Indoor positioning method, indoor positioning system, indoor positioning device and medium

Abstract

The invention discloses an indoor positioning method, an indoor positioning system, an indoor positioning device and a medium. The method comprises the following steps: acquiring a plurality of sounding reference signals uploaded by at least one radio frequency unit; the sounding reference signal is a signal sent by the terminal; grouping the plurality of sounding reference signals according to the time domain information in each sounding reference signal to obtain a plurality of groups of sounding reference signals; the time domain information in the same group of sounding reference signals is the same; determining a target IMSI (International Mobile Subscriber Identity) corresponding to the target time domain information by utilizing a one-to-one correspondence mapping relationship between the time domain information and the IMSI of the terminal; the target time domain information is any one of multiple pieces of time domain information; determining a target sounding reference signal with the highest signal strength in a group of sounding reference signals corresponding to the target time domain information; determining position information of equipment corresponding to an equipment mark according to the equipment mark in the target detection reference signal; and taking the position information as the position information of a terminal corresponding to the target IMSI.

Description

Technical Field

[0001] The present application relates to the field of indoor positioning technology, and in particular to an indoor positioning method, indoor positioning system, device and medium. Background Art

[0002] Indoor positioning technology is an important research area in the field of 5G network technology. Current indoor positioning technologies mostly rely on outdoor positioning systems such as GPS. However, in indoor environments, GPS signals are often blocked by buildings, making it impossible to provide accurate positioning services. Summary of the Invention

[0003] Based on the above problems, the present application provides an indoor positioning method to improve the accuracy of indoor positioning.

[0004] In a first aspect, the present application provides an indoor positioning method, the method comprising:

[0005] Acquire multiple sounding reference signals uploaded by at least one radio frequency unit; the sounding reference signals are signals sent by the terminal;

[0006] Grouping the plurality of sounding reference signals according to the time domain information in each of the sounding reference signals to obtain a plurality of groups of sounding reference signals; the time domain information in the same group of sounding reference signals is the same;

[0007] Determining a target IMSI corresponding to the target time domain information by using a one-to-one mapping relationship between the time domain information and the international mobile subscriber identity (IMSI) of the terminal; the target time domain information is any one of the multiple time domain information;

[0008] Determine a target detection reference signal with the highest signal strength among a group of detection reference signals corresponding to the target time domain information;

[0009] Determining, based on the device tag in the target detection reference signal, the location information of the device corresponding to the device tag;

[0010] The location information is used as the location information of the terminal corresponding to the target IMSI.

[0011] In a possible implementation, the radio frequency unit includes multiple radio frequency antennas; the multiple radio frequency antennas of the radio frequency unit are arranged at different positions;

[0012] The determining, according to the device tag in the target detection reference signal, the location information of the device corresponding to the device tag includes:

[0013] parsing the target detection reference signal to determine the device tag;

[0014] Determining a target radio frequency unit and a target radio frequency antenna according to the device tag; the target radio frequency antenna is an antenna in the target radio frequency unit that receives the target detection reference signal;

[0015] Determine the location information of the target radio frequency antenna.

[0016] In a possible implementation, the receiving multiple sounding reference signals uploaded by at least one radio frequency unit includes:

[0017] Receive multiple sounding reference signals sent by a hub HUB; the HUB is used to receive at least one sounding reference signal uploaded by each radio frequency unit.

[0018] In a possible implementation, the method further includes:

[0019] When the terminal connects to or switches networks, obtaining the IMSI of the terminal through the International Mobile Station Equipment Identity and Software Version Number IMEISV field in the application protocol NGAP message;

[0020] Configuring unique time domain information for the terminal at a media access control (MAC) layer, and establishing a correspondence between the time domain information and the IMSI of the terminal at a radio resource control (RRC) layer;

[0021] An RRC reconfiguration message is sent to the terminal through the radio frequency unit, where the RRC reconfiguration message includes the IMSI of the terminal and time domain information allocated to the terminal.

