Base station device, control method, and program for estimating the location of terminal devices.
By employing a random access preamble with extended guard time and optimized transmission parameters, the method addresses the issue of inaccurate RAN-based position estimation, achieving precise location determination of terminal devices.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- KDDI CORP
- Filing Date
- 2022-09-20
- Publication Date
- 2026-07-29
AI Technical Summary
In RAN-based position estimation methods, the orthogonality between subcarriers is compromised due to timing deviations in wireless signals from terminal devices, leading to inaccurate reception and estimation of the terminal device's position, especially when the device is close to one base station and far from others.
Utilizing a random access preamble (RA preamble) with a longer guard time than conventional signals, and specifying the sequence and transmission parameters to ensure accurate reception by multiple base stations, including adjusting transmission power and resources to enhance measurement accuracy.
Enables high-precision location estimation of terminal devices by ensuring accurate reception and measurement of wireless signals across multiple base stations, even with significant distance variations.
Smart Images
Figure 0007897094000001 
Figure 0007897094000002 
Figure 0007897094000003
Abstract
Description
Technical Field
[0003] , ,
[0001] The present invention relates to a position estimation technique for a terminal device.
Background Art
[0002] In a wireless communication system, by specifying the position of a terminal device, a communication service corresponding to that position can be provided to the terminal device. The terminal device can, for example, specify its own position by measuring radio waves transmitted from artificial satellites using a Global Navigation Satellite System (GNSS), and notify the network of that information via a base station device. On the other hand, there may be cases where the terminal device cannot use GNSS-based positioning or has disabled the GNSS-based positioning function. In such cases, for example, a Radio Access Network (RAN)-based position estimation method can be used, in which a plurality of base station devices measure a wireless signal transmitted from the terminal device and estimate the position of the terminal device based on the difference in the timing (propagation time) at which the radio waves arrive or the direction of arrival.
Summary of the Invention
Problems to be Solved by the Invention
[0003] In the RAN-based position estimation method, it may be necessary for the base station device to accurately receive the wireless signal transmitted by the terminal device. In this case, for example, in an Orthogonal Frequency Division Multiplexing (OFDM)-based cellular communication system, the orthogonality between subcarriers is not ensured due to a large deviation in the reception timing of the wireless signal transmitted from the terminal device from the assumption, and the wireless signal cannot be accurately received. On the other hand, it can be assumed that the terminal device exists at a position close to a part of the base station device that it measures and at a position far from another part. In such a case, if the terminal device transmits a wireless signal at a timing adjusted to any of those base station devices, that base station device can accurately receive the wireless signal, but the other base station devices cannot accurately receive the wireless signal. For this reason, the position of the terminal device cannot be accurately estimated. [Means for solving the problem]
[0004] This invention provides a technology that enables high-precision estimation of the location based on wireless signals transmitted by a terminal device.
[0005] A base station device according to one aspect of the present invention includes: notification means for notifying other base station devices of an instruction to measure the random access preamble transmitted by a terminal device for positioning of the terminal device, and information indicating the sequence used to transmit the random access preamble; instruction means for instructing the terminal device to transmit the random access preamble by specifying the sequence; and measurement means for measuring the random access preamble transmitted by the terminal device using the sequence for positioning of the terminal device, wherein the position of the terminal device is estimated based on the results of the measurement of the random access preamble at the base station device and the other base station devices.
[0006] A base station device according to another aspect of the present invention includes receiving means for receiving information from another base station device indicating an instruction to measure a random access preamble transmitted by a terminal device for positioning of the terminal device, and a sequence used for transmitting the random access preamble; and measuring means for measuring the random access preamble transmitted by the terminal device for positioning of the terminal device using the sequence in response to receiving the instruction, wherein the position of the terminal device is estimated based on the results of the measurement of the random access preamble at the base station device and the other base station device. [Effects of the Invention]
[0007] According to the present invention, it is possible to estimate the position based on the wireless signal transmitted by the terminal device with high accuracy. [Brief explanation of the drawing]
[0008] [Figure 1]This is a diagram showing an example configuration of a wireless communication system. [Figure 2] This figure shows an example of the device's hardware configuration. [Figure 3] This figure shows an example of the functional configuration of a base station device connected to a terminal device. [Figure 4] This figure shows an example of the functional configuration of a base station device that is not connected to a terminal device. [Figure 5] This figure shows an example of the functional configuration of a terminal device. [Figure 6] This diagram shows an example of the processing flow performed in a wireless communication system. [Modes for carrying out the invention]
[0009] The embodiments will be described in detail below with reference to the attached drawings. Note that the following embodiments do not limit the invention as defined in the claims, and not all combinations of features described in the embodiments are essential to the invention. Two or more of the features described in the embodiments may be combined in any way. Furthermore, identical or similar configurations will be given the same reference numeral, and redundant descriptions will be omitted.
