User device, base station, and communication system

Abstract

To provide a user device capable of calculating a terminal position.SOLUTION: A terminal device 20, which is a user device, includes a communication unit that receives higher layer parameters related to a positioning reference signal (PRS) and a control unit that performs positioning using the positioning reference signal received based on the higher layer parameters. The higher layer parameters are hierarchical information including a resource set parameter having a plurality of resource parameters.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a base station, a terminal device, a positioning method, and a wireless communication system for determining the position of a terminal device. [Background technology]

[0002] In wireless communication systems, frequency selectivity and time fluctuations occur in the transmission path due to multipath fading, which occurs when a signal transmitted from a transmitting device is reflected by buildings and other objects, and Doppler fluctuations, which occur when a receiving device moves. In a multipath environment where multipath fading occurs, the signal received by the receiving device is a signal in which symbols arriving directly from the transmitting device and symbols arriving with a delay after being reflected by buildings and other objects interfere with each other.

[0003] In order to obtain better reception characteristics in a frequency-selective transmission path, a wireless communication system may use an Orthogonal Frequency Division Multiplexing (OFDM) transmission method, which is a Multiple Carrier (MC) block transmission method. In the Third Generation Partnership Project (3GPP), OFDM is used in the downlink, and OFDM and DFT-s-OFDM (Discrete Fourier Transform-Spread-OFDM) are used in the uplink.

[0004] In 3GPP Release.15, NR (New Radio) was studied and standardized for the 5th generation mobile communication system (see Non-Patent Documents 1-3). NR aims to increase communication capacity by using multi-element antennas and performing beamforming toward users.

[0005] In LTE (Long Term Evolution), physical layer and upper layer technologies for positioning are standardized. For example, Cell_ID (IDentification), ECID (Enhanced Cell ID), OTDOA (Observed Time Difference Of Arrival), and UTDOA (Uplink Time Difference Of Arrival) are assumed in the standard. Non-Patent Document 4 discloses a positioning method using the OTDOA method in which a PRS (Positioning Reference Signal) is transmitted from each of multiple base stations to a terminal device, and the terminal device estimates its position by calculating the difference in the reception time of the PRS.

[0006] In the ECID method, the time required from transmission to reception of uplink and downlink signals and the angle of arrival are estimated to determine the location of the terminal device. CRS (Cell Reference Signal) is used in the downlink, and SRS (Sounding Reference Signal) is used in the uplink. In addition, a base station equipped with a transmitter that transmits a PRS used in OTDOA positioning arranges the PRS in the time domain and frequency domain so as to avoid CRS (Cell-specific Reference Signal) used only in LTE. CRS is a cell-specific reference signal defined in LTE that is used for measuring the reception quality of downlink signals. [Prior art documents] [Non-patent literature]

[0007] [Non-Patent Document 1] 3GPP, “Physical layer procedures for data (Release 15)”, TS 38.214, v 15.2.0, 2018 / 6. [Non-Patent Document 2] 3GPP, “Physical channels and modulation (Release 15)”, TS 38.211, v 15.2.0, 2018 / 6. [Non-Patent Document 3] 3GPP, “Physical layer procedures for control (Release 15)”, TS 38.213, v 15.2.0, 2018 / 6. [Non-Patent Document 4] S. Fischer, “Observed Time Difference Of Arrival (OTDOA) positioning in 3GPP LTE”, Qualcomm White Paper Summary of the Invention [Problem to be solved by the invention]

[0008] However, since the Cell_ID, ECID, OTDOA method, and UTDOA method used in LTE are based on LTE, they may not be usable as is in systems other than LTE, such as the 5th generation mobile communication system that is applied to a wide range of frequency bands. For this reason, it is desirable to be able to calculate the terminal location even in systems other than LTE.

[0009] The present invention has been made in view of the above, and has an object to provide a user device capable of calculating a terminal position. [Means for solving the problem]

[0010] In order to solve the above-mentioned problems and achieve the object, a user equipment according to the present invention includes a communication unit that receives higher layer parameters related to a positioning reference signal, and a control unit that performs positioning using the received positioning reference signal based on the higher layer parameters, and the higher layer parameters are hierarchical information including a resource set parameter having a plurality of resource parameters. Effect of the Invention

[0011] The present invention has an effect of providing a user device capable of calculating a terminal position. [Brief description of the drawings]

[0012] [Figure 1] FIG. 1 is a diagram showing a configuration of a wireless communication system according to a first embodiment; [Diagram 2] FIG. 1 is a diagram showing functional blocks of a base station according to a first embodiment; [Diagram 3] FIG. 1 is a diagram showing a control circuit according to a first embodiment; [Figure 4] FIG. 1 is a diagram showing an example of positioning by a base station according to a first embodiment; [Diagram 5] 1 is a flowchart showing a procedure for positioning according to the first embodiment. [Figure 6] FIG. 13 is a diagram showing another example of positioning by the base station according to the first embodiment; [Figure 7] Another flowchart showing the procedure of positioning according to the first embodiment [Figure 8] FIG. 1 is a diagram showing an example of positioning by a base station and a terminal device according to a first embodiment; [Figure 9] FIG. 1 is a diagram showing positioning using two TRPs according to a first embodiment. [Figure 10] FIG. 13 is a diagram showing positioning using an OTDOA method according to a second embodiment. [Figure 11] A flowchart showing a procedure for positioning in an OTDOA system according to a second embodiment. [Figure 12] FIG. 11 is a diagram showing a first example of an arrangement of PRSs according to a second embodiment; [Figure 13] FIG. 11 is a diagram showing a second example of an arrangement of PRSs according to the second embodiment; [Figure 14] FIG. 11 is a diagram showing a third example of an arrangement of PRSs according to the second embodiment; [Figure 15] FIG. 11 is a fourth example of an arrangement of PRSs according to the second embodiment; [Figure 16] FIG. 11 is a fifth example of an arrangement of PRSs according to the second embodiment; [Figure 17]FIG. 11 is a diagram showing a sixth example of an arrangement of PRSs according to the second embodiment; [Figure 18] FIG. 7 is a diagram showing a seventh example of an arrangement of PRSs according to the second embodiment. [Figure 19] FIG. 13 is a diagram showing an eighth example of an arrangement of PRSs according to the second embodiment. [Figure 20] FIG. 13 illustrates a ninth example of an arrangement of PRSs according to the second embodiment. [Figure 21] FIG. 10 is a diagram showing a tenth example of an arrangement of PRSs according to the second embodiment. [Figure 22] FIG. 11 is a diagram showing an eleventh example of an arrangement of PRSs according to the second embodiment. [Figure 23] FIG. 12 is a diagram showing a twelfth example of an arrangement of PRSs according to the second embodiment. [Figure 24] FIG. 13 is a diagram showing a thirteenth example of an arrangement of PRSs according to the second embodiment. [Diagram 25] FIG. 13 is a diagram showing an example of muting according to the second embodiment. [Figure 26] FIG. 13 is a diagram showing another example of muting according to the second embodiment. [Figure 27] FIG. 13 shows positioning by switching between LTE and NR according to the fifth embodiment. [Figure 28] FIG. 23 is a diagram showing an example of an arrangement of positioning reference signals according to the sixth embodiment; [Figure 29] FIG. 30 is a diagram showing a waveform of a signal in one OFDM symbol in which the positioning reference signal shown in FIG. 28 is arranged. [Diagram 30] FIG. 1 shows an example in which a positioning reference signal is arranged in multiple symbols. [Diagram 31] FIG. 23 shows an example of switching beams for each section in which the same waveform occurs within one OFDM symbol according to the sixth embodiment. [Diagram 32] FIG. 13 is a diagram showing an example of application of linking of panel numbers, resource sets, and resources when multiple panels are used according to the seventh embodiment. [Diagram 33] FIG. 23 is a diagram showing an example in which a UE according to a seventh embodiment transmits SRS to different base stations; [Diagram 34] FIG. 23 is a diagram showing an example of SRS multiplexed in the time domain according to the eighth embodiment; [Diagram 35] FIG. 23 is a diagram showing an example of arrangement of SRSs multiplexed in the frequency domain according to the eighth embodiment; [Diagram 36] FIG. 23 is a diagram showing an example of transmitting SRS resource information from a terminal device to a base station according to an eighth embodiment; [Figure 37] FIG. 23 is a diagram showing an example of transmitting SRS resource information from a terminal device according to an eighth embodiment to a plurality of base stations. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] A base station, a terminal device, a positioning method, and a wireless communication system according to an embodiment of the present invention will be described in detail below with reference to the drawings. Note that the present invention is not limited to the embodiment.

[0014] Embodiment 1 FIG. 1 is a diagram showing a configuration of a wireless communication system according to a first embodiment. The wireless communication system includes a base station 10 and a plurality of terminal devices 20. In the ECID method in LTE, a distance is measured based on the time it takes for a signal transmitted between the base station 10 and the terminal device 20 to be received by the receiving side. The base station 10 estimates the AoA (Angle of Arrival) of the signal received from the terminal device 20. The base station 10 also performs positioning of the terminal device 20 based on the angle and distance information. In downlink communication, the base station 10 is a transmitting device, and the terminal device 20 is a receiving device. Since a terminal device is generally called a UE (User Equipment), the terminal device 20 is also called a UE in this embodiment. The positioning method in this embodiment is called the ECID method, but this does not mean that it is the same as the ECID method in LTE, and since it is a name, a different name may be used. In addition, the base station is also called a gNodeB in the 3GPP standard.

[0015] FIG. 2 is a diagram showing functional blocks of the base station 10 according to the first embodiment. The base station 10 includes a control unit 101, a transmission signal generation unit 102, a transmission processing unit 103, a reception processing unit 104, a reception signal decoding unit 105, and a positioning processing unit 106. The control unit 101 receives an instruction from the server 200 and transmits a control signal to the transmission signal generation unit 102. The control signal transmitted by the control unit 101 may be in the form of RRC (Radio Resource Control), MAC-CE (Medium Access Control-Control Element), or DCI (Downlink Control Information). The transmission signal generation unit 102 generates a signal to be transmitted to the terminal device 20 based on the control signal. The transmission processing unit 103 performs transmission processing on the signal generated by the transmission signal generation unit 102 to generate a transmission signal. The transmission processing unit 103 transmits a beam to the terminal device 20. The transmission processing unit 103 also transmits a synchronization signal, which is a signal for synchronizing with the terminal device 20, is used for communication with the terminal device 20, and stores resource information indicating resources associated with the beams on a one-to-one basis. The synchronization signal includes an SSB (Synchronization Signal Block). The SSB is a signal used for initial connection and synchronization in 3GPP Release.15.

[0016] The reception processing unit 104 performs reception processing on the received signal. The reception signal decoding unit 105 decodes the received signal that has been subjected to reception processing, and transmits the decoded information to the server 200. The positioning processing unit 106 obtains the position of the terminal device 20 using the resource selected by the terminal device 20. The resource information is distributed in the time domain and the frequency domain, with the SSB being the target. The positioning processing unit 106 also identifies the beam selected by the terminal device 20 using the resource information included in the synchronization signal to which the terminal device 20 responded, and calculates the position of the terminal device 20 using the beam. The operation of the positioning processing unit 106 will be described in detail later. The information transmitted from the reception signal decoding unit 105 is a report, frequency information, or a reference signal transmitted from the terminal device 20. A Location Management Function (LMF) functioning in the server 20 issues an instruction to start or end positioning to the base station 10 using NRPPa (New Radio Positioning Protocol A). The terminal device 20 may obtain the position of the terminal device 20 by positioning. For example, the terminal device 20 may obtain the position of the terminal device 20 by performing positioning when making a call. This call may be, for example, when making an emergency call. In addition, the location information of the terminal device 20 obtained by positioning may be notified to the called party by the above-mentioned call. The notification may be made, for example, when the call is an emergency call. This allows, for example, the called party to quickly obtain the location information of the terminal device that is the call source. When the terminal device 20 performs positioning, the terminal device 20 may or may not notify the base station 10 of the start of positioning. The base station 10 may notify the LMF of the start of positioning of the terminal device 20. The notification from the base station 10 to the LMF may be made using the notification made from the terminal device 20 to the base station 10, or may not be made using the notification.

[0017] The control unit 101, transmission signal generation unit 102, transmission processing unit 103, reception processing unit 104, reception signal decoding unit 105, and positioning processing unit 106 are realized by processing circuits, which are electronic circuits that perform each process.

[0018] This processing circuit may be a dedicated hardware, or a control circuit including a memory and a CPU (Central Processing Unit) that executes a program stored in the memory. Here, the memory includes, for example, a non-volatile or volatile semiconductor memory such as a RAM (Random Access Memory), a ROM (Read Only Memory), or a flash memory, a magnetic disk, or an optical disk. Fig. 3 is a diagram showing a control circuit according to the first embodiment. When this processing circuit is a control circuit including a CPU, this control circuit is, for example, a control circuit 400 having a configuration shown in Fig. 3.

[0019] As shown in Fig. 3, the control circuit 400 includes a processor 400a, which is a CPU, and a memory 400b. When the control circuit 400 shown in Fig. 3 is realized, the processor 400a reads out and executes a program corresponding to each process stored in the memory 400b. The memory 400b is also used as a temporary memory for each process performed by the processor 400a.

[0020] When estimating the reception angle, the base station 10 can extract angle information using a transmission and reception beam. The transmission and reception beam is configured in two dimensions, but may be configured in three dimensions. The base station 10 can also extract three-dimensional angle information. When the base station 10 extracts angle information using a transmission and reception beam, the base station 10 receives information on appropriate beam information from the terminal device 20 during positioning, and converts it into AoA information based on the beam information.

[0021] FIG. 4 is a diagram showing an example of positioning by the base station 10 according to the first embodiment. In FIG. 4(a), the base station 10 uses a beam to find the terminal device 20. In FIG. 4(b), the base station 10 finds the terminal device 20, and then measures the distance and angle between the base station 10 and the terminal device 20. As shown in FIG. 4(a), when performing the initial connection, the base station 10 uses a beam to sweep a wide range to find the terminal device 20. Therefore, the accuracy of the obtained angle information is lower than that when sweeping a narrow range. However, if the base station 10 wants to quickly obtain the angle information of the terminal device 20, the base station 10 may perform positioning of the terminal device 20 using the angle information at the time of the initial connection. Note that, in addition to the received power, BLER (BLock Error Rate) prediction information or the like may be used as a criterion for selecting a beam. Note that the terminal device 20 may report to the base station 10 the identification number of the SSB corresponding to the beam with the strongest received power from among the identification numbers of multiple SSBs transmitted from the base station 10 during initial synchronization. In addition, since the base station 10 transmits one SSB for one beam, the beam and the SSB are associated one-to-one. In other words, if the base station 10 can grasp the identification number of the SSB, it can grasp which beam has been selected by the terminal device 20.