[0022] In a possible implementation, configuring unique time domain information for the terminal at a media access control (MAC) layer includes:

[0023] A target subframe number is selected from a plurality of subframe numbers at the MAC layer; a target time slot number is selected from a plurality of time slot numbers corresponding to the target subframe number; an unoccupied number of symbols is selected as a target number of symbols from a plurality of symbol numbers corresponding to the target time slot number; and the target subframe number, the target time slot number, and the number of symbols are used as time domain information of the terminal.

[0024] In a possible implementation, obtaining multiple sounding reference signals uploaded by at least one radio frequency unit includes:

[0025] A management plane message is received by packaging each of the sounding reference signals through a management plane; the management plane message includes a subframe number, a time slot number, a symbol number, a radio frequency unit number, a radio frequency antenna number, and a signal strength.

[0026] In a possible implementation, the method further includes:

[0027] After the radio frequency unit and the radio frequency antenna are set up indoors, position information of the radio frequency unit and the radio frequency antenna indoors is acquired and recorded.

[0028] In a second aspect, the present application provides an indoor positioning system, comprising a hub, a baseband processing unit, and at least one radio frequency unit; the hub is connected to the baseband processing unit and at least one radio frequency unit respectively;

[0029] The radio frequency unit is configured to receive a sounding reference signal sent by a terminal and upload the sounding reference signal to the hub;

[0030] The hub is configured to receive the sounding reference signal uploaded by the radio frequency unit and forward a plurality of the sounding reference signals to the baseband processing unit;

[0031] The baseband processing unit is used to execute the indoor positioning method according to any one of claims 1 to 7.

[0032] In a third aspect, the present application provides a control device comprising a processor and a memory, wherein the memory is used to store programs, instructions or codes, and the processor is used to execute the programs, instructions or codes in the memory to complete the indoor positioning method as described in any one of the first aspects.

[0033] In a fourth aspect, the present application provides a computer-readable storage medium storing a computer program, wherein the computer program is loaded by a processor to execute the indoor positioning method as described in any one of the first aspects.

[0034] The indoor positioning method provided by this application can rely on the SRS signal emitted by the terminal itself, achieve accurate association of the terminal by grouping the time domain information and binding it with the IMSI, and accurately lock the terminal position by combining the signal strength screening. The entire process is efficient and does not require additional positioning equipment, and can stably achieve terminal positioning in indoor environments. The indoor positioning method provided by this application gets rid of the dependence on GPS signals, avoiding the problem of insufficient positioning accuracy caused by the obstruction of indoor GPS signals; and does not require the coordination of multiple base stations, and can complete positioning only through the radio frequency unit, solving the problems of UL-TDOA technology requiring a high number of base stations, strict inter-station synchronization, and complex maintenance, and improving the applicability of indoor scenes; it also does not require the configuration of special antenna arrays and strict calibration of antenna directions, reducing the engineering requirements for hardware deployment, and overcoming the defect of UL-AOA technology being difficult to deploy indoors. At the same time, this method does not rely on emerging technologies of 3GPP R16 and later, and can be implemented based on existing equipment, avoiding the limitation that related technologies cannot be commercialized due to low industry maturity and lack of equipment support. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0036] Figure 1 A schematic diagram of an indoor positioning method provided in an embodiment of the present application;

[0037] Figure 2 A schematic diagram of an indoor positioning method provided in an embodiment of the present application;

[0038] Figure 3 A schematic diagram of the format of a management plane message data frame;

[0039] Figure 4 A schematic diagram of another indoor positioning method provided in an embodiment of the present application;

[0040] Figure 5 A schematic diagram of a control device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0041] As described above, current indoor positioning technologies mostly rely on outdoor positioning systems such as GPS. When the GPS signal is severely blocked, the accuracy and speed of indoor positioning will drop significantly.

[0042] In one implementation, indoor positioning can be achieved using technologies such as uplink time difference of arrival (UL-TDOA), uplink power angle of arrival (UL-AOA), downlink angle of departure (DL-AOD), and multiple round trip time (Multi-RTT). DL-AOD and Multi-RTT are based on 3GPP Release 16 and later technologies, but the industry is currently at a low level of maturity and lacks the necessary equipment support.