[0010] The embodiments will be described in detail below with reference to the attached drawings. Note that the following embodiments do not limit the invention as defined in the claims, and not all combinations of features described in the embodiments are essential to the invention. Two or more of the features described in the embodiments may be combined in any way. Furthermore, identical or similar configurations will be given the same reference numeral, and redundant descriptions will be omitted.
[0011] (System Configuration) Figure 1 shows an example of the configuration of a wireless communication system according to this embodiment. The wireless communication system may be a cellular communication system comprising, for example, base station devices 101 to 103 and a terminal device 111. The terminal device 111 can receive wireless communication services by connecting to any of the base station devices 101 to 103. The cellular communication system is configured according to existing standards such as Long-Term Evolution (LTE) or fifth-generation (5G), or their successor standards. Furthermore, the base station devices 101 to 103 are assumed to have established time synchronization with each other by adjusting their time based on, for example, the Global Positioning System (GPS) radio waves, and their frame timings are assumed to be in sync.
[0012] In this embodiment, base station devices 101 to 103 measure the radio signal transmitted by terminal device 111, and the position of terminal device 111 is estimated based on the measurement results. Base station devices 101 to 103 measure, for example, the direction of arrival and the timing of arrival of the radio signal. Then, base station devices 101 to 103 notify the device that performs position estimation of the measurement results. The device that performs position estimation may be included in any of base station devices 101 to 103, or it may be provided as a separate device from base station devices 101 to 103. Position estimation can be performed, for example, by conventional techniques based on the direction of arrival and the difference in arrival time at three or more base station devices.
[0013] For base station devices 101 to 103 to accurately receive radio signals from terminal device 111, the timing of the reception of those radio signals must be within a certain range of the timing of the subframes in base station devices 101 to 103. In other words, in orthogonal frequency division multiplexing (OFDM) based systems, signals with cyclic prefixes (CPs) added to OFDM symbols are transmitted to absorb the effects of delayed waves, but radio signals that arrive beyond the length of the CP cannot be accurately received.
[0014] The terminal device 111 adjusts the transmission timing of the radio signal using a timing advance (TA) value instructed by the base station device 101, for example, so that the radio signal is received at the beginning of the subframe at the connected base station device 101. The radio signal transmitted at this timing reaches the base station device 101 at a time when it can be received accurately, while it reaches base station devices 102 and 103 with a delay depending on the distance. Here, for example, as shown in Figure 1, if the position of the terminal device 111 is very close to the base station device 101, the distance between the terminal device 111 and the base station devices 102 and 103 is very short compared to the distance between the terminal device 111 and the base station devices 102 and 103, the timing at which the radio signal reaches base station devices 102 and 103 may be significantly delayed. If the magnitude of this delay exceeds the length of the CP, base station devices 102 and 103 will not be able to receive the radio signal accurately. For example, the sounding reference signal (SRS) transmitted by the terminal device 111 has a CP length of 2.34 microseconds when the subcarrier spacing (SCS) is 30 kHz. According to the length of this CP, if the difference between the distance between terminal device 111 and base station device 101 and the distance between terminal device 111 and base station devices 102 or 103 exceeds 700 meters, the magnitude of the delay will exceed the length of the CP. Therefore, when estimating the position of terminal device 111 using SRS in situations with such a distance difference, the estimation accuracy deteriorates.