[0022] There are various methods for identifying SSBs and beams, and the terminal device 20 can report identification information to the base station 10 by various methods of SSB. For example, the terminal device 20 and the base station 10 can report by transmitting frequency information or a reference signal in the time domain and the frequency domain. A collection of REs (Resource Elements) distributed in the time domain and the frequency domain is called a resource. For example, in LTE, as described in Non-Patent Document 2, a resource block is made up of 12 subcarriers in the frequency direction. In this embodiment, the subcarriers are replaced with REs for explanation. The base station 10 stores and transmits information indicating resources in the SSB. The terminal device 20 responds to the base station 10 using resources specified in the SSB, so that the base station 10 can grasp which SSB the terminal device 20 responded with. In addition, the base station 10 can grasp which beam the terminal device 20 selected by grasping which SSB the response is for. If the terminal device 20 selects only one beam, the terminal device 20 responds using one time and one frequency resource. Specifically, an example of an SSB identification number is the SS Block Resource Indicator (SSBRI). The SSBRI is an index that specifies a predetermined arrangement of which symbols and REs are used to transmit the SSB in frequency and time. In other words, if the SSBRI changes, the beam used to transmit the SSB corresponding to the SSBRI also changes. Note that positioning using beams is effective when used in the frequency band called FR2, which is from around 24 GHz to around 52 GHz, where a relatively narrow beam can be formed compared to lower frequencies. Positioning using beams allows angle information to be obtained accurately and in a short time, realizing low-latency positioning.

[0023] The server 200 may set the link between the beam and the resource used by the terminal device 20 to respond. In 3GPP, the response from the terminal device 20 to the base station 10 is called Msg.1. The access permission from the base station 10 to Msg.1 is called Msg.2. The information transmitted in Msg.1 is called PRACH (Physical Random Access Channel). Note that Msg.3 and Msg.4 may be provided, the terminal device 20 may issue a request for RRC connection in Msg.3, and the base station 10 may transmit setting information for the RRC connection in Msg.4. Note that the beam for the uplink of Msg.3 may be the beam used when sending Msg.1, or a different beam. The waveform of the transmission signal and the resource of the transmission signal used for sending Msg.3 are specified by the base station 10 for the terminal device 20. That is, the base station 10 may perform positioning after processing Msg.1.

[0024] 5 is a flowchart showing a procedure of positioning according to the first embodiment. The base station 10 performs an initial connection with the terminal device 20 (step S1). The base station 10 receives beam information and information required for distance measurement (step S2). The base station 10 performs positioning of the terminal device 20 using the beam information and information required for distance measurement (step S3). In this embodiment, the position of the base station 10 is known, and if the beam selected by the terminal device 20 can be grasped, the base station 10 can know the direction in which the terminal device 20 is located. The base station 10 may measure the distance by measuring the time required for a round trip using a method such as a TA (Timing Advance) method for distance estimation or PRACH.

[0025] Fig. 6 is a diagram showing another example of positioning by the base station 10 according to the first embodiment. In Fig. 6(a), a coarse search is performed. In Fig. 6(b), a fine search is performed. In Fig. 6(c), positioning is performed after the fine search. The base station 10 may perform positioning after the fine search as shown in Fig. 6(b).

[0026] FIG. 7 is another flowchart showing the procedure of positioning according to the first embodiment. The base station 10 performs an initial connection with the terminal device 20 and synchronizes with it (step S11). The initial connection is completed, and the state becomes RRC_CONNECTED, that is, a state after connection (step S12). The base station 10 performs beam management using SSB or a reference signal, CSI-RS (Channel State Information-Reference Signal), and performs beam search toward the terminal device 20 by narrowing the interval of the beams compared to the initial connection to increase the resolution (step S13). After the initial connection or beam management process is completed, the base station 10 transmits CSI-RS or SSB to the terminal device 20 in the downlink. The base station 10 also receives beam information and information required for distance measurement, which are fed back from the terminal device 20 (step S14). The base station 10 also uses these pieces of information to select a beam ID, and uses the fed back information as angle information. The terminal device 20 transmits SRS (Sounding Reference Signal) to the base station 10. The base station 10 measures the distance by measuring the time required for the round trip between the SBB and the SRS, and performs positioning (step S15). Note that if the positioning time of the base station 10 is limited, positioning may be performed by a rough search in beam selection.

[0027] When the base station 10 performs a beam search using the CSI-RS, the terminal device 20 may report the port number used for the CSI-RS with the strongest power among the received CSI-RS. In this embodiment, NZP-CSI-RS (Non Zero Powered-CSI-RS) defined in Non-Patent Document 2 and the like is used as an example. The port number is a number for identifying the service used by the base station 10 and the terminal device 20 for communication. The port number is linked to the frequency and time position where the CSI-RS is placed, and to the type of code when code multiplexing is performed. If the port number can be grasped, the terminal device 20 can grasp the position of the CSI-RS and the code applied to the CSI-RS. Here, the CSI-RS port and the transmission beam are linked in a one-to-one relationship, so the base station 10 can grasp which beam has been selected from the reported port number. The terminal device 20 may also report a CSI-RS Reference Indicator (CRI) to the base station 10 instead of the CSI-RS port. In short, when the CRI changes, the beam that transmits the CSI-RS corresponding to the CRI changes. By knowing the reported CRI, the base station 10 can ascertain which beam transmitted from the base station 10 has been selected by the terminal device 20.

[0028] FIG. 8 is a diagram showing an example of positioning by the base station 10 and the terminal device 20 according to the first embodiment. In FIG. 8(a), the base station 10 performs a rough search. In FIG. 8(b), the base station 10 performs a fine search. The terminal device 20 also performs a search. In FIG. 8(c), the base station 10 calculates the angle and distance of the terminal device 20 using the beam of the terminal device 20. As shown in FIG. 8(c), the angle information may be a beam number on the base station 10 side or a beam pair link (BPL) combining the beam number on the base station 10 side and the beam number on the terminal device 20 side. The BPL is used to store which beam combination was optimal, and if communication is interrupted and communication is to be resumed, the stored BPL can be used to establish a transmission / reception pair without performing beam sweep again on the transmitting side and receiving side. Furthermore, highly accurate positioning can be achieved by the base station 10 and the terminal device 20 performing positioning using the optimal beam for each other. In the above example, the terminal device 20 uses the criterion of selecting a beam with strong received power, but a characteristic evaluation value such as BLER obtained from a received signal may also be used.

[0029] The base station 10 can perform beam management using the SRS transmitted in the uplink. In this case, the base station 10 observes the SRS transmitted from the terminal device 20 and selects an appropriate beam for the uplink. Then, the base station 10 creates a BPL using the information of the CSI-RS and the SRS. If the information of the SRS and the CSI-RS is obtained, more accurate angle information can be obtained. In addition, when digital precoding is performed, the terminal device 20 selects an appropriate codebook number. The codebook is specified by 3GPP TS38.214 as shown in Non-Patent Document 1. The processing of the protocol of the upper layer extracts angle information using the SSB identification number, CSI-RS port number, beam ID number, or codebook number reported by the terminal device 20. In the CSI-RS, the CRI may be used as the beam ID number, and in the SRS, the SRI (SRS Resource Indicator) may be used as the beam ID number. Like the CRI, the SRI is also linked to the frequency and time location where the SRS is placed.

[0030] In NR, RSRP (Reference Signal Received Power), RSRQ (Reference Signal Received Quality), RSSI (Reference Signal Strength Indicator), or RI (Rank Indicator) are used as information to be reported, and the base station 10 may estimate the distance using these. In this case, RSRP, RSRQ, or RSSI is transmitted from the base station 10 to the LMF. For example, by using RSRP, the amount of attenuation of the received power can be known, which can be used to measure the distance. RSRQ or RI is used when determining whether the signal received by the terminal device 20 is suitable for positioning. For example, a high value of RI indicates that there are many reflected waves, and it can be known that the signal is not suitable for positioning.

[0031] In this embodiment, the distance between the base station 10 and the terminal device 20 is measured based on the transmission time required for uplink and downlink. In the downlink, SSB, CSI-RS, etc. may be used as a signal used for measuring the distance, but PRACH, SRS, or DMRS (DeModulation Reference Signal) may be used in the uplink. In the SRS, the processing flow is specified in the RRC. In this embodiment, the usage, which is an RRC parameter of the SRS, may be clearly indicated as being used for positioning, such as "positioning". By the base station 10 informing the terminal device 20 that the SRS is for positioning, the terminal device 20 can perform appropriate processing, such as prioritizing the positioning process. In addition, a parameter name that can be recognized as being for positioning, such as CSI-RS-Resource-Positioning, may be prepared.

[0032] It is also possible to perform positioning using a plurality of TRPs (Transmission Reception Points) or panels. A panel is an antenna equipped with a plurality of antenna elements, and it is also possible to perform communication using a plurality of panels at a base station. The panels may be physically separated. Also, if there is an obstacle in front of the panels, it is also possible to turn off the power of some panels and set them not to be used. In this case, positioning may be performed using an average value using a plurality of estimated values ​​of the arrival angle and distance. Also, positioning may be performed using a candidate value excluding the maximum or minimum value. FIG. 9 is a diagram showing positioning using two TRPs according to the first embodiment. In FIG. 9, the base station 10 performs positioning using two TRPs. In this case, there are two sets of obtained angle information and distance information, so that the base station 10 performs positioning using the two sets of information. Also, as in the example shown in FIG. 9, when positioning is performed using a plurality of TRPs, PRACH is sent for the number of received beams. In this case, the obtained angle information and distance information can be combined for each panel or TRP, so an identification number such as an ID number for the TRP may be created for each combination and reported to the positioning processing unit 106.

[0033] In addition, a node (NG_RAN_NODE) ​​connected to the 5G core network transmits information required for positioning calculation to the LMF. Examples of information required for positioning calculation include carrier frequency, band used, number of antenna ports used, beam information or beam pair number of the base station 10 or terminal device 20, selected codebook information, etc. In addition, this information may include a value indicating the SFN (Slot Frame Number), the position of the antenna and panel, and the subcarrier spacing used. In NR, subcarrier spacings of 15 kHz, 30 kHz, 60 kHz, 120 kHz, or 480 kHz are provided. In addition, information such as RSRQ or RSRP may be sent. Furthermore, although OFDM or DFT-s-OFDM is used in the uplink, information regarding the applied CP length and BWP (BandWidth Parts) may be sent from the NG_RAN_NODE to the LMF.

[0034] As described above, in this embodiment, the base station 10 transmits a synchronization signal or a reference signal that stores resource information indicating a resource associated with a beam on a one-to-one basis, and calculates the position of the terminal device 20 using the resource information. Therefore, even if multipath occurs, the base station 10 can identify the beam selected by the terminal device 20 by referring to the resource information included in one of the multiple signals generated by the multipath, and can calculate the position using the beam selected by the terminal device 20. Therefore, by using a beam, directivity is increased, and even in a multipath environment, by reducing the number of reflected waves, the receiving side can receive only the main signal without being affected by reflection. In an environment where reflected waves exist, there are multiple arrival angles, so by using a transmission method that can receive only the main signal, the accuracy of selecting the optimal beam on the receiving side is improved. In addition, when calculating the round trip time in distance measurement, if a reflected wave is received, the calculation accuracy of the round trip time of the main signal deteriorates. As a result, even in a multipath environment, the deterioration of the calculation accuracy of the position of the terminal device 20 can be suppressed.

[0035] Embodiment 2 FIG. 10 is a diagram showing positioning using the OTDOA method according to the second embodiment. As shown in FIG. 10, a plurality of base stations 10 transmit positioning reference signals to the terminal device 20 for positioning. In the present embodiment, as an example, it is assumed that the TRP in FIG. 10 is the base station 10, and a unique cell ID (Identification) is given to each TRP. It is assumed that synchronization is achieved between the base stations 10 when implementing this method. The terminal device 20 receives a reference signal and performs positioning using the difference in reception time of each reference signal. Details of positioning using the OTDOA method are described in Non-Patent Document 4. In FIG. 10, t1 indicates the difference between the reception time of the slot containing the PRS transmitted from TRP1 and the reception time of the slot containing the PRS transmitted from TRP2, and t2 indicates the difference between the reception time of the slot containing the PRS transmitted from TRP2 and the reception time of the slot containing the PRS transmitted from TRP3. t3 indicates the difference between the reception time of the PRS transmitted from TRP3 and the reception time of the PRS transmitted from TRP4. t4 indicates the difference between the reception time of the PRS transmitted from TRP4 and the reception time of the PRS transmitted from TRP1. In downlink communication, a slot is a unit consisting of 14 OFDM symbols, and in uplink communication, a slot consists of 14 OFDM symbols or DFT-s-OFDM symbols. Although a slot including a PRS is used as an example, a PRS may be included in a unit of length shorter than a slot, for example, a non-slot consisting of 2, 4, or 7 symbols, and the time difference when a non-slot is received may be used. The reception time difference is called RSTD (Reference Signal Time Difference). The PRS may be called NR PRS.

[0036] The positioning reference signal may be transmitted after beam sweeping is completed and the beam for the terminal device 20 is determined. That is, the PRS is transmitted in the above-mentioned Msg.4 or after Msg.4 is transmitted. When the positioning signal is transmitted after beam sweeping is completed, the position of the terminal device 20 can be grasped and the power for transmitting the positioning reference signal can be concentrated toward the terminal device 20.

[0037] 11 is a flowchart showing a procedure of positioning in the OTDOA method according to the second embodiment. Steps S21 to S23 are the same as steps S11 to S13. The base station 10 transmits a PRS to the terminal device 20 (step S24). Step S25 is the same as step S15. Note that in the OTDOA method, synchronization may be established between the base station 10 and the terminal device 20, and a positioning reference signal may be transmitted in the RRC_CONNECTED state defined by 3GPP.

[0038] The positioning reference signal needs to be orthogonal in the frequency domain and the time domain. In LTE, the positioning reference signal is arranged so as not to overlap with the CRS. However, in NR, which is a standard for 5G, the CRS is not arranged, so that an efficient arrangement different from that of LTE is possible. FIG. 12 is a diagram showing a first example of the arrangement of the PRS according to the second embodiment. The diagram of the arrangement of the RRS shown in this embodiment is an arrangement of the PRS in which 1 RB (Resource Block) is made up of 12 REs and 14 OFDM symbols. A scheduler provided in the base station 10 allocates multiple continuous or discrete RBs for communication to the terminal device 20. Here, a time unit made up of 14 OFDM symbols is defined as 1 slot.

