User equipment, base stations, and communication systems

Abstract

To obtain a user device capable of calculating the terminal's location. [Solution] The user device, terminal device 20, comprises a communication unit that communicates wirelessly with the base station 10, and a control unit that configures the positioning sounding reference signal based on positioning wireless resource control parameters related to the positioning sounding reference signal received from the base station 10. The communication unit transmits the positioning sounding reference signal on the uplink and receives related information from the base station that indicates the association between the positioning sounding reference signal on the uplink and the control signal on the downlink.

Description

Technical Field

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

Background Art

[0002] In a wireless communication system, due to multipath fading caused by the reflection of a transmission signal from a transmission device by a building or the like and Doppler fluctuations caused by the movement of a receiving device, frequency selectivity and time variation of the transmission path occur. In a multipath environment where multipath fading occurs, the signal received by the receiving device is a signal in which a symbol directly arriving from the transmission device and a symbol arriving late after being reflected by a building or the like interfere with each other.

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

[0004] In 3GPP's Release.15, NR (New Radio) was studied and standardized for the fifth-generation mobile communication system (see Non-Patent Documents 1-3). In NR, it is aimed to increase the communication capacity by using a multi-element antenna and performing beamforming toward the user.

[0005] Furthermore, in LTE (Long Term Evolution), physical and upper-layer technologies for positioning have been standardized. For example, Cell_ID (IDentification), ECID (Enhanced Cell ID), OTDOA (Observed Time Difference Of Arrival) method, and UTDOA (Uplink Time Difference Of Arrival) method are envisioned in the standard. Non-patent document 4 discloses a positioning method using the OTDOA method, in which a Positioning Reference Signal (PRS) 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 times of the PRS.

[0006] Furthermore, in the ECID system, the time and angle of arrival required from transmission to reception of both the uplink and downlink are estimated to determine the position of the terminal device. CRS (Cell Reference Signal) is used for the downlink, and SRS (Sounding Reference Signal) is used for the uplink. In addition, base stations equipped with transmitting devices that transmit PRS used in OTDOA positioning arrange the PRS in the time domain and frequency domain to avoid CRS (Cell-specific Reference Signal) which is used only in LTE. CRS is a cell-specific reference signal defined in LTE and used for measuring the reception quality of the downlink. [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 [Overview of the project] [Problems that the invention aims to solve]

[0008] However, the Cell_ID, ECID, OTDOA, and UTDOA methods used in LTE are based on LTE, and therefore may not be usable in systems other than LTE, such as fifth-generation mobile communication systems that operate across a wide frequency band. For this reason, it is desirable that terminal location can be calculated even in systems other than LTE.

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

[0010] To solve the above-mentioned problems and achieve the objective, the user device according to the present invention comprises a communication unit that wirelessly communicates with a base station, and a control unit that configures a positioning sounding reference signal based on positioning radio resource control parameters relating to a positioning sounding reference signal received from the base station. The communication unit transmits a positioning sounding reference signal on the uplink and receives related information from the base station indicating the association between the positioning sounding reference signal on the uplink and a control signal on the downlink. [Effects of the Invention]

[0011] The present invention has the effect of providing a user device capable of calculating the terminal location. [Brief explanation of the drawing]

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

[0013] The base station, terminal device, positioning method, and wireless communication system according to embodiments of the present invention will be described in detail below with reference to the drawings. However, the present invention is not limited to these embodiments.

[0014] Embodiment 1. Figure 1 shows the configuration of a wireless communication system according to Embodiment 1. The wireless communication system includes a base station 10 and a plurality of terminal devices 20. In the ECID method in LTE, 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 the transmitting device and the terminal device 20 is the receiving device. Generally, terminal devices are called UE (User Equipment), so in this embodiment, the terminal device 20 is also called UE. 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; it is just a name and another name may be used. The base station is also called a gNodeB in the 3GPP standard.

[0015] Figure 2 shows the functional blocks of the base station 10 according to Embodiment 1. The base station 10 comprises 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 instructions 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. Furthermore, the transmission processing unit 103 transmits a synchronization signal, which is used for communication with the terminal device 20 and contains resource information indicating a resource that is linked one-to-one with a beam. The synchronization signal includes an SSB (Synchronization Signal Block). The SSB is a signal used during initial connection and synchronization in 3GPP Release 15.

[0016] The receiving processing unit 104 performs receiving processing on the received signal. The receiving signal decoding unit 105 decodes the received signal after receiving processing and transmits the decoded information to the server 200. The positioning processing unit 106 determines the position of the terminal device 20 using the resources selected by the terminal device 20. The resource information is SSB and is distributed in the time domain and frequency domain. The positioning processing unit 106 also identifies the beam selected by the terminal device 20 using the resource information contained in the synchronization signal to which the terminal device 20 responded, and calculates the position of the terminal device 20 using the beam. Details of the operation of the positioning processing unit 106 will be described later. The information transmitted from the receiving signal decoding unit 105 is the report, frequency information, or reference signal transmitted from the terminal device 20. The LMF (Location Management Function) functioning on the server 200 issues instructions to the base station 10 to start or end positioning using NRPPa (New Radio Positioning Protocol A). Alternatively, the terminal device 20 may determine its position through positioning. For example, when a call is made, the terminal device 20 may determine its own location by performing positioning. This call may be, for example, an emergency call. The location information of the terminal device 20 obtained by positioning may also be notified to the recipient by the aforementioned call. This notification may be made, for example, when the call is an emergency call. This allows the recipient to quickly obtain the location information of the calling terminal device. 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 by the terminal device 20. This notification from the base station 10 to the LMF may or may not be made using the notification made from the terminal device 20 to the base station 10.

[0017] The control unit 101, the transmission signal generation unit 102, the transmission processing unit 103, the reception processing unit 104, the reception signal decoding unit 105, and the positioning processing unit 106 are all implemented by processing circuits, which are electronic circuits that perform their respective functions.

[0018] This processing circuit may be dedicated hardware, or it may be a control circuit equipped with memory and a CPU (Central Processing Unit) that executes the program stored in memory. Here, memory refers to non-volatile or volatile semiconductor memory such as RAM (Random Access Memory), ROM (Read Only Memory), flash memory, magnetic disks, optical disks, etc. Figure 3 is a diagram showing the control circuit according to Embodiment 1. When this processing circuit is a control circuit equipped with a CPU, this control circuit becomes, for example, the control circuit 400 with the configuration shown in Figure 3.

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

[0020] When estimating the reception angle, base station 10 can extract angle information using the transmit and receive beams. The transmit and receive beams are composed of two dimensions, but may also be composed of three dimensions. Furthermore, base station 10 can extract three-dimensional angle information. When base station 10 extracts angle information using the transmit and receive beams, during positioning, base station 10 receives appropriate beam information information from terminal device 20 and converts it into AoA information based on the beam information.

[0021] Figure 4 shows an example of positioning by a base station 10 according to Embodiment 1. In Figure 4(a), the base station 10 finds the terminal device 20 using a beam. In Figure 4(b), after finding the terminal device 20, the base station 10 measures the distance and angle between the base station 10 and the terminal device 20. As shown in Figure 4(a), during initial connection, the base station 10 finds the terminal device 20 by sweeping a wide range using a beam. Therefore, the accuracy of the angle information obtained is lower compared to 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 use the angle information from the initial connection to position the terminal device 20. In addition to received power, BLER (Block Error Rate) prediction information may also be used as a beam selection criterion. The terminal device 20 may also report to the base station 10 the identification number of the SSB corresponding to the beam with the strongest received power from among the multiple SSB identification numbers transmitted from the base station 10 during initial synchronization. Furthermore, since base station 10 sends one SSB for each beam, there is a one-to-one correspondence between the beam and the SSB. In other words, if base station 10 can determine the identification number of the SSB, it can determine which beam was selected by the terminal device 20.

[0022] There are various SSB and beam identification methods, and the terminal device 20 can report identification information to the base station 10 using various SSB methods. 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 frequency domain. A collection of REs (Resource Elements) distributed in the time domain and frequency domain is called a resource. For example, in LTE, as described in Non-Patent Literature 2, a resource block consists of 12 subcarriers in the frequency direction. In this embodiment, we will replace subcarriers with REs for explanation. The base station 10 stores and transmits information indicating the resource within the SSB. The terminal device 20 responds to the base station 10 using the resource specified within the SSB, allowing the base station 10 to understand which SSB the terminal device 20 responded with. Furthermore, by understanding which SSB the response corresponds to, the base station 10 can understand which beam the terminal device 20 selected. If the terminal device 20 selects only one beam, it 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 SSB at a given frequency and time. In short, if the SSBRI changes, the beam used for transmitting the corresponding SSB also changes. Beam-based positioning is effective when used in the FR2 frequency band, from around 24 GHz to around 52 GHz, where a relatively narrow beam can be formed compared to lower frequencies. By performing beam-based positioning, angular information can be obtained accurately and quickly, enabling low-latency positioning.

[0023] The association between the beam and the resources used by the terminal device 20 to respond may be configured by the server 200. 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). Msg.3 and Msg.4 may also be provided, in which the terminal device 20 requests an RRC connection in Msg.3 and the base station 10 transmits RRC connection configuration information in Msg.4. The uplink beam for Msg.3 may be the same beam used to send Msg.1, or a different beam may be used. The waveform of the transmission signal and the resources of the transmission signal used for transmitting Msg.3 are specified by the base station 10 to the terminal device 20. That is, the base station 10 may perform positioning after processing Msg.1.

[0024] Figure 5 is a flowchart illustrating the positioning procedure according to Embodiment 1. The base station 10 makes an initial connection with the terminal device 20 (step S1). The base station 10 receives beam information and information necessary for distance measurement (step S2). The base station 10 uses the beam information and information necessary for distance measurement to perform positioning of the terminal device 20 (step S3). In this embodiment, the location of the base station 10 is known, and if the beam selected by the terminal device 20 is known, the base station 10 can determine the direction in which the terminal device 20 is located. The base station 10 may also measure the distance by measuring the time required for round trip using a method such as the TA (Timing Advance) method or PRACH for distance estimation.

[0025] Figure 6 shows another example of positioning by the base station 10 according to Embodiment 1. In Figure 6(a), a coarse search is performed. In Figure 6(b), a fine search is performed. In Figure 6(c), positioning is performed after the fine search. The base station 10 may perform positioning after a fine search as shown in Figure 6(b).

[0026] Figure 7 is another flowchart showing the positioning procedure according to Embodiment 1. The base station 10 performs an initial connection with the terminal device 20 and synchronizes (step S11). After the initial connection is complete, the base station enters the RRC_CONNECTED state, i.e., the post-connection state (step S12). The base station 10 performs beam management using SSB or the reference signal CSI-RS (Channel State Information-Reference Signal) to increase the resolution by narrowing the beam spacing compared to the initial connection state and performs beam search directed towards the terminal device 20 (step S13). After the initial connection or beam management process is complete, the base station 10 transmits CSI-RS or SSB to the terminal device 20 via the downlink. The base station 10 also receives beam information and information necessary for distance measurement as feedback from the terminal device 20 (step S14). The base station 10 also uses this information to select a beam ID and uses the feedback information as angle information. The terminal device 20 transmits SRS (Sounding Reference Signal) to the base station 10. Base station 10 measures the distance by measuring the time required for the round trip between the SBB and SRS, and performs positioning (step S15). If the positioning time for base station 10 is limited, positioning may be performed using a coarse search in beam selection.