[0015] In this embodiment, in view of these circumstances, positioning is made possible using a random access preamble (hereinafter sometimes referred to as "RA preamble") which has a longer guard time compared to the length of CPs such as SRS. By using an RA preamble, even when there is a large difference between the distance between the terminal device 111 and the base station device 101 and the distance between the terminal device 111 and base station devices 102 and 103, the position of the terminal device 111 can be accurately estimated. However, when using an RA preamble, it is assumed that base station devices 101 to 103 cannot determine whether or not the RA preamble was transmitted by the terminal device 111. For this reason, in this embodiment, a non-contention-based RA preamble used during handover is reused. That is, in this embodiment, just as identification information (ID) specifying the series of RA preambles is notified from the handover source base station device to the terminal device and the handover destination base station device during handover, the same ID is notified from the connected base station device. For example, base station device 101 notifies the connected terminal device 111 and base station devices 102 and 103, which are involved in measurements for estimating the location of terminal device 111, of information such as an ID that can identify the sequence of RA preambles. The base station devices involved in measurements for estimating the location of terminal device 111 may be, for example, base station devices adjacent to base station device 101 that forms the cell in which terminal device 111 is located. That is, for example, base station device 101 may identify the base station devices that form the cell to be included in the adjacent cell list as base station devices involved in estimating the location of terminal device 111, and notify them of information for measuring the RA preamble.
[0016] Furthermore, base station device 101 can notify base station devices involved in position estimation of terminal device 111 that an RA preamble will be transmitted for position estimation. That is, base station devices involved in position estimation of terminal device 111 can be notified that an RA preamble will be transmitted for position estimation, not for normal handover, and that measurements for positioning, such as the direction and timing of arrival of the RA preamble, should be taken. In addition to the information that can identify the sequence of RA preambles as described above, base station device 101 can also notify base station devices involved in position estimation of terminal device 111 of information such as the resource on which the RA preamble is transmitted and the transmission timing. That is, since terminal device 111 does not transmit an RA preamble for handover, it can transmit the RA preamble using a different resource than the RA preamble resource used by the base station devices involved in position estimation of terminal device 111. Therefore, the base station device 101 can specify the resource to which the RA preamble will be transmitted (for example, the base station device 101's own resource for RA preambles or a separately prepared dedicated resource), instruct the terminal device 111 to transmit the RA preamble, and can also notify the base station device involved in the terminal device 111's position estimation of that resource.
[0017] Instructions from base station device 101 to terminal device 111 are transmitted via radio resource control (RRC) messages, and information provision from base station device 101 to base station devices 102 and 103 can be performed using interfaces that enable communication between base station devices, such as the Xn interface or NG interface.
[0018] Subsequently, terminal device 111 generates an RA preamble using the sequence corresponding to the instructed ID and transmits the RA preamble at the specified resource. Then, not only base station device 101, but also base station devices 102 and 103 perform measurements for position estimation, such as the direction and timing of arrival of the RA preamble. Then, base station devices 101 to 103 notify the device that performs position estimation of terminal device 111 of the measurement results. With this, the guard time is sufficiently long compared to the length of the CP such as SRS, so that even if there is a large difference between the distance between terminal device 111 and base station device 101 and the distance between terminal device 111 and base station device 102 or base station device 103, base station devices 102 and 103 can accurately receive the radio signal from terminal device 111. And by accurately receiving the radio signal, the accuracy of position estimation of terminal device 111 can be improved.
[0019] Furthermore, if terminal device 111 transmits an RA preamble with the same transmission power used when transmitting a signal to base station device 101, it is conceivable that base station devices 102 and 103 may not be able to receive the RA preamble with sufficient power. For this reason, base station device 101 may instruct terminal device 111 to transmit the RA preamble with sufficient power so that base station devices 102 and 103 can receive the RA preamble with sufficient power. For example, base station device 101 may instruct terminal device 111 to transmit an RA preamble for position estimation with maximum transmission power. This ensures that surrounding base station devices involved in position estimation of terminal device 111 can reliably detect the RA preamble. Also, base station device 101 may, for example, instruct terminal device 111 to measure the radio quality of radio signals transmitted from surrounding base station devices and obtain the measurement results. For example, base station device 101 may instruct terminal device 111 to transmit a Measurement Report (MR). The base station device 101 transmits this instruction to the terminal device 111, for example, by an RRC message. The base station device 101 may also set up an event A4 that triggers the transmission of MR, for example, when the radio quality of an adjacent cell exceeds a predetermined threshold. The radio quality used here may be a value that can identify propagation loss, such as the reference signal received power (RSRP). However, this is just an example, and any radio quality that can determine the transmit power may be used.