[0043] UL-TDOA positioning works by measuring the time difference between the uplink wireless signal transmitted by a terminal and reaching different base stations. The time differences measured by at least three base stations are used to determine two hyperbolas, and the intersection of the two hyperbolas is the terminal's location. UL-TDOA requires multiple base stations for collaborative positioning, placing stringent requirements on time synchronization between base stations, which can easily affect positioning accuracy. Furthermore, after a period of operation, the clocks of each base station will drift, requiring base station manufacturers to regularly calibrate the time synchronization between base stations, which is time-consuming and labor-intensive to maintain. Furthermore, in most indoor environments, only one base station is deployed per floor, while this technology requires at least three base stations for accurate positioning, limiting its application scenarios.

[0044] The positioning principle of UL-AOA is to measure the angle of incidence of the uplink signal transmitted by the terminal reaching the receiver. When the uplink signal is sent from the terminal and received simultaneously by multiple antennas of the receiver, a phase difference will be generated due to the different signal path lengths. By measuring these phase differences, the angle of arrival of the signal can be calculated. Using the angle information, combined with the known position of the receiver, the position of the signal source is determined through geometric calculations. In order to accurately measure the angle of incidence of the uplink signal, the receiver needs to be equipped with a highly directional antenna array. The actual deployment has extremely high requirements on engineering conditions. It is necessary to very accurately record the deployment location of the base station and strictly align the direction of the base station antenna array to improve the accuracy of the angle of incidence measurement. UL-AOA technology has high requirements on the number of base station antennas and is suitable for outdoor macro base station scenarios.

[0045] In summary, existing indoor positioning technologies all have certain defects, or the technical implementation is difficult, or the application scenarios are limited. In response to this technical problem, the present application provides an indoor positioning method, indoor positioning system, device and medium. First, the sounding reference signal (SRS) uploaded by the radio frequency unit and transmitted by the terminal is collected, and classified according to the time domain information in the SRS signal, so that the SRS signals with the same time domain information are grouped together; then, with the help of the unique correspondence between the time domain information and the terminal International Mobile Subscriber Identity (IMSI), the terminal IMSI associated with the target time domain information is found; then, from a group of SRS signals corresponding to the target time domain information, the SRS signal with the highest signal strength is selected; finally, based on the device tag carried in the strongest signal, the device location corresponding to the tag is determined, and this location is used as the specific location of the terminal corresponding to the terminal IMSI.

[0046] The indoor positioning method provided in this application can rely on the SRS signal emitted by the terminal itself, realize accurate association of the terminal by grouping the time domain information and binding it with the IMSI, and accurately lock the terminal position by combining the screening of the signal strength. The entire process is efficient and does not require additional positioning equipment, and can stably realize terminal positioning in indoor environments.

[0047] The indoor positioning method provided by this application gets rid of the dependence on GPS signals, avoiding the problem of insufficient positioning accuracy caused by indoor GPS signals being blocked; and there is no need for the coordination of multiple base stations, positioning can be completed only through the radio frequency unit, solving the problems of UL-TDOA technology requiring a high number of base stations, strict synchronization between stations, and complex maintenance, thereby improving the applicability of indoor scenarios; there is no need to equip special antenna arrays and strictly calibrate the antenna direction, reducing the engineering requirements for hardware deployment and overcoming the defect of UL-AOA technology being difficult to deploy indoors. At the same time, this method does not rely on emerging technologies of 3GPP R16 and later, and can be implemented based on existing equipment, avoiding the limitation that related technologies cannot be commercialized due to low industry maturity and lack of equipment support.

[0048] In order to help those skilled in the art better understand the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of this application.

[0049] To facilitate understanding of the indoor positioning method provided in the embodiments of the present application, the indoor positioning system is first introduced with reference to the accompanying drawings.

[0050] like Figure 1 As shown, Figure 1 This is an architecture diagram of an indoor positioning system provided in an embodiment of the present application. The indoor positioning system includes a baseband unit (BBU), a hub, and a pico RRU (pRRU). The indoor positioning system may include one or more pRRUs.