[0039] FIG. 12 is a diagram showing the arrangement of PRSs, with the vertical axis being frequency and the horizontal axis being time. In FIG. 12, the tiles with diagonal lines at the bottom right indicate the position of the PRS. Also, the tiles with dots are tiles where the PRS cannot be arranged. In this embodiment, the tiles with no color are empty REs where data information or control information is not arranged. That is, in this embodiment, the PRS and data (PDSCH: Physical Downlink Shared Channel) are not multiplexed. By not placing data information and control information (PDCCH: Physical Downlink Control Channel), it is possible to prevent interference from data and control signals transmitted from other TRPs or base stations 10 during positioning. Also, since there is a possibility that downlink control information such as PDCCH is arranged in the tiles with dots, the PRS is not arranged. And the PRS is not arranged in the places where the PBCH (Physical Broadcast Channel), PSS (Primary Synchronization Signal), or SSS (Secondary Synchronization Signal) is arranged. In the 3GPP Rel. 15 standard, the PDCCH is arranged at the beginning of the slot with 1, 2, or 3 symbols. For this reason, the first symbol in which the PRS is arranged may be determined according to the number of PDCCHs. Since the maximum number of symbols in the PDCCH is three, the position of the symbol in which the PRS is always arranged first in a slot may be fixed to the symbol number 3 as shown in Fig. 12. Fig. 13 is a diagram showing a second example of the arrangement of PRSs according to the second embodiment. When the number of symbols in the PDCCH is two, the arrangement is as shown in Fig. 13.

[0040] FIG. 14 is a diagram showing a third example of the arrangement of PRS according to the second embodiment. In FIG. 14, PRS is not arranged in the last two symbols in addition to the first three symbols. In 5G, uplink and downlink transmissions are time-multiplexed. For this reason, the last symbols in the downlink transmission slot may not be usable for downlink transmission as a preparation section for analog equipment for uplink reception or for uplink reception in the next slot. For this reason, it may be set so that the last PRS is not transmitted. In FIG. 14, the last two symbols are used for uplink communication, so PRS is not transmitted. Also, since the symbol used for uplink or downlink control information transmission changes, multiple PRS arrangements may be prepared so that a higher layer can select one.

[0041] FIG. 15 is a diagram showing a fourth example of the arrangement of PRS according to the second embodiment. The PRS may be given a cyclic shift so that it can be orthogonal in the frequency domain. When PRSs are transmitted from a plurality of base stations 10, the terminal device 20 receives a plurality of PRSs, so it is important that the PRSs are orthogonal in frequency so as not to interfere with each other. For this reason, as shown in FIG. 15, the PRS may be given a cyclic shift in frequency. Also, the amount of cyclic shift may be changed for each base station 10, so that the PRSs transmitted from each TRP are orthogonal in frequency. For example, in the example of FIG. 10, the PRS arrangement transmitted from TRP1 may be the default arrangement shown in FIG. 12, the PRS arrangement transmitted from TRP2 may be the arrangement in which the PRS arrangement shown in FIG. 12 is given a cyclic shift of 1RE, the PRS arrangement transmitted from TRP3 may be the arrangement in which the PRS arrangement shown in FIG. 12 is given a cyclic shift of 2RE, that is, the PRS arrangement shown in FIG. 15, and the PRS arrangement transmitted from TRP4 may be the arrangement in which the PRS arrangement shown in FIG. 12 is given a cyclic shift of 3RE. The shift amount of the RE may be set by a PRS identification number, i.e., PRS_ID, which is an ID, set by a higher layer. For example, it may be set as NPRSIDmod6.

[0042] 12, the positions of the REs in adjacent OFDM symbols are shifted cyclically by 1 RE. In the case of such an arrangement, positioning becomes easier with flat frequency characteristics.

[0043] Fig. 16 is a diagram showing a fifth example of PRS arrangement according to the second embodiment. As in the PRS pattern shown in Fig. 16, PRSs may be arranged in adjacent OFDM symbols at positions cyclically spaced apart by 2 REs or more. By using such an arrangement, robust PRS transmission is possible even in a frequency-selective transmission path. Note that a plurality of RE-shifted patterns as shown in Fig. 12 or 16 may be prepared, and an upper layer such as RRC (Radio Resource Control) may select a RE-shifted pattern and notify the terminal device 20. In this manner, PRSs compatible with various transmission paths can be selected.

[0044] FIG. 17 is a diagram showing a sixth example of the arrangement of PRS according to the second embodiment. As shown in FIG. 17, one base station 10 may transmit two or more patterns of PRS. The tile with the diagonal line at the lower left indicates the position of the PRS of the second pattern. If one pattern is called one resource, the base station 10 transmits two patterns of PRS. With such a setting, it becomes possible to perform highly accurate positioning using more PRS. In addition, when performing positioning using multiple panels, it becomes possible to set different PRS patterns for each panel. Note that when performing positioning at a high frequency around 30 GHz, the accuracy of positioning is improved by performing the positioning in a line-of-sight environment, so the terminal device 20 may notify each TRP that it is in a line-of-sight environment.

[0045] Fig. 18 is a diagram showing a seventh example of the arrangement of PRSs according to the second embodiment. Fig. 19 is a diagram showing an eighth example of the arrangement of PRSs according to the second embodiment. As shown in Fig. 18 and Fig. 19, the arrangement of PRSs may maintain orthogonality for each RB. Creating orthogonality in RB units makes it possible to increase the number of orthogonal elements in the frequency domain.

[0046] In LTE, the PRS differs depending on the number of ports used for the PBCH, but in this embodiment, different PRS settings may be used depending on the number of ports used for the PBCH. As described in Non-Patent Document 2, in 3GPP TS 36.211, the PBCH is set to only one port. In LTE, only one density is set for the number of ports for the PBCH, but in this embodiment, different positioning accuracy may be required in a high frequency band called FR2 in NR or a low frequency band called FR1 from 450 MHz to 6 GHz. In addition, since the frequency, time, or power resources on the transmitting side are limited, it is necessary to change the density of the PRS. For this reason, multiple densities may be set, and the density may be set in a higher layer in RRC or the like. The density may be set by setting the mode with a selection number as a bit or a parameter. For example, the selection number can be expressed as 0=standard, 1=low density, and 2=high density. In addition, a parameter indicating the density of the PRS, such as PRS_DENSITY, may be prepared, and the mode may be indicated as PRS_DENSITY="DEFAULT", "HIGH", or "LOW". Alternatively, a mode number may be set, multiple densities of PRS may be prepared, and the density corresponding to each mode number may be determined in advance by a standard, and the density may be notified to the terminal device by RRC. By setting the PRS density high, accurate positioning can be performed in a short time, and low-latency positioning can be realized.

[0047] Fig. 20 is a diagram showing a ninth example of PRS arrangement according to the second embodiment. Fig. 20 shows an example of PRS arrangement in which the density of PRS is changed. In the PRS arrangement diagram in Fig. 20, PRS are arranged at a higher density than the arrangement in Fig. 12. In Fig. 20, PRS are arranged at a higher density, but orthogonality on the frequency is lost.

[0048] FIG. 21 is a diagram showing a tenth example of the arrangement of PRS according to the second embodiment. FIG. 21 shows an example of an arrangement in which PRSs are arranged at low density. In FIG. 21, the density of PRSs is low compared to the arrangement of PRSs in FIG. 12, but orthogonality on the frequency is obtained. The PRSs may be arranged in a part or all of the active BWP. When only a part of the BWPs in the assigned band is used, it is appropriate to use a BWP that is close to the center of the assigned band close to the center frequency and is less susceptible to interference from adjacent bands. For example, when the band is divided into four and divided into BWP1, BWP2, BWP3, and BWP4 from the lowest frequency, accurate positioning is possible by using BWP2 or BWP3, or both BWP2 and BWP3. When multiple BWPs are used, the measurement in each BWP may be observed during the measurement gap. During the measurement gap, channels or signals are not transmitted from each TRP or panel, and the terminal device performs observation. During the measurement gap, only one BWP is used, and a PRS is arranged in the corresponding BWP. For example, if t2>t1 at a certain time, only the PRS included in BWP1 is transmitted during the measurement gap period from t1 to t2. If t4>t3>t2>t1, only the PRS included in BWP2 is transmitted in the BWP during the period from t3 to t4. When the bandwidth in use is large, if the entire bandwidth is used for transmission and reception processing, the bandwidth is divided using the BWP to prevent interference with other users or the bandwidth from becoming unavailable for other users, improving frequency utilization efficiency and minimizing interference with other users. The measurement gap setting is notified to the terminal device 20 using RRC or the like. The measurement gap may be used to synchronize between base stations, and the timing of transmitting the reference signal used for positioning may be aligned. Furthermore, since communication or positioning is performed using a wideband in NR, RSTD may be calculated when the TRP uses a different center frequency or the same center frequency but a different BWP or band. RSTD is generally observed using the following formula (1).In the following formula (1), RSTDi,1 is the time difference between TRPi, which is the i-th TRP, and TRP1, which is the reference TRP. Ti-T1 is the time difference between the transmission of slots including PRS from TRPi and TRP1, respectively. Ti-T1 is called the transmit time offset, and there is no offset between synchronized TRPs, and the value is zero. ni is the measurement error of the time of arrival in the terminal device. The speed of light is c. The position of the terminal device is indicated by coordinates (xt, yt), and the position of TRPi is indicated by (xi, yi). When positioning is performed in the terminal device, the position information of the base station, the transmit time offset, etc. may be included in the System Information Block, the PDCCH, the PDSCH, etc. As described above, since the RSTD can be calculated in the terminal device 20, the terminal device 20 may be provided with a positioning function. In addition, information required for positioning may be transmitted from the terminal device 20 to the base station 10, and the base station 10 may perform the positioning process. In this case, the terminal device 20 includes a transmission processing unit, a positioning processing unit, and a reception processing unit, which correspond to the transmission processing unit 103, the positioning processing unit 106, and the reception processing unit 104 of the base station 10, respectively. In this case, the reception processing unit of the terminal device 20 receives a signal used for positioning transmitted from the base station 10, and the positioning processing unit of the terminal device 20 calculates the position of the terminal device 20 using the signal used for positioning. An example of a signal used for positioning is a PRS. In addition, although the TRP is used in the explanation of formula (1), formula (1) is applicable to any transmitting device that can transmit a PRS, not limited to the TRP, and is a formula that can be applied to positioning using a panel.

[0049]

number

[0050] Also, it is possible to design a PRS for a short slot consisting of 2 symbols, 4 symbols, or 7 symbols, called a non-slot. FIG. 22 is a diagram showing an eleventh example of a PRS arrangement according to the second embodiment. FIG. 22 is a diagram showing an example of a PRS arrangement in a slot consisting of 2 symbols. FIG. 23 is a diagram showing a twelfth example of a PRS arrangement according to the second embodiment. FIG. 23 is a diagram showing an example of a PRS arrangement in a slot consisting of 4 symbols. FIG. 24 is a diagram showing a thirteenth example of a PRS arrangement according to the second embodiment. FIG. 24 is a diagram showing an example of a PRS arrangement in a slot consisting of 7 symbols. In the examples shown in FIG. 12 to FIG. 24, an example is shown in which the RE in which the PRS is arranged is downward to the right on the time-frequency coordinate plane, that is, a subcarrier with a lower frequency is used as the symbol becomes later, but it is also possible to use a subcarrier with an upward to the right on the time-frequency coordinate plane, that is, a subcarrier with a higher frequency is used as the symbol becomes later. Also, a power difference between the PRS and other reference signals or channels may be set in a higher layer such as RRC to suppress interference caused by the PRS. Alternatively, the power of the PRS may be set higher than that of other signals, so that the PRS is less susceptible to interference than other signals. The comparison standard for the power difference may be the power of the DMRS, CSI-RS, or PTRS (Phase Tracking Reference Signal). Alternatively, the difference with the power of the PDSCH may be used.

[0051] The sequence used for the PRS may be generated by a random number generator set by a seed number. Then, the seed for the random number generator may be set in a higher layer using RRC or the like so that a different seed is set for each TRP. The random number generator may be, for example, a pseudo-random number generator using pseudo-random number generation as described in Chapter 5.2 of Non-Patent Document 2.

[0052] The PRS is based on QPSK (Quadrature Phase Shift Keying). The QPSK sequence used in the PRS may be generated by a random number generator set by a seed number. Then, the seed for the random number generator may be set in a higher layer using RRC or the like so that a different seed is set for each TRP or panel. For this random number generator, for example, a pseudo-random number generator to which pseudo-random number generation as described in Non-Patent Document 2 is applied may be used. The shift register of the pseudo-random number generator specified by 3GPP is set by the parameter cinit. cinit depends on the symbol position or slot number where the PRS is placed. The PRS may be generated based on the PRS_ID set in a higher layer. The PRS_ID can be freely changed and may be set in a higher layer so that a different PRS is used for each cell, each TRP, or each panel. The value of the PRS_ID may be, for example, 2^16, which is the same upper limit as the cell_ID. For example, in the case of NR, the number is 2^10=1024 (the number of cell_IDs is 1008). If the range of PRS_ID values ​​is {0, 1023}, the initial value setting for the shift register for sequence generation may use the following equation (2). Note that the PRS may be other sequences, such as a Zadoff Chu sequence, instead of a QPSK sequence. In that case, the sequence number of the Zadoff Chu sequence is generated by a pseudo-random number generator.

[0053]

number

[0054] Here, ns is the slot number. l is the symbol number within the slot. NCP is a variable that changes depending on the CP length, and may be set as NCP=0 for normal_CP and NCP=1 for extended_CP. The generated sequence may be masked with a coefficient specific to the TRP. If PRS_ID is not set by RRC, the default setting such as cell ID may be used.

[0055] Note that the PRS sequence may be generated for up to the maximum number of RBs per OFDM symbol. That is, if the terminal device 20 can grasp the seed number for random number generation, it can grasp the PRS value for each RE. An alternative to this generation method is a method of generating a sequence for each number of RBs required by the PRS. That is, the sequence differs depending on the number of RBs, and more diverse PRS sequences can be generated compared to the above-mentioned method. On the other hand, in the above-mentioned method, if the terminal device 20 can grasp the seed number for random number generation, it can grasp the value of the PRS placed in the RE, so that less overhead is required. Either method may be used in this embodiment.

