Terminal, base station and wireless communication method

Abstract

This terminal is provided with: a receiving unit for receiving first configuration information and second configuration information that are related to a reference signal for tracking; and a control unit which configures a resource for the reference signal that is used in a connected state on the basis of the first configuration information, and configures a resource for the reference signal that is used in an idle state or a non-active state on the basis of the second configuration information.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is based on and claims the benefit of priority from Japanese Patent Application No. 2021-052281, filed on March 25, 2021, the entire contents of which are incorporated herein by reference. [Technical Field]

[0002] The present disclosure relates to a terminal and a wireless communication method. [Background technology]

[0003] 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).

[0004] NR supports a tracking reference signal (hereinafter referred to as a "Tracking Reference Signal (TRS)") that is configured specifically for a terminal in a connected state. [Prior art documents] [Non-patent literature]

[0005] [Non-Patent Document 1] 3GPP TS 38.300 V15.2.0 (2018-06) Summary of the Invention

[0006] Currently, 3GPP is considering supporting a TRS that is set commonly to one or more terminals (e.g., terminals in a cell) for terminals in an idle state or an inactive state. However, if a TRS for terminals in an idle state or an inactive state is supported, there is a risk that the terminal will not be able to properly control communications. For example, there is a risk that a terminal that has transitioned from an idle state or an inactive state to a connected state will not be able to properly control operations using a TRS for the connected state.

[0007] An object of the present disclosure is to provide a terminal and a wireless communication method that can appropriately control communication when supporting TRS for terminals in an idle or inactive state.

[0008] A terminal according to one embodiment of the present disclosure includes a receiving unit that receives first configuration information and second configuration information regarding a reference signal for tracking, and a control unit that sets resources for the reference signal to be used in a connected state based on the first configuration information, and sets resources for the reference signal to be used in an idle state or an inactive state based on the second configuration information.

[0009] According to one aspect of the present disclosure, communication can be appropriately controlled when TRS for a terminal in an idle or inactive state is supported. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a diagram showing an example of an overview of a wireless communication system according to this embodiment. [Figure 2] FIG. 2 is a diagram showing an example of state transition of the terminal according to this embodiment. [Figure 3] FIG. 3 is a diagram showing an example of the setting of individual TRS resources according to this embodiment. [Figure 4]4A and 4B are diagrams showing an example of the use of a TRS for a terminal 10 in an idle state or an inactive state according to this embodiment. [Figure 5] FIG. 5 is a diagram showing an example of the configuration of individual TRS resources and common TRS resources according to this embodiment. [Figure 6] FIG. 6 is a diagram showing an example of the first TRS resource control according to this embodiment. [Figure 7] FIG. 7 is a diagram showing another example of the first TRS resource control according to the present embodiment. [Figure 8] FIG. 8 is a diagram showing yet another example of the first TRS resource control according to this embodiment. [Figure 9] FIG. 9 is a diagram showing an example of the hardware configuration of each device in the wireless communication system according to this embodiment. [Figure 10] FIG. 10 is a diagram showing an example of a functional block configuration of a terminal according to this embodiment. [Figure 11] FIG. 11 is a diagram showing an example of a functional block configuration of a base station according to this embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] 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.

[0012] 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.

[0013] 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.

[0014] 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.

[0015] 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), etc. For example, the base station 20 may configure one primary cell and one or more secondary cells for the terminal 10 and communicate with the terminal 10 (also referred to as carrier aggregation). That is, the one or more cells C may include at least a primary cell and may also include a secondary cell.

[0016] The base station 20 may also be called a gNodeB (gNB), en-gNB, Next Generation-Radio Access Network (NG-RAN) node, low-power node, Central Unit (CU), Distributed Unit (DU), gNB-DU, Remote Radio Head (RRH), Integrated Access and Backhaul / Backhauling (IAB) node, etc. The base station 20 is not limited to one 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).

[0017] 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).

[0018] 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).

[0019] In the wireless communication system 1, the terminal 10 receives a downlink (DL) signal and / or transmits an uplink (UL) signal from the 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. That is, one or more BWPs may be configured in each of one or more cells C configured in the terminal 10. For example, up to four BWPs may be configured in one cell C for the terminal 10.

[0020] One or more control resource sets (CORESET) may be configured in one BWP. A CORESET is a time domain and frequency domain resource for a downlink control channel (for example, a physical downlink control channel (PDCCH)). For example, a CORESET is composed of a predetermined number of symbols (for example, 1 to 3 symbols) and a predetermined number of resource blocks (RBs) (for example, 6n (n≧1) RBs). Note that the downlink control channel is not limited to the PDCCH, and any name may be used as long as it is a channel used to transmit downlink control information (DCI).

[0021] Here, one or more formats may be defined for DCI transmission. A format defined for DCI transmission is referred to as a DCI format. For example, a DCI format (also referred to as downlink assignment, DCI format 1_x (x = 0, 1, 2, etc.)) used for scheduling a downlink shared channel (e.g., a Physical Downlink Shared Channel (PDSCH)) may be defined. Also, a DCI format (also referred to as uplink grant, DCI format 0_x (x = 0, 1, 2, etc.)) used for scheduling an uplink shared channel (e.g., a Physical Uplink Shared Channel (PUSCH)) may be defined.

[0022] The downlink shared channel and the uplink shared channel are not limited to the PDSCH and the PUSCH, respectively, and may be any channel used for transmitting user data and / or control information of a layer higher than the physical layer (for example, a Medium Access Control Element (MAC CE), a Radio Resource Control (RRC) message, etc.). The names of other channels may also be any channel having a similar function. The terminal 10 controls reception of the PDSCH based on the DCI.

[0023] Furthermore, the terminal 10 detects a synchronization signal (for example, a primary synchronization signal (PSS) and / or a secondary synchronization signal (PSS)) from the base station 20 to acquire time and frequency synchronization in the cell C. A block including a synchronization signal, a broadcast channel (for example, a physical broadcast channel (PBCH)), and a demodulation reference signal (DMRS) for the broadcast channel is also called a synchronization signal block (SSB), an SS / PBCH block, etc. The SSB is provided at a predetermined period.

