit 203 may control repeated transmission of the PDCCH among a plurality of frequency domain resources corresponding to the one or more CORESETs (see (2) above).

[0203] Here, the search space may be associated with a single CORESET, and the plurality of frequency domain resources may correspond to the single CORESET (see (2.1) above).

[0204] The CORESET information for the single CORESET may include a plurality of pieces of frequency domain resource information indicating the plurality of frequency domain resources, respectively. The control unit 203 may determine the plurality of frequency domain resources based on the plurality of pieces of frequency domain resource information (e.g., FIGS. 11 and 12).

[0205] Furthermore, the CORESET information for the single CORESET may include frequency domain resource information indicating one of the frequency domain resources and repetition number information indicating the number of PDCCH repetitions R. The control unit 203 may determine the plurality of frequency domain resources based on the frequency domain resource information and the repetition number information (e.g., FIGS. 13 and 14).

[0206] Furthermore, the CORESET information for the single CORESET may include frequency domain resource information indicating one of the plurality of frequency domain resources and offset information indicating offsets for other frequency domain resources of the plurality of frequency domain resources. The control unit 203 may determine the plurality of frequency domain resources based on the frequency domain resource information and the offset information (e.g., FIGS. 15 to 17).

[0207] Furthermore, the search space may be associated with multiple CORESETs, and the multiple frequency domain resources may correspond to the multiple CORESETs, respectively (see (2.2) above).

[0208] The control unit 203 may determine the plurality of frequency domain resources based on a plurality of pieces of CORESET information relating to the plurality of CORESETs (for example, FIGS. 18 to 20).

[0209] The control unit 203 may determine a monitoring period T of a predetermined cycle in which the PDCCH is repeatedly transmitted using the search space based on the search space information. Furthermore, the control unit 203 may determine the plurality of frequency domain resources corresponding to the same time domain resource within the monitoring period T (see (1) above). Alternatively, the control unit 203 may determine a plurality of frequency domain resources corresponding to different time domain resources within the monitoring period T (see (3) above).

[0210] Furthermore, control unit 203 may control switching of search space groups (see (4) above).

[0211] (Operation of wireless communication system) Next, a description will be given of the operation of the wireless communication system 1 configured as above. Note that Figures 28 and 29 are merely examples, and it goes without saying that some steps may be omitted, or steps not shown may be performed.

[0212] Fig. 28 is a diagram showing an example of the operation of PDCCH monitoring in the wireless communication system according to this embodiment. As shown in Fig. 28, in step S101, the terminal 10 receives one or more pieces of search space information and / or one or more pieces of CORESET information. The search space information and / or the CORESET information may be included in, for example, an RRC reconfiguration message, but is not limited to this.

[0213] In step S102, the terminal 10 sets a search space for monitoring the PDCCH that is repeatedly transmitted within a monitoring period T of a predetermined cycle, based on the search space information and / or the CORESET information.

[0214] In step S103, the terminal 10 monitors the PDCCH that is repeatedly transmitted using different time domain resources and / or different frequency domain resources, using the search space set in step S102 (see (1) to (3) above).

[0215] As described above, the wireless communication system 1 according to this embodiment can appropriately control monitoring of PDCCHs that are repeatedly transmitted using different time domain resources and / or different frequency domain resources.

[0216] Fig. 29 is a diagram showing an example of the operation of switching search space groups in the wireless communication system according to this embodiment. As shown in Fig. 29, in step S201, terminal 10 receives DCI.

[0217] In step S202, terminal 10 controls switching of search space groups based on the value of a predetermined field in the DCI received in step S201. Specifically, terminal 10 may switch the search space group used for monitoring the PDCCH to the search space group indicated by the value of the predetermined field.

[0218] In step S203, the terminal 10 may determine the number of repetitions R of the PDCCH to be monitored in the search space associated with the search space group to which the switch is made in step S202, based on the value of a predetermined field in the DCI received in step S201.

[0219] In step S204, the terminal 10 monitors the PDCCH, which is repeatedly transmitted the number of repetitions R determined in step S203, using the search space (see (1) to (3) above).

[0220] (Other embodiments) The various signals, information, and parameters in the above embodiments may be signaled at any layer. That is, the various signals, information, and parameters may be replaced with signals, information, and parameters of any layer, such as an upper layer (e.g., a Non Access Stratum (NAS) layer, an RRC layer, a MAC layer, etc.) or a lower layer (e.g., a physical layer). Furthermore, notification of predetermined information is not limited to being explicitly performed, and may be performed implicitly (e.g., by not notifying information or by using other information).

[0221] Furthermore, the names of various signals, information, parameters, IEs, channels, time units, and frequency units in the above embodiments are merely examples and may be replaced with other names. For example, a slot may be named in any way as long as it is a time unit having a predetermined number of symbols. Furthermore, an RB may be named in any way as long as it is a frequency unit having a predetermined number of subcarriers.