[0056] In addition, in order to avoid interference and provide resistance to selectivity in the frequency domain, frequency hopping of the PRS may be applied. By performing frequency hopping, it is possible to transmit the PRS while frequency multiplexing with data for other terminal devices in FR2 and the like, without dedicating a wide band for a certain period of time. In addition, by performing frequency hopping, time and frequency diversity can be obtained. When performing frequency hopping, the PRS is frequency hopped according to a predetermined pattern. The hopping pattern may be performed in RB units. The PRS is transmitted in slot units, and the number of slots to be transmitted continuously may be specified by a higher layer. The hopping pattern is specified by a higher layer from among predetermined patterns, and the hopping pattern is notified to the terminal device by RRC. The terminal device may use the PRS to perform positioning in a band specified in each frequency hopping. In addition, when transmitting an aperiodic PRS, a slot containing only the PRS may be transmitted in a burst format using multiple slots. By using a PRS for multiple slots, the accuracy of positioning is improved.

[0057] The PRS may be periodically transmitted in the time domain as set by the upper layer. The PRS may be arranged in every slot or every two slots. An offset may be added to the transmission start time. The PRS may be transmitted in units of multiple slots. The PRS may be set to a mode such as periodic, semi-persistent, or aperiodic and transmitted. For example, in the case of periodic, the period and the offset value of the transmission start are set by RRC parameters or the like. The period and the offset value of the transmission start are managed by a table or the like, and the index of the table is specified by the upper layer, and the period and the offset value are set. In the case of semi-persistent, the time interval during which the PRS is periodically transmitted is specified by the upper layer. The aforementioned period is managed by a timer that records the passage of time, and when the period set by the upper layer or the like has elapsed, the transmission of the PRS is automatically suspended. Even during the period, the base station 10 may stop transmitting the PRS and inform the terminal device 20 of the suspension of the transmission of the semi-persistent PRS by DCI, MAC-CE, or the like. When the specified time has elapsed, the PRS transmission ends. The period may be specified in slot units. In aperiodic transmission, a PRS transmission request is sent from the terminal device 20 to the base station 10, and the base station 10 transmits the PRS after receiving an instruction from the terminal device 20. In this case, the PRS may be transmitted over multiple slots. In order to improve positioning accuracy, the base station 10 may set a period for transmitting the PRS every slot or every two slots in order to transmit at high density in time. Note that the PRS may collide with other channels or reference signals in the transmission schedule. In that case, it is necessary to determine the transmission priority between the PRS and other channels or reference signals in the standard. When a control channel such as PDCCH, a data channel such as PDSCH, or a reference signal such as RS is scheduled in a slot or symbol in which the PRS is placed, the PRS may be placed with priority.For example, if a PDSCH is scheduled and arranged in advance in a slot or symbol in which a PRS is arranged, the PRS is arranged with priority, and the previously scheduled PDSCH may not be transmitted. If a slot in which a PRS is arranged overlaps with a slot in which a PDSCH is arranged, the slot including the PDSCH is not transmitted, and the slot including the PRS is transmitted. That is, multiplexing in the time and frequency domains, such as transmitting a part of the data and a part of the PRS, is not performed. The priority of PRS transmission may be lowered compared to channels including important control information such as PDCCH. Then, when a mode such as periodic, semi-persistent, or aperiodic is set as described above, if a collision occurs between a PRS and a PDSCH, the priority of the aperiodic mode may be set to the highest. The above-mentioned priority may be applied even if a mode such as periodic, semi-persistent, or aperiodic is not set for the PRS. Furthermore, if a collision occurs between PRSs, the priority may be determined according to the type of PRS. For example, when the arrangements of periodic, semi-persistent, and aperiodic PRS overlap, the priority order may be aperiodic>semi-persistent>periodic, that is, the priority order may be set to be the highest for the aperiodic PRS.

[0058] In LTE, the minimum value of the period is 160 subframes, but any of the values ​​of 1, 2, 4, 8, 16, 32, 64, and 128 slots, which are shorter than the period, may be included. The period may also be set in non-slot units. The above-mentioned upper layer parameters related to the PRS may be managed under names called resource setting, resource set, and resource. In this way, overhead is reduced by performing hierarchical parameter management. A plurality of resources are included in a resource set, and a plurality of resource sets are included in a resource setting. The resource setting may be called PRS-ResourceConfig in the upper layer, and manages the resource set and includes information such as an identification number of each resource set. It may be managed by TS 38.331. In the resource setting, the behavior in the time domain of the resources included in the resource set, for example, periodic, semi-persistent, aperiodic, etc. may be specified. In this case, when the behavior in the time domain is defined in the resource setting, all resources included in the resource setting have the same setting. In the resource set, parameters of multiple resources are defined. For example, resource identification numbers and the like are included. In addition, when an aperiodic PRS is included, the resource set may indicate that all the included PRSs are aperiodic. Then, the slot or frequency position in which the PRS is placed may be specified in the resource. Alternatively, instead of hierarchical parameters, RRC parameters for PRS configuration may be prepared. For example, RRC parameters including parameter information indicating the density of the PRS in time or frequency, or the above-mentioned operation in the time domain such as periodic, semi-persistent, or aperiodic, such as PRS-config, may be used.

[0059] In 3GPP, the antenna port number is used to apply an identification number to the reference signal. The antenna port number is a number that is not used by other reference signals. Currently, as defined in TS38.211 for NR, the 1000s are used for PDSCH, the 2000s for PDCCH, the 3000s for CSI-RS, and the 4000s for SS or PBCH. For example, the PRS may use a port number in the 5000s. Also, an identification number may be created for the resource with a name such as PRS Indicator. Note that the PRS may be used for low frequency bands below 6 GHz, called FR1 in NR, assuming that a wide beam is used. In FR1, a relatively wide beam is used, so there is no need to link the PRS to a beam number, and the PRS may be transmitted over a wide range like a broadcast signal. In a frequency band called FR2, which is higher than FR1, a relatively narrow beam is used, so that the base station 10 needs to transmit to the terminal device 20 beam information on which the PRS is transmitted so that the terminal device 20 can accurately receive the PRS. In this case, the base station 10 may link the beam selected for transmitting the SSB used at the time of initial connection with the beam transmitting the PRS. Also, the base station 10 may link the beam used for beam management and suitable for transmitting the selected CSI-RS or SSB with the beam transmitting the PRS. The beam information is indicated by, for example, SSBRI or CRI. By performing positioning using a beam, angle information can be obtained accurately and in a short time, and low-latency positioning can be realized.

[0060] Also, a process of not transmitting a PRS that is periodically transmitted at a designated PRS timing may be performed. This is aimed at not interfering with other signals or frequencies during transmission interruption. FIG. 25 is a diagram showing an example of muting according to the second embodiment. In the muting of FIG. 25, a part of the PRS in the indicated section is not periodically transmitted. FIG. 26 is a diagram showing another example of muting according to the second embodiment. For example, in an opportunity to transmit a PRS four times, it is expressed as "1001" using a bitmap. By determining the number of transmissions to be subject to muting in this way, it becomes possible to periodically interrupt some PRS transmissions using a bitmap.

[0061] In NR, CSI-RS is generally used for beam management, but beam sweep may be performed using PRS for beam management for positioning. It is also possible to perform positioning using other RSs without using PRS. For example, CSI-RS is used for beam management, etc., and a highly accurate beam is directed toward the direction in which the terminal device 20 is located. In this case, CSI-RS is used for positioning, and the terminal device 20 may be notified of the CSI-RS port number used for positioning. In this embodiment, NZP-CSI-RS defined in Non-Patent Document 2 and the like is used as an example. In this case, the terminal device 20 calculates the difference in reception timing of CSI-RS received from multiple base stations 10, and can grasp the position in the same way as when positioning is performed using PRS. For example, in FIG. 10, it may be set so that TRP1 uses CSI-RS port 1, TRP2 uses CSI-RS port 2, TRP3 uses CSI-RS port 3, and TRP4 uses CSI-RS port 4. In NR, the position where the CSI-RS is placed is determined by the maximum number of ports, so the base station 10 needs to notify the terminal device 20 of the maximum number of ports. In addition, some CSI-RS ports are multiplexed by OCC (Orthogonal Cover Code), but in positioning such as OTDOA, the CSI-RS arrives at the terminal device 20 with a time lag, so it is not appropriate to use ports multiplexed by OCC. Using CSI-RS ports where REs do not overlap in time and frequency can provide optimal positioning accuracy. When using CSI-RS, the terminal device 20 can know that CSI-RS is used for positioning by informing the terminal device 20 that CSI-RS is used for positioning in the upper layer. Below is an example in which multiple parameters are included in the upper layer for positioning.

[0062] In addition, when using CSI-RS, the CSI-RS for positioning may be set in the upper layer. For example, the parameters for positioning may be set so that the CSI-RS is arranged so as not to overlap with the CSI-RS used for purposes other than positioning in the time symbol or the frequency RE. In the upper layer, such as RRC, a parameter that can be recognized as for positioning, such as CSI-RS-Resource-Positioning, may be prepared. In addition, in order to indicate that the CSI-RS is used for positioning, it may be indicated that it is used for positioning in the resource setting, resource set, or resource. In order to use it for positioning in the upper layer, a flag named positioning or a flag such as PRS may be set in the resource setting, resource set, or resource, and if the value of the flag is 1, it may be indicated that the CSI-RS is used for positioning, and if the value of the flag is 0, it may be indicated that it is used for CSI observation. In addition, a muting function may be used for CSI-RS. By using a bitmap on a slot-by-slot basis, it is possible to specify which slot the CSI-RS can be transmitted in. By using the muting function, it becomes possible to avoid interference and perform positioning. In addition, when PRS or CSI-RS is transmitted from multiple TRPs, panels, or base stations, the length of the CP (Cyclic Prefix) of the transmitted OFDM signal is assumed to be the same. For example, normal CP and extended CP are specified in 3GPP TS36.211, and the extended CP is a longer CP. In the case where PRS or CSI-RS is transmitted by OFDM signals simultaneously from multiple base stations 10, with the flag value being TRP or the flag value being panel, it is suitable that the CP length of all waveforms is the same in order to accurately calculate the time difference of the received multiple PRS or CSI-RS signals. In addition, by using CPs of the same length, it is not necessary to read the CP length from the control information during calculation, and the overhead required for the control information is reduced.

[0063] In addition, when performing positioning using PRS, it is appropriate to use the same numerology, i.e., subcarrier spacing, for the PRS transmitted from each TRP. Since the subcarrier spacing is unified between the PRSs from each TRP, the calculation of RSTD becomes easy. In addition, when the UE calculates its own location information in the OTDOA method or the like, the location information of the terminal device 20 may be notified to the base station 10 from the terminal device 20 using a CSI report or the like. This is because if the base station 10 can periodically grasp the location information, it is possible to manage and select appropriate beams in beam management or the like. In addition, by being able to grasp the location of the terminal device 20 in MU-MIMO or the like, the scheduling of the terminal device can be optimally performed. In addition, positioning may be performed using PRS in FR1 and CSI-RS in FR2. As described above, a wide beam is used in a low frequency band, and the UE cannot know the transmitted beam information, so it may receive the notified PRS and perform RSTD calculation. In high frequency bands, beam management using CSI-RS is performed, and a beam suitable for the UE is set, so that the method of performing positioning using CSI-RS has high positioning accuracy. In addition, although the above description has described using CSI-RS as beam management, SSB may be used for beam management. In addition, periodic transmission of PRS or CSI-RS for positioning may be interrupted using DCI (Downlink Control Information). This is to include a process of immediately interrupting communication since periodic communication may cause an interruption to data transmission. In addition, when PRS, CSI-RS, or SSB for positioning is transmitted, RNTI (Radio Network Temporary Identifier), which is an identification number given to a terminal device, may be C-RNTI (Cell-RNTI), CS-RNTI (Configured Scheduling RNTI), or SP-CSI-RNTI (Semi-Persistent CSI RNTI).

[0064] A ZP-CSI-RS (Zero-Power CSI-RS) may be used as an interference measurement CSI-RS for the CSI-RS used in NR. For example, when interference occurs with the base station 10 of an adjacent cell, the ZP-CSI-RS is transmitted while the base station 10 of the adjacent cell is transmitting the positioning CSI-RS, so as not to interfere with the base station 10 of the adjacent cell. Note that, like the PRS, the PDSCH does not need to be placed in the slot in which the positioning CSI-RS is placed. This is to reduce interference due to the PDSCH. Positioning using the DMRS may also be performed. Since multiple symbols are placed in the slot, it is suitable for positioning. Also, the power difference between the positioning CSI-RS and other reference signals or channels may be set in a higher layer such as RRC to suppress interference due to the CSI-RS. Alternatively, the power of the CSI-RS may be set higher than that of other signals, so that the CSI-RS is less susceptible to interference than other signals. The comparison standard for the power difference may be the power of the DMRS, the CSI-RS for channel estimation or interference measurement, or the PTRS, or the difference with the power of the PDSCH.

[0065] When multiple panels are used, PRS is received from the multiple panels. Since the multiple panels are connected to the base station 10, multiple TRPs exist in the same cell. In this case, the PRS_ID may be changed for each panel to set a different PRS sequence. Also, since the positioning accuracy decreases if there is an obstacle in front of the panel, a flag may be used to indicate whether or not to transmit a PRS for each panel. This flag may be notified to the terminal device 20 using a control signal in an upper or lower layer. The parameters used in the upper layer may be RRC or MAC-CE, and DCI may be used in the lower layer.

[0066] Positioning using OTDOA from IDLE state or INACDTIVE state is also possible. The terminal device 20 starts positioning while monitoring paging information included in the PDCCH transmitted from the base station 10 or the PDSCH specified in the PDCCH. Note that a notification is sent to the terminal device 20 in the paging information, and the terminal device 20 decodes the notification and reads the SIB (System Information Block). The SIB is included in the PBCH and PDSCH.

[0067] The SIB includes information necessary for OTDOA. For example, when a base station 10 of multiple cells is used in OTDOA, the SIB may include the cell ID of the cell to be used. The SIB may also include information on the reference cell. When multiple panels are used for positioning in the same cell, the SIB may include the panel ID of the panel to be used or the ID of the panel to be used as the reference, and when a beam is irradiated from each panel, the SIB may include information on the group to which the beam belongs, with each panel linked to a group. The SIB used for positioning may be given a name of the SIB type so that it can be recognized as a SIB for positioning.

[0068] In addition, when multiple panels are used in the same cell, the ID of the cell and the number of panels used for positioning may be included in the SIB. The positioning instruction may include information for positioning, information indicating that the SIB for positioning is to be received, and the like. The terminal device 20 receives the SIB for positioning. The SIB information for positioning may be transmitted periodically, or may be transmitted in advance when the base station 10 causes the terminal device 20 to perform positioning. In addition, information on the time and frequency resources for transmitting the PRS may be included in the SIB. The time and frequency resources for the PRS transmitted periodically may be described. In addition, when the PRS is transmitted non-periodically, the time and frequency resources for transmitting the PRS non-periodically may be specified.