[0024] (UE state) Next, the states of the terminal 10 will be described. The states of the terminal 10 include an idle state, an inactive state, and a connected state, and are also called RRC states, etc. Fig. 2 is a diagram showing an example of state transitions of the terminal 10. In Fig. 2, the idle state is a state in which an RRC connection between the terminal 10 and the base station 20 is not established, and is also called RRC_IDLE, idle mode, RRC idle mode, etc.

[0025] A terminal 10 in an idle state camps on a cell C selected by cell selection and / or cell reselection (hereinafter referred to as "cell selection / reselection") and receives system information broadcast in the cell C. "Camping on a cell C" may be rephrased as "being present in the coverage area of ​​cell C" or the like. Furthermore, the terminal 10 in an idle state performs paging monitoring at a predetermined period of a predetermined cycle (for example, paging occasion (PO) and discontinuous reception (DRX) set by a non-access stratum (NAS)). When an RRC connection is established, the terminal 10 in an idle state transitions to a connected state.

[0026] The inactive state is a state in which the RRC connection is established but suspended, and is also called an RRC_INACTIVE state, an inactive mode, an RRC inactive mode, etc. A terminal 10 in the inactive state camps on a cell C selected by cell selection / reselection and receives system information broadcast in the cell C. Furthermore, a terminal 10 in the inactive state monitors paging for a predetermined period (e.g., PO) at a predetermined cycle, and performs DRX set by the NAS or RRC, etc. When the terminal 10 in the inactive state resumes the RRC connection, it transitions to a connected state.

[0027] The connected state is a state in which the RRC connection is established, and is also called an RRC_CONNECTED state, connected mode, RRC connected mode, etc. The terminal 10 in the connected state monitors the PDCCH and controls reception of the PDSCH based on the detected DCI. The terminal 10 in the connected state transitions to an idle state when the RRC connection is released, and transitions to an inactive state when the RRC connection is suspended.

[0028] (TRS in connected state) A terminal 10 in a connected state needs to perform tracking in order to receive a PDSCH. Here, tracking means tracking and / or compensating for time and / or frequency variations of a local oscillator of the terminal 10. A TRS is a reference signal for the tracking. Note that the TRS may be used not only for tracking but also for estimating, for example, a path delay spread and a Doppler spread.

[0029] The TRS may be, for example, a Channel State Information-Reference Signal (CSI-RS), but is not limited to this and may be any reference signal used for tracking. The TRS may also be referred to as a tracking CSI-RS, a non-zero power CSI-RS (NZP-CSI-RS), a TRS / CSI-RS, etc.

[0030] Such resources for TRS (hereinafter "TRS resources" may be configured, for example, as a set (hereinafter "NZP-CSI-RS resource set") of one or more resources for NZP-CSI-RS (hereinafter "NZP-CSI-RS resources"). The TRS resources may be configured with a predetermined number of symbols and a predetermined number of subcarriers in a predetermined number of slots of a predetermined period (hereinafter "TRS period", for example, a period of 10, 20, 40, or 80 ms). A period of a predetermined period (for example, the above-mentioned predetermined number of slots) including the TRS resources is also referred to as a TRS occasion, a TRS / CSI-RS opportunity, etc.

[0031] For example, the base station 20 may set a predetermined period including a TRS resource and indicate the availability of a TRS during the predetermined period. That is, the base station 20 may indicate to the terminal 10 whether or not a TRS will actually be transmitted in the set TRS resource. For example, the base station 20 may transmit information indicating whether a TRS is available (also referred to as information indicating whether a TRS exists) in a DCI format. For example, the information indicating whether the TRS is available may be included in a DCI format (e.g., downlink assignment) to which a CRC (Cyclic Redundancy Check, also referred to as a CRC parity bit) scrambled by a predetermined identifier (e.g., a Paging Radio Network Temporary Identifier: P-RNTI) is attached. In addition, information indicating whether the TRS is available may be transmitted together with information indicating whether the terminal 10 monitors a DCI format (e.g., a downlink assignment) to which a CRC scrambled by the P-RNTI is attached (e.g., information indicating whether the terminal 10 is paged, also referred to as a paging early indication).

[0032] In this way, the TRS resource may be controlled based on higher layer parameters (e.g., RRC parameters and / or MAC CE, etc.) and / or physical layer parameters (e.g., DCI format, etc.). Hereinafter, the configuration of the TRS resource can be rephrased as the configuration of the TRS opportunity. Furthermore, the configuration of the TRS resource can be rephrased as the configuration of the TRS / CSI-RS opportunity.

[0033] The terminal 10 may configure a TRS resource specific to the terminal 10 (hereinafter referred to as an "individual TRS resource") based on information (hereinafter referred to as "individual TRS resource information") related to the configuration of the TRS resource from the base station 20. The individual TRS resource information can be rephrased as first configuration information specific to the terminal 10 regarding TRS. In this way, the individual TRS resource information is a parameter specific to the terminal 10 related to the configuration of the TRS resource. For example, the configuration of the individual TRS resource may be associated with each of one or multiple BWPs. That is, the individual TRS resource may be configured for each of one or multiple BWPs. For example, the individual TRS resource information may include information (bwp-id) used to identify a certain BWP, and the certain BWP may be associated with the configuration of a certain individual TRS resource. Here, the value set for the information (bwp-id) used to identify the BWP may be "0 (e.g., indicating an Initial Downlink BWP)" and / or "a value other than 0 (e.g., indicating an Active Downlink BWP)."

[0034] Fig. 3 is a diagram showing an example of a configuration of dedicated TRS resources according to this embodiment. For example, Fig. 3 shows an example in which an NZP-CSI-RS resource set including NZP-CSI-RS resources #0 to #3 is used as dedicated TRS resources. Note that Fig. 3 is merely an example, and the dedicated TRS resources are not limited to those shown in the figure.

[0035] For example, in Fig. 3, NZP-CSI-RS resources #0 to #3 in an NZP-CSI-RS resource set used as dedicated TRS resources are allocated to two consecutive slots, #n and #n+1. Each NZP-CSI-RS resource in an NZP-CSI-RS resource set may be configured based on information related to the configuration of each NZP-CSI-RS resource (hereinafter referred to as "NZP-CSI-RS resource information", for example, the "NZP-CSI-RS-Resource" information element (IE) of RRC). Here, the information element may be referred to as a parameter.