[0051] The pRRU can be connected to the HUB via a wired link (such as optical fiber or network cable) or wirelessly. When the indoor positioning system includes multiple pRRUs, a star connection is formed between the HUB and multiple pRRUs. The pRRU is used to upload the received SRS signal to the HUB in real time.

[0052] The HUB can also be connected to the BBU through a wired link (such as optical fiber) or wirelessly to forward the SRS signal uploaded by the pRRU to the BBU.

[0053] The pRRU includes multiple RF antennas. The pRRU can be installed in concealed locations such as indoor ceilings or walls. The pRRU's multiple RF antennas (ANT1-4) can be deployed in different locations indoors (such as corridor corners, room doorways, and elevator entrances) based on positioning requirements, achieving comprehensive indoor coverage.

[0054] The HUB can be installed in an indoor weak current room or equipment room, serving as an intermediate node between the pRRUs and the BBU, facilitating centralized management of signal transmissions from multiple pRRUs. The BBU can be installed in an indoor equipment room (either co-located with or adjacent to the HUB) as the core processing unit of the indoor positioning system, centrally processing all positioning-related data.

[0055] The pRRU, acting as the direct interaction node between the terminal and the indoor positioning system, receives the SRS signal transmitted by the terminal through its RF antenna, measures the Received Signal Strength Indication (RSSI), and encapsulates the SRS signal's time domain information, RF unit number, and RF antenna number into a message, which is then uploaded to the hub in real time. The pRRU's multi-antenna remote deployment enables precise signal coverage and acquisition at various locations indoors.

[0056] The hub serves as a signal aggregation and forwarding node, receiving SRS signals from multiple pRRUs. It aggregates and packages these signals in a fixed format (including time domain information, device identifiers, and signal strength), and forwards them to the BBU via the management plane (M-plane). The hub also provides power for the pRRUs, simplifying cabling.

[0057] As the core control and processing node of the indoor positioning system, the BBU receives multiple SRS signals uploaded by the HUB, parses the SRS signals through the built-in positioning application, uses the time domain information in the SRS signal to match the terminal IMSI (based on the pre-stored time domain information and IMSI binding relationship), and filters out the SRS signal with the highest signal strength from the multiple SRS signals uploaded by the terminal. The location of the device receiving the SRS signal with the highest signal strength is used as the terminal location and reported to the positioning server, realizing the core logic processing of indoor high-precision positioning.

[0058] Below, the indoor positioning method provided by the embodiment of the present application is introduced and described with reference to the accompanying drawings.

[0059] like Figure 2 As shown, Figure 2 A schematic diagram of an indoor positioning method provided in an embodiment of the present application, the method comprising:

[0060] S201: The BBU obtains multiple SRS signals uploaded by at least one pRRU.

[0061] Sounding Reference Signals (SRSs) are signals emitted by terminals. Terminals (such as mobile phones and IoT devices) periodically transmit SRSs. SRSs are uplink signals used by the network to detect the terminal's channel status. In indoor positioning scenarios, SRSs are reused as positioning reference signals. The pRRU uses multiple RF antennas to monitor SRS signals in the air in real time. When an SRS signal enters the antenna's coverage area, the antenna converts the electromagnetic wave into an electrical signal and transmits it to the pRRU's RF receiver module.

[0062] After receiving the SRS signal, the pRRU filters out environmental noise (such as interference from other wireless signals), amplifies the power of the weak SRS signal, and measures the signal strength of the SRS signal. The pRRU's own RF antenna number and RF antenna number are automatically added to the amplified SRS signal to facilitate associating the specific receiving position during subsequent positioning.

[0063] After completing the above processing and measurement, the pRRU sends the SRS signal including time domain information, device identification and signal strength to the HUB.

[0064] After receiving the SRS signal uploaded by the pRRU, the HUB can forward the SRS signal to the BBU so that the BBU can perform subsequent processing based on the SRS signal.

[0065] As an example, for indoor positioning scenarios that require rapid response to changes in terminal location, the HUB can adopt a pipeline mode of receiving and forwarding at the same time to avoid the delay caused by the centralized caching of SRS signals in the HUB, ensuring that the BBU can obtain the latest SRS signals in a timely manner.