[0069] After receiving the PRS, the terminal device 20 in the IDLE or INACTIVE state calculates the difference in reception time of multiple PRSs as described above, and reports the calculation result and / or the positioning result to the base station 10 according to the instruction of the base station 10 or at the discretion of the terminal device 20. When positioning is performed using multiple panels or TRPs, the positions of the TRPs or panels may be close to each other and may not be distinguishable from the terminal device 20. In such a case, it may be possible to know that the positions of the panels or TPRs are close by using QCL (Quasi Co-Location) information or measurement results. When the positions of the panels or TRPs are close to each other, it may be possible to average the measurement results or calculate the maximum and minimum values ​​and report them to the base station 10.

[0070] In addition, an OTDOA_INFORMATION_REQ is transmitted from the LMF to the NG_RAN_NODE, and positioning using the OTDOA is started. In this case, an OTDOA_INFORMATION_RESPONSE is transmitted from the LMF to the NG_RAN_NODE, and the information may include PRS setting information. For example, the information may include carrier frequency, PRS band, frequency offset amount, time offset amount or transmission interval of PRS, number of slots transmitted continuously, number of antenna ports used, whether the period setting is periodic / semi-persistent / aperiodic, beam information or beam pair number on the base station 10 or terminal device 20 side, selected codebook information, etc. In addition, the report information may include SFN (Slot Frame Number), antenna or panel position, PRS muting information, PRS hopping pattern, PRS density information such as standard, high density, and low density. In addition, a value indicating the subcarrier interval to be used may be included. In addition, CP (Cyclic Prefix) information may be transmitted. In addition, in OTDOA, since CSI-RS or PRS is transmitted from different TRPs, information is required for the UE to understand the relationship between the TRP and the PRS or CSI-RS. For this purpose, the PRS ID set in advance in each TRP or the parameter nID for generating the CSI-RS defined in TS 38.211 may be notified from the higher layer. Such information may be notified using RRC, or the PRS_ID or parameter nID of the PRS or CSI-RS transmitted from each TRP may be included in the OTDOA assistance data transmitted from the location server.

[0071] In NR, TDD (Time Division Duplexing) is used, and as described in Chapter 11.1.1 of Non-Patent Document 3, symbols in a slot are set to "D" for downlink, "U" for uplink, or "F" for flexible symbols. PRS may be transmitted only using symbols set for downlink indicated as "D". Alternatively, if not used by other symbols, "F" symbols may also be used to transmit PRS.

[0072] In addition, numerology such as subcarrier spacing may change during measurement. In NR, subcarrier spacings of 15 kHz, 30 kHz, 60 kHz, 120 kHz, and 480 kHz are provided, and these values ​​are set not to change during positioning in order to maintain accuracy during positioning. In addition, PRSs of different numerologies may be transmitted to the terminal device 20 in the frequency domain. For example, if a resource of 20 RBs is allocated to the terminal device 20 for positioning, it may be set so that 10 RBs are sent at 15 kHz and 10 RBs are sent at 120 kHz. All may be the same numerology, but in the case of different numerologies, frequency errors are included in the positioning calculation.

[0073] In addition, the location information may be defined using a predetermined grid when performing positioning. A grid is determined in advance, and beam candidates are prepared so that a beam can be emitted from the base station 10 to the center of the grid. For example, when performing positioning in a stationary environment, when grid information is obtained, the terminal device 20 selects a beam and reports it to the transmitting side, and the transmitting side can grasp the location of the terminal device 20. This method is effective in a place where the installation environment is determined. As another example of positioning in the IDLE or INACTIVE state, SSB can be used. The terminal device 20 may receive SSB from multiple base stations 10 and / or multiple panels or TRPs. The terminal device 20 may hold information regarding the reception time of the SSB. The information may be, for example, the difference between the reception times of the multiple SSBs. As a result, for example, the base station 10 does not need to transmit settings regarding PRS to the terminal device 20, and as a result, it is possible to reduce the amount of signaling between the base station 10 and the terminal device 20. The terminal device 20 may derive the location of its own terminal device using information regarding the reception time of the SSB. The base station 10 and / or the panel or TRP may report information on the location of the base station and / or the panel or TRP, or may notify the terminal device 20 individually. The terminal device 20 may use the information on the location to derive the location of the terminal device. This, for example, makes it unnecessary for the terminal device 20 to transmit a measurement result to the base station 10, which results in a reduction in the amount of signaling between the base station 10 and the terminal device 20, and makes it unnecessary to resume communication between the terminal device 20 and the base station 10, which results in rapid positioning in the communication system. As another example, the base station 10 may derive the location of the UE using information on the reception time of the SSB. The terminal device 20 may notify the base station of information on the reception time of the SSB. The notification may be included, for example, in a measurement result report from the terminal device 20 to the base station 10, or may be included in a different signaling. The base station 10 may derive the location of the terminal device using information on the reception time of the SSB. This makes it possible to reduce the load imposed on the terminal device 20 due to position derivation, for example.Moreover, the first embodiment and the second embodiment may be used in combination. In the first embodiment, angle information is obtained from a selected beam, and distance information is used to perform positioning. In the second embodiment, the RSTD is calculated from the reception time of reference signals transmitted from multiple transmitters, and positioning is performed. The average of the positions obtained by both methods may be calculated. In addition, when performing positioning using multiple base stations, some base stations may use the method described in the first embodiment, and the other base stations may use the method described in the second embodiment. As described above, the reference signal used for positioning is set to a period of periodic, semi-persistent, or aperiodic type, but the position information of the terminal device 20 after positioning may also be notified from the terminal device 20 to the base station, or from the base station to the terminal device 20, in any of the forms of periodic, semi-persistent, and aperiodic. By notifying the position periodically, such as in the case of periodic or semi-persistent, the accuracy of services that are sensitive to position information, such as emergency notification, is improved. In addition, in the aperiodic case, the base station or the terminal device 20 that wants to receive a report of position information requests a report of position information, and the report of position information occurs at a time set in the upper layer or lower layer. The aperiodic location information report is an effective reporting method when the base station or the terminal device 20 urgently needs location information. When the periodic report is selected, the base station or the terminal device 20 reports the location information calculated according to a cycle determined by a higher layer, for example, a cycle in units of slots. When the semi-persistent report is set, the base station or the terminal device 20 reports the location information calculated according to a cycle determined by a higher layer, for example, a cycle in units of slots, for a period determined by a higher layer. The above-mentioned reporting method may be called a periodic position report, a semi-persistent position report, or an aperiodic position report.

[0074] Embodiment 3 In UTDOA, a terminal device 20 transmits a signal for positioning to multiple base stations 10 or TRPs, and the base stations 10 or TRPs cooperate to calculate the difference in reception time of the signal for positioning transmitted from the terminal device 20, and use the difference in reception time for positioning the terminal device 20. In this case, the terminal devices 20 may transmit signals simultaneously or according to a fixed timing. The signal transmitted from the terminal device 20 may use SRS or PRS used in the downlink. In NR, OFDM or DFT-s-OFDM is used in the uplink, but when PRS, SRS, DMRS, or DFT-s-OFDM is used for OFDM, SRS or DMRS may be used.

[0075] In addition, in NR, OFDM or DFT-s-OFDM is used in the uplink. DFT-s-OFDM is characterized by a lower PAPR (Peak to Average Power Ratio) than OFDM, so it can be transmitted at a higher power than OFDM. In positioning, low uplink power reduces the accuracy of positioning, so DFT-s-OFDM may always be used in positioning as a default setting. In NR, since the frequency or reference signal settings are different between DFT-s-OFDM and OFDM in the uplink, it is desirable for one method to always be set as a default during positioning for the eNB. In addition, if sufficient power can be secured, a mechanism may be provided to switch to ODFM. This is an embodiment example that can be applied to the E-CID, OTDOA, or UTDOA method.

[0076] In addition, while performing a beam search during positioning, there are times when the search fails. In such a state, the terminal device 20 may notify the base station 10 that the beam search has failed. Also, it is possible that the beam search will fail when the terminal device 20 moves to another TRP or cell during positioning, but even in this case, the terminal device 20 may notify the base station 10 that the search has failed and stop positioning. In addition, in beam recovery, the terminal device 20 may request the base station 10 to change the mutual beam pair between the base station 10 and the terminal device 20, but positioning is not performed during beam recovery.

[0077] Embodiment 4 In the ECID method, the distance between the base station 10 and the terminal device 20 may follow the calculation method of TA (Timing Advance). In addition, in UTDOA, PRACH may be used for uplink signals. In this embodiment, the configuration of PRACH used for ECID and PRACH will be described. The BS is called PDCCH_order, and can request the terminal device 20 to transmit PRACH, and the request is included in the PDCCH. At this time, the PDCCH may include a PRACH configuration for positioning. Also, it may be indicated that the PDCCH is a PDCCH_order for positioning. Also, a search space indicating a resource on frequency and time where DCI is placed in the PDCCH may be set for positioning. Also, the CRC of the PDCCH is scrambled by the RNTI, but the RNTI for positioning may be used. In this way, by setting the location where the CRC or DCI of the PDCCH is placed specially for positioning, it is implied that information for positioning is included for the terminal device 20 after receiving the PDCCH. TA is calculated using PDCCH_order and PRACH. Normally, the base station 10 transmits a RAR (Random Access Response) after receiving a PRACH, but may not transmit an RAR if a PRACH for positioning is received. Since positioning can be performed by receiving a PRACH for positioning, there is no need to perform the subsequent RA process. After transmitting a PRACH for positioning, the terminal device 20 may not receive an RAR from the base station 10. As a PRACH configuration for positioning, frequency and time resources or a preamble format are set. Also, the PRACH configuration for positioning may be made different in advance from PRACH configurations for other uses.

[0078] The configuration of the PRACH for positioning transmitted in the IDLE or INACTIVE state may be set in the RRC_CONNECTED state. The parameters to be set are the PRACH position on frequency and time, the preamble format, and the period if the PRACH is sent periodically, which are set in the RRC_CONNECTED state. These settings are also applied to the PRACH for positioning when the state changes to the IDLE or INACTIVE state. The settings of the IDLE or INACTIVE state may be set using the SIB. Information used for positioning may also be included in the paging information. For example, the setting information of the PRACH may also be included. Only a part of the information may also be set. For example, only the transmission timing may be set.

[0079] When an RNA (RAN based Notification Area) is applied, which is the range of paging sent in the INACTIVE state, the PRACH configuration for positioning sent in INACTIVE may be set for each RNA. It may be set differently from the PRACH configuration for other purposes. Also, the PRACH configuration for positioning sent in IDLE may be set for each paging area. It may be set differently from the PRACH configuration for other purposes. Also, when multiple TRPs are used in the same cell, a special configuration may be used. The PRACH configuration for positioning may be set for each cell. It may be set differently from the PRACH configuration for other purposes.

[0080] The PRACH for positioning may be placed in a time and frequency resource set for positioning. A special sequence or preamble format may be prepared for positioning. Multiple candidates may be prepared so that the PRACH band can be selected.

[0081] Embodiment 5. FIG. 27 is a diagram showing positioning by switching between LTE and NR according to the fifth embodiment. Since the coverage of an LTE cell is wide, positioning may be performed in an NR cell by referring to positioning information obtained from LTE. Positioning may also be performed by switching between the NR and LTE positioning methods. The switching is instructed by a higher layer.

[0082] Embodiment 6 FIG. 28 is a diagram showing an example of the arrangement of positioning reference signals according to the sixth embodiment. FIG. 28 is an arrangement diagram of positioning reference signals with the vertical axis representing frequency and the horizontal axis representing time. In this embodiment, a case where the positioning reference signals are arranged at the positions shown in FIG. 28 will be described. In FIG. 28, OFDM symbols hatched with multiple dots represent positioning reference signals. In the example shown in FIG. 28, the positioning reference signals are arranged every other RE in the third OFDM symbol in the time axis direction. In FIG. 28, only symbols used for transmitting positioning reference signals are inserted in the third OFDM symbol in the time axis direction, and data symbols, control signals, and other types of reference signals are not inserted. In addition, any signal may be arranged in the symbols in FIG. 28 where no reference signal is arranged, which are indicated by diagonal lines.

[0083] FIG. 29 is a diagram showing the waveform of a signal in one OFDM symbol in which the positioning reference signal shown in FIG. 28 is arranged. FIG. 29 shows that the transmission waveform is repeated in units of half of one OFDM symbol time. As an example, one OFDM time is divided into two, a first half 0.5 OFDM symbol time and a second half 0.5 OFDM symbol time. The waveform of the signal in the first half 0.5 OFDM symbol time and the waveform of the signal in the second half 0.5 OFDM symbol time have the same shape. In other words, in FIG. 29, waveforms with similar amplitude and phase are repeated in one OFDM symbol.

[0084] Fig. 30 is a diagram showing a comparative example in which a positioning reference signal is arranged in a plurality of symbols. When the waveform of a signal in the first half of 0.5 OFDM symbol time as shown in Fig. 29 is the same as the waveform of a signal in the second half of 0.5 OFDM symbol time, a synchronization error is likely to occur when performing symbol synchronization. For this reason, it is necessary to transmit a positioning reference signal over a plurality of symbols as shown in the comparative example in Fig. 30. In addition, a synchronization error is also likely to occur in a signal in which signals with the same power characteristics are repeated a plurality of times in one OFDM symbol interval.

[0085] In order to solve the problem that synchronization deviation is likely to occur when performing symbol synchronization, in this embodiment, the base station 10 switches beams for each section in which the same waveform occurs within one OFDM symbol and transmits a signal, thereby preventing the same waveform from being observed repeatedly at the terminal device 20. The terminal device 20 receives signals for each beam switched for each section. With this method, the terminal device 20 does not receive the same waveform, so that synchronization deviation in the terminal device 20 can be suppressed.

[0086] FIG. 31 is a diagram showing an example of switching beams for each section in which the same waveform occurs within one OFDM symbol according to the sixth embodiment. FIG. 31 shows an example in which the same waveform occurs twice within one OFDM symbol. In FIG. 31, there are two beams transmitted from the base station 10, which are indicated as beam 1 and beam 2. In FIG. 31, it is assumed that beam 1 and beam 2 are oriented in different directions, that is, in different spatial directions. The directions of beam 1 and beam 2 are adjusted by the base station 10. The base station 10 can direct the beams using an analog beam or a digital beam using digital precoding. The terminal device 20 cannot receive a signal at maximum power unless it uses a receiving beam oriented in the direction of beam 1 or beam 2 transmitted from the base station 10.