[0036] Each NZP-CSI-RS resource information may include information regarding the symbols and / or subcarriers on which each NZP-CSI-RS resource is allocated (hereinafter referred to as "resource mapping information", for example, the RRC IE "CSI-RS-ResourceMapping"), information regarding the periodicity of the NZP-CSI-RS resource (hereinafter referred to as "periodicity information", for example, the RRC IE "periodicityAndOffset"), etc.

[0037] Each resource mapping information may include at least one of, for example, information on frequency domain resources for each NZP-CSI-RS resource (hereinafter referred to as "frequency domain allocation information", for example, the RRC IE "frequencyDomainAllocation"), information on time domain resources for each NZP-CSI-RS resource (hereinafter referred to as "time domain allocation information", for example, the RRC IE "firstOFDMSymbolInTimeDomain"), information on the density of each NZP-CSI-RS (hereinafter referred to as "density information", for example, the RRC IE "density"), information on the number of antenna ports (hereinafter referred to as "number of ports information", for example, the RRC IE "nrofPorts").

[0038] 3, subcarriers #2, #6, and #10 within one resource block (RB) are configured for NZP-CSI-RS resource #0 based on frequency domain allocation information for NZP-CSI-RS resource #0. Here, since the density of NZP-CSI-RS resource #0 is 3, NZP-CSI-RS resource #0 is composed of three subcarriers k0, k0+4, and k0+8, and the position of subcarrier k0 may be indicated by a bitmap as the frequency domain allocation information. In FIG. 3, subcarrier k0 = subcarrier #2 for NZP-CSI-RS resource #0 is derived from a 4-bit bitmap "0010" corresponding to subcarriers #0 to #3, and subcarriers #6 and #10 for NZP-CSI-RS resource #0 are derived from subcarriers k0+4 and k0+8. Similarly, subcarriers #2, #6, and #10 for NZP-CSI-RS resources #1 to #3 are configured based on the frequency domain allocation information for each of NZP-CSI-RS resources #1 to #3.

[0039] Also, in FIG. 3, symbol #5 in slot #n is configured for NZP-CSI-RS resource #0 based on the time domain allocation information for NZP-CSI-RS resource #0. For example, if NZP-CSI-RS resource #0 is configured with one symbol 10, the position of symbol 10 may be indicated by the time domain allocation information. In FIG. 3, the time domain allocation information indicates symbol index "5," so symbol #5 becomes symbol 10. Also, symbol #9 in slot #n is configured for NZP-CSI-RS resource #1 based on the time domain resource information for NZP-CSI-RS resource #1.

[0040] Slot #n may be determined based on the periodicity information of NZP-CSI-RS resources #0 and #1. Similarly, slot #n+1 may be determined based on the periodicity information of NZP-CSI-RS resources #2 and #3. Furthermore, symbols #5 and #9 in slot #n+1 are determined for NZP-CSI-RS resources #2 and #3, respectively, based on the time domain allocation information of NZP-CSI-RS resources #2 and #3.

[0041] The NZP-CSI-RS resource set including NZP-CSI-RS resources #0 to #3 may be configured based on information related to the configuration of the NZP-CSI-RS resource set (hereinafter referred to as "NZP-CSI-RS resource set information", for example, the RRC IE "NZP-CSI-RS-ResourceSet"). The NZP-CSI-RS resource set information may include NZP-CSI-RS resource information for each of NZP-CSI-RS resources #0 to #3.

[0042] Furthermore, the NZP-CSI-RS resource set information may include information indicating that the NZP-CSI-RS resources in the NZP-CSI-RS resource set are associated with the same antenna port (hereinafter referred to as "TRS information", for example, the RRC IE "trs-Info" with a value of "true"). When terminal 10 receives NZP-CSI-RS resource set information including TRS information, terminal 10 may recognize that all NZP-CSI-RS resources in the NZP-CSI-RS set are used as TRS resources. In this way, the NZP-CSI-RS resource set information including TRS information may be used as the individual TRS resource information.

[0043] The individual TRS resource information is transmitted from the base station 20 to the terminal 10, for example, by being included in an RRC connection setup message (hereinafter referred to as an "RRC setup message", for example, an RRCSetup message), a resumption message (hereinafter referred to as an "RRC resumption message", for example, an RRCResume message), or a reconfiguration message (hereinafter referred to as an "RRC reconfiguration message", for example, an RRCReconfiguration message).

[0044] (Idle or inactive TRS) Currently, 3GPP is considering supporting TRS common to one or more terminals 10 for terminals 10 in an idle state or an inactive state. Specifically, it is considering including information (hereinafter referred to as "common TRS resource information") related to the configuration of TRS resource information (hereinafter referred to as "common TRS resource") common to one or more terminals 10 for an idle state or an inactive state in system information or an RRC connection release message (e.g., an RRCRelease message) and transmitting the information from base station 20 to terminal 10. The common TRS resource information can be rephrased as second configuration information common to terminals 10 regarding TRS.

[0045] Here, the system information includes a Master Information Block (MIB) and one or more System Information Blocks (SIB). Terminal 10 receives the MIB via the PBCH and receives the SIBX (X is an arbitrary number) via the PDSCH. The common TRS resource information may be included in SIB1, or may be included in an SIBX other than SIB1 (for example, any of SIB2 to SIB14 specified in Release 16, or a new SIB introduced in Release 17 or later). The common TRS resource information may be included in the SIBX as cell-specific or terminal-common information.

[0046] In this way, the common TRS resource information (second configuration information) is a cell-specific or terminal-common parameter related to the configuration of the TRS resource. For example, the configuration of the common TRS resource may be associated with each of one or more cells C. That is, the common TRS resource may be configured for each of one or more cells C. Here, the configuration of the common TRS resource may be associated with only one BWP in a certain cell C. For example, the certain cell C may be a primary cell. Furthermore, the certain BWP may be an initial downlink BWP (that is, a BWP identified by bwp-id="0"). That is, the common TRS resource may be configured for only one BWP in a certain cell C. For example, the second configuration information does not include information (bwp-id) used to identify a certain BWP, and the certain cell C and / or the certain BWP associated with the configuration of the common TRS resource may be specified in advance by a specification or the like.