[0020] When the base station device 101 receives the MR, based on the value, it can determine the transmission power to be used by the terminal device 111 and instruct the terminal device 111 to transmit the RA preamble using the determined transmission power. Thereby, the RA preamble transmitted by the terminal device 111 can reach the base station device that should measure the RA preamble with sufficient power. Also, the base station device 101 may notify the terminal device 111 of information specifying the number of ramp-up times of the transmission power so that it can reach the base station device that should measure the RA preamble with sufficient power. For example, when the transmission power increases by a predetermined power in one ramp-up, the base station device 101 can determine the number of ramp-up times by dividing the value obtained by subtracting the current transmission power from the target transmission power by the predetermined power. Note that the information specifying the transmission power and the information specifying the number of ramp-up times can be newly defined as information elements in the RRC message instructing the transmission of the RA preamble. For example, information such as "preambleTransPowerForPositioning" can be defined as information specifying the transmission power of the RA preamble for position estimation. Also, information such as "preambleTransRampNum" may be defined as information specifying the number of ramp-up times of the RA preamble. Note that conventionally, "preambleTransMax" has already been defined as the maximum value of the number of ramp-up times, but information such as "preambleTransRampNum" can be defined as a different value.
[0021] As described above, by using the RA preamble as a radio signal for position estimation from the terminal device 111 and further specifying the transmission power as necessary, the base station devices existing around the terminal device 111 can accurately receive the radio signal. As a result, those base station devices can accurately identify the arrival direction and arrival timing of the radio signal transmitted from the terminal device 111, and can accurately estimate the position of the terminal device 111.
[0022] (Device Configuration) FIG. 2 is a diagram showing an example of the hardware configuration of a base station device and a terminal device. In one example, the base station device and the terminal device are configured to include a processor 201, a ROM 202, a RAM 203, a storage device 204, and a communication circuit 205. The processor 201 is a computer including one or more processing circuits such as a general-purpose CPU (Central Processing Unit) or an ASIC (Application Specific Integrated Circuit), and reads and executes programs stored in the ROM 202 and the storage device 204 to execute the overall processing of the device and each of the above-described processes. The ROM 202 is a read-only memory that stores information such as programs and various parameters related to the processes executed by the base station device and the terminal device, respectively. The RAM 203 functions as a workspace when the processor 201 executes a program and is a random access memory that stores temporary information. The storage device 204 is configured by, for example, a detachable external storage device or the like. The communication circuit 205 is configured by, for example, a circuit for wireless communication conforming to a cellular communication standard of LTE, 5G, or a later-generation standard. In FIG. 2, one communication circuit 205 is illustrated, but the base station device and the terminal device may have a plurality of communication circuits. For example, the base station device and the terminal device may have a plurality of wireless communication circuits and antennas for LTE, 5G, a successor standard, and the like, respectively. Further, the base station device may have, for example, a communication circuit 205 for wired or wireless communication with another base station device, and the terminal device may have a communication circuit 205 conforming to a wireless communication standard other than a cellular communication standard such as a wireless LAN or Bluetooth (registered trademark).
[0023] Figure 3 shows an example of the functional configuration of a base station device (e.g., base station device 101) connected to a terminal device. Note that this base station device may also have the functions shown in Figure 4, described later, if it performs measurements for estimating the location of a terminal device connected to another base station device. The base station device includes, for example, a measurement information notification unit 301, an instruction unit 302, a setting determination unit 303, and a measurement unit 304. Furthermore, the base station device may have a location estimation unit 305 if it performs a process to estimate the location of a terminal device. These functional units may be implemented, for example, by a processor 201 executing a program stored in a ROM 202 or a storage device 204. However, it is not limited to this, and for example, some or all of these functional units may be implemented using dedicated hardware. Note that Figure 3 only shows functions relevant to this embodiment for simplicity of explanation, and the base station device may naturally have functions as a base station device compliant with, for example, LTE, 5G, or its successor standards. Since the processing that the base station equipment connected to the terminal equipment should perform has been described above as the processing of base station equipment 101, only a general overview of the functional configuration will be given here.
[0024] The measurement information notification unit 301 notifies other base station devices not connected to the terminal device that it should perform measurement of the RA preamble to estimate the terminal device's location, an ID indicating the sequence of the RA preamble, and information indicating the resource to which the RA preamble will be transmitted. The instruction unit 302 sends information to the terminal device instructing it to transmit the RA preamble for location estimation, along with an ID indicating the sequence to be used and information indicating the resource.