[0087] In the example shown in FIG. 31, beam 1 is used to transmit signal A in the first half of one OFDM symbol time. Beam 2 is used to transmit signal B in the second half of one OFDM symbol time. If the beam is not switched for each section in which the same waveform occurs within one OFDM symbol, the terminal device 20 will receive signals A and B within one OFDM symbol. On the other hand, if the beam is switched for each section in which the same waveform occurs within one OFDM symbol, the terminal device 20 will receive only signal A when the direction of the receiving beam is adjusted to receive a signal transmitted by beam 1. Also, the terminal device 20 will receive only signal B when the direction of the receiving beam is adjusted to receive a signal transmitted by beam 2. For example, in FIG. 31, if the terminal device 20 receives using beam 3, it is possible to receive a signal transmitted by beam 1. When beam 3 is used, the reception power of the signal transmitted from beam 2 in the terminal device 20 is smaller than the reception power of the signal transmitted from beam 1. On the other hand, if the terminal device 20 receives using beam 4, it is possible to receive a signal transmitted by beam 2. When beam 4 is used, the received power of the signal transmitted from beam 1 at the terminal device 20 is smaller than the received power of the signal transmitted from beam 2. That is, the terminal device 20 cannot see the repeated signal in one OFDM symbol interval or in an interval where signals with equal power characteristics are repeated multiple times.

[0088] In this embodiment, as described above, no other signal is placed in the OFMD symbol into which the positioning reference signal is inserted. Since the positioning reference signal is placed in a predetermined position, if the terminal device 20 obtains information on the positioning reference signal, such as the placement interval of the positioning reference signal in the frequency domain and the sequence used as the reference signal, the terminal device 20 can know the characteristics of the signal in one OFDM section in advance, and can demodulate the signal even if it receives only signal A or signal B as shown in FIG. 31. When the sequence used for the reference signal is a PN (Pseudo Noise) sequence, a value such as C_init used to initialize a shift register for sequence generation may be notified to the terminal device 20 as information on the positioning reference signal. In addition, when the sequence changes depending on the slot, symbol number, or relative position from other reference signals in which the positioning reference signal is placed, the above-mentioned parameters may be notified to the terminal.

[0089] In addition, when the base station 10 switches the transmission beam within one OFDM symbol as in this embodiment, the time for the beam sweep of the base station 10 is shorter than when the beam is not switched within one OFDM symbol. For example, in the conventional method, when one same beam is used for one OFDM symbol period and 64 beams are swept and transmitted, the base station 10 needs at least 64 OFDM symbol times to transmit the 64 beams. In addition, if time is required to switch the beams, the base station 10 needs more than 64 OFDM symbol times to transmit the 64 beams. However, as an example of the present method, when the base station 10 sweeps 64 beams using two beams within one OFDM symbol, the beams are switched every 0.5 symbol time, so that the transmission of the 64 beams is completed in a minimum of 32 symbol times. If the terminal device 20 sets a fixed reception beam while the base station 10 is beam sweeping the reception beam, it becomes possible to observe the reception power of the beams transmitted from the base station 10 and radiated in multiple directions within one OFDM symbol. The base station 10 may increase the number of beams to be swept, that is, the number of resources, to the extent that the time for beam sweeping is shortened. In order to shorten the time for beam sweeping and increase the efficiency of beam sweeping during beam sweeping, the base station 10 needs to set the direction or range in which the beam sweeping starts. As shown in FIG. 10, when the terminal device 20 performs positioning using multiple base stations or TRPs, the terminal device 20 may notify the surrounding base stations of the beam sweep result of the TRP to be referenced. Here, the result of the beam sweep is, for example, the reception power of each beam when the base station 10 is beam sweeping, which is acquired by the terminal device 20. Alternatively, the result of the beam sweep is, for example, the transmission beam number selected after the beam sweeping. For example, using the example of FIG. 10, the terminal device 20 may notify the result of the beam sweeping of TRP1 to TRP2, 3, and 4 through the server 200. Alternatively, the terminal device 20 may notify the TRPs 2, 3, and 4 using a broadcast channel such as a PBCH (Physical Broadcast Channel).

[0090] Various methods can be considered for notifying the terminal device 20 of the setting notification information, which is information notifying that the beam will be switched within one OFDM symbol, from the base station 10. The base station 10 may notify the terminal device 20 of the setting notification information by including the setting notification information in an upper layer signal and transmitting the upper layer signal including the setting notification information to the terminal device 20. The notification may be a flag, or an RRC parameter of the upper layer signal may be used. The method of transmitting the information notified to the terminal device 20 is not limited to a method using an RRC parameter, and may use a method other than the RRC parameter.

[0091] Also, the server 200 performing positioning may notify the terminal device 20 of the setting notification information. For example, the server 200 using LPP (LTE Positioning Protocol) may notify the terminal device 20 of the setting information. Also, the server 200 may notify the terminal device 20 using a protocol defined in NRPPa. The setting information may be notified through the base station 10. For example, information may be transmitted from the LMF to the base station 10 through NRPPa. Also, a server having a positioning function for the downlink and a server having a positioning function for the uplink may be separately installed. By installing these servers, the processing power can be distributed, and the calculation time required for positioning can be reduced.

[0092] Embodiment 7 When the terminal device 20 performs positioning using positioning reference signals transmitted from multiple base stations 10 in downlink or uplink, it is necessary to manage beam information. The beam information is, for example, the power of the beam and the irradiation direction of the beam. In addition, when the reference signal is transmitted by a beam, the beam information is, for example, the frequency at which the reference signal is transmitted and the position in the time domain and frequency domain of the reference signal. The positions of the time domain and frequency domain of the reference signal are predetermined for each beam, and the terminal device 20 can estimate the strength of the received power by measuring the received signal at the position where the reference signal is disposed. When the terminal device 20 performs positioning by using the positioning reference signal of the downlink and transmitting the positioning reference signal from each of the multiple base stations 10 to the terminal device 20 as shown in FIG. 10, it is necessary to manage the beam information to which each positioning reference signal is transmitted by the base station 10 or the terminal device 20. In this embodiment, the TRP in FIG. 10 is called the base station 10. In addition, the base station 10 may be present in the same cell as the terminal device 20, or may be present in another cell. In such a case, a resource set may be allocated to each base station 10. Note that a resource set is generally used to configure CSI-RS, which is a reference signal used in downlink, or SRS, which is a reference signal used in uplink.

[0093] The resource set used for positioning may be set as a resource set different from the CSI-RS. Since special settings such as muting or periodic PRS transmission for positioning are made for each resource set, it may be set as a resource set different from the CSI-RS. Note that the muting setting may be set on a resource set basis or on a resource basis.

[0094] The resource set may be applied to the positioning reference signal in the uplink. In 3GPP LTE, the SRS is used as the positioning reference signal in the uplink. The SRS used for positioning is referred to as the positioning SRS here. For example, as described above, the usage, which is an RRC parameter, may be set as Positioning. Also, as described above, the server or the function performing positioning may notify the terminal device 20 of the setting information of the usage used in the RRC parameter. In this case, the usage is set as higher-level information of the information notified from the server or the function performing positioning, rather than being used as an RRC parameter. Note that the beam information of the SRS may be defined as the resource, and multiple beam information may be defined as the resource set. Also, in the case of positioning using the uplink, the terminal device 20 transmits the positioning reference signal to multiple base stations 10. The base station 10 records the reception time of the positioning reference signal transmitted from the terminal device 20, and the multiple base stations 10 refer to the information of the reception time with each other to grasp the position of the terminal device 20 from the time difference between the reception times with other base stations 10. The positioning reference signal is not limited to SRS, and PRS for uplink may be used. The positioning reference signal also includes frequency domain and time domain position information in which the SRS transmitted from the terminal device 20 is arranged using a beam corresponding to each resource. That is, the base station 10 measures the received power of the beam using the SRS arranged at the frequency domain and time domain position in which the SRS transmitted from the terminal device 20 is arranged. The frequency domain and time domain position information in which the SRS transmitted from the terminal device 20 is arranged may be information in units of multiple symbols or information in units of one symbol.

[0095] When the terminal device 20 transmits a reference signal to multiple base stations 10, it is necessary to link the reference signal transmitted by the terminal device 20 with the destination base station 10 and the beam number or resource number, which increases the amount of control information required. If the amount of control information increases, it takes time to transmit, and the bandwidth, number of symbols, and number of bits required for the control information increase.

[0096] Here, a reference signal may be transmitted by linking the resource set of the SRS with the destination base station 10. If the resource set of the SRS and the destination base station 10 are linked, the information transmitted to the terminal device 20 is only information related to the resource set, such as the identification number of the resource set, and therefore the amount of control information is kept to a minimum.

[0097] The settings related to the resource set and resources of the SRS may be performed using RRC. Note that a setting method other than RRC may also be used. The settings related to the resource set and resources of the SRS may be performed individually by each base station 10. Also, setting information may be notified to the terminal device 20 from a server or a function that performs positioning.

[0098] The terminal device 20 only needs to transmit the resource set and the SRS according to the resource-related settings. Therefore, it is only necessary to set the resource sets for the number of expected base stations 10.

[0099] When the terminal device 20 determines the beam to be used when transmitting the positioning SRS, which is the SRS used for positioning in the uplink, the terminal device 20 needs to perform beam sweeping and select an appropriate beam. However, when the terminal device 20 performs beam sweeping, it requires time to perform a sweep in a determined range, and the time required for positioning increases. For this reason, in order to omit the beam sweeping or reduce the time required for the beam sweeping, the beam information used when transmitting the positioning SRS may be associated with the beam information used when using the reference signal or synchronization signal in the downlink and uplink that have already been used. The association of the beam information may be performed, for example, by the base station 10 or a server. By linking the beam information in this way, the effect of omitting the beam sweeping or reducing the time required for the beam sweeping can be obtained.

[0100] Here, the linking of the positioning SRS with other reference signals will be described in detail. The reference signal or synchronization signal used in the downlink may be CSI-RS, SSB, PRS, or TRS (Tracking Reference Signal). When transmitting the reference signal or synchronization signal, the base station 10 transmits them using any of the beams. At this time, if the beam of the positioning SRS in the uplink is linked to the beam that transmits the reference signal or synchronization signal in the downlink, the terminal device 20 may transmit the beam of the uplink positioning SRS linked to the beam used to transmit the reference signal or synchronization signal in the downlink.

[0101] In the uplink, the positioning SRS may be transmitted using a beam associated with an SRS used for purposes other than positioning. In 3GPP NR, the SRS in Release 15 is divided into use cases, UL codebook-based, UL non-codebook-based, UL beam management, and Antenna switching. The above-mentioned use cases are set for a resource set. Then, unique parameters are set for each of the above-mentioned use cases and notified to the terminal device 20. The beam for transmitting the positioning SRS may be set to the beam direction for SRS positioning using the beam used in the above-mentioned use case. Setting the beam direction of the SRS used for other use cases in this way eliminates the need for beam sweeping, and the time required to determine an appropriate direction can be reduced. Setting the beam direction of the SRS used for other use cases can reduce the amount of control data sent to the base station 10 and a server equipped with a function for performing positioning.

[0102] When the CSI-RS for positioning is used as the PRS, the reference signal to which the spatial information is to be linked may be SSB, SRS, PRS in the uplink, etc. Also, the PRS in the downlink may be linked to the spatial information of the DMRS. Here, the spatial information of the DMRS is the direction of the beam in which the DMRS is transmitted. For example, the direction of the beam in which the DMRS is transmitted is linked to the beam number of another downlink reference signal. Alternatively, for example, the direction of the beam in which the DMRS is transmitted is linked to the QCL state of the PRS and the RS including the DMRS and another DMRS. Linking to the QCL state indicates that when the port number X of the PRS and the port number Y of the DMRS are in the QCL state, the spatial information of the transmission path of the port number X of the PRS, the transmission path characteristics such as Doppler shift and Doppler spread, and the spatial information of the transmission path of the port number Y of the DMRS, the transmission path characteristics such as Doppler shift and Doppler spread are similar. In other words, the direction of the beam used for transmitting the PRS may be used for the DMRS. The spatial information setting may be applied within a resource set. In this case, the setting is applied to all resources within the resource set.

[0103] When multiple panels are used in the terminal device 20 during positioning, a resource set may be set for each panel. By installing multiple panels in the terminal device 20 and orienting each of the multiple panels in a different direction, it becomes possible to transmit SRS from the terminal device 20 in all directions. In this case, spatial information is set for each panel. When the panels are oriented in different directions, it is necessary to set spatial information for each panel. Therefore, if spatial information is managed for each resource set, the overhead required for setting can be reduced. In such an operation, the number of panels on the UE side and the number of resource sets may be set to be equal. Also, a panel identifier may be set for each resource set. By setting a panel identifier for each resource set, it becomes possible to link multiple resource sets to the same panel. Also, a panel identifier may be linked to a resource in a resource set. In this case, the panel to which a resource or beam is linked becomes clear, and the operation of multiple panels can be managed within a resource set. FIG. 32 is a diagram showing an application example of linking panel numbers, resource sets, and resources when multiple panels according to the seventh embodiment are used. In FIG. 32, five resources are set in the base stations 10-1 and 10-2, and two resource sets are set in each of the two panels of the terminal device 20. For example, a beam for transmission and a beam for reception are prepared in one resource set from the terminal device 20 toward the base station 10-1. In FIG. 32, two resources corresponding to two beams from the terminal device 20 facing the direction of the base station 10-1 are prepared in one resource set. In addition, the resource for transmission or the resource for reception is linked to the resource number #2 and the resource number #4 of each base station 10-1. That is, different panels of the terminal device 20 are associated with beams facing different directions of the base station 10-1. In the example of FIG. 32, control information that associates an identifier of a resource set with two resource numbers of the base station 10-1 is generated by a server having a function of performing positioning or the base station 10-1.In addition, the downlink reference signal and the uplink reference signal may be associated not only with the own cell but also with other cells. For example, the cell in which the terminal device 20 exists may be associated with a reference signal transmitted from the base station 10 of an adjacent cell. By associating the direction of the beam transmitted from the base station 10 of the adjacent cell with the direction of the beam of the terminal device 20, the terminal device 20 can perform positioning using the adjacent cell base station. For this reason, a cell identifier, a TRP identifier, or a base station identifier may be added to the associated beam information to indicate that it is linked to another cell.