[0047] 4(A) and 4(B) are diagrams showing an example of the use of TRS for a terminal 10 in an idle state or an inactive state according to this embodiment. FIG. 4(A) shows an example in which a terminal 10 in an idle state or an inactive state acquires time and frequency synchronization in a cell C using SSB before a paging occasion (PO) at a predetermined period. The period of the PO is also called a paging cycle. On the other hand, FIG. 4(B) shows an example in which the terminal 10 acquires time and frequency synchronization in a cell C using TRS before a PO.

[0048] 4(A) and 4(B), the terminal 10 is awake only during the PO due to DRX and sleeps at other times. The terminal 10 monitors the PDCCH in the PO, detects (also referred to as blind decoding) DCI (DCI format) to which a CRC scrambled by a predetermined identifier (e.g., a Paging radio network temporary identifier: P-RNTI) is attached, and receives a paging message via a PDSCH scheduled using the DCI.

[0049] As shown in Figure 4(A), when time and frequency synchronization is obtained using SSB before the next PO, the terminal 10 is in a deep sleep (DS) state until it detects the first SSB from the previous PO. However, once it detects the first SSB, it is expected that even if it goes to sleep, it will enter a light sleep (LS) state, which has less power consumption reduction effect than deep sleep.

[0050] On the other hand, as shown in FIG. 4(B), when time and frequency synchronization is acquired using a TRS before the next PO, the terminal 10 is expected to be able to maintain a DS state for a longer period of time than in FIG. 4(A). That is, time and frequency synchronization using a TRS can contribute to reducing power consumption of the terminal 10 compared to synchronization using an SSB. Here, a TRS and an SSB may be used for time and frequency synchronization. For example, in FIG. 4(B), the terminal 10 may acquire time and frequency synchronization using a TRS before the next PO and an SSB closest to the next PO. That is, a TRS may be used to complement time and frequency synchronization using an SSB. Even in this case, the terminal 10 does not need to detect the first SSB, and is expected to be able to maintain a DS state for a longer period of time than in FIG. 4(A). This can contribute to reducing power consumption of the terminal 10 compared to synchronization using only an SSB.

[0051] 4A and 4B are merely examples, and the TRS may be used for purposes other than time and frequency synchronization before a PO. For example, the TRS for the terminal 10 in the idle or inactive state may be used for automatic gain control (AGC) or radio resource management (RRM) measurement.

[0052] As described above, when a TRS for a terminal 10 in an idle state or an inactive state is newly supported, there is a risk that the terminal 10 will be unable to appropriately control communication. For example, there is a risk that a terminal 10 that has transitioned from an idle state or an inactive state to a connected state will be unable to appropriately control operations using a TRS for the connected state (for example, at least one of the above-mentioned tracking, path delay spread estimation, and Doppler spread estimation).

[0053] Fig. 5 is a diagram showing an example of configuration of dedicated TRS resources and common TRS resources according to this embodiment. In Fig. 5, as described in Fig. 3, an NZP-CSI-RS resource set including NZP-CSI-RS resources #0 to #4 is configured as terminal-specific TRS resources. Also in Fig. 5, an NZP-CSI-RS resource set including NZP-CSI-RS resources #5 to #7 is configured as terminal-common TRS resources.

[0054] For example, in FIG. 5, dedicated TRS resources may be configured as described in FIG. 3 based on NZP-CSI-RS resource set information included as dedicated TRS resource information in an RRC setup message, an RRC resumption message, or an RRC reconfiguration message. Furthermore, common TRS resources may be configured as described in FIG. 3 based on NZP-CSI-RS resource set information included as common TRS resource information in system information or an RRC release message (e.g., an RRCRelease message). Note that, in FIG. 5, the density of dedicated TRS resources and the number of NZP-CSI-RS resources are the same as those of common TRS resources, but are not limited to this. Dedicated TRS resources may be configured using an allocation pattern different from that of common TRS resources (e.g., an allocation pattern that differs in at least one of density, periodicity, number of NZP-CSI-RS resources, and positions in the time domain and frequency domain).

[0055] For example, as shown in Fig. 5, if the dedicated TRS resources and the common TRS resources are allocated to different resource elements (RE), terminal 10 that transitions from an idle state or an inactive state to a connected state may confuse the dedicated TRS resources with the common TRS resources, resulting in a risk of being unable to operate properly. In Fig. 5, base station 20 transmits a PDSCH assuming that terminal 10 in a connected state will perform at least one of tracking, path delay spread estimation, Doppler spread estimation, etc. using the dedicated TRS resources (NZP-CSI-RS resources #0 to #3). In this case, if terminal 10 performs at least one of tracking, path delay spread estimation, Doppler spread estimation, etc. using the common TRS resources (NZP-CSI-RS resources #4 to #7), there is a risk of being unable to properly receive the PDSCH.

[0056] Therefore, in this embodiment, when terminal 10 transitions from an idle state or an inactive state to a connected state, it releases the common TRS resources (first TRS resource control). Alternatively, terminal 10 configures the common TRS resources independently of the dedicated TRS resources (second TRS resource control). For example, in the second TRS resource control, the common TRS resources (common TRS resource configuration) may be defined as a configuration to be used when terminal 10 is in the idle state or the inactive state. Also, in the second TRS resource control, the dedicated TRS resources (dedicated TRS resource configuration) may be defined as a configuration to be used when terminal 10 is in the connected state. This makes it possible to prevent confusion between the dedicated TRS resources and the common TRS resources in terminal 10 when common TRS resources are supported in addition to dedicated TRS resources.

[0057] (First TRS resource control) In the first TRS resource control, when the terminal 10 transitions from an idle state or an inactive state to a connected state, the terminal 10 releases the common TRS resource information (second configuration information). Here, the common TRS resource information may be based on at least a part of the dedicated TRS resource information (first configuration information). For example, as described above, NZP-CSI-RS resource set information may be used as the common TRS resource information and the dedicated TRS resource information.