[0025] The configuration determination unit 303 determines the settings that the terminal device should use when transmitting the RA preamble. For example, the configuration determination unit 303 selects a sequence of RA preambles from among the sequences available for use in a Non-Contention-based random access procedure. A sequence used for position estimation may be provided as a sequence that is not used in the case of handover. In this case, the measurement information notification unit 301 implicitly notifies that the terminal device should perform a measurement of the RA preamble for position estimation by notifying an ID that specifies the sequence used for position estimation. That is, the measurement information notification unit 301 does not need to explicitly notify that the terminal device should perform a measurement of the RA preamble for position estimation. The configuration determination unit 303 can also determine the resources required to transmit the RA preamble. Furthermore, the configuration determination unit 303 may determine the transmission power and ramp-up count that the terminal device should use when transmitting the RA preamble for position estimation. In one example, the configuration determination unit 303 may send a message or set an event to the terminal device to transmit the MR. The setting determination unit 303 receives measurement results of the radio quality of signals from surrounding base station devices from the terminal device and may determine the transmission power and the number of ramp-up cycles based on these measurement results. The setting determination unit 303 may also decide that the RA preamble should be transmitted at the terminal device's maximum transmission power. The settings determined by the setting determination unit 303 are notified to other base station devices and terminal devices by the measurement information notification unit 301 and the instruction unit 302.
[0026] The measurement unit 304 measures the RA preamble for terminal device location estimation transmitted from the terminal device, based on the measurement settings determined by the setting determination unit 303. For example, the measurement unit 304 identifies the RA preamble sequence corresponding to the aforementioned ID as the RA preamble transmitted from the terminal device and identifies its direction of arrival and arrival timing. The location estimation unit 305 estimates the location of the terminal device based on the direction of arrival and arrival timing identified by the measurement unit 304 and information indicating the direction of arrival and arrival timing received from other base station devices. If location estimation processing is performed in another device, the measurement unit 304 notifies that device of the identified direction of arrival and arrival timing. In this case, the location estimation unit 305 may be omitted.
[0027] Figure 4 shows an example of the functional configuration of a base station device (e.g., base station device 102 and base station device 103) that performs measurements for estimating the location of an unconnected terminal device. Note that this base station device may also have the functions shown in Figure 3 above when, for example, it performs measurements for estimating the location of a terminal device connected to itself. The base station device includes, for example, a measurement information receiving unit 401, a measurement unit 402, and a measurement result notification unit 403. Although not illustrated, the base station device may also have a function equivalent to the location estimation unit 305 above when, for example, it performs processing to estimate the location of a terminal device. These functional units can be implemented, for example, by the processor 201 executing a program stored in the ROM 202 or storage device 204. However, it is not limited to this, and for example, some or all of these functional units may be implemented using dedicated hardware. Note that Figure 4 only shows functions relevant to this embodiment for simplicity of explanation, and the base station device may naturally have functions as a base station device compliant with, for example, LTE, 5G, or its successor standards. Since the processing performed by the base station device to estimate the location of an unconnected terminal device has already been described as the processing of base station device 102 and base station device 103, only a general overview of the functional configuration will be given here.
[0028] The measurement information receiving unit 401 receives information from the base station equipment to which the terminal equipment is connected, for receiving the RA preamble transmitted from the terminal equipment for position estimation of the terminal equipment. The measurement information receiving unit 401 receives from other base station equipment connected to the terminal equipment that it should perform measurement of the RA preamble for position estimation of the terminal equipment, an ID indicating the sequence of the RA preamble, and information indicating the resource to which the RA preamble is transmitted. The measurement unit 402 measures the RA preamble for position estimation of the terminal equipment transmitted from the terminal equipment, based on the measurement information received by the measurement information receiving unit 401. For example, the measurement unit 402 identifies the sequence of RA preambles corresponding to the above-mentioned ID as the RA preamble transmitted from the terminal equipment, and identifies its direction of arrival and timing of arrival. The measurement result notification unit 403 notifies the equipment performing position estimation of the information indicating the direction of arrival and timing of arrival measured by the measurement unit 402. Furthermore, if the device has a function corresponding to the position estimation unit 305 described above, that function can be used to obtain information on the direction and timing of arrival of the RA preamble from other base station devices, thereby estimating the position of the terminal device.
[0029] Figure 5 shows an example of the functional configuration of a terminal device (for example, terminal device 111). The terminal device includes, for example, a setting information receiving unit 501 and a preamble transmitting unit 502. These functional units can be implemented, for example, by a processor 201 executing a program stored in a ROM 202 or a storage device 204. However, it is not limited to this, and for example, some or all of these functional units may be implemented using dedicated hardware. Note that for the sake of simplicity, Figure 5 shows only the functions related to this embodiment, and the terminal device can naturally have functions as a terminal device compliant with, for example, LTE, 5G, or a successor standard. Since the processing of the terminal device has been described above as the processing of terminal device 111, only a general overview of the functional configuration will be given here.