[0104] Also, beams may be used for different purposes within the same resource set. For example, as described above, the application methods of SRS are divided into UL codebook-based, UL non-codebook-based, UL beam management, and Antenna switching, and positioning resources, i.e., beams, may be defined within the use cases to which each is applied. At this time, the characteristics of the beams become characteristics suitable for positioning. For example, only settings for periodically transmitting positioning beams may be prepared.

[0105] Even if multiple panels are not used in the uplink, when the UE transmits SRS to multiple different base stations 10, a resource set may be set for each base station 10. When the UE transmits SRS to different base stations 10, the base stations 10 cooperate with each other to compare the time when the SRS was received, thereby making it possible to estimate the location of the UE.

[0106] Fig. 33 is a diagram showing an example in which a UE according to the seventh embodiment transmits an SRS to different base stations 10. In Fig. 33, the UE needs to transmit a positioning SRS to two base stations 10, and two resource sets are set, with resource set #1 corresponding to base station 10-1 and resource set #2 corresponding to base station 10-2. For example, a transmission beam or a reception beam directed from the terminal device 20 toward base station 10-1 is associated with resource number #4 of base station 10-1. By setting resource sets to different base stations 10 in this way, the terminal device 20 can reduce overhead required for transmitting control information.

[0107] A port for transmitting the PRS is also set. The port is assigned a number, and up to one or two ports can be set. The port may be set for each resource. In this embodiment, the port indicates a logical antenna. In the example of this embodiment, the port setting will be described using an example of a PRS used in the downlink. For example, if two ports are used, up to two polarizations of a physical antenna can be supported. For example, the relationship between one port and the other port can be set for the port. In addition, the relationship between the resource and the QCL can be set, and the same spatial information can be set. Types A, B, C, and D are set for the QCL, and Type A includes information related to the Doppler shift, Doppler spread, average delay, and delay dispersion. Type B includes information related to the Doppler shift and Doppler spread. Type C includes information related to the average delay and Doppler shift. Type D includes spatial information related to reception. The QCL may be set for the port or resource of the PRS.

[0108] If the QCL state is the same between ports, it indicates that the characteristics of the propagation path are almost the same, so the same transmission processing can be performed on the transmitting side. When two ports are configured for PRS, the same or different QCL states can be configured between the two ports. When the same QCL state is configured, similar transmission paths are propagated between the two ports. Also, different QCL states may be configured for the two ports configured for PRS. The PRS port may be linked to the SSB, DMRS, PTRS, TRS, or CSI-RS port. The port linked to the QCL state of the resource may be linked to the SSB, DMRS, PTRS, TRS, or CSI-RS port. The resource may be linked to the SSB, DMRS, PTRS, TRS, or CSI-RS port. Note that the port configuration for PRS is applied to the PRS used in the downlink or the PRS configuration used in the uplink.

[0109] Embodiment 8 In the section in which the reference signal used for positioning in the uplink is transmitted, it is desirable that there is no interference from other signals. In addition, by transmitting a large number of uplink reference signals for positioning, the receiving side can average the received signals, and the positioning accuracy can be improved. For this reason, the positioning SRS or the uplink PRS may be placed in a predetermined slot. Here, the SRS is used as an example. Only the SRS is placed in the predetermined slot, and the SRS is not multiplexed with other reference signals, data signals, or control signals in the frequency domain. Here, the slot indicates a symbol consisting of 14 OFDM symbols or 14 DFT-s-OFDM symbols, but the slot may also indicate a set consisting of fewer than 14 symbols. By setting a slot in which only the positioning SRS is placed, interference from other signals is reduced when positioning is performed on the base station 10 side.

[0110] It is to be noted that all of the 14 symbols in the slot do not have to be used as positioning SRS for the UE. Unused symbols may be used as positioning SRS for other UEs. FIG. 34 is a diagram showing an example of SRS multiplexed in the time domain according to the eighth embodiment. In FIG. 34, white symbols indicate unused symbols. The SRS symbols in the SRS resource for the second terminal device 20-2 are arranged at the 12th and 14th symbols, and the SRS resource for the SRS for the first terminal device 20-1 is arranged at the 11th and 13th symbols. That is, the base station 10 transmits a reference signal for the first terminal device 20-1 and a reference signal for the second terminal device 20-2 at different symbol times.

[0111] FIG. 35 is a diagram showing an example of the arrangement of SRSs multiplexed in the frequency domain according to the eighth embodiment. The positioning SRS may be frequency-multiplexed with a plurality of SRSs corresponding to a plurality of terminal devices 20. In FIG. 35, the SRSs of the first terminal device 20-1 and the second terminal device 20-2 are multiplexed in the frequency domain at the 14th symbol. That is, in the example shown in FIG. 35, the base station 10 multiplexes a reference signal for the second terminal device 20-2 and a reference signal for the first terminal device 20-1 at the same symbol time. The position of the symbol of the positioning SRS may be shown as a bit arrangement. For example, the position of the symbol of the positioning SRS of the first terminal device 20-1 in FIG. 34 can be shown as 00000000001010. Such information on the position of the symbol of the positioning SRS is notified to the first terminal device 20-1 by a server having a function of performing positioning or the base station 10 through an upper layer or a lower layer. Furthermore, the terminal device 20 transmits an SRS based on information on the position of the symbol of the positioning SRS.

[0112] FIG. 36 is a diagram showing an example of transmitting SRS resource information from the terminal device 20 according to the eighth embodiment to the base station 10. In this embodiment, information indicating the location of the SRS resource is called SRS resource information. The SRS resource indicates the location in the frequency domain and the time domain where the SRS is arranged. The SRS resource may be arranged across a plurality of OFDM or a plurality of DFT-s-OFDM symbol units, or may be arranged in one OFDM or one DFT-s-OFDM symbol unit. When transmitting SRS resource information from the terminal device 20 to the base station 10, it is necessary to determine the transmission timing before transmitting each SRS resource information from the terminal device 20. By the base station 10 knowing the transmission interval of the SRS transmitted from the terminal device 20, it is possible to improve the SNR (Signal to Noise Ratio) of the received SRS signal by averaging processing or the like. In addition, when SRS is transmitted from a plurality of terminal devices 20, the plurality of terminal devices 20 need to set the SRS transmission interval and the relative transmission timing in advance by scheduling and grasp the transmission schedule so that the SRS transmitted from the plurality of terminal devices 20 do not collide with each other. The SRS resource information is transmitted, for example, periodically. Note that the interval between resources is indicated as T in FIG. 36. The unit of T may be the number of symbols or time, and the unit of T may be, for example, seconds. Furthermore, the arrangement of resources in the time and frequency domain within a slot is not related to determining the timing of transmitting the SRS resource information, and the interval between slots is important. At this time, the base station 10 transmits the SRS resource information to a plurality of different beams. In this case, the base station 10 may perform beam sweeping, or may transmit the SRS with the beam direction already determined. When the base station 10 performs beam sweeping, the beams that transmit each SRS resource information are candidate beams. When the beam direction is already determined and the SRS is transmitted, the positioning SRS is transmitted.

[0113] Fig. 37 is a diagram showing an example of transmitting SRS resource information from a terminal device 20 according to the eighth embodiment to a plurality of base stations 10. In the example shown in Fig. 37, separate positioning SRS slots are used for base stations 10-1, 10-2, and 10-3. Although the examples shown in Figs. 36 and 37 show examples in which SRS is transmitted at regular intervals, irregular intervals may be used as long as each base station 10 can grasp the intervals. In the example shown in Fig. 37, the interval between resources is indicated by T'. The unit of T' may be the number of symbols or time, for example, seconds.

[0114] When the upper layer parameter "usage" is "Positioning", it is desirable that the positioning SRS is not multiplexed with data or control channels within the slot. Since positioning slots are set on a slot-by-slot basis, different usages may be time-multiplexed on a slot-by-slot basis. Multiplexing slots with different usages in this way allows for flexible configuration. The SRS used for positioning is sometimes called PRS, uplink PRS, or uplink PRS.

[0115] Embodiment 9 3GPP proposes that the terminal device 20 derives its own location information. However, conventionally, the terminal device 20 only performs positioning in LTE, for example, deriving the difference in the reception time of the PRS, and the terminal device 20 cannot derive its own location information. To solve this problem, the base station 10 may notify the terminal device 20 of base station information, which is information related to the base station 10. The terminal device 20 derives its own location information by using the base station information notified by the base station 10.

[0116] The following five items are given as examples of the base station information. The first item of base station information is an identifier of the base station 10. The second item of base station information is information relating to the position of the base station 10. The third item of base station information is information relating to the beam of the base station 10. The fourth item of base station information is information relating to the synchronization of the base station 10. The fifth item of base station information is information combining the first to fourth items of base station information. These items of information can be used as base station information for positioning by the terminal device 20. The terminal device 20 performs positioning using, for example, at least one of the first to fourth items of base station information. Also, for example, the terminal device 20 performs positioning using information combining the first to fourth items of base station information.

[0117] The identifier of the base station 10 is, for example, a cell identifier. Alternatively, the identifier of the base station 10 may be a TRP identifier. The information on the position of the base station 10 may be, for example, position information derived by the base station 10 using a Global Navigation Satellite System (GNSS). The information on the beam of the base station 10 may be, for example, a beam identifier, information on the beam direction of each beam, and the like. The information on the beam direction of each beam may be information on the irradiation angle of the beam, and the like. The information on the beam direction may be information on the horizontal direction and the vertical direction.

[0118] The information related to the synchronization of the base station 10 may be, for example, base station information of the surrounding base stations 10 with which synchronization is established. As for time synchronization, base stations 10 having the same DL frame timing may be regarded as surrounding base stations 10 with which synchronization is established. The base station information of the surrounding base stations 10 may be a cell identifier. A plurality of groups of the surrounding base stations 10 with which synchronization is established may be provided. An identifier for each group may be provided for each group. It is possible to recognize which base station 10 is synchronized with which synchronization is established by the group identifier.

[0119] A method in which the base station 10 notifies the terminal device 20 of the base station information will be described. The base station 10 includes the base station information in the broadcast information and broadcasts it. The base station 10 may transmit the broadcast information on the PBCH. Alternatively, the base station 10 may transmit the broadcast information on the PDSCH. Information indicating that the base station information is for positioning by the terminal device 20 may be generated, and the broadcast information may be notified together with information indicating that the base station information is the base station information. The base station 10 may generate an SIB of information indicating the base station information for positioning by the terminal device 20. In this way, it is possible to obtain the base station information not only in the RRC CONNECTED state, but also when the terminal device 20 is in the RRC IDLE state or the RRC INACTIVE state. The RRC CONNECTED state may also be referred to as the CONNECTED state. The RRC INACTIVE state may also be referred to as the INACTIVE state.

[0120] The base station 10 may notify the terminal device 20 of the base station information by RRC individual signaling. Information indicating that the base station information is for positioning by the terminal device 20 may be provided, and the base station information may be notified together with the information indicating that the base station information is for positioning. The base station information notified in the RRC CONNECTED state may be used in the RRC INACTIVE state. When the terminal device 20 transitions to the INACTIVE state, it is desirable for the terminal device 20 to hold the base station information notified in the RRC CONNECTED state. In this way, it becomes possible to set base station information for each terminal device 20.

[0121] The base station 10 may notify the terminal device 20 of the base station information of the surrounding base stations 10. In this way, the terminal device 20 can obtain the base station information of the surrounding base stations 10 from the base station 10. Here, the base stations 10 around the base station 10 are called surrounding base stations. The base station information of the first base station may be included in the base station information of the surrounding base stations transmitted by the first base station, which is one of the base stations 10. In this way, the terminal device 20 can obtain the base station information of the surrounding base stations of the first base station from the first base station. For example, the terminal device 20 obtains the base station information of the surrounding base stations from the first base station. The terminal device 20 receives information indicating that the base station information is for positioning by the terminal device 20 together with the base station information of the surrounding base stations, and performs positioning using the obtained base station information of the surrounding base stations. The positioning may be performed by using the above-mentioned method as appropriate or a conventional method as appropriate, and the method of positioning is not limited. The terminal device 20 derives the position information of the terminal device 20 itself using the base station information of each surrounding base station that has performed positioning. For example, the location information of the terminal device 20 itself may be derived using the location information of a plurality of base stations 10, beam irradiation angle information, and the like.

[0122] The terminal device 20 may perform positioning using information indicating a synchronized base station from the received information on synchronization for each base station 10. For example, there may be cases where unsynchronized base stations 10 are also located in the vicinity. If positioning and location information are derived using base station information transmitted from an unsynchronized base station 10, the difference in reception timing between the base stations 10 cannot be derived accurately, and accurate location information cannot be obtained. For this reason, the terminal device 20 performs positioning and derives location information using base station information of synchronized surrounding base stations, thereby making it possible to derive accurate location information of the terminal device 20 itself.

[0123] As another method, the base station 10 may notify the terminal device 20 of the base station information of the base station itself. In this way, it is possible to reduce the amount of information that the first base station notifies the terminal device 20. For example, the base station 10 notifies the base station information of the base station itself by including it in the notification information. The terminal device 20 acquires the base station information by receiving the notification information of the base station 10. For example, the terminal device 20 may perform positioning using the base station information of the base station 10 that has received the base station information for positioning. For example, the terminal device 20 may perform positioning using the base station information of the first base station that has acquired the base station information and the base station information of the surrounding base stations. The terminal device 20 derives the position information of the terminal device 20 itself using the base station information of each base station 10 that has performed positioning. For example, the position information of the terminal device 20 itself may be derived using the position information of a plurality of base stations 10 and the irradiation angle information of the beam.

[0124] When the base station information of the first base station includes information related to synchronization, the terminal device 20 may perform positioning using the base station information of the synchronized neighboring base stations. By performing positioning and deriving location information using the base station information of the synchronized neighboring base stations, it becomes possible to derive accurate location information of the terminal device 20 itself.

[0125] When the reception power of the base station 10 falls below a threshold, the terminal device 20 in the IDLE state or the INACTIVE state searches for neighboring base stations. The terminal device 20 searches for neighboring base stations as a cell reselection process. When searching for neighboring base stations, the terminal device 20 may perform positioning by itself. When searching for neighboring base stations, the terminal device 20 may receive notification information of the neighboring base stations and derive position information of the terminal device 20 itself. In this way, it becomes possible to derive position information of the terminal device 20 itself. However, if positioning by the terminal device 20 is performed only when searching for neighboring base stations in this way, problems may occur. This is because, depending on the service, position information of the terminal device 20 may be required in a timely manner. A method for solving such a problem will be described.