[0058] <When transitioning from idle state to connected state> Fig. 6 is a diagram showing an example of the first TRS resource control according to the present embodiment. For example, Fig. 6 shows a case where the terminal 10 in the idle state transitions to the connected state.

[0059] 6, in step S101, terminal 10 in an idle state receives system information from base station 20. The system information may include common TRS resource information that is common to terminals 10 in cell C on which terminal 10 is camped. Note that the common TRS resource information may be included in an RRC release message received from base station 20 when terminal 10 transitions from a connected state or an inactive state to an idle state.

[0060] In step S102, terminal 10 in idle state operates based on the common TRS resource information. For example, terminal 10 in idle state may perform time and frequency synchronization before PO as shown in FIG. 4(B) using a TRS resource common to terminals (e.g., NZP-CSI-RS resources #4 to #7 in FIG. 5) set based on the common TRS resource information.

[0061] In step S103, the terminal 10 in an idle state starts a random access procedure. Specifically, the terminal 10 transmits a random access preamble to the base station 20. In step S104, the base station 20 transmits a random access response (RAR) to the terminal 10 in response to the random access preamble from the terminal 10.

[0062] In step S105, the terminal 10 starts a procedure for establishing an RRC connection in response to the RAR. Specifically, the terminal 10 transmits an RRC setup request message (for example, an RRCSetupRequest message) to the base station 20.

[0063] In step S106, the base station 20 transmits an RRC setup message to the terminal 10 in response to the RRC setup request message from the terminal 10. Upon receiving the RRC setup message, the terminal 10 transitions from the idle state to the connected state. The RRC setup message may include dedicated TRS resource information.

[0064] In step S107, terminal 10 in the connected state releases the common TRS resource information. That is, terminal 10 that has transitioned from the idle state to the connected state based on reception of an RRC setup message including dedicated TRS resource information (dedicated TRS resource configuration) may release the common TRS resource information (common TRS resource configuration). Specifically, it may release the common TRS resources (for example, NZP-CSI-RS resources #4 to #7 in FIG. 5) configured based on the common TRS resource information. Note that release may also be expressed as removal, deletion, or the like. That is, terminal 10 in the connected state may release the common TRS resource information when it receives both the common TRS resource information and the dedicated TRS resource information. Furthermore, terminal 10 in the connected state may use the dedicated TRS resources configured based on the dedicated TRS resource information when it receives both the common TRS resource information and the dedicated TRS resource information. Furthermore, the terminal 10 in the connected state may assume that a TRS is transmitted in the dedicated TRS resource. For example, when the terminal 10 in the connected state receives information indicating that a TRS is available from the base station 20, the terminal 10 may receive a TRS in the dedicated TRS resource.

[0065] In step S108, terminal 10 in the connected state operates based on the dedicated TRS resource information received in step S106. For example, terminal 10 performs at least one of tracking, path delay spread estimation, and Doppler spread estimation using the dedicated TRS resources (e.g., NZP-CSI-RS resources #0 to #3 in FIG. 5) configured based on the dedicated TRS resource information.

[0066] In addition, when a terminal 10 in a connected state receives an RRC reconfiguration message to reconfigure an RRC connection established between the terminal 10 in a connected state and the base station 20, the terminal 10 may perform the operation in step S108 based on the individual TRS resource information included in the RRC reconfiguration message.

[0067] In step S109, terminal 10 in the connected state receives system information including common TRS resource information from base station 20. In step S110, terminal 10 in the connected state discards the common TRS resource information. Note that discarding may also be rephrased as ignoring. That is, when an RRC setup message is received, terminal 10 transitions to the connected state, and if the system information includes common TRS resource information (common TRS resource configuration), it may discard the common TRS resource information (common TRS resource configuration) included in the system information (i.e., acquired from the system information).

[0068] For example, when the terminal 10 is in a connected state and a certain timer (also referred to as T311) is not running, if the terminal 10 receives common TRS resource information (common TRS resource configuration), the terminal 10 may discard the common TRS resource information (common TRS resource configuration). Here, the terminal 10 may start the certain timer based on the start of an RRC connection re-establishment procedure. Furthermore, the terminal 10 may stop the certain timer based on the selection of an appropriate cell (also referred to as an NR cell) or the selection of a cell using another radio access technology.

[0069] As described above, when terminal 10 transitions from the idle state to the connected state, the common TRS resources (for example, NZP-CSI-RS resources #4 to #7 in FIG. 5) intended for terminal 10 in the idle state are released. Therefore, when common TRS resources are supported in addition to dedicated TRS resources, terminal 10 that has transitioned from the idle state to the connected state can be prevented from confusing the dedicated TRS resources with the common TRS resources.

[0070] <When transitioning from inactive state to connected state> Fig. 7 is a diagram showing another example of the first TRS resource control according to the present embodiment. For example, Fig. 7 shows a case where the terminal 10 in the inactive state transitions to the connected state. Note that Fig. 7 will be mainly described with reference to Fig. 6, focusing on differences therebetween.

[0071] 7, in step S201, terminal 10 in an inactive state receives system information from base station 20. The system information may include common TRS resource information that is common to terminals 10 in cell C on which terminal 10 is camped. Note that the common TRS resource information may be included in an RRC release message received from base station 20 when terminal 10 transitions from a connected state to an inactive state.

[0072] In step S202, terminal 10 in an inactive state operates based on the common TRS resource information. For example, terminal 10 in an inactive state may perform time and frequency synchronization before PO, as shown in FIG. 4(B), using common TRS resources (e.g., NZP-CSI-RS resources #4 to #7 in FIG. 5) configured based on the common TRS resource information.

[0073] In step S203, the terminal 10 in the inactive state starts a procedure to resume the RRC connection. Specifically, the terminal 10 transmits an RRC resumption request message (for example, an RRCResumeRequest message) to the base station 20.

[0074] In step S204, in response to the RRC Restart Request message, the base station 20 transmits an RRC Restart message to the terminal 10. Upon receiving the RRC Restart message, the terminal 10 transitions from the inactive state to the connected state. The RRC Restart message may include dedicated TRS resource information.