[0027] When base station 10 performs a beam search using CSI-RS, terminal device 20 may report the port number to be used for the CSI-RS with the highest power among the received CSI-RS signals. In this embodiment, NZP-CSI-RS (Non Zero Powered-CSI-RS), as defined in Non-Patent Document 2, is used as an example. A port number is a number used to identify the service used for communication by base station 10 and terminal device 20. The port number is linked to the frequency and temporal location where the CSI-RS is deployed, and, if code multiplexing is performed, to the code type. If the port number is known, terminal device 20 can determine the location of the CSI-RS and the code applied to the CSI-RS. Here, since the CSI-RS port and the transmitting beam are linked in a one-to-one relationship, base station 10 can determine which beam has been selected from the reported port number. Alternatively, terminal device 20 may report the CRI (CSI-RS Reference Indicator) to base station 10 instead of the CSI-RS port. In short, a change in the CRI will result in a change in the beam transmitting the CSI-RS corresponding to the CRI. By knowing the reported CRI, base station 10 can determine which beam transmitted from base station 10 was selected by terminal device 20.

[0028] Figure 8 shows an example of positioning using a base station 10 and a terminal device 20 according to Embodiment 1. In Figure 8(a), the base station 10 performs a coarse search. In Figure 8(b), the base station 10 performs a fine search. The terminal device 20 also performs a search. In Figure 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 Figure 8(c), the angle information may be the beam number on the base station 10 side or a BPL (Beam Pair Link) which is a combination of the beam number on the base station 10 side and the beam number on the terminal device 20 side. The BPL is used to remember which beam combination was optimal, and if communication is interrupted and wants to be resumed, the stored BPL can be used to establish a transmit / receive pair again without performing a beam sweep on the transmit and receive sides. Furthermore, by having the base station 10 and the terminal device 20 use the optimal beams for positioning, highly accurate positioning can be achieved. In the example above, the terminal device 20 used a criterion for selecting a beam with strong received power, but it may also use a characteristic evaluation value such as BLER obtained from the received signal.

[0029] Base station 10 can perform beam management using the SRS transmitted on the uplink. In this case, base station 10 observes the SRS transmitted from terminal equipment 20 and selects an appropriate uplink beam. Then, it creates a BPL using the CSI-RS and SRS information. If SRS and CSI-RS information is available, even more accurate angle information can be obtained. Also, when performing digital precoding, terminal equipment 20 selects an appropriate codebook number. The codebook is defined by 3GPP TS38.214 as shown in Non-Patent Literature 1. Higher layer protocol processing extracts angle information using the SSB identification number, CSI-RS port number, beam ID number, or codebook number reported by terminal equipment 20. In CSI-RS, the CRI may be used as the beam ID number, and in SRS, the SRI (SRS Resource Indicator) may be used as the beam ID number. Like the CRI, the SRI is associated with the beam and the frequency and temporal location where the SRS is deployed.

[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 base station 10 may use these to estimate distance. In this case, RSRP, RSRQ, or RSSI is transmitted from base station 10 to LMF. For example, by using RSRP, the amount of attenuation of received power can be determined and used to measure distance. RSRQ or RI is used when determining whether the signal received by terminal device 20 is suitable for positioning. For example, a high RI value indicates a large amount of reflected waves, and it can be determined 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. For downlink, signals such as SSB and CSI-RS may be used to measure the distance, but for uplink, PRACH, SRS, or DMRS (DeModulation Reference Signal) may be used. In the case of SRS, the processing flow is specified in the RRC. In this embodiment, the usage parameter of the SRS RRC may be explicitly indicated as "positioning" or similar to indicate that it is used for positioning. By informing the terminal device 20 that SRS is for positioning, the base station 10 can perform appropriate processing, such as prioritizing positioning processing. Alternatively, a parameter name that indicates it is for positioning, such as CSI-RS-Resource-Positioning, may be provided.

[0032] Furthermore, positioning can be performed using multiple TRPs (Transmission Reception Points) or panels. A panel is an antenna equipped with multiple antenna elements, and it is conceivable that a base station could use multiple panels for communication. The panels do not need to be physically separated. Also, if there are obstacles in front of the panels, it is conceivable to turn off the power to some panels and not use them. In this case, positioning can be performed using the average value of multiple estimated values ​​of arrival angle and distance. Alternatively, positioning can be performed using candidate values ​​excluding the maximum or minimum value. Figure 9 is a diagram showing positioning using two TRPs according to Embodiment 1. In Figure 9, the base station 10 performs positioning using two TRPs. In this case, there are two sets of angle information and distance information obtained, so the base station 10 performs positioning using two sets of information. Also, as shown in the example in Figure 9, when positioning is performed using multiple TRPs, PRACH is sent for each beam received. In this case, since the angle information and distance information obtained can be combined for each panel or TRP, an identification number such as an ID number for the TRP can be created for each combination and reported to the positioning processing unit 106.

[0033] Furthermore, the node connected to the 5G core network (NG_RAN_NODE) ​​transmits information necessary for positioning calculation to the LMF. This information includes, for example, the carrier frequency, the bandwidth used, the number of antenna ports used, the beam information or beam pair number of the base station 10 or terminal equipment 20, and the selected codebook information. This information may also include values ​​indicating the SFN (Slot Frame Number), the position of the antenna and panel, and the subcarrier spacing used. For NR, subcarrier spacings of 15kHz, 30kHz, 60kHz, 120kHz, or 480kHz are available. In addition, information such as RSRQ or RSRP may be transmitted. Furthermore, if OFDM or DFT-s-OFDM is used on the uplink, information regarding the applicable CP length and BWP (BandWidth Parts) may be transmitted from NG_RAN_NODE to the LMF.

[0034] As described above, in this embodiment, the base station 10 transmits a synchronization signal or reference signal containing resource information indicating a resource linked one-to-one with a beam, and uses the resource information to calculate the position of the terminal device 20. 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 contained in one of the multiple signals generated by the multipath, and can calculate the position using the beam selected by the terminal device 20. As a result, directivity is increased by using a beam, 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 reflections. In an environment where reflected waves exist, there are multiple angles of arrival, so by using a transmission method that allows only the main signal to be received, the accuracy of selecting the optimal beam at the receiving side is improved. In addition, when calculating the round-trip time in distance measurement, receiving reflected waves degrades the accuracy of calculating the round-trip time of the main signal. This makes it possible to suppress the degradation of the accuracy of calculating the position of the terminal device 20 even in a multipath environment.

[0035] Embodiment 2. Figure 10 shows a positioning method using the OTDOA method according to Embodiment 2. As shown in Figure 10, multiple base stations 10 transmit positioning reference signals to a terminal device 20 for positioning. In this embodiment, as an example, in Figure 10, TRPs are assumed to be base stations 10, and each TRP is assigned a unique cell ID (Identification). It is assumed that the base stations 10 are synchronized when implementing this method. The terminal device 20 receives the reference signals and performs positioning using the difference in reception times of each reference signal. Details of positioning using the OTDOA method are described in Non-Patent Literature 4. In Figure 10, t1 is 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, t2 is 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, and t3 is the difference between the reception time of the PRS transmitted from TRP3 and the reception time of the PRS transmitted from TRP4. t4 represents 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, while in uplink communication, a slot consists of either 14 OFDM symbols or DFT-s-OFDM symbols. Although a slot containing a PRS is used as an example, a PRS may also be included in a unit shorter than a slot, such as a non-slot consisting of 2, 4, or 7 symbols, and the time difference for receiving a non-slot may also be used. The reception time difference is called RSTD (Reference Signal Time Difference). The PRS may also be called NR PRS.

[0036] The positioning reference signal may be transmitted after beam sweeping is complete and the beam for terminal device 20 has been determined. In other words, the PRS is transmitted in or after Msg.4.

[0037] Figure 11 is a flowchart showing the positioning procedure in the OTDOA method according to Embodiment 2. 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. In the OTDOA method, synchronization is established between the base station 10 and the terminal device 20, and the positioning reference signal may be sent in the RRC_CONNECTED state as defined by 3GPP.

[0038] The positioning reference signal must 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, since the CRS is not used in NR, the 5G standard, a more efficient arrangement different from LTE is possible. Figure 12 shows a first example of the PRS arrangement according to Embodiment 2. The RRS arrangement diagram shown in this embodiment is an arrangement of a PRS in which 1 RB (Resource Block) consists of 12RE and 14OFDM symbols. The scheduler in base station 10 allocates multiple consecutive or discrete RBs for communication to terminal devices 20. Here, a time unit consisting of 14OFDM symbols is defined as 1 slot.

[0039] Figure 12 is a PRS (Primary Downlink Shared Channel) layout diagram with frequency on the vertical axis and time on the horizontal axis. In Figure 12, the diagonal diagonal line tiles in the lower right indicate the location of the PRS. Tiles with dots are tiles where a PRS cannot be placed. In this embodiment, blank tiles are empty REs where no data information or control information is placed. In other words, 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), interference from data and control signals transmitted from other TRPs or base stations 10 during positioning can be prevented. Also, PRS is not placed on tiles with dots because downlink control information such as PDCCH may be placed there. Furthermore, PRS is not placed in locations where PBCH (Physical Broadcast Channel), PSS (Primary Synchronization Signal), or SSS (Secondary Synchronization Signal) are placed. In the 3GPP Rel.15 standard, PDCCH is placed as 1, 2, or 3 symbols at the beginning of the slot. Therefore, the first symbol in which the PRS is placed may be determined according to the number of PDCCHs. Since the maximum number of symbols for PDCCH is 3, the position of the symbol in which the PRS is always placed first in the slot may be fixed at symbol number 3, as shown in Figure 12. Figure 13 is a diagram showing a second example of the PRS arrangement according to Embodiment 2. When the number of symbols for PDCCH is 2, the arrangement will be as shown in Figure 13.

[0040] Figure 14 shows a third example of the PRS arrangement according to Embodiment 2. In Figure 14, PRS is not placed in the first three symbols as well as the last two symbols. In 5G, uplink and downlink transmissions are time-multiplexed. Therefore, in order to receive the uplink or the uplink of the next slot, the last multiple symbols in the downlink transmission slot may become unavailable for downlink transmission as a preparation section for analog equipment. For this reason, it is possible to set the system not to transmit the last PRS. In Figure 14, the last two symbols are used for uplink communication, so PRS is not transmitted. Also, since the symbols used for transmitting control information for uplink or downlink change, multiple PRS arrangements may be prepared and selected at the higher layer.

[0041] Figure 15 shows a fourth example of the PRS arrangement according to Embodiment 2. The PRS may be given a cyclic shift so that they are orthogonal in the frequency domain. When PRS is transmitted from multiple base stations 10, the terminal device 20 receives multiple PRS, so it is important that they are orthogonal in frequency to prevent interference with each other. For this reason, as shown in Figure 15, the PRS may be given a cyclic shift in frequency. In addition, the amount of cyclic shift may be changed for each base station 10 so that the PRS transmitted from each TRP are orthogonal in frequency. For example, in the example in Figure 10, the PRS arrangement transmitted from TRP1 is the default arrangement shown in Figure 12, the PRS arrangement transmitted from TRP2 is the arrangement shown in Figure 12 with a cyclic shift of 1RE, the PRS arrangement transmitted from TRP3 is the arrangement shown in Figure 12 with a cyclic shift of 2RE, i.e., the PRS arrangement shown in Figure 15, and the PRS arrangement transmitted from TRP4 is the arrangement shown in Figure 12 with a cyclic shift of 3RE. The RE shift amount may also be set by the PRS_ID, which is the PRS identification number, or ID, set by the higher layer. For example, it may be set as NPRSIDmod6.

[0042] Note that the PRS arrangement in Figure 12 is one in which the RE position of adjacent OFDM symbols is cyclically shifted by 1RE. In such an arrangement, positioning is easier to perform with a flat frequency response.