[0030] The configuration information receiving unit 501 receives information from the connected base station device instructing it to transmit an RA preamble for position estimation, along with an ID indicating the sequence to be used and information indicating the resource. The configuration information receiving unit 501 may also receive information indicating the transmission power from the connected base station device. The preamble transmission unit 502 generates and transmits an RA preamble based on the information received by the configuration information receiving unit 501. That is, the preamble transmission unit 502 generates an RA preamble using the sequence corresponding to the notified ID and transmits the RA preamble at the specified resource. Furthermore, if a transmission power is specified, the preamble transmission unit 502 may transmit the RA preamble at that specified transmission power. As is typical for a terminal device, it naturally has the function of measuring the radio quality of radio signals transmitted from surrounding base station devices and the function of transmitting an MR containing the measurement results to the connected base station device.
[0031] (Process flow) Next, an example of the processing flow performed in a wireless communication system will be explained using Figure 6. Here, we assume that in a wireless communication system as shown in Figure 1, the terminal device 111 is connected to the base station device 101 (S601). In this state, the base station device 101 decides to perform position estimation of the terminal device 111, for example, in response to instructions from the network or when the time for position estimation to be performed at predetermined time intervals has been reached. In this case, the base station device 101 decides the transmission settings for the RA preamble for position estimation of the terminal device 111 (S604). The base station device 101 decides, for example, the sequence that the terminal device 111 should use to generate the RA preamble and the resources that should be used when transmitting the RA preamble. The base station device 101 may also decide on settings regarding the transmission power of the RA preamble. As an example, the base station device 101 may decide, for example, that the RA preamble should be transmitted at maximum transmission power. Furthermore, the base station device 101 may determine the transmission power and the number of ramp-ups depending on the radio quality (propagation loss) between the terminal device 111 and base station devices 102 or 103. In this case, the base station device 101 may, for example, instruct the transmission of the MR or notify the terminal device 111 of the setting of an event for the transmission of the MR (S602). Then, the base station device 101 receives the MR from the terminal device 111 (S603) and may determine the transmission power and the number of ramp-ups to be used for transmitting the RA preamble based on the radio quality measurement results.
[0032] Base station device 101 notifies base station devices 102 and 103 of configuration information including an ID indicating the sequence of RA preambles to be transmitted by terminal device 111, and information on the frequency and time resources on which the RA preambles will be transmitted (S605). This configuration information may also include information indicating that the RA preambles should be measured for the location estimation of terminal device 111. If a sequence ID usable only for RA preambles for location estimation is available, the notification of this sequence ID as the ID of the RA preamble sequence may implicitly indicate that the RA preambles should be measured for the location estimation of terminal device 111. Furthermore, base station device 101 notifies terminal device 111 of information instructing it to transmit an RA preamble for location estimation of terminal device 111 (S606). At this time, the base station device 101 may notify the terminal device 111 of the ID corresponding to the sequence that the terminal device 111 should use to generate the RA preamble, as well as information on the frequency and time resources to which the RA preamble should be transmitted. The base station device 101 may also notify the terminal device 111 of information regarding the transmission power of the RA preamble.
[0033] In response to receiving the instruction in S606, terminal device 111 generates an RA preamble using a sequence corresponding to the specified ID and transmits the RA preamble at the specified frequency and time resources (S607). Then, base station device 101 measures the direction and timing of arrival of the RA preamble transmitted from terminal device 111 using the settings determined in S604 (S608). Base station devices 102 and 103 also measure the direction and timing of arrival of the RA preamble transmitted from terminal device 111 based on the setting information received in S605 (S608). Subsequently, the direction and timing of arrival measured by base station devices 101 to 103 are provided to a device that performs position estimation processing for terminal device 111, such as base station device 101, and the position of terminal device 111 is estimated by that device (not shown).
[0034] As described above, base station equipment surrounding the terminal device 111 can accurately determine the direction and timing of arrival of the radio signal transmitted from the terminal device 111, and thus accurately estimate the position of the terminal device 111. Therefore, it becomes possible to contribute to Goal 9 of the United Nations-led Sustainable Development Goals (SDGs), "Build resilient infrastructure, promote sustainable industrialization and foster innovation."