[0066] As another example, if the HUB receives multiple SRS signals uploaded by the pRRU within a short period of time, the HUB can sort them by reception time and then batch-pack and forward them, reducing the number of transmissions from the HUB to the BBU and improving transmission efficiency.

[0067] In one possible implementation, obtaining multiple sounding reference signals uploaded by at least one radio frequency unit includes:

[0068] The management plane receives a management plane message obtained by the radio frequency unit packaging each of the sounding reference signals; the management plane message includes a subframe number, a time slot number, a symbol number, a radio frequency unit number, a radio frequency antenna number and a signal strength.

[0069] After receiving the SRS signals from each pRRU, the hub aggregates and integrates the information in the SRS signals and packages them into a management plane message according to a preset format. The SRS signals include time domain information, the radio unit number, the radio antenna number, and signal strength. The time domain information includes the subframe number (SFN), the number of time slots, and the number of symbols.

[0070] The management plane message obtained by the HUB by integrating the SRS signal includes the subframe number, time slot number, symbol number, radio frequency unit number, radio frequency antenna number and signal strength.

[0071] Based on its management interface with the BBU, the HUB transmits messages through a multi-layer protocol stack. The bearer layer uses the User Datagram Protocol (UDP) and Internet Protocol (IP) to encapsulate management plane messages into network layer packets, ensuring data routing and transmission within the IP network. The access layer uses the AP:C protocol to handle access control and link establishment between the HUB and BBU, ensuring the stability of the underlying connection. The access layer uses the VP:A protocol to control access permissions for management plane messages and define data exchange rules. The monitoring layer uses the MCP:C protocol to monitor and manage message transmission, ensuring the reliability and traceability of data transmission.

[0072] Through the above-mentioned protocol stack combination and docking mechanism, the HUB can accurately and efficiently report management plane messages including key information of SRS signals to the BBU, providing basic data support for the BBU to perform indoor positioning processing based on this information.

[0073] In some embodiments, after multiple pRRUs upload SRS signals to the HUB, the HUB integrates and merges the multiple SRS signals to obtain a management plane message. In other words, the HUB uploads only one management plane message to the BBU, which includes multiple SRS signals.

[0074] To avoid the BBU being unable to distinguish the measurement results of each pRRU, the embodiment of the present application configures unique time domain information for each terminal and adds a device tag (RF unit number and RF antenna number) to the SRS signal. The BBU can determine the corresponding terminal and device by retrieving the time domain information and device tag in each SRS signal.

[0075] As an example, the format of the SRS signal in the management plane message transmitted between the HUB and the BBU may be as shown in Table 1.

[0076] Table 1 SRS signal

[0077]

[0078] As an example, it is planned to report the SRS signals acquired by 32 pRRUs within 10 milliseconds. Each pRRU includes four RF antennas, and the time domain information corresponding to four terminals is configured within 10 milliseconds. In this 10 millisecond period, 512 SRS signals (32*4*4) can be uploaded, each SRS signal being 32 bits. To reduce the impact of Ethernet maximum transmission unit on signal transmission efficiency, the 512 SRS signals can be split into two data packets for upload. That is, the 512 SRS signals are combined into two management plane messages, each containing 256 32-bit data packets.

[0079] In addition, the embodiment of the present application may further define a monitoring layer protocol parameter identifier on the BBU network management side, as shown in Table 2.

[0080] Table 2 Monitoring layer protocol SRS measurement reporting parameter format

[0081]

[0082] The embodiment of the present application also provides a format of a management plane message data frame, such as Figure 3 shown.

[0083] Among them, (1) is used to indicate the start flag and is fixed to 0x7E.

[0084] (2) Used to indicate the AP layer protocol type. 0x03 represents AP:C.

[0085] (3) Used to indicate the bearer protocol type. 0x01 indicates that the upper layer protocol type of the bearer is VP:A.

[0086] (4) Used to indicate address unit component 1, which includes the site number and multi-byte reverse order, Figure 3 The site number is 0x00000000.

[0087] (5) Used to indicate address unit component 2, which includes the device number of the HUB device.