[0043] Figure 16 shows a fifth example of the PRS arrangement according to Embodiment 2. As shown in the PRS pattern in Figure 16, PRS may be arranged cyclically at positions 2RE or more apart in adjacent OFDM symbols. By using such an arrangement, robust PRS transmission becomes possible even in frequency-selective transmission lines. Alternatively, multiple RE-shifted patterns as shown in Figure 12 or Figure 16 may be prepared, and a higher layer such as RRC (Radio Resource Control) may select the RE-shifted pattern and notify the terminal device 20. This method allows for the selection of PRS compatible with various transmission lines.

[0044] Figure 17 shows a sixth example of the PRS arrangement according to Embodiment 2. As shown in Figure 17, a single base station 10 may transmit two or more PRS patterns. The tile with the diagonal diagonal line in the lower left indicates the position of the second PRS pattern. If we refer to one pattern as one resource, the base station 10 transmits two PRS patterns. With this setting, it becomes possible to perform highly accurate positioning using more PRSs. Also, when performing positioning using multiple panels, it is possible to set different PRS patterns for each panel. Note that when performing positioning at high frequencies around 30 GHz, the accuracy of positioning is improved by performing it 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] Figure 18 shows a seventh example of the PRS arrangement according to Embodiment 2. Figure 19 shows an eighth example of the PRS arrangement according to Embodiment 2. As shown in Figures 18 and 19, the PRS arrangement may maintain orthogonality for each RB. Creating orthogonality at the RB level makes it possible to increase the number of orthogonalities in the frequency domain.

[0046] In LTE, the PRS differs depending on the number of ports used for the PBCH, and in this embodiment, different PRS settings may be used depending on the number of ports used for the PBCH. As described in Non-Patent Literature 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 used for the PBCH, but in this embodiment, different positioning accuracies may be required in the high-frequency band called FR2 or the low-frequency band called FR1 from 450MHz to 6GHz in NR. Also, because the frequency, time, or power resources of the transmitting side are limited, it is necessary to change the PRS density. For this reason, multiple densities may be set, and the density may be set at a higher layer in RRC, etc. The density may be set by setting the mode with a selection number as bits or parameters. For example, the selection number can be expressed as 0=standard, 1=low density, 2=high density. Alternatively, the mode display may be provided as a parameter indicating the PRS density, such as PRS_DENSITY, and shown as PRS_DENSITY=“DEFAULT”, “HIGH”, “LOW”. Alternatively, a mode number may be set, multiple PRS densities may be prepared, the density corresponding to each mode number may be predetermined in the standard, and the density may be notified to the terminal device via RRC. By setting a high density for the PRS, accurate positioning can be performed in a short time, and low-latency positioning can be achieved.

[0047] Figure 20 shows a ninth example of the PRS arrangement according to Embodiment 2. Figure 20 shows an example of the PRS arrangement with a different density. In the PRS arrangement diagram of Figure 20, the PRS are arranged at a higher density compared to the arrangement in Figure 12. Also, in Figure 20, the frequency orthogonality is lost in exchange for the high density of PRS arrangement.

[0048] Figure 21 shows a tenth example of the PRS arrangement according to Embodiment 2. Figure 21 shows an example of a low-density PRS arrangement. Although the density of PRS in Figure 21 is lower than that of the PRS arrangement in Figure 12, frequency orthogonality is obtained. Note that PRS may be placed in part or all of the active BWP. When only a portion of the BWP in the allocated band is used, it is appropriate to use a BWP that is close to the center of the allocated band, close to the center frequency, and less susceptible to interference from adjacent bands. For example, if the band is divided into four parts, and divided from the lowest frequency as BWP1, BWP2, BWP3, and BWP4, accurate positioning is possible by using BWP2 or BWP3, or both BWP2 and BWP3. Also, when multiple BWPs are used, measurements in each BWP may be observed within the measurement gap. During the measurement gap, no channels or signals are transmitted from each TRP or panel, and the terminal device performs observations. During the measurement gap period, only one BWP is used, and the PRS is placed within that BWP. For example, if time t2 > t1, then during the measurement gap period from t1 to t2, only PRS included in BWP1 is transmitted. Then, if t4 > t3 > t2 > t1, then during the BWP period from t3 to t4, only PRS included in BWP2 is transmitted. When the bandwidth used is large, if the entire bandwidth is used for transmission and reception processing, BWP is used to divide the bandwidth to prevent interference to other users or to prevent the bandwidth from becoming unavailable to other users, thereby improving frequency utilization efficiency and minimizing interference to other users. The setting of the measurement gap is notified to the terminal device 20 using RRC or the like. Furthermore, the measurement gap may be used to synchronize between base stations and synchronize the timing of the transmission of the reference signal used for positioning. In addition, since communication or positioning is performed using a wide bandwidth in NR, RSTD may be calculated when TRPs have different center frequencies or when the same center frequency is used but different BWPs or bandwidths are used. RSTD is generally observed using the following equation (1).In equation (1) below, RSTDi,1 is the time difference between the i-th TRP, TRPi, and the reference TRP, TRP1. 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, so the value is zero. ni is the measurement error of 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 System Information Block, PDCCH, or PDSCH may include the base station's position information and the Transmit time offset. As mentioned above, since RSTD can be calculated in the terminal device 20, the terminal device 20 may be equipped with a positioning function. Alternatively, the terminal device 20 may transmit the information necessary for positioning to the base station 10, and the base station 10 may perform the positioning process. In this case, the terminal device 20 is equipped with a transmission processing unit, a positioning processing unit, and a receiving processing unit, which correspond to the transmission processing unit 103, positioning processing unit 106, and receiving processing unit 104 of the base station 10, respectively. In this case, the receiving processing unit of the terminal device 20 receives the 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 PRS. Although TRP was used in the explanation of equation (1), equation (1) is not limited to TRP and is applicable to any transmitting device that can transmit PRS, and is a mathematical formula that can be applied to positioning using a panel.

[0049]

number

[0050] Furthermore, PRS can also be designed for short slots consisting of 2, 4, or 7 symbols, known as non-slots. Figure 22 shows an eleventh example of PRS arrangement according to Embodiment 2. Figure 22 shows an example of PRS arrangement for a slot consisting of 2 symbols. Figure 23 shows a twelfth example of PRS arrangement according to Embodiment 2. Figure 23 shows an example of PRS arrangement for a slot consisting of 4 symbols. Figure 24 shows a thirteenth example of PRS arrangement according to Embodiment 2. Figure 24 shows an example of PRS arrangement for a slot consisting of 7 symbols. In the examples shown in Figures 12 to 24, the RE on which the PRS is placed slopes downward to the right on the time-frequency coordinate plane, meaning that lower frequency subcarriers are used for later symbols. However, it is also possible to use subcarriers that slope upward to the right on the time-frequency coordinate plane, meaning that higher frequency subcarriers are used for later symbols. In addition, the power difference between the PRS and other reference signals or channels may be set in a higher layer such as RRC to suppress interference by the PRS. Alternatively, the power of the PRS can be set higher than that of other signals to make the PRS less susceptible to interference. The power difference can be compared using the power of the DMRS, CSI-RS, or PTRS (Phase Tracking Reference Signal). Alternatively, the difference with the power of the PDSCH can be used.

[0051] The sequences used in PRS may be generated by a random number generator set by a seed number. Furthermore, a different seed may be set for each TRP in a higher layer using RRC or similar. The random number generator can be, for example, a pseudo-random number generator using pseudo-random number generation as described in Chapter 5.2 of Non-Patent Literature 2.

[0052] PRS is based on QPSK (Quadrature Phase Shift Keying). The QPSK sequence used for PRS may be generated by a random number generator set by a seed number. Furthermore, a seed for the aforementioned random number generator may be set in a higher layer using RRC or similar so that a different seed is set for each TRP or panel. As this random number generator, for example, a pseudo-random number generator that applies pseudo-random number generation as described in Non-Patent Document 2 can be used. The shift register of the pseudo-random number generator specified in 3GPP is set by the parameter cinit. cinit depends on the symbol position or slot number where the PRS is placed. In addition, PRS may be generated based on a PRS_ID set in a higher layer. 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 PRS_ID may be, for example, 2^16, which is the same upper limit as cell_ID. For example, in the case of NR, 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 can also be done using the following equation (2). Note that PRS may be a sequence other than a QPSK sequence, such as a Zadoff Chu sequence. In that case, the sequence number of the Zadoff Chu sequence will be generated by the pseudo-random number generator.

[0053]

number

[0054] Here, ns is the slot number, and l is the symbol number within the slot. NCP is a variable that changes depending on the CP length; it can be set to NCP=0 for normal_CP and NCP=1 for extended_CP. The generated series may be masked with TRP-specific coefficients. If PRS_ID is not set in RRC, it can be set to a default value such as the cell ID.

[0055] Furthermore, PRS sequences may be generated up to the maximum number of RBs per OFDM symbol. That is, if the terminal device 20 can determine the PRS value of each RE, it can determine the random number generation seed number. An alternative to this generation method is a method that generates sequences for each number of RBs required by the PRS. In other words, the sequence differs depending on the number of RBs, and a wider variety of PRS sequences can be generated compared to the method described above. On the other hand, with the method described above, if the terminal device 20 can determine the PRS values ​​of the REs if it can determine the random number generation seed number, overhead is reduced. Either method may be used in this embodiment.

[0056] Furthermore, frequency hopping of the PRS may be applied to provide resistance to interference avoidance and selectivity in the frequency domain. By performing frequency hopping, it is possible to transmit PRS in FR2 and other systems while frequency multiplexing with data for other terminal devices, without dedicating a wide bandwidth for a fixed period of time. Frequency hopping also provides time and frequency diversity. When performing frequency hopping, the PRS is frequency-hopped according to a predetermined pattern. The hopping pattern may be performed on a RB basis. The PRS is transmitted in slot units, and the number of slots transmitted consecutively may be specified from the higher layer. The hopping pattern is specified from a predetermined pattern at the higher layer, and the hopping pattern is notified to the terminal device via RRC. The terminal device may use the PRS to perform positioning in the bandwidth specified for each frequency hop. Furthermore, when transmitting aperiodic PRS, multiple slots containing only PRS may be used and transmitted in a burst manner. Using PRS for multiple slots improves the accuracy of positioning.

[0057] PRS may be transmitted periodically in the time domain, as configured at the higher layer. PRS may be placed in every slot or every two slots. An offset may be added to the transmission start time. PRS may also be transmitted in units of multiple slots. Furthermore, PRS may be transmitted with modes such as periodic, semi-persistent, and aperiodic. For example, in the case of periodic, the period and the offset value of the transmission start are set by RRC parameters, etc. The period and the offset value of the transmission start are managed by a table, and the index of the table is specified at the higher layer to set the period and offset value. In the case of semi-persistent, the time interval in which PRS is transmitted periodically is specified at the higher layer. The aforementioned period is managed by a timer that records the passage of time, and when the period set at the higher layer has elapsed, the transmission of PRS is automatically stopped. Even during the period, base station 10 may stop transmitting PRS and inform terminal device 20 that it has stopped transmitting semi-persistent PRS via DCI or MAC-CE, etc. PRS transmission ends after a specified time has elapsed. 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 after receiving the instruction from the terminal device 20, the base station 10 transmits the PRS. In this case, the PRS may be transmitted across multiple slots. 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 a high density over time. Note that the PRS may conflict with other channels or reference signals in the transmission schedule. In that case, the transmission priority between the PRS and other channels or reference signals must be determined by the standard. If a control channel such as PDCCH, a data channel such as PDSCH, or a reference signal such as RS is scheduled in the slot or symbol where the PRS is placed, the PRS may be given priority.For example, if a PDSCH is pre-scheduled and to be placed in the same slot or symbol where a PRS is to be placed, the PRS will be prioritized, and the pre-scheduled PDSCH does not need to be transmitted. However, if the slot where the PRS is to be placed and the slot where the PDSCH is to be placed overlap, the slot containing the PRS will not be transmitted, and only the slot containing the PRS will be transmitted. In other words, multiplexing in the time and frequency domain, such as sending part of the data and part of the PRS, will not be performed. Furthermore, the priority of PRS transmission may be lowered compared to channels containing important control information such as PDCCH. And, as mentioned above, if modes such as periodic, semi-persistent, and aperiodic are set, and a collision occurs between a PRS and a PDSCH, the priority of the aperiodic mode may be set to the highest. The aforementioned priority may be applied even if modes such as periodic, semi-persistent, and aperiodic are not set for the PRS. Also, if a collision occurs between PRSs, the priority may be determined by the type of PRS. For example, if periodic, semi-persistent, and aperiodic PRS configurations overlap, the priority order aperiodic > semi-persistent > periodic, meaning the aperiodic PRS has the highest priority, may be set accordingly.