[0075] In step S205, terminal 10 in the connected state releases the common TRS resource information. That is, terminal 10 that has transitioned from the inactive state to the connected state based on reception of an RRC resumption message including dedicated TRS resource information (dedicated TRS resource configuration) may release the common TRS resource information (common TRS resource configuration). Specifically, it may release the common TRS resources (for example, NZP-CSI-RS resources #4 to #7 in FIG. 5) that have been configured based on the common TRS resource information.

[0076] In step S206, terminal 10 in the connected state operates based on the dedicated TRS resource information received in step S204. Note that details of steps S206 to S208 are the same as steps S108 to S110 in Fig. 6. That is, when terminal 10 receives common TRS resource information (common TRS resource configuration) in the connected state, it may discard the common TRS resource information (common TRS resource configuration). Furthermore, when an RRC setup message including dedicated TRS resource information is received, terminal 10 transitions to the connected state, and, if system information includes common TRS resource information (common TRS resource configuration), it may discard the common TRS resource information (common TRS resource configuration) included in the system information (acquired from the system information).

[0077] In step S204, the base station 20 may transmit an RRC setup message including dedicated TRS resource information to the terminal 10 in response to the RRC resumption request message, instead of an RRC resumption message.

[0078] As described above, when terminal 10 transitions from the inactive state to the connected state, the common TRS resources (for example, NZP-CSI-RS resources #4 to #7 in FIG. 5) intended for terminal 10 in the inactive state are released. Therefore, when common TRS resources are supported in addition to dedicated TRS resources, terminal 10 that has transitioned from the inactive state to the connected state can be prevented from confusing the dedicated TRS resources with the common TRS resources.

[0079] <When transitioning from connected state to idle state or inactive state> Fig. 8 is a diagram showing yet another example of the first TRS resource control according to this embodiment. For example, Fig. 8 shows a case where the terminal 10 in the connected state transitions to the idle state or the inactive state. Note that Fig. 8 will be mainly described with reference to differences from Fig. 6 or Fig. 7.

[0080] 8, in step S301, the terminal 10 in the connected state operates based on the individual TRS resource information. Note that the details of step S301 are the same as step S108 in FIG. 6 or step S206 in FIG.

[0081] In step S302, the terminal 10 in the connected state receives an RRC release message from the base station 20. When the terminal 10 receives an RRC release message including a specific parameter (for example, an RRC IE "suspendConfig"), the terminal 10 transitions from the connected state to the inactive state. On the other hand, when the terminal 10 receives an RRC release message that does not include the specific parameter, the terminal 10 transitions from the connected state to the idle state.

[0082] In step S303, terminal 10 in an inactive state or an idle state may operate based on at least a part of the dedicated TRS resource information used in step S301. For example, terminal 10 in an inactive state or an idle state may use at least a part of the NZP-CSI-RS resources (e.g., at least one of NZP-CSI-RS resources #0 to #3 in FIG. 5) indicated by the NZP-CSI-RS resource set information as dedicated TRS resource information. Furthermore, terminal 10 in an inactive state or an idle state may use TRS information as dedicated TRS resource information. This allows at least a part of the dedicated TRS resources to be used as common TRS resources as well.

[0083] In step S303, terminal 10 in the inactive state or idle state may release the dedicated TRS resource information and operate based on the common TRS resource information included in the RRC release message in step S302 or the common TRS resource information included in system information (not shown). That is, terminal 10 in the inactive state or idle state may assume that a TRS is transmitted in a TRS resource determined based on at least a part of the dedicated TRS resource information. For example, when terminal 10 in the inactive state or idle state receives information indicating that a TRS is available from base station 20, terminal 10 may receive a TRS in a TRS resource determined based on at least a part of the dedicated TRS resource information. Furthermore, terminal 10 may release the dedicated TRS resource information (the dedicated TRS resource settings) when transitioning from the connected state to the inactive state or idle state.

[0084] As described above, when terminal 10 transitions from a connected state to an inactive state or an idle state, it can set TRS resources that can be used both as terminal-specific TRS resources and as terminal-common TRS resources by operating based on at least a portion of the individual TRS resource information.

[0085] In the first TRS resource control, when a terminal 10 transitions from an idle state or an inactive state to a connected state, the TRS resources common to the terminals are released, thereby preventing confusion between the common TRS resources and the individual TRS resources. Furthermore, by designing the common TRS resource information based on at least a part of the individual TRS resource information, an increase in the design load associated with supporting the common TRS resources can be prevented.

[0086] (Second TRS resource control) In the second TRS resource control, common TRS resources are configured independently of dedicated TRS resources. Furthermore, the common TRS resource information (common TRS resource configuration) may be defined as a configuration to be used when the terminal 10 is in an idle state or an inactive state. That is, the common TRS resource information (common TRS resource configuration) may be defined as a configuration to be used only when the terminal 10 is in an idle state or an inactive state, and not used when the terminal 10 is in a connected state. Furthermore, the dedicated TRS resource information (individual TRS resource configuration) may be defined as a configuration to be used when the terminal 10 is in a connected state. That is, the dedicated TRS resource information (individual TRS resource configuration) may be defined as a configuration to be used only when the terminal 10 is in a connected state, and not used when the terminal 10 is in an idle state or an inactive state. In this way, the dedicated TRS resource information and the common TRS resource information may each be configuration information defined for a specific state of the terminal 10 (for example, the idle state, the inactive state, and the connected state).

[0087] For example, when terminal 10 is in an idle state or an inactive state, it uses common TRS resources determined based on common TRS resource information. Also, when terminal 10 is in a connected state, it uses individual TRS resources determined based on individual TRS resource information. For example, when terminal 10 transitions from a connected state to an idle state or an inactive state, it does not need to release the common TRS resource information (common TRS resource settings) (also referred to as retaining or suspending the common TRS resource information (common TRS resource settings)).

[0088] Here, the independent formats may include a case where some or all of the information elements (also referred to as parameter sets) used for configuring dedicated TRS resources are different from some or all of the information elements (also referred to as parameter sets) used for configuring common TRS resources. For example, as described above, the dedicated TRS resource information may include information (bwp-id) used to identify a certain BWP (downlink BWP), while the common TRS resource information may not include information (bwp-id) used to identify the certain BWP (downlink BWP). Furthermore, the dedicated TRS resource information may include information used to indicate the type of TRS resource (e.g., information used to indicate that the TRS resource is configured aperiodic, semi-persistent, or periodic), while the common TRS resource information may not include information used to indicate the type of the TRS resource. For example, the terminal 10 may assume that periodic is always used as the TRS resource type when in an idle state or an inactive state.