[0088] (6) Used to indicate the communication packet identification number. The communication packet identification number is generated by the initiator and is 2 bytes in reverse order. Figure 3 The communication packet identification number is 0x800d.

[0089] (7) Used to indicate the VP layer interaction flag, 0x80 indicates a normal command request.

[0090] (8) Used to indicate the MCP layer protocol identifier, MCP:C protocol is 0x03.

[0091] (9) Used to indicate the command identifier. The embodiment of the present application adopts the custom command 0x92, which indicates that it is an SRS signal measurement report.

[0092] (10) Used to indicate the response flag. The command initiator fills this field with 0xFF.

[0093] (11) Used to indicate data unit. LL is the length, TT is the monitoring identifier, and VV is the value.

[0094] (12) Used to indicate reporting identification.

[0095] (13) Used to indicate the content of reported data.

[0096] (14) Used to indicate the CRC check unit, 2 bytes in reverse order.

[0097] (15) Used to indicate the end flag, fixed to 0x7E.

[0098] S202: The BBU groups multiple SRS signals according to time domain information in each SRS signal to obtain multiple groups of SRS signals.

[0099] The BBU groups SRS signals based on time domain information and associates SRS signals sent by the same terminal at different locations, laying the foundation for subsequent IMSI matching and screening of the SRS signal with the highest signal strength.

[0100] The BBU extracts the time domain information carried by each SRS signal from the management plane message received from the HUB. If the time domain information (i.e., subframe number, timeslot number, and symbol number) of two SRS signals is identical, they are considered to be transmitted by the same terminal at the same time (although they may be received by different pRRUs or different RF antennas). All SRS signals with the same time domain information are grouped together. Each group corresponds to a specific time domain window (i.e., a precise point in time). In other words, the SRS signals transmitted by a terminal are grouped together, received by each pRRU and each RF antenna. The time domain information of each sounding reference signal in the same group is identical.

[0101] As an example, SRS signal A and SRS signal B belong to the same group, and the time domain information of SRS signal A and SRS signal B is (SFN=100, Slot=5, Symbol=12); SRS signal C belongs to another group, SRS signal C (SFN=100, Slot=5, Symbol=13).

[0102] S203: The BBU determines the target IMSI corresponding to the target time domain information by using the one-to-one mapping relationship between the time domain information and the IMSI of the terminal.

[0103] In the embodiments of the present application, the time domain information of each SRS signal in a group is the same, and a group of SRS signals corresponds to the same time domain information. Alternatively, the indoor positioning system receives SRS signals transmitted by multiple terminals within the coverage area of the indoor positioning system, and a group of SRS signals is multiple SRS signals transmitted by the same terminal. The target time domain information is the time domain information corresponding to a group of SRS signals. In other words, the target time domain information is the time domain information corresponding to a specific terminal.

[0104] In step S202 of the embodiment of the present application, multiple SRS signals are grouped to obtain multiple groups of SRS signals. The target time domain information can be any one of the multiple time domain information.

[0105] The BBU can store a mapping between time domain information and IMSIs. This mapping can be established when a terminal accesses or switches networks. Time domain information and IMSIs have a one-to-one correspondence. Based on this mapping, the BBU can search for a unique IMSI corresponding to the target time domain information, thereby determining the target IMSI corresponding to the target terminal based on the target time domain information.

[0106] Specifically, the BBU parses the target time domain information to obtain the target subframe number, target timeslot number, and target symbol number, and constructs a query keyword. The BBU then uses the query keyword to search pre-stored mapping relationship data. For example, the mapping relationships in the BBU can be stored in an indexed manner. The query process can be implemented using efficient algorithms such as hash searches or binary tree traversals, locating records associated with the target time domain information in a very short time.

[0107] In some embodiments, the target terminal may be offline or disconnected from the network, or the corresponding time domain information may be reconfigured for the target terminal and the mapping relationship stored by the BBU may not be changed. To ensure the accuracy of the query result, the BBU may also perform a secondary verification of the queried target IMSI. The BBU checks whether the terminal corresponding to the queried IMSI