[0058] In LTE, the minimum period is 160 subframes, but any of the following values ​​with lower periods, such as 1, 2, 4, 8, 16, 32, 64, or 128 slots, may be included. The period may also be set in non-slot units. The higher-layer parameters related to the aforementioned PRS may be managed under names such as resource setting, resource set, and resource. This layered parameter management reduces overhead. Multiple resources are contained within a resource set, and multiple resource sets are contained within a resource setting. The resource setting may also be called PRS-ResourceConfig in the higher layer, and it manages resource sets and includes information such as the identification number of each resource set. It may also be managed under TS 38.331. Furthermore, within the resource setting, the time-domain behavior of the resources included in the resource set, such as periodic, semi-persistent, or aperiodic, may be defined. In this case, if the time-domain behavior is defined in the resource setting, all resources included in the resource setting will have the same settings. In a resource set, parameters for multiple resources are defined. For example, this may include the resource identification number. If aperiodic PRS is included, the resource set may also indicate that all included PRS are aperiodic. Furthermore, the slot and frequency position where the PRS will be placed may be specified in the resource. Alternatively, instead of hierarchical parameters, RRC parameters for PRS configuration may be provided. For example, an RRC parameter like PRS-config may include parameter information indicating the density of the PRS in time or frequency, or the time-domain operation such as periodic, semi-persistent, or aperiodic.

[0059] Furthermore, in 3GPP, antenna port numbers are used to assign identification numbers to reference signals. Antenna port numbers should be unique and not used by other reference signals. Currently, for NR, as defined in TS38.211, the 1000 series is used for PDSCH, the 2000 series for PDCCH, the 3000 series for CSI-RS, and the 4000 series for SS or PBCH. For example, PRS may use port numbers in the 5000 series. Alternatively, an identification number may be created for a resource, such as a PRS Indicator. Note that PRS may also be used in NR for lower frequency bands below 6 GHz, known as FR1, assuming the use of a wide beam. In FR1, a relatively wide beam is used, so there is no need to associate PRS with a beam number, and PRS may be transmitted over a wide range, similar to a broadcast signal. In the higher frequency band compared to FR1, known as FR2, a relatively narrow beam is used. Therefore, the base station 10 needs to transmit beam information on which the PRS is transmitted to the terminal device 20 so that the terminal device 20 can accurately receive the PRS. In this case, the base station 10 may associate the beam selected for transmitting the SSB used during the initial connection with the beam transmitting the PRS. Alternatively, the base station 10 may associate the beam used for beam management and suitable for transmitting the selected CSI-RS or SSB with the beam transmitting the PRS. Beam information is indicated, for example, using SSBRI or CRI. By performing positioning using beams, angle information can be obtained accurately and quickly, enabling low-latency positioning.

[0060] Furthermore, for periodically transmitted PRS signals, a process may be applied to prevent transmission at specified PRS timings. This is intended to prevent interference with other signals or frequencies during transmission interruptions. Figure 25 shows an example of muting according to Embodiment 2. In the muting shown in Figure 25, a portion of the PRS signals in the indicated interval are periodically not transmitted. Figure 26 shows another example of muting according to Embodiment 2. For example, on the occasion of transmitting PRS signals four times, the bitmap is used to represent "1001". By determining the number of transmissions to be muted 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 PRS may be used for beam sweeping for positioning beam management. It is also possible to perform positioning using other RSs without using PRS. For example, CSI-RS is used for beam management, directing a highly accurate beam towards the terminal device 20. In this case, CSI-RS is used for positioning, and the terminal device 20 may be notified of the CSI-RS port number to be used for positioning. In this embodiment, NZP-CSI-RS, as defined in Non-Patent Document 2, is used as an example. In this case, the terminal device 20 can calculate the difference in reception timing of CSI-RS received from multiple base stations 10 and determine its position in the same way as when positioning is performed using PRS. For example, in Figure 10, TRP1 may be set to use CSI-RS port 1, TRP2 to use CSI-RS port 2, TRP3 to use CSI-RS port 3, and TRP4 to use CSI-RS port 4. In NR, the placement of CSI-RS 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. While some CSI-RS ports are multiplexed by OCC (Orthogonal Cover Code), in positioning like OTDOA, CSI-RS signals arrive at the terminal device 20 with a time delay, making it inappropriate to use ports multiplexed by OCC. Optimal positioning accuracy is achieved by using CSI-RS ports where REs do not overlap in terms of time and frequency. When using CSI-RS, the terminal device 20 understands that CSI-RS is being used for positioning by informing it at a higher layer. The following shows an example where multiple parameters are included at the higher layer for positioning.

[0062] When using CSI-RS, positioning-specific CSI-RS may be configured at a higher layer. For example, positioning parameters may be set so that CSI-RS is positioned so that it does not overlap with CSI-RS used for purposes other than positioning in terms of temporal symbol or frequency RE. At a higher layer, parameters such as CSI-RS-Resource-Positioning may be provided to indicate that it is for positioning, similar to RRC. To indicate that CSI-RS is used for positioning, this may be indicated in resource setting, resource set, or resource. At a higher layer, to indicate that it is used for positioning, a flag named "positioning" or a flag such as PRS may be set in resource setting, resource set, or resource. If the flag value is 1, it may indicate that CSI-RS is used for positioning, and if the flag value is 0, it may indicate that it is used for CSI observation. Muting functionality may also be used for CSI-RS. By using a bitmap on a slot-by-slot basis, it is possible to specify which slots are capable of transmitting CSI-RS. By using the Muting function, interference can be avoided and positioning can be performed. Furthermore, when PRS or CSI-RS is transmitted from multiple TRPs, panels, or base stations, the length of the Cyclic Prefix (CP) of all transmitted OFDM signals is assumed to be the same. For example, 3GPP TS36.211 specifies normal CP and extended CP, with the extended CP being longer. When multiple base stations 10, or a flag value from a TRP or a flag value from a panel, simultaneously transmit PRS or CSI-RS via OFDM signals, it is appropriate for all waveforms to have the same CP length in order to accurately calculate the time difference between the multiple received PRS or CSI-RS signals. Additionally, using CPs of the same length eliminates the need to read the CP length from control information during calculations, reducing the overhead required for control information.

[0063] Furthermore, when positioning is performed 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 standardized among the PRS from each TRP, the calculation of RSTD becomes easier. Note that when the UE calculates its own position information using methods such as OTDOA, the position information of the terminal device 20 may be notified from the terminal device 20 to the base station 10 using a CSI report or the like. This is because if the base station 10 can periodically obtain the position information, it will be possible to manage and select the appropriate beam in beam management, etc. Also, in MU-MIMO, knowing the position of the terminal device 20 will allow for optimal scheduling of the terminal device. In addition, positioning may be performed using PRS in FR1 and CSI-RS in FR2. As mentioned above, a wide beam is used in the low frequency band, and the UE cannot know the transmitted beam information, so it may receive the reported PRS and perform RSTD calculation. In the high-frequency band, beam management is performed using CSI-RS, and a suitable beam is set for the UE, so positioning using CSI-RS is highly accurate. Although the above explanation mentions using CSI-RS for beam management, SSB may also be used for beam management. Periodic transmission of positioning PRS or CSI-RS may be interrupted using DCI (Downlink Control Information). This is because periodic communication may interfere with data transmission, so a process to immediately interrupt it is included. When positioning PRS, CSI-RS, or SSB is transmitted, the identification number RNTI (Radio Network Temporary Identifier) ​​assigned to the terminal device may be C-RNTI (Cell-RNTI), CS-RNTI (Configured Scheduling RNTI), or SP-CSI-RNTI (Semi-Persistent CSI RNTI).

[0064] In NR, ZP-CSI-RS (Zero-Power CSI-RS) may be used as an interference measurement CSI-RS for the CSI-RS used. For example, if interference occurs with a base station 10 in an adjacent cell, ZP-CSI-RS is transmitted while the base station 10 in the adjacent cell is transmitting a positioning CSI-RS to prevent interference with the base station 10 in the adjacent cell. Similar to PRS, a PDSCH does not need to be placed in the slot where the positioning CSI-RS is placed. This is to reduce interference caused by the PDSCH. Positioning may also be performed using DMRS. Since multiple symbols are placed in the slot, it is suitable for positioning. In addition, the power difference between the positioning CSI-RS and other reference signals or channels may be set at a higher layer such as RRC to suppress interference by CSI-RS. Alternatively, the power of the CSI-RS may be set higher than that of other signals to make the CSI-RS less susceptible to interference than other signals. The power difference can be compared using the power of DMRS, CSI-RS for transmission path estimation or interference measurement, or PTRS. Alternatively, the difference with the power of PDSCH may be used.

[0065] When multiple panels are used, PRS signals are received from multiple panels. Since the multiple panels are connected to the base station 10, multiple TRPs will exist within the same cell. In this case, the PRS_ID may be changed for each panel so that the PRS sequence is different. Also, since positioning accuracy decreases if there are obstacles in front of the panels, 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 control signals in the upper or lower layer. The parameters used in the upper layer may be RRC or MAC-CE, and in the lower layer, DCI may be used.

[0066] Positioning using OTDOA from the IDLE or INACDTIVE state is also possible. The terminal device 20 starts positioning while monitoring the paging information contained in the PDCCH transmitted from the base station 10, or the PDSCH specified within the PDCCH. 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 contained in the PBCH and PDSCH.

[0067] The SIB contains information necessary for OTDOA. For example, if base stations 10 with multiple cells are used in OTDOA, the SIB may include the cell IDs of the cells used. It may also include information about the reference cell. Furthermore, if multiple panels are used for positioning within the same cell, the SIB may include the panel IDs of the panels used or the ID of the reference panel. If beams are emitted from each panel, each panel may be associated with a group, and the SIB may include information about the group to which the beam belongs. SIBs used for positioning may be given a type name to indicate that they are SIBs for positioning.

[0068] Furthermore, if multiple panels are used within the same cell, the cell ID and the number of panels used for positioning may be included in the SIB. Positioning instructions may include information for positioning, information indicating that a positioning SIB has been received, etc. Terminal device 20 receives the positioning SIB. Positioning SIB information may be transmitted periodically, or it may be transmitted in advance when the base station 10 instructs the terminal device 20 to perform positioning. Information on the time and frequency resources for which PRS is transmitted may also be included in the SIB. The time and frequency resources for periodically transmitted PRS may also be described. Furthermore, if PRS is transmitted aperiodically, the time and frequency resources for which PRS is transmitted aperiodicly may be specified.