[0222] Furthermore, the applications of the terminal 10 in the above embodiments (for example, RedCap, IoT, etc.) are not limited to those exemplified, and the terminal 10 may be used for any application (for example, eMBB, URLLC, Device-to-Device (D2D), Vehicle-to-Everything (V2X), etc.) as long as it has similar functions. Furthermore, the format of the various information is not limited to that in the above embodiments, and may be changed as appropriate to bit representation (0 or 1), boolean value (Boolean: true or false), integer value, character, etc. Furthermore, the singular and plural in the above embodiments may be interchangeable.

[0223] The above-described embodiments are intended to facilitate understanding of the present disclosure and are not intended to limit the present disclosure. The flowcharts, sequences, elements included in the embodiments, and their arrangements, indexes, conditions, etc. described in the embodiments are not limited to those exemplified and can be modified as appropriate. Furthermore, at least some of the configurations described in the above embodiments can be partially replaced or combined. [Explanation of symbols]

[0224] 1...wireless communication system, 20...base station, 30...core network, 101...receiving unit, 102...transmitting unit, 103...control unit, 201...receiving unit, 202...transmitting unit, 203...control unit, 11...processor, 12...storage device, 13...communication device, 14...input / output device

Claims

1. A control unit that controls monitoring of a physical downlink control channel; receiving a radio resource control reconfiguration message including information indicating a symbol for monitoring a physical downlink control channel within a slot, information indicating that a search space is included in a plurality of search spaces in which the physical downlink control channel is repeated, information indicating a period for determining a slot for monitoring the physical downlink control channel and an offset for determining the slot, and information for associating the plurality of search spaces in which the physical downlink control channel is repeated with one search space group; a receiving unit for receiving a downlink control information format used for scheduling a physical downlink shared channel, the downlink control information format including a field of a value corresponding to the one search space group; the control unit monitors the repeated physical downlink control channel in the plurality of search spaces associated with the one search space group based on information indicating a symbol for monitoring the physical downlink control channel in the slot, information indicating that the search space is included in a plurality of search spaces in which the physical downlink control channel is repeated, information indicating a period for determining a slot for monitoring the physical downlink control channel and an offset for determining the slot, information for associating the plurality of search spaces in which the physical downlink control channel is repeated with one search space group, and a value corresponding to the one search space group. Terminal.

2. information indicating a symbol for monitoring a physical downlink control channel within the slot, information indicating that the search space is included in a plurality of search spaces in which the physical downlink control channel is repeated, information indicating a period for determining a slot for monitoring the physical downlink control channel and an offset for determining the slot, and information for associating a plurality of search spaces in which the physical downlink control channel is repeated with one search space group are set for each of one or a plurality of bandwidth parts (BWPs). The terminal according to claim 1 .

3. A control unit that controls transmission of a physical downlink control channel; transmit a radio resource control reconfiguration message including information indicating a symbol for monitoring a physical downlink control channel within a slot, information indicating that a search space is included in a plurality of search spaces in which the physical downlink control channel is repeated, information indicating a period for determining a slot for monitoring the physical downlink control channel and an offset for determining the slot, and information for associating a plurality of search spaces in which the physical downlink control channel is repeated with one search space group; a transmitter configured to transmit a downlink control information format used for scheduling a physical downlink shared channel, the downlink control information format including a field of a value corresponding to the one search space group; the control unit controls transmission of the repeated physical downlink control channel in the plurality of search spaces associated with the one search space group based on information indicating a symbol for monitoring the physical downlink control channel in the slot, information indicating that the search space is included in a plurality of search spaces in which the physical downlink control channel is repeated, information indicating a period for determining a slot for monitoring the physical downlink control channel and an offset for determining the slot, information for associating the plurality of search spaces in which the physical downlink control channel is repeated with one search space group, and a value corresponding to the one search space group. Base station.

4. A step of controlling monitoring of a physical downlink control channel; receiving a radio resource control reconfiguration message including information indicating a symbol for monitoring a physical downlink control channel within a slot, information indicating that a search space is included in a plurality of search spaces in which the physical downlink control channel is repeated, information indicating a period for determining a slot for monitoring the physical downlink control channel and an offset for determining the slot, and information for associating the plurality of search spaces in which the physical downlink control channel is repeated with one search space group; receiving a downlink control information format used for scheduling a physical downlink shared channel, the downlink control information format including a field with a value corresponding to the one search space group; In the controlling step, the repeated physical downlink control channel is monitored in the plurality of search spaces associated with the one search space group based on information indicating a symbol for monitoring the physical downlink control channel in the slot, information indicating that the search space is included in a plurality of search spaces in which the physical downlink control channel is repeated, information indicating a period for determining a slot for monitoring the physical downlink control channel and an offset for determining the slot, information for associating the plurality of search spaces in which the physical downlink control channel is repeated with one search space group, and a value corresponding to the one search space group. The device's wireless communication method.

Images