[0089] Also, for example, in the independent format, the dedicated TRS resource information may include a TRS period and an offset, and the common TRS resource information may also include a TRS period and an offset. Here, the TRS period and offset values ​​included in the dedicated TRS resource information may be different from the TRS period and offset values ​​included in the common TRS resource information. Thus, the independent format may include specifying information elements (also referred to as parameter sets) used to configure dedicated TRS resources for the connected state and information elements used to configure common TRS resources for the idle state or inactive state, respectively.

[0090] In the second TRS resource control, common TRS resources are configured using common TRS resource information in a format independent of the individual TRS resource information. Furthermore, the common TRS resource information (common TRS resource configuration) may be defined as a configuration to be used when the terminal 10 is in an idle state or an inactive state. Furthermore, the individual TRS resource information (individual TRS resource configuration) may be defined as a configuration to be used when the terminal 10 is in a connected state. This allows the common TRS resources to be flexibly configured depending on the use of TRS for the idle state or the non-idle state. Furthermore, when the terminal 10 transitions from the idle state or the inactive state to the connected state, the common TRS resource information can be appropriately configured based on the individual TRS resource information without releasing the common TRS resource information, without causing confusion with the individual TRS resource information.

[0091] (Configuration of wireless communication system) 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.

[0092] <Hardware configuration> 9 is a diagram showing an example of the hardware configuration of each device in the wireless communication system according to this embodiment. Each device (e.g., terminal 10, base station 20, CN 30, etc.) in the wireless communication system 1 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.

[0093] 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.

[0094] 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.).

[0095] 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.

[0096] 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.

[0097] 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.

[0098] 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.

[0099] <Function block configuration> Terminal 10 is a diagram showing an example of a functional block configuration of a terminal according to this embodiment. As shown in FIG. 10, the terminal 10 includes a receiving unit 101, a transmitting unit 102, and a control unit 103.

[0100] 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.

[0101] 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.

[0102] 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, the TRS, CSI-RS, NZP-CSI-RS, a demodulation reference signal (DMRS) of the PDCCH or PDSCH, etc.

[0103] Specifically, receiving unit 101 receives individual TRS resource information (first setting information individual to terminal) and common TRS resource information (second setting information common to terminals). In the second TRS resource control, the individual TRS resource information is setting information that is used in the connected state and is not used in the idle state or the inactive state, and the common TRS resource information is setting information that is used in the idle state or the inactive state and is not used in the connected state. In this way, in the second TRS resource control, the individual TRS resource information and the common TRS resource information are each defined for a specific state of terminal 10 (for example, the idle state, the inactive state, and the connected state). On the other hand, in the first TRS resource control, the individual TRS resource information and the common TRS resource information may each be defined without being limited to a specific state of terminal 10.

[0104] In addition, the common TRS resource information may be included in the system information or the RRC release message, and the dedicated TRS resource information may be included in the RRC setup message or the RRC reconfiguration message.

[0105] The transmitter 102 transmits an uplink signal. The transmitter 102 may also transmit information and / or data transmitted via the uplink signal. Here, "transmitting" may include performing processing related to transmission, 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, a random access preamble (Physical Random Access Channel: PRACH), an uplink reference signal, etc.

[0106] The control unit 103 performs various controls in the terminal 10. Specifically, the control unit 103 controls the transition between a connected state in which a TRS set based on individual TRS resource information is used, and an idle state or an inactive state in which a TRS set based on common TRS resource information is used. Note that "TRS" can also be referred to as "TRS resource."

[0107] When the state transitions from the idle state or the inactive state to the connected state, the control unit 103 may release the common TRS resource information (first TRS resource control).

[0108] When common TRS resource information is received by the receiving unit while in the connected state, the control unit 103 may discard the common TRS resource information (first TRS resource control).

[0109] When transitioning from a connected state to an idle state or an inactive state, the control unit 103 may control the reception of TRS based on at least a part of the individual TRS resource information, or may release the individual TRS resource information (first TRS resource control).

[0110] ≪Base station≫ 11 is a diagram showing an example of a functional block configuration of a base station according to this embodiment. As shown in FIG. 11, the base station 20 includes a receiving unit 201, a transmitting unit 202, and a control unit 203.

[0111] 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.

[0112] The receiving unit 201 receives the uplink signal. The receiving unit 201 may also receive information and / or data transmitted via the uplink signal.

[0113] The transmitting unit 202 transmits the downlink signal. The transmitting unit 202 may also transmit information and / or data transmitted via the downlink signal. Specifically, the transmitting unit 202 transmits the dedicated TRS resource information and common TRS resource information.

[0114] The control unit 203 performs various controls in the base station 20. The control unit 203 controls the transmission of the individual TRS resource information and the common TRS resource information.

[0115] (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).

[0116] 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.

[0117] 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.

[0118] 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.

[0119] In the above embodiment, the first TRS resource control and the second TRS resource control may be combined. Specifically, in the second TRS resource control, when the terminal 10 transitions from the connected state to the idle state or the inactive state, the terminal 10 may discard or release the common TRS resource information (the common TRS resource configuration). Furthermore, when the terminal 10 transitions from the connected state to the idle state or the inactive state, the base station 20 may consider the common TRS resource information (the common TRS resource configuration) received by the terminal 10 to be discarded or released.

[0120] As described above, the terminal of this embodiment includes a receiving unit that receives terminal-specific first setting information regarding a reference signal for tracking and terminal-common second setting information regarding the reference signal, and a control unit that controls transitions between a connected state that uses the reference signal set based on the first setting information and an idle state or an inactive state that uses the reference signal set based on the second setting information, and the control unit may release the second setting information when transitioning from the idle state or the inactive state to the connected state.

[0121] Furthermore, in the terminal, when the second setting information is received by the receiving unit while the terminal is in the connected state, the control unit may discard the second setting information.

[0122] In addition, in the above terminal, when the connected state is transitioned to the idle state or the inactive state, the control unit may control reception of the reference signal based on at least a part of the first setting information, or release the first setting information.