[0069] Furthermore, when terminal device 20 is in an IDLE or INACTIVE state, after receiving a PRS, it calculates the difference in reception times of multiple PRSs as described above, and reports the calculation result and / or the positioning result to base station 10, either according to instructions from base station 10 or at the discretion of terminal device 20. In addition, when positioning is performed using multiple panels or TRPs, the positions of the TRPs or panels may be close together and may not be distinguishable from terminal device 20. In such cases, QCL (Quasi Co-Location) information or measurement results may be used to determine that the positions of the panels or TRPs are close together. Alternatively, if the positions of the panels or TRPs are close together, the average of the measurement results or the maximum and minimum values ​​may be calculated and reported to base station 10.

[0070] Furthermore, the LMF sends OTDOA_INFORMATION_REQ to NG_RAN_NODE, initiating positioning using OTDOA. In this case, OTDOA_INFORMATION_RESPONSE is sent from the LMF to NG_RAN_NODE, and the information may include PRS configuration information. For example, it may include carrier frequency, PRS bandwidth, frequency offset amount, time offset amount of PRS or transmission interval, number of consecutively transmitted slots, 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, and selected codebook information. The report information may also include SFN (Slot Frame Number), antenna or panel position, PRS muting information, PRS hopping pattern, and PRS density information such as standard, high density, and low density. It may also include a value indicating the subcarrier interval used. Cyclic Prefix (CP) information may also be sent. Furthermore, in OTDOA, CSI-RS or PRS are transmitted from different TRPs, so information is needed at the UE to understand the relationship between the TRP and the PRS or CSI-RS. To this end, the PRS ID set in advance for each TRP or the parameter nID for CSI-RS generation defined in TS 38.211 may be notified from the upper 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 sent 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, the symbols in the slot are set to "D" for Downlink, "U" for Uplink, or "F" for symbols with degrees of freedom. PRS may be transmitted using only the symbol set for the downlink, indicated as "D". Alternatively, PRS may be transmitted using the "F" symbol as well, if it is not being used by another symbol.

[0072] Furthermore, the numerology, such as the subcarrier interval, may change during measurement. NR provides subcarrier intervals of 15kHz, 30kHz, 60kHz, 120kHz, and 480kHz, and these values ​​are set to remain unchanged during positioning to maintain accuracy. Additionally, PRS signals with different numerologies may be transmitted to the terminal device 20 in the frequency domain. For example, if 20RB resources are allocated to the terminal device 20 for positioning, 10RB may be set to send at 15kHz and 10RB at 120kHz. While all signals may use the same numerology, if different numerologies are used, the positioning calculation will include a frequency error.

[0073] Furthermore, position information may be defined using a predetermined grid during positioning. A grid is predetermined, 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 positioning is performed in a stationary environment, once grid information is obtained, the terminal device 20 selects a beam and reports it to the transmitting side, allowing the transmitting side to determine the position of the terminal device 20. This method is effective in locations where the installation environment is predetermined. 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 retain information regarding the reception time of the SSB. This information may be, for example, the difference between the reception times of multiple SSBs. This eliminates the need for the base station 10 to transmit PRS settings to the terminal device 20, and as a result, the amount of signaling between the base station 10 and the terminal device 20 can be reduced. The terminal device 20 may derive its own position using the information regarding the reception time of the SSB. Base station 10, and / or a panel or TRP, may broadcast information regarding the location of its own base station, and / or its own panel or TRP, or may individually notify terminal device 20. Terminal device 20 may use this location information to derive its own location. This eliminates the need for terminal device 20 to transmit measurement results to base station 10, thereby reducing the amount of signaling between base station 10 and terminal device 20, and eliminates the need to restart communication between terminal device 20 and base station 10, thereby enabling rapid positioning in the communication system. As another example, base station 10 may derive the location of UE using information regarding the SSB reception time. Terminal device 20 may notify base station 10 of information regarding the SSB reception time. This notification may be included, for example, in the measurement result report from terminal device 20 to base station 10, or in a different signaling. Base station 10 may derive the location of the terminal device using information regarding the SSB reception time. This makes it possible to reduce the load on the terminal device 20 due to position derivation, for example.Furthermore, Embodiment 1 and Embodiment 2 may be used in combination. Embodiment 1 obtains angle information from a selected beam and performs positioning using distance information. Embodiment 2 calculates the RSTD from the reception time of reference signals transmitted from multiple transmitters and performs positioning. The average of the positions obtained from both methods may also be calculated. In addition, when performing positioning using multiple base stations, some base stations may use the method described in Embodiment 1, and the other base stations may use the method described in Embodiment 2. As mentioned above, the reference signals used for positioning have periodic, semi-persistent, and aperiodic types of periods set, 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 one of the forms of periodic, semi-persistent, or aperiodic. Periodically notifying the position, such as in periodic or semi-persistent, improves the accuracy of location-sensitive services such as emergency notifications. In addition, with aperiodic, the base station or terminal device 20 that wants to receive location information requests the report of location information, and the report of location information occurs at a time set in the upper or lower layer. Aperiodic location reporting is an effective reporting method when the base station or terminal device 20 urgently needs location information. If periodic reporting is selected, the base station or terminal device 20 reports the calculated location information according to a period determined by the higher layer, for example, a period in units of slots. If set to semi-persistent, the base station or terminal device 20 reports the calculated location information for a period determined by the higher layer, for example, a period in units of slots. The aforementioned reporting methods may also be named periodic position report, semi-persistent position report, or aperiodic position report.

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

[0075] Furthermore, in NR, OFDM or DFT-s-OFDM is used on the uplink. A characteristic of DFT-s-OFDM is that it has a lower PAPR (Peak to Average Power Ratio) than OFDM, so it is possible to transmit at higher power than OFDM. In positioning, low uplink power reduces positioning accuracy, so DFT-s-OFDM may always be used as the default setting for positioning. In NR, the frequency or reference signal settings differ between DFT-s-OFDM and OFDM on the uplink, so it is desirable for eNB to always have one method set as the default during positioning. Also, a mechanism may be provided to switch to ODFM if sufficient power can be guaranteed. This is an example of an embodiment that can be applied to E-CID, OTDOA, or UTDOA systems.

[0076] Note that during positioning, beam searching may fail. In such cases, the terminal device 20 may notify the base station 10 that the beam search has failed. Also, if the terminal device 20 moves into another TRP or cell during positioning, the beam search may fail. In this case as well, the terminal device 20 may notify the base station 10 that the search has failed and cancel positioning. Furthermore, during beam recovery, the terminal device 20 may request the base station 10 to change the beam pair between the base station 10 and the terminal device 20, but positioning will not be performed during beam recovery.

[0077] Embodiment 4. In the ECID scheme, the distance between the base station 10 and the terminal device 20 can be calculated according to the method for calculating TA (Timing Advance). In addition, PRACH may be used for the uplink signal in UTDOA. In this embodiment, the configuration of PRACH used for ECID and PRACH will be described. BS is called PDCCH_order and can request the terminal device 20 to transmit PRACH, and this request is included in PDCCH. At this time, the PDCCH may include a PRACH configuration for positioning. It may also be indicated that the PDCCH is a PDCCH_order for positioning. Furthermore, a search space indicating the frequency and time resources where DCI is placed may be set up within the PDCCH for positioning purposes. In addition, the CRC of the PDCCH is scrambled by RNTI, but a positioning RNTI may be used. By specially setting up the location where the CRC or DCI of the PDCCH is placed for positioning purposes in this way, it is implied to the terminal device 20 that positioning information is included after receiving the PDCCH. TA is calculated using PDCCH_order and PRACH. Normally, base station 10 sends a RAR (Random Access Response) after receiving a PRACH, but if it receives a PRACH for positioning, it may choose not to send a RAR. Since positioning becomes possible by receiving a PRACH for positioning, subsequent RA processing is unnecessary. Terminal device 20 does not need to receive a RAR from base station 10 after sending a PRACH for positioning. The PRACH configuration for positioning is set by configuring frequency and time resources or a pre-amplifier format. In addition, the PRACH configuration for positioning may be set differently from the PRACH configuration for other purposes in advance.

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

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

[0080] Furthermore, the PRACH for positioning may be placed in resources designated for positioning, with time and frequency allocated for positioning. A special sequence or preamble format may be prepared for positioning. Multiple options may be provided for selecting the PRACH bandwidth.

[0081] Embodiment 5. Figure 27 shows the positioning method switching between LTE and NR according to Embodiment 5. Since the coverage by LTE cells is wide, positioning may be performed within NR cells by referring to the positioning information obtained from LTE. Alternatively, positioning may be performed by switching between the NR and LTE positioning methods. The switching is instructed by the higher layer.

[0082] Embodiment 6. Figure 28 is a diagram showing an example of the arrangement of positioning reference signals according to Embodiment 6. Figure 28 is an arrangement diagram of positioning reference signals with frequency on the vertical axis and time on the horizontal axis. In this embodiment, we will describe the case where the positioning reference signals are arranged at the positions shown in Figure 28. In Figure 28, OFDM symbols hatched with multiple dots represent positioning reference signals. In the example shown in Figure 28, the positioning reference signals are placed every other RE in the third OFDM symbol in the time axis direction. Note that in Figure 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 placed in the symbols in Figure 28 that are not indicated by diagonal lines and where no reference signal is placed.

[0083] Figure 29 shows the waveform of the signal within a 1 OFDM symbol where the positioning reference signal shown in Figure 28 is placed. Figure 29 shows that the transmitted waveform is repeated in units of half the 1 OFDM symbol time. For example, suppose that 1 OFDM time is divided into two parts: the first 0.5 OFDM symbol time and the second 0.5 OFDM symbol time. The waveform of the signal in the first 0.5 OFDM symbol time and the waveform of the signal in the second 0.5 OFDM symbol time will have the same shape. In other words, in Figure 29, waveforms with similar amplitude and phase are repeated within 1 OFDM symbol.

[0084] Figure 30 shows a comparative example in which the positioning reference signal is arranged across multiple symbols. When the waveform of the signal for the first 0.5 OFDM symbol time and the waveform of the signal for the second 0.5 OFDM symbol time are the same, as shown in Figure 29, synchronization errors are likely to occur when performing symbol synchronization. For this reason, as shown in the comparative example in Figure 30, it is necessary to send the positioning reference signal across multiple symbols. Synchronization errors are also likely to occur in signals where signals with the same power characteristics are repeated multiple times within a 1 OFDM symbol interval.

[0085] To address the issue of synchronization errors occurring during symbol synchronization, in this embodiment, the base station 10 switches beams and transmits signals for each section in which the same waveform occurs within one OFDM symbol, thereby preventing the terminal device 20 from repeatedly observing the same waveform. The terminal device 20 receives a signal for each beam that is switched for each section. This method prevents the terminal device 20 from receiving the same waveform, thus suppressing the occurrence of synchronization errors in the terminal device 20.

[0086] Figure 31 shows an example of switching beams for each section in which the same waveform occurs within a single OFDM symbol according to Embodiment 6. Figure 31 shows an example in which the same waveform occurs twice within a single OFDM symbol. In Figure 31, there are two beams transmitted from the base station 10, which are shown as beam 1 and beam 2. In Figure 31, beam 1 and beam 2 are assumed to be pointing in different directions, i.e., 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 analog beams or digital beams using digital precoding. The terminal device 20 cannot receive the signal at maximum power unless it uses a receiving beam pointed in the direction of beam 1 or beam 2 transmitted from the base station 10.