[0035] The invention is not limited to the embodiments described above, and various modifications and changes are possible within the scope of the gist of the invention.
Claims
1. Base station equipment, A notification means for notifying other base station devices of an instruction to measure the random access preamble transmitted by the terminal device for positioning purposes, and information indicating the sequence used to transmit the random access preamble; An instruction means for instructing the terminal device to transmit the random access preamble, specifying the series, For positioning of the terminal device, a measurement means for measuring the random access preamble transmitted by the terminal device using the sequence, It has, Based on the measurement results of the random access preamble in the aforementioned base station device and the other base station devices, the location of the terminal device is estimated. A base station device characterized by the following features.
2. The base station device according to claim 1, further comprising the instruction means transmitting an instruction to the terminal device for the transmission power to transmit the random access preamble.
3. The base station device according to claim 2, characterized in that the instruction for the transmission power is an instruction to transmit the random access preamble with the maximum transmission power of the terminal device.
4. The terminal device further has means for acquiring measurement results of the radio quality of signals from other base station devices, The base station device according to claim 2, characterized in that the instruction for the transmission power is an instruction to transmit the random access preamble with power based on the propagation loss corresponding to the radio quality.
5. The terminal device further has means for acquiring measurement results of the radio quality of signals from other base station devices, The base station device according to claim 2, characterized in that the instruction for the transmission power is an instruction indicating the number of times the transmission power is ramped up based on the propagation loss corresponding to the radio quality.
6. An acquisition means for acquiring the measurement results of the random access preamble in the other base station device, Estimation means for estimating the location of the terminal device based on the measurement results of the random access preamble in the base station device and the other base station device, The base station device according to claim 1, further comprising the above.
7. Base station equipment, A receiving means that receives information from another base station device indicating that the random access preamble transmitted by the terminal device for positioning of the terminal device should be measured, and the sequence used to transmit the random access preamble. In response to receiving the aforementioned instruction, a measuring means measures the random access preamble transmitted by the terminal device for positioning the terminal device using the aforementioned sequence, It has, Based on the measurement results of the random access preamble in the aforementioned base station device and the other base station devices, the location of the terminal device is estimated. A base station device characterized by the following features.
8. An acquisition means for acquiring the measurement results of the random access preamble in the other base station device, Estimation means for estimating the location of the terminal device based on the measurement results of the random access preamble in the base station device and the other base station device, The base station device according to claim 7, further comprising the above.
9. A control method performed by a base station device, To notify other base station equipment of an instruction to measure the random access preamble transmitted by the terminal device for positioning purposes, and information indicating the sequence used to transmit the random access preamble, The terminal device is instructed to transmit the random access preamble, specifying the series. For positioning of the terminal device, the random access preamble transmitted by the terminal device is measured using the sequence, Includes, Based on the measurement results of the random access preamble in the aforementioned base station device and the other base station devices, the location of the terminal device is estimated. A control method characterized by the following:
10. A control method performed by a base station device, Receiving instructions from other base station equipment to measure the random access preamble transmitted by the terminal device for positioning purposes, and information indicating the sequence used to transmit the random access preamble, In response to receiving the aforementioned instruction, the random access preamble transmitted by the terminal device is measured using the aforementioned sequence for positioning of the terminal device, Includes, Based on the measurement results of the random access preamble in the aforementioned base station device and the other base station devices, the location of the terminal device is estimated. A control method characterized by the following:
11. The computer installed in the base station equipment, The system notifies other base station devices of an instruction to measure the random access preamble transmitted by the terminal device for positioning purposes, and information indicating the sequence used to transmit the random access preamble. The terminal device is instructed to transmit the random access preamble, specifying the series. In order to determine the position of the terminal device, the random access preamble transmitted by the terminal device is measured using the sequence. It is a program for that purpose, Based on the measurement results of the random access preamble in the aforementioned base station device and the other base station devices, the location of the terminal device is estimated. A program characterized by the following features.
12. The computer installed in the base station equipment, The system receives instructions from other base station equipment to measure the random access preamble transmitted by the terminal device for positioning purposes, and information indicating the sequence used to transmit the random access preamble. In response to receiving the aforementioned instruction, the sequence is used to measure the random access preamble transmitted by the terminal device for positioning the terminal device. It is a program for that purpose, Based on the measurement results of the random access preamble in the aforementioned base station device and the other base station devices, the location of the terminal device is estimated. A program characterized by the following features.