[0123] In addition, the terminal of this embodiment is equipped with a receiving unit that receives terminal-specific first setting information regarding a reference signal for tracking and terminal-common second setting information regarding the reference signal, and a control unit that controls transitions between a connected state that uses the reference signal set based on the first setting information and an idle state or an inactive state that uses the reference signal set based on the second setting information, wherein the first setting information is setting information that is used in the connected state and is not used in the idle state or the inactive state, and the second setting information is setting information that is used in the idle state or the inactive state and is not used in the connected state.

[0124] In the terminal, the second configuration information may be included in system information or a radio resource control (RRC) connection release message.

[0125] In the terminal, the first configuration information may be included in a setup message, a resumption message, or a reconfiguration message of a radio resource control (RRC) connection.

[0126] In addition, the wireless communication method of this embodiment includes a step of receiving terminal-specific first setting information regarding a reference signal for tracking and terminal-common second setting information regarding the reference signal, and a step of controlling a transition between a connected state using the reference signal set based on the first setting information and an idle state or an inactive state using the reference signal set based on the second setting information, and in the control step, when a transition is made from the idle state or the inactive state to the connected state, the second setting information may be released.

[0127] In addition, the wireless communication method of this embodiment includes a step of receiving terminal-specific first setting information regarding a reference signal for tracking and terminal-common second setting information regarding the reference signal, and a step of controlling a transition between a connected state using the reference signal set based on the first setting information and an idle state or an inactive state using the reference signal set based on the second setting information, wherein the first setting information may be setting information used in the connected state and not used in the idle state or the inactive state, and the second setting information may be setting information used in the idle state or the inactive state and not used in the connected state.

Claims

1. A terminal, receiving system information including first configuration information for configuring a resource of a tracking reference signal used by the terminal in an idle state or an inactive state; and receiving a radio resource control message including second configuration information for configuring a resource of a tracking reference signal used by the terminal in a connected state; a receiving unit that receives downlink control information used for scheduling a physical downlink shared channel via a physical downlink control channel; In the idle state or the inactive state, controlling reception of a physical downlink shared channel for paging based on a tracking reference signal in a resource configured based on first configuration information for configuring a resource for the tracking reference signal; a control unit that, in the connected state, controls reception of the physical downlink shared channel scheduled using the downlink control information, based on a tracking reference signal in resources that are configured based on second configuration information for configuring resources for the tracking reference signal, in a manner that ignores resources that are configured based on first configuration information for configuring resources for the tracking reference signal; A terminal comprising:

2. the receiving unit receives a setting of a period of a predetermined cycle, and receives, in the idle state or the inactive state, downlink control information including information indicating availability of the tracking reference signal in a resource of the tracking reference signal, during the period of the predetermined cycle via the physical downlink control channel. The terminal according to claim 1 .

3. The downlink control information including information indicating the availability of the tracking reference signal is added with a CRC (Cyclic Redundancy Check) scrambled by a P-RNTI (Paging radio network temporary identifier). The terminal according to claim 2.

4. The paging early indication is included in downlink control information including information indicating availability of the tracking reference signal. The terminal according to claim 2 or claim 3.

5. Transmitting system information including first configuration information for setting a resource of a tracking reference signal to be used when the terminal is in an idle state or an inactive state, and transmitting a radio resource control message including second configuration information for setting a resource of a tracking reference signal to be used when the terminal is in a connected state; a transmitter configured to transmit downlink control information used for scheduling a physical downlink shared channel via a physical downlink control channel; controlling transmission of a physical downlink shared channel for paging for the terminal in the idle state or the inactive state, based on a tracking reference signal in a resource configured based on first configuration information for configuring a resource for the tracking reference signal; a control unit that controls transmission of the physical downlink shared channel, which is scheduled using the downlink control information for the terminal in the connected state, based on a tracking reference signal in resources that are set based on second configuration information for setting resources for the tracking reference signal, in a manner that ignores the resources that are set based on first configuration information for setting resources for the tracking reference signal; A base station comprising:

6. the transmitter transmits a setting of a period of a predetermined cycle, and transmits downlink control information including information indicating availability of the tracking reference signal in a resource of the tracking reference signal to the terminal in the idle state or the inactive state, during the period of the predetermined cycle, via the physical downlink control channel. The base station of claim 5.

7. The downlink control information including information indicating the availability of the tracking reference signal is added with a CRC (Cyclic Redundancy Check) scrambled by a P-RNTI (Paging radio network temporary identifier). The base station of claim 6.

8. The PEI (paging early indication) is included in downlink control information including information indicating availability of the tracking reference signal. The base station according to claim 6 or claim 7.

9. A wireless communication method for a terminal, comprising: receiving system information including first configuration information for configuring a resource of a tracking reference signal used by the terminal in an idle state or an inactive state, and receiving a radio resource control message including second configuration information for configuring a resource of a tracking reference signal used by the terminal in a connected state; receiving downlink control information used for scheduling a physical downlink shared channel via a physical downlink control channel; controlling, in the idle state or the inactive state, reception of a physical downlink shared channel for paging based on a tracking reference signal in a resource configured based on first configuration information for configuring a resource for the tracking reference signal; controlling, in the connected state, reception of the physical downlink shared channel scheduled using the downlink control information, based on a tracking reference signal in resources configured based on second configuration information for configuring resources of the tracking reference signal, so as to ignore resources configured based on first configuration information for configuring resources of the tracking reference signal; A wireless communication method for a terminal having the above configuration.

10. the terminal receives a configuration of a period of a predetermined cycle, and receives, in the idle state or the inactive state, downlink control information including information indicating availability of the tracking reference signal in a resource of the tracking reference signal, during the period of the predetermined cycle, via the physical downlink control channel. The wireless communication method according to claim 9.

11. The downlink control information including information indicating the availability of the tracking reference signal is added with a CRC (Cyclic Redundancy Check) scrambled by a P-RNTI (Paging radio network temporary identifier). The wireless communication method according to claim 10.

12. The PEI (paging early indication) is included in downlink control information including information indicating availability of the tracking reference signal. The wireless communication method according to claim 10 or 11.

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