[0087] In the example shown in Figure 31, beam 1 is used to transmit signal A during the first half of the 1 OFDM symbol time. Beam 2 is used to transmit signal B during the second half of the 1 OFDM symbol time. If the beams are not switched for each section in which the same waveform occurs within the 1 OFDM symbol, the terminal device 20 will receive both signal A and signal B within the 1 OFDM symbol. On the other hand, if the beams are switched for each section in which the same waveform occurs within the 1 OFDM symbol, the terminal device 20 will only receive signal A if it adjusts the direction of the receiving beam to receive the signal transmitted by beam 1. Similarly, if the terminal device 20 adjusts the direction of the receiving beam to receive the signal transmitted by beam 2, it will only receive signal B. For example, in Figure 31, if the terminal device 20 uses beam 3 for reception, it will be able to receive the signal transmitted by beam 1. When using beam 3, the received power of the signal transmitted from beam 2 at the terminal device 20 is less than the received power of the signal transmitted from beam 1. On the other hand, if the terminal device 20 uses beam 4 for reception, it will be able to receive the signal transmitted by beam 2. When using beam 4, the received power of the signal transmitted from beam 1 at the terminal device 20 is less than the received power of the signal transmitted from beam 2. In other words, the terminal device 20 cannot detect repeated signals in a 1 OFDM symbol interval or in intervals where signals with the same power characteristics are repeated multiple times.

[0088] In this embodiment, as described above, no other signals are 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 can obtain information about the positioning reference signal, such as the spacing of the positioning reference signal in the frequency domain and the sequence used as the reference signal, it can also know the characteristics of the signals in one OFDM section in advance, and thus demodulation is possible even if only signal A or signal B is received, as shown in Figure 31. If the sequence used as the reference signal is a PN (Pseudo Noise) sequence, a value such as C_init, which is used to initialize the shift register for sequence generation, may be notified to the terminal device 20 as information about the positioning reference signal. Furthermore, if 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 aforementioned parameters may be notified to the terminal.

[0089] Furthermore, in this embodiment, when the base station 10 switches the transmit beam within one OFDM symbol, the beam sweep time of the base station 10 is shorter compared to when the beam is not switched within one OFDM symbol. For example, in the conventional method, when transmitting 64 beams by sweeping using one identical beam for one OFDM symbol interval, the base station 10 requires a minimum of 64 OFDM symbol time to transmit 64 beams. In addition, if time is required to switch beams, the base station 10 will need more than 64 OFDM symbol time to transmit 64 beams. However, as an example of this method, when the base station 10 sweeps 64 beams using two beams within one OFDM symbol, the beam is switched every 0.5 symbol time, so the transmission of 64 beams can be completed in a minimum of 32 symbol time. While the base station 10 is beam sweeping the receive beam, the terminal device 20 can set a fixed receive beam, and then observe the received power of the beams radiated in multiple directions transmitted from the base station 10 within one OFDM symbol. As the beam sweep time is shortened, the base station 10 may increase the number of beams swept, i.e., the number of resources. During beam sweeping, in order to shorten the beam sweep time and improve the efficiency of beam sweeping, the base station 10 needs to set the direction or range in which to start the beam sweep. As shown in Figure 10, when the terminal device 20 performs positioning using multiple base stations or TRPs, the terminal device 20 may notify surrounding base stations of the beam sweep results of the reference TRP. Here, the beam sweep results refer to, for example, the received power of each beam while the base station 10 is beam sweeping, acquired by the terminal device 20. Alternatively, the beam sweep results refer to, for example, the transmitted beam number selected after the beam sweep. For example, using the example in Figure 10, the terminal device 20 may notify TRP2, 3, and 4 of the beam sweep results of TRP1 through the server 200. Alternatively, terminal device 20 may notify TRP2, 3, and 4 using a broadcast channel such as PBCH (Physical Broadcast Channel).

[0090] Furthermore, there are various possible methods for notifying the terminal device 20 of the setting notification information, which is information that notifies the base station 10 that the beam switches within one OFDM symbol. The base station 10 may notify the terminal device 20 of the setting notification information by including the setting notification information in the upper layer signal and transmitting the upper layer signal containing the setting notification information to the terminal device 20. The notification may be made using a flag, or the RRC parameter of the upper layer signal may be used. Furthermore, the method of transmitting the information notified to the terminal device 20 is not limited to the method using the RRC parameter, and other methods may be used.

[0091] Furthermore, configuration notification information may be sent from the positioning server 200 to the terminal device 20. For example, configuration information may be sent from the server 200 using LPP (LTE Positioning Protocol) to the terminal device 20. Alternatively, it may be sent from the server 200 using a protocol defined in NRPPa. Configuration information may also be sent through the base station 10. For example, information may be transmitted from the LMF to the base station 10 via NRPPa. In addition, separate servers equipped with positioning functions for the downlink and servers equipped with positioning functions for the uplink may be installed. By installing these servers, processing power can be distributed, and the computation 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 via downlink or uplink, it is necessary to manage beam information. Beam information includes, for example, the beam power and the beam direction of illumination. Additionally, if the reference signal is transmitted as a beam, beam information also includes, for example, the frequency at which the reference signal is sent and its position in the time domain and frequency domain. The position in the time domain and frequency domain of the reference signal is 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 located. When using downlink positioning reference signals, as shown in Figure 10, the positioning reference signals are sent from each of the multiple base stations 10 to the terminal device 20, and the terminal device 20 performs positioning, the beam information to which each positioning reference signal is sent must be managed by either the base station 10 or the terminal device 20. In this embodiment, the TRP in Figure 10 is referred to as the base station 10. The base station 10 may be located in the same cell as the terminal device 20, or it may be located in a different cell. In such cases, a resource set may be assigned to each base station 10. Note that resource sets are generally used to configure the CSI-RS reference signal used on the downlink or the SRS reference signal used on the uplink.

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

[0094] The resource set may also be applied to the positioning reference signal on the uplink. In 3GPP LTE, SRS is used as the positioning reference signal on the uplink. The SRS used for positioning is referred to here as the positioning SRS. For example, as mentioned above, the RRC parameter usage may be set to Positioning. Alternatively, the setting information for the usage used in the RRC parameter may be notified to the terminal device 20 from the server or the positioning function, as mentioned above. In this case, usage is not used as an RRC parameter, but rather as higher-level information notified from the server or the positioning function. The beam information of the SRS may be defined as a resource, and multiple beam information sets may be defined as a resource set. In addition, when positioning using the uplink, the terminal device 20 transmits a positioning reference signal to multiple base stations 10. The base stations 10 record the reception time of the positioning reference signal transmitted from the terminal device 20, and the multiple base stations 10 refer to each other's reception time information to determine the position of the terminal device 20 from the time difference in reception times with other base stations 10. The positioning reference signal is not limited to SRS; PRS for the uplink may also be used. The positioning reference signal also includes location information in the frequency domain and time domain where the SRS transmitted from the terminal device 20 is located using the beam corresponding to each resource. That is, the base station 10 measures the received power of the beam using the SRS located at the location in the frequency domain and time domain where the SRS transmitted from the terminal device 20 is located. The location information in the frequency domain and time domain where the SRS transmitted from the terminal device 20 is located may be information in units of multiple symbols or information in units of one symbol.

[0095] When a terminal device 20 transmits a reference signal to multiple base stations 10, the terminal device 20 needs to associate the transmitted reference signal with the destination base station 10 and the beam number or resource number, which increases the amount of control information required. An increase in control information leads to longer transmission times and increases the bandwidth, symbol count, and bit count required for the control information.

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

[0097] The SRS resource set and resource settings may be performed using RRC. Alternatively, other configuration methods may be used. The SRS resource set and resource settings may be performed individually from each base station 10. Furthermore, configuration information may be notified to the terminal device 20 from a server or positioning function.

[0098] The terminal device 20 only needs to transmit an SRS according to the resource set and resource settings. Therefore, it is sufficient to set up a resource set for each expected number of base stations 10.

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

[0100] Here, we will explain the details of the linking of the positioning SRS with other reference signals. The reference signal or synchronization signal used on 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 one of these beams. At this time, if the beam of the positioning SRS on the uplink and the beam to which the reference signal or synchronization signal was sent on the downlink are linked, the terminal device 20 only needs to transmit the uplink positioning SRS beam that is linked to the beam used to transmit the reference signal or synchronization signal on the downlink.

[0101] Furthermore, on the uplink, a positioning SRS may be transmitted using a beam linked to 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 aforementioned use cases are also set for the resource set. Then, unique parameter settings are made for each of the aforementioned use cases and notified to the terminal device 20. The beam from which the positioning SRS is transmitted should be set to the beam direction for SRS positioning, using the beam direction used in the aforementioned use case. By setting the beam direction of the SRS used for other use cases in this way, the need for beam sweeping is eliminated, and the time required to determine the appropriate direction can be reduced. In addition, by setting the beam direction of the SRS used for other use cases, the amount of control data sent to the base station 10 and the server equipped with positioning functionality can be reduced.

[0102] When a CSI-RS for positioning is used as a PRS, the reference signals to which spatial information can be linked include SSB, SRS, and PRS on the uplink. Alternatively, the PRS on the downlink may be linked to the spatial information of the DMRS. Here, the spatial information of the DMRS refers to the direction of the beam transmitted by the DMRS. For example, the direction of the beam transmitted by the DMRS is linked to the beam number of a reference signal on another downlink. Or, for example, the direction of the beam transmitted by the DMRS is linked to the QCL state of the PRS and the RS, which includes the DMRS and other DMRSs. Linking to the QCL state means that when the PRS port number X and the DMRS port number Y are in a QCL state, the spatial information, Doppler shift, Doppler spread, and other transmission path characteristics of the transmission path of the PRS port number X are similar to the spatial information, Doppler shift, Doppler spread, and other transmission path characteristics of the transmission path of the DMRS port number Y. In other words, the beam direction used for PRS transmission may be used for the DMRS. Note that spatial information settings may also be applied within a resource set. In this case, these settings will be applied to all resources within the resource set.

[0103] When multiple panels are used during positioning in the terminal device 20, a resource set may be set for each panel. By installing multiple panels in the terminal device 20 and orienting each panel in a different direction, SRS transmission from the terminal device 20 becomes possible in all directions. In this case, spatial information is set for each panel. Since spatial information needs to be set for each panel when they are facing different directions, managing spatial information for each resource set reduces the overhead required for setting. When performing such operations, the number of panels on the UE side and the number of resource sets should be set to be equal. Furthermore, a panel identifier may be set for each resource set. Setting a panel identifier for each resource set makes it possible to link multiple resource sets to the same panel. Alternatively, the panel identifier may be linked to a resource within 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 the resource set. Figure 32 shows an example of applying the linking of panel numbers, resource sets, and resources when using multiple panels according to Embodiment 7. In Figure 32, five resources are configured at base stations 10-1 and 10-2, and two resource sets are configured on each of the two panels of the terminal device 20. For example, a transmit beam and a receive beam are provided within one resource set from the terminal device 20 toward base station 10-1. In Figure 32, two resources corresponding to the two beams from the terminal device 20 facing the direction of base station 10-1 are provided within one resource set. In addition, the transmit resource or the receive resource is associated with resource numbers #2 and #4 of the respective base station 10-1. That is, different panels of the terminal device 20 are associated with beams of the base station 10-1 facing different directions. In the example in Figure 32, control information associating the resource set identifier with the two resource numbers of base station 10-1 is generated by a server with positioning capabilities or by base station 10-1.Furthermore, the association between the downlink reference signal and the uplink reference signal may be performed not only within the same cell but also with other cells. For example, the reference signal transmitted from the base station 10 of an adjacent cell to the cell where the terminal device 20 resides may be associated. By associating the beam direction transmitted from the base station 10 of the adjacent cell with the beam direction of the terminal device 20, the terminal device 20 can perform positioning using the adjacent cell base station. For this reason, a cell identifier, TRP identifier, or base station identifier may be added to the associated beam information to indicate that it has been linked with another cell.