[0126] The base station 10 notifies the terminal device 20 of information instructing the terminal device 20 to perform positioning. For example, the base station 10 may notify the terminal device 20 of the information instructing the terminal device 20 to perform positioning by using paging. The base station 10 may notify the terminal device 20 in a CONNECTED state, an IDLE state, or an INACTIVE state. In this manner, for example, the base station 10 can cause the terminal device 20 to perform positioning at a timing suitable for the service.

[0127] The paging information may include information of an SIB including base station information. According to the information included in the paging information, the terminal device 20 can receive the SIB including the base station information and obtain the base station information. The terminal device 20 uses the base station information to derive its own location information.

[0128] As another method of notifying the information instructing the terminal device 20 to perform positioning, for example, the base station 10 may notify by RRC individual signaling. The base station 10 may notify the information on the base station 10 in association with the information instructing the terminal device 20 to perform positioning. Alternatively, the base station 10 may notify the instruction to perform positioning by the terminal device 20 by MAC signaling. The base station 10 may notify by associating with the information on the base station 10 notified by RRC signaling. Alternatively, the base station 10 may notify by using the PDCCH. The base station 10 may notify by associating with the information on the base station 10 notified by RRC signaling the information instructing the terminal device 20 to perform positioning. In this way, it is possible to cause the terminal device 20 to perform positioning by the terminal device 20 at an early stage.

[0129] The base station 10 may cause the terminal device 20 to periodically perform positioning. For example, the base station 10 notifies the terminal device 20 of periodic information which is information indicating a period of positioning by the terminal device 20. Alternatively, the period of positioning by the terminal device 20 may be statically determined in advance by a standard or the like. Alternatively, the periodic information may be set from a higher layer to a lower layer of the terminal device 20. For example, the periodic information may be set from an application layer to a NAS (Non Access Stratum) or AS (Access Stratum) layer.

[0130] The base station 10 may appropriately apply a method for notifying the base station information of the base station 10 to the terminal device 20 of periodic information related to positioning by the terminal device 20. Alternatively, the base station 10 may notify the periodic information related to positioning by including it in the base station information. As another method, the base station 10 may appropriately apply a method for notifying information instructing the terminal device 20 to perform positioning to the terminal device 20 to notify the periodic information by the terminal device 20 to the terminal device 20. In this way, the terminal device 20 can periodically perform positioning by the terminal device 20.

[0131] The terminal device 20 may notify the base station 10 of the positioning result by the terminal device 20. The terminal device 20 may include its own location information derived by the terminal device 20 as the positioning result. The terminal device 20 may use RRC signaling to notify the result. A method in which the terminal device 20 in the IDLE state or INACTIVE state transmits the positioning result by the terminal device 20 to the base station 10 is to once transition to the CONNECTED state and then notify. By transitioning to the CONNECTED state, the terminal device 20 becomes able to notify the base station 10 by RRC signaling.

[0132] As another method for the terminal device 20 in the IDLE state or INACTIVE state to transmit the positioning result by the terminal device 20 to the base station 10, the terminal device 20 may notify by RA (Random Access) processing. Alternatively, the terminal device 20 may notify as data on the control plane. For example, the terminal device 20 notifies by including the positioning result in an RRC connection request. The terminal device 20 may notify by including information that the RRC connection request is a notification of the positioning result. The base station 10 that has acquired the positioning result from the terminal device 20 may stop the RRC connection processing. In this way, the terminal device 20 can notify the base station 10 of the positioning result by the terminal device 20 without establishing an RRC connection. The terminal device 20 can notify the base station 10 of the positioning result of the terminal device 20 at an early stage.

[0133] The base station 10 configures one or more cells. For example, the information on the beam may be information on the beam for each cell. The above-mentioned base station 10 may be a TRP. For example, the information on the beam may be information on the beam for each TRP.

[0134] In this embodiment, the base station 10 notifies the terminal device 20 of information related to the beam, but in the case where the LMF is provided in another node, the node in which the LMF is provided may notify the terminal device 20. In this case, the base station information, etc. may be added and notified by the base station 10. Alternatively, the base station 10 may notify the node in which the LMF is provided. In this way, it becomes possible to cause the terminal device 20 to perform positioning from the LMF. The LMF may be provided in the base station 10, in which case the above-mentioned method may be applied.

[0135] Embodiment 10 The positioning by the terminal device 20 may be performed in multiple stages. For example, the first stage of positioning may be performed by the terminal device 20 in the RRC_IDLE or RRC_INACTIVE state, and the second stage of positioning may be performed by the terminal device 20 in the RRC_CONNECTED state. As another example, the first stage of positioning and the second stage of positioning may be performed by the terminal device 20 in the RRC_IDLE or RRC_INACTIVE state. In each of the multiple stages of positioning performed by the terminal device 20, the base station 10 used for positioning may be different, the positioning method may be different, the signal used for positioning may be different, or the entity that determines the base station 10 used for positioning may be different.

[0136] For example, in the first stage of positioning, positioning using SSB may be performed for the terminal device 20 in the RRC_INACTIVE or RRC_IDLE state. The terminal device 20 in the RRC_INACTIVE or RRC_IDLE state may determine the base station 10 to be used for positioning by itself. For example, the terminal device 20 may determine the base station 10 to be used for positioning that transmits an SSB that can be received by the terminal device itself.

[0137] The LMF may notify the terminal device 20 in the RRC_INACTIVE or RRC_IDLE state that positioning using SSB will be performed. The notification of positioning using SSB may be performed, for example, via the base station 10. The notification of positioning using SSB may be performed, for example, in the RRC_CONNECTED state before the terminal device 20 transitions to the RRC_INACTIVE or RRC_IDLE state.

[0138] The LMF may notify the terminal device 20 in the RRC_INACTIVE or RRC_IDLE state that positioning using SSB will be performed. This notification may be performed, for example, via the base station 10. Eight pieces of information are included in this notification. The first piece of information is information about the RRC state in which the positioning signal is received. The second piece of information is information about whether or not the position of the terminal device 20 is required to be derived. The third piece of information is information about the system used for positioning. The fourth piece of information is information about the positioning signal. The fifth piece of information is information about the number of times the positioning signal is received. The sixth piece of information is information about the period in which the positioning signal is received. The seventh piece of information is information about the notification condition to the base station 10. The eighth piece of information is information obtained by combining the first piece of information to the seventh piece of information. The terminal device 20 derives the position of the terminal device 20, for example, by using at least one of the first piece of information to the seventh piece of information included in the notification. Also, the terminal device 20 derives the position of the terminal device 20, for example, by using information obtained by combining the first piece of information to the seventh piece of information.

[0139] The information included in the first information may be, for example, RRC_INACTIVE, RRC_IDLE, or a combination of the above. The terminal device 20 may receive a positioning signal when it transitions to the RRC state included in the first information. This allows the terminal device 20 to receive a positioning signal when the RRC state of the terminal device 20 changes, for example.

[0140] The information included in the second information may be, for example, information indicating that the position of the terminal device 20 is to be derived. When the second information includes information indicating that the position of the terminal device 20 is to be derived, the terminal device 20 may derive the position of the terminal device. For example, the reception result of a positioning signal from the base station 10 used for positioning may be used to derive the position of the terminal device. The terminal device 20 may notify the LMF of the derivation result. The notification of the derivation result may be made to the base station 10. The notification of the derivation result by the terminal device 20 may be made when the terminal device 20 is in an RRC_CONNECTED state.

[0141] Another example of the information included in the second information may be information indicating that the position of the terminal device 20 is not to be derived. When the information included in the second information includes information indicating that the position of the terminal device 20 is not to be derived, the terminal device 20 may report the reception result of the positioning signal to the base station 10. The notification of the report of the reception result of the positioning signal by the terminal device 20 may be performed when the terminal device 20 is in the RRC_CONNECTED state.

[0142] The information included in the third information may be, for example, a 5G system, an LTE system, a GNSS, Wifi (registered trademark), Bluetooth (registered trademark), or another system. The terminal device 20 may perform positioning or may receive a positioning signal using the third information. This makes it possible to improve the flexibility of the positioning of the terminal device 20, for example.

[0143] The information included in the fourth information may be, for example, an SSB, a CSI-RS, a DMRS, or a signal used in another system.

[0144] The information included in the fifth information may be, for example, once or multiple times. The terminal device 20 may perform a series of operations for receiving a positioning signal the number of times included in the fifth information. For example, by performing a series of operations for receiving a positioning signal multiple times, the terminal device 20 can improve the accuracy of positioning in the RRC_INACTIVE or RRC_IDLE state.

[0145] The information included in the sixth information may be specified in milliseconds, in radio frames, or by using a parameter associated with a predetermined time. The terminal device 20 may periodically receive a positioning signal using the information. This makes it possible to capture the position of the terminal device 20 in the communication system, even if the position of the terminal device 20 changes.

[0146] The information included in the seventh information may be, for example, a movement to a different RAN Notification Area (RNA), a movement to a different Tracking Area (TA), or may be given as a condition related to RSSI. The condition related to RSSI may be, for example, that the RSSI in the terminal device 20 is equal to or exceeds a predetermined value, or may be equal to or falls below a predetermined value. As another example, the condition may be given using the received power from the base station 10 to which the terminal device 20 was connected in the RRC_CONNECTED state and the received power from another base station 10. The terminal device 20 may start receiving a positioning signal using the information. This makes it possible to quickly capture a change in the position of the terminal device 20 in a communication system, and as a result, for example, it is possible to improve the stability of the communication system when returning to RRC_CONNECTED.

[0147] As another example of positioning in the IDLE or INACTIVE state, CSI-RS may be used. The terminal device 20 may receive CSI-RS from multiple base stations 10, multiple panels, or TRP. The terminal device 20 may hold information on the reception time of the CSI-RS. The information on the reception time of the CSI-RS may be, for example, a difference between the reception times of the multiple CSI-RS. By using the CSI-RS, for example, positioning using a narrow beam is possible, and as a result, the accuracy of positioning can be improved. The base station 10 may notify the terminal device 20 of settings related to the CSI-RS. The notification from the base station 10 to the terminal device 20 may be performed when the terminal device 20 is in the RRC_CONNECTED state. The settings related to the CSI-RS may include, for example, information on the base station 10, DU (Distributed Unit), TRP, panel that transmits the CSI-RS, or information on the frequency, time, or code resource on which the CSI-RS is transmitted. The information related to the panel includes, for example, an identifier of the base station 10, an identifier of the DU, an identifier of the TRP, an identifier of the panel, and information related to the position.

[0148] The terminal device 20 may use the information on the location to derive the location of the terminal device itself. This, for example, makes it unnecessary to transmit a measurement result, for example, a difference in the reception time of PRS, from the terminal device 20 to the base station 10, and as a result, it is possible to reduce the amount of signaling between the base station 10 and the terminal device 20, and it is unnecessary to resume communication between the terminal device 20 and the base station 10. As a result, it is possible to perform quick positioning in the communication system. As another example, the base station 10 may derive the location of the terminal device 20 using information on the reception time of CSI-RS. The terminal device 20 may notify the base station 10 of information on the reception time of CSI-RS. The notification may be included, for example, in a measurement result report from the terminal device 20 to the base station 10, or may be included in different signaling. The base station 10 may derive the location of the terminal device 20 using information on the reception time of CSI-RS. This, for example, makes it possible to reduce the load due to the location derivation in the terminal device 20. Also, as with SSB, the first and second embodiments may be used in combination. In the first embodiment, angle information is obtained from a selected beam, and positioning is performed using distance information. In the second embodiment, the RSTD is calculated from the reception times of reference signals transmitted from multiple transmitters, and positioning is performed. The average of positions obtained by both methods may be calculated. Also, when positioning is performed using multiple base stations 10, some of the base stations 10 may use the method described in the first embodiment, and the other base stations 10 may use the method described in the second embodiment.

[0149] In the second stage, positioning using the CSI-RS may be performed. The LMF may determine the base station 10 used in the second stage positioning using the positioning result of the terminal device 20 obtained in the first stage positioning. The base station 10 may transmit the CSI-RS to the terminal device 20. The terminal device 20 may receive the CSI-RS. The terminal device 20 may notify the base station 10 of the reception result of the CSI-RS. The base station 10 may use the reception result to determine the position of the terminal device 20. This makes it possible to reduce the amount of signaling in the communication system while improving the positioning accuracy, for example.

[0150] According to the tenth embodiment, it is possible to improve the accuracy of positioning and the flexibility of positioning, and also to improve the efficiency in the communication system.

[0151] The configurations shown in the above embodiments are examples of the contents of the present invention, and may be combined with other known technologies. Parts of the configurations may be omitted or modified without departing from the gist of the present invention. [Explanation of symbols]

[0152] 1 to 4 beams, 10, 10-1, 10-2 base station, 20 terminal device, 20-1 first terminal device, 20-2 second terminal device, 101 control unit, 102 transmission signal generation unit, 103 transmission processing unit, 104 reception processing unit, 105 reception signal decoding unit, 106 positioning processing unit, 200 server, 400 control circuit, 400a processor, 400b memory.

Claims

1. A communication unit for receiving higher layer parameters related to a positioning reference signal; a control unit that performs positioning using the positioning reference signal received based on the upper layer parameters; Equipped with The upper layer parameter is hierarchical information including a resource set parameter having a plurality of resource parameters. User equipment.

2. In adjacent orthogonal frequency division multiplexing symbols, the positioning reference signals are arranged at least two resource elements apart. The user device of claim 1.

3. The positioning reference signals are arranged so that they are spaced apart by n resource elements in the frequency domain when spaced apart by n symbols in the time domain. The user device of claim 1.

4. The communication unit receives the upper layer parameters including information regarding a density of the positioning reference signal. The user device of claim 1.

5. the positioning reference signal is located in an active bandwidth portion; The control unit performs measurement of the positioning reference signal in a measurement gap. The user device of claim 1.

6. The communication unit receives the positioning reference signals transmitted from a plurality of transmitting / receiving points using a common cyclic prefix length and a common subcarrier interval. The user device of claim 1.

7. The communication unit receives the positioning reference signal transmitted using only symbols set for downlink. The user device of claim 1.

8. In the upper layer parameters, muting is set in units of the resource set parameters. The user device of claim 1.

9. A control unit that configures higher layer parameters related to a positioning reference signal used for positioning in a user equipment; A communication unit that transmits the higher layer parameters to the user equipment, The upper layer parameter is hierarchical information including a resource set parameter having a plurality of resource parameters. Base station.

10. A communication system comprising a user equipment and a base station, The base station transmits higher layer parameters related to a positioning reference signal to the user equipment; The user equipment performs positioning using the positioning reference signal received based on the higher layer parameters; The upper layer parameter is hierarchical information including a resource set parameter having a plurality of resource parameters. Communication systems.

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