[0104] Furthermore, beams may be used for different purposes within the same resource set. For example, as mentioned above, SRS application methods 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 each applicable use case. In this case, the characteristics of the beam become characteristics suitable for positioning. For example, a positioning beam may only be configured to be sent periodically.

[0105] Furthermore, even if multiple panels are not used in the uplink, if the UE transmits SRS to multiple different base stations 10, a resource set may be configured for each base station 10. By the UE transmitting SRS to different base stations 10, the base stations 10 can coordinate with each other, compare the times when the SRS was received, and estimate the UE's location.

[0106] Figure 33 shows an example of a UE according to Embodiment 7 sending an SRS to different base stations 10. In Figure 33, the UE needs to transmit a positioning SRS to two base stations 10, and two resource sets are set up, with resource set #1 corresponding to base station 10-1 and resource set #2 corresponding to base station 10-2. For example, a transmit beam or receive beam directed from the terminal device 20 towards 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 the overhead required to transmit control information.

[0107] Ports for transmitting PRS are also configured. Ports are assigned numbers, and up to one or two ports can be configured. Ports may be configured for each resource. In this embodiment, ports represent logical antennas. In this embodiment, port configuration will be explained using an example of a PRS used for the downlink. For example, using two ports can support up to two polarizations of a physical antenna. Ports can configure, for example, the relationship between one port and the other. Ports can also configure the relationship between a resource and a QCL, and it can be configured that they have the same spatial information. QCLs can be configured with Types A, B, C, and D. Type A includes information related to Doppler shift, Doppler spread, mean delay, and delay variance. Type B includes information related to Doppler shift and Doppler spread. Type C includes information related to mean delay and Doppler shift. Type D includes spatial information relevant at reception. QCLs may be configured for PRS ports or resources.

[0108] If the QCL state is the same between ports, it indicates that the characteristics of the propagation path are nearly identical, so the same transmission process can be applied on the transmitting side. When two ports are configured for PRS, the same or different QCL states can be set between the two ports. If the same QCL state is set, similar transmission paths will be propagated between the two ports. Alternatively, different QCL states may be set for the two ports configured for PRS. PRS ports may be associated with SSB, DMRS, PTRS, TRS, or CSI-RS ports. Ports associated with the QCL state of a resource may be associated with SSB, DMRS, PTRS, TRS, or CSI-RS ports. Resources may be associated with SSB, DMRS, PTRS, TRS, or CSI-RS ports. Note that the port settings for PRS apply to PRS used on the downlink or PRS settings used on the uplink.

[0109] Embodiment 8. In the uplink, it is desirable that there be no interference from other signals within the section where the reference signal used for positioning is transmitted. Furthermore, by transmitting multiple uplink reference signals for positioning, the receiving side can perform signal averaging, thereby improving positioning accuracy. For this reason, positioning SRS or uplink PRS may be placed in designated slots. Here, SRS is used as an example. Only SRS is placed in the designated slot, and SRS is not multiplexed with other reference signals, data signals, or control signals in the frequency domain. Here, a slot refers to a symbol consisting of 14OFDM symbols or 14DFT-s-OFDM symbols, but a slot may also refer to a set consisting of fewer than 14 symbols. By setting a slot in which only positioning SRS is placed, interference from other signals is reduced when positioning is performed on the base station 10 side.

[0110] Note that not all 14 symbols in a slot are to be used as positioning SRS for the UE. Unused symbols may be used as positioning SRS for other UEs. Figure 34 shows an example of SRS multiplexed in the time domain according to Embodiment 8. In Figure 34, white symbols indicate unused symbols. The SRS symbols in the SRS resource for the second terminal device 20-2 are placed at the 12th and 14th symbols, and the SRS resources for the SRS for the first terminal device 20-1 are placed at the 11th and 13th symbols. In other words, base station 10 transmits the reference signal for the first terminal device 20-1 and the reference signal for the second terminal device 20-2 at different symbol times.

[0111] Figure 35 shows an example of the arrangement of SRS multiplexed in the frequency domain according to Embodiment 8. The positioning SRS may be configured such that multiple SRSs corresponding to multiple terminal devices 20 are frequency multiplexed. In Figure 35, the SRS of the first terminal device 20-1 and the second terminal device 20-2 are multiplexed in the frequency domain at the 14th symbol. In other words, in the example shown in Figure 35, the base station 10 multiplexes the reference signal for the second terminal device 20-2 and the reference signal for the first terminal device 20-1 with the same symbol time. The position of the positioning SRS symbols may be shown as a bit array. For example, the position of the positioning SRS symbol for the first terminal device 20-1 in Figure 34 can be shown as 00000000001010. Information on the position of such positioning SRS symbols is notified to the first terminal device 20-1 from a server equipped with positioning functionality or the base station 10 via a higher or lower layer. Furthermore, the terminal device 20 transmits SRS based on the positional information of the positioning SRS symbols.

[0112] Figure 36 shows an example of transmitting SRS resource information from a terminal device 20 to a base station 10 according to Embodiment 8. In this embodiment, information indicating the location of an SRS resource is called SRS resource information. An SRS resource indicates the location in the frequency domain and time domain where the SRS is located. An SRS resource may be located across multiple OFDMs or multiple DFT-s-OFDM symbol units, or it may be located in a single OFDM or a single 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 timing of transmission before the terminal device 20 transmits each piece of SRS resource information. By the base station 10 understanding the transmission interval of the SRS sent from the terminal device 20, it is possible to improve the SNR (Signal to Noise Ratio) of the received SRS signal through averaging processing, etc. Furthermore, when SRS is transmitted from multiple terminal devices 20, each terminal device 20 must pre-set its SRS transmission interval and relative transmission timing by scheduling to ensure that the SRS transmitted from each terminal device 20 do not collide, and must understand the transmission schedule. SRS resource information is transmitted periodically, for example. In Figure 36, the interval between resources is shown as T. The unit of T may be the number of symbols, time, or, for example, seconds. The arrangement of resources in the time and frequency domains within a slot is irrelevant to determining the timing of transmitting SRS resource information; the interval between slots is what matters. At this time, the base station 10 transmits SRS resource information to multiple different beams. In this case, the base station 10 may perform a beam sweep, or it may send SRS with the beam direction already determined. When the base station 10 performs a beam sweep, the beams to which each SRS resource information is transmitted are candidate beams. When the beam direction is already determined and transmission is performed, positioning SRS is sent.

[0113] Figure 37 shows an example of transmitting SRS resource information from a terminal device 20 according to Embodiment 8 to multiple base stations 10. In the example shown in Figure 37, separate positioning SRS slots are used for base stations 10-1, 10-2, and 10-3. Although the examples in Figures 36 and 37 show examples of transmitting SRS at regular intervals, irregular intervals are also acceptable as long as each base station 10 can keep track of them. In the example in Figure 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 set to `Positioning`, it is desirable that the positioning SRS is not multiplexed with data or control channels within the slot. Since positioning slots are configured on a per-slot basis, different `usage` values ​​may be time-multiplexed within each slot. This multiplexing of slots with different `usage` values ​​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 itself derive its own location information. However, conventionally, the terminal device 20 can only perform positioning in LTE, for example, by deriving the difference in PRS reception time, and cannot derive its own location information. To solve this problem, the base station 10 should notify the terminal device 20 of base station information, which is information about the base station 10. The terminal device 20 then uses the base station information notified by the base station 10 to derive its own location information.

[0116] The following five items are examples of base station information. The first item of base station information is the identifier of base station 10. The second item of base station information is information about the location of base station 10. The third item of base station information is information about the beam of base station 10. The fourth item of base station information is information about the synchronization of base station 10. The fifth item of base station information is information that combines the first to fourth items of base station information. This 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. Alternatively, the terminal device 20 performs positioning using information that combines the first to fourth items of base station information.

[0117] The identifier of base station 10 may be, for example, a cell identifier. Alternatively, the identifier of base station 10 may be a TRP identifier. The information regarding the location of base station 10 may be, for example, location information derived by base station 10 using GNSS (Global Navigation Satellite System). The information regarding the beam of base station 10 may include, for example, a beam identifier and information regarding the beam direction for each beam. Information regarding the beam direction for each beam may include information regarding the beam's irradiation angle. The information regarding the beam direction may include horizontal and vertical information.

[0118] Information regarding the synchronization of base station 10 may include, for example, base station information of surrounding base stations 10 that are time-synchronized. As for time synchronization, base stations 10 with the same DL frame timing may be considered surrounding base stations 10 that are time-synchronized. The base station information of surrounding base stations 10 may also be a cell identifier. Multiple groups of synchronized surrounding base stations 10 may be established. Each group may be assigned an identifier. The group identifier makes it possible to recognize which base station 10 is synchronized with.

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

[0120] Base station 10 may notify terminal device 20 of base station information using RRC individual signaling. Alternatively, information indicating that the information is for positioning purposes may be provided, and the base station information may be notified along with this information. Base station information notified in the RRC CONNECTED state may be used in the RRC INACTIVE state. It is desirable for terminal device 20 to retain the base station information notified in the RRC CONNECTED state when transitioning to the INACTIVE state. This allows for setting base station information for each terminal device 20.

[0121] Base station 10 may notify terminal device 20 of base station information of surrounding base stations 10. In this way, terminal device 20 can obtain base station information of surrounding base stations 10 from base station 10. Here, base stations 10 surrounding base station 10 are referred to as surrounding base stations. Base station information of the first base station, which is one of the base stations 10, may include base station information of the first base station in the base station information of surrounding base stations that it transmits. In this way, terminal device 20 can obtain base station information of the surrounding base stations of the first base station from the first base station. For example, terminal device 20 obtains base station information of surrounding base stations from the first base station. After receiving information indicating that it is base station information for positioning by terminal device 20, along with the base station information of surrounding base stations, terminal device 20 performs positioning using the acquired base station information of surrounding base stations. Positioning may be performed using the method described above as appropriate, or using a conventional method as appropriate, and the method of positioning is not limited. Terminal device 20 derives its own location information using the base station information of each surrounding base station for which positioning was performed. For example, the location information of the terminal device 20 itself can be derived using the location information of multiple base stations 10, beam irradiation angle information, etc.

[0122] The terminal device 20 may perform positioning using information indicating synchronized base stations from the synchronization information received for each base station 10. For example, there may be unsynchronized base stations 10 located nearby. If positioning and location information are derived using base station information transmitted from unsynchronized base stations 10, it becomes impossible to accurately derive the difference in reception timing between base stations 10, and accurate location information cannot be obtained. Therefore, by performing positioning and location information deriving using base station information from synchronized surrounding base stations, the terminal device 20 can derive accurate location information for itself.

[0123] Alternatively, base station 10 may notify terminal device 20 of its own base station information. This reduces the amount of information that the first base station notifies terminal device 20 of. For example, base station 10 includes its own base station information in the broadcast information. Terminal device 20 obtains base station information by receiving the broadcast information from base station 10. For example, terminal device 20 may perform positioning using the base station information of base station 10 that received the positioning base station information. For example, terminal device 20 may perform positioning using the base station information of the first base station and surrounding base stations from which base station information was obtained. Terminal device 20 derives its own location information using the base station information of each base station 10 from which positioning was performed. For example, terminal device 20 may derive its own location information using the location information and beam irradiation angle information of multiple base stations 10.

[0124] If the base station information of the first base station includes information regarding synchronization, the terminal device 20 may perform positioning using the base station information of a synchronized surrounding base station. By performing positioning and deriving location information using the base station information of a synchronized surrounding base station, it becomes possible to derive accurate location information for the terminal device 20 itself.

[0125] When terminal device 20 is in an IDLE or INACTIVE state, if the received power of base station 10 falls below a threshold, it searches for nearby base stations. Terminal device 20 performs the search for nearby base stations as a cell reselection process. Terminal device 20 may also perform positioning when performing a search for nearby base stations. When searching for nearby base stations, terminal device 20 may receive broadcast information from nearby base stations and derive its own location information. In this way, it becomes possible to derive the location information of terminal device 20 itself. However, there may be problems if positioning by terminal device 20 is performed only when searching for nearby base stations. This is because some services require the location information of terminal device 20 in a timely manner. A method for solving this 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 information instructing positioning using paging. The base station 10 may notify the terminal device 20 whether it is in the CONNECTED state, the IDLE state, or the INACTIVE state. In this way, for example, the base station 10 can make the terminal device 20 perform positioning at a timing appropriate for the service.

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

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

[0129] The base station 10 may instruct 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 the period of positioning performed by the terminal device 20. Alternatively, the period of positioning performed 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 the upper layer to the lower layer of the terminal device 20. For example, the periodic information may be set from the application layer to the NAS (Non Access Stratum) or AS (Access Stratum) layer.

[0130] The notification of periodic information regarding positioning by the terminal device 20 from the base station 10 may be appropriately applied to the notification method of base station information of the base station 10. Alternatively, the base station 10 may include the periodic information regarding positioning in the base station information when notifying the terminal device 20. Another method is to appropriately apply the notification method of information instructing positioning by the terminal device 20 when notifying the terminal device 20 of periodic information from the base station 10. In this way, the terminal device 20 can periodically perform positioning.

[0131] The terminal device 20 may notify the base station 10 of the positioning results obtained by the terminal device 20. The terminal device 20 may include its own location information derived by the terminal device 20 as part of the positioning results. The terminal device 20 may use RRC signaling to notify the results. As a method for a terminal device 20 in the IDLE or INACTIVE state to transmit the positioning results obtained by the terminal device 20 to the base station 10, it may first transition to the CONNECTED state before notifying. By transitioning to the CONNECTED state, the terminal device 20 becomes capable of notifying the base station 10 using RRC signaling.

[0132] As an alternative method for a terminal device 20 in an IDLE or INACTIVE state to transmit its positioning result to the base station 10, the terminal device 20 may notify the base station 10 via RA (Random Access) processing. Alternatively, the terminal device 20 may notify the base station 10 as data on the control plane. For example, the terminal device 20 may include the positioning result in the RRC connection request. The terminal device 20 may also include information that the RRC connection request is a notification of a positioning result. The base station 10, having received 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 its positioning result without establishing an RRC connection. The terminal device 20 can notify the base station 10 of its positioning result at an early stage.

[0133] The base station 10 constitutes one or more cells. For example, the beam information may be beam information for each cell. The aforementioned base station 10 may also be a TRP. For example, the beam information may be beam information for each TRP.

[0134] In this embodiment, beam information was notified from the base station 10 to the terminal device 20. However, if the LMF is installed at another node, the node where the LMF is installed may notify the terminal device 20. In this case, base station information, etc., may be added and notified by the base station 10. Alternatively, the base station 10 may notify the node where the LMF is installed. By doing so, it becomes possible to have the terminal device 20 perform positioning from the LMF. The LMF may also be installed at the base station 10, in which case the method described above should be applied.

[0135] Embodiment 10. 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 when it is in the RRC_IDLE or RRC_INACTIVE state, and the second stage of positioning may be performed by the terminal device 20 when it is in the RRC_CONNECTED state. As another example, both the first and second stages of positioning may be performed by the terminal device 20 when it is 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, and the entity that determines which base station 10 is used for positioning may be different.

[0136] For example, in the first stage of positioning, SSB-based positioning may be performed for terminal devices 20 in the RRC_INACTIVE or RRC_IDLE state. Terminal devices 20 in the RRC_INACTIVE or RRC_IDLE state may decide for themselves which base station 10 to be used for positioning. For example, terminal device 20 may use a base station 10 that transmits SSB that can be received by its own terminal device as the base station 10 to be used for positioning.

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

[0138] LMF may notify terminal devices 20 in the RRC_INACTIVE or RRC_IDLE state that it will perform positioning using SSB. This notification may be made, for example, via base station 10. Eight pieces of information may be included in this notification. The first piece of information is information about the RRC state for receiving the positioning signal. The second piece of information is information about whether it is necessary to derive the position of the terminal device 20. 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 has been received. The sixth piece of information is information about the period during which the positioning signal is received. The seventh piece of information is information about the notification conditions to base station 10. The eighth piece of information is a combination of the first to seventh pieces of information. Terminal devices 20 may, for example, derive their position using at least one of the first to seventh pieces of information included in the notification. Alternatively, terminal devices 20 may, for example, derive their position using a combination of the first to seventh pieces of information.

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

[0140] The information included in the second piece of information may, for example, be information indicating that the position of the terminal device 20 should be derived. The terminal device 20 may derive its own position if the second piece of information includes information indicating that the position of the terminal device 20 should be derived. For example, the result of receiving 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 the RRC_CONNECTED state.

[0141] Another example of information included in the second piece of information is information indicating that the terminal device 20 will not perform position derivation. If the information included in the second piece of information includes information indicating that the terminal device 20 will not perform position derivation, the terminal device 20 may report the result of receiving the positioning signal to the base station 10. Notification of the report of the result of receiving the positioning signal by the terminal device 20 may be made when the terminal device 20 is in the RRC_CONNECTED state.

[0142] The information included in the third piece of information may be, for example, a 5G system, an LTE system, a GNSS, Wi-Fi®, Bluetooth®, or another system. The terminal device 20 may use the third piece of information to perform positioning or to receive positioning signals. 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 piece of information may be, for example, SSB, CSI-RS, DMRS, or signals used in other systems.

[0144] The information included in the fifth piece of information may be, for example, one instance or multiple instances. The terminal device 20 may perform a series of operations to receive the positioning signal the number of times included in the fifth piece of information. For example, by performing a series of operations to receive the 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 piece of information may be specified, for example, in milliseconds, in wireless frames, or using parameters that are pre-associated with a predetermined time. The terminal device 20 may use this information to periodically receive positioning signals. This makes it possible for the communication system to capture the position of the terminal device 20 even when the terminal device 20's position changes.

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

[0147] Another example of positioning in the IDLE or INACTIVE state may be the use of CSI-RS. Terminal device 20 may receive CSI-RS from multiple base stations 10, multiple panels, or TRPs. Terminal device 20 may maintain information regarding the reception time of the CSI-RS. This information may be, for example, the difference between the reception times of multiple CSI-RSs. Using CSI-RS enables positioning using, for example, narrow beams, thereby improving positioning accuracy. Base station 10 may notify terminal device 20 of settings related to CSI-RS. This notification from base station 10 to terminal device 20 may be made when terminal device 20 is in the RRC_CONNECTED state. The settings related to CSI-RS may include, for example, information about the base station 10, DU (Distributed Unit), TRP, and panel transmitting the CSI-RS, or information about the frequency, time, or code resource on which the CSI-RS is transmitted. Panel information includes, for example, the identifier of base station 10, the identifier of DU, the identifier of TRP, the panel identifier, and location information.

[0148] The terminal device 20 may use location information to derive its own location. This eliminates the need to transmit measurement results, such as the difference in PRS reception times, from the terminal device 20 to the base station 10. As a result, the amount of signaling between the base station 10 and the terminal device 20 can be reduced, and the resumption of communication between the terminal device 20 and the base station 10 can be eliminated. This enables rapid 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 the CSI-RS. The terminal device 20 may notify the base station 10 of information on the reception time of the CSI-RS. This notification may be included, for example, in the measurement result report from the terminal device 20 to the base station 10, or in a different signaling. The base station 10 may derive the location of the terminal device 20 using information on the reception time of the CSI-RS. This reduces, for example, the load on the terminal device 20 due to location derivation. Furthermore, similar to SSB, Embodiment 1 and Embodiment 2 may be used in combination. Embodiment 1 obtains angle information from a selected beam and performs positioning using distance information. Embodiment 2 calculates the RSTD from the reception time of reference signals transmitted from multiple transmitters and performs positioning. The average of the positions obtained from both methods may be calculated. Also, when performing positioning using multiple base stations 10, some base stations 10 may use the method described in Embodiment 1, and the other base stations 10 may use the method described in Embodiment 2.

[0149] In the second stage, positioning may be performed using CSI-RS. The LMF may use the positioning result of the terminal device 20 obtained in the first stage of positioning to determine the base station 10 to be used in the second stage of positioning. The base station 10 may transmit 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 result of receiving the CSI-RS. The base station 10 may use the result of receiving the CSI-RS 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 accuracy of positioning, for example.

[0150] This embodiment 10 makes it possible to improve the accuracy of positioning while also improving the flexibility of positioning. Furthermore, it makes it possible to improve the efficiency of the communication system.

[0151] The configurations shown in the above embodiments are merely examples of the content of the present invention, and can be combined with other known technologies. It is also possible to omit or modify parts of the configuration without departing from the spirit of the present invention. [Explanation of Symbols]

[0152] 1-4 Beams, 10, 10-1, 10-2 Base stations, 20 Terminal devices, 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 Receiving signal decoding unit, 106 Positioning processing unit, 200 Server, 400 Control circuit, 400a Processor, 400b Memory.

Claims

1. A communication unit that communicates wirelessly with the base station, Based on positioning radio resource control parameters relating to the positioning sounding reference signal received from the base station, a control unit that constitutes the positioning sounding reference signal, Equipped with, The communication unit transmits the positioning sounding reference signal on the uplink and receives related information from the base station indicating the association between the positioning sounding reference signal on the uplink and the control signal on the downlink. A user device characterized by the following features.

2. The aforementioned related information is spatial information relating to the spatial relationship between the positioning sounding reference signal and the control signal. The user device according to feature 1.

3. The communication unit receives transmission / reception point information from the base station, which functions as a transmission / reception point, including at least one of the information regarding the location of the transmission / reception point and the information regarding the beam of the transmission / reception point. The user device according to feature 1.

4. The pseudo-collocation state of the positioning reference signal and synchronization signal blocks is set. The user device according to feature 1.

5. The communication unit transmits the positioning sounding reference signal, which is received by the base station and whose received power is measured. The positioning measurement information relating to the received power of the positioning sounding reference signal is reported from the base station to the position management function. The user device according to feature 1.

6. The received power of the positioning sounding reference signal is the reference signal received power of the positioning sounding reference signal. The user device according to feature 5.

7. A communication unit that communicates wirelessly with the user device, A control unit that configures positioning radio resource control parameters related to the positioning sounding reference signal, Equipped with, The communication unit transmits the positioning wireless resource control parameters to the user device, receives the positioning sounding reference signal transmitted from the user device, and transmits relevant information indicating the association between the positioning sounding reference signal in the uplink and the control signal in the downlink to the user device. A base station characterized by the following features.

8. User equipment and A base station that communicates wirelessly with the user device, A communication system comprising, The base station transmits positioning radio resource control parameters relating to the positioning sounding reference signal to the user device. The user device transmits the positioning sounding reference signal configured based on the positioning radio resource control parameters on the uplink. The base station transmits relevant information indicating the association between the positioning sounding reference signal on the uplink and the control signal on the downlink to the user device. A communication system characterized by the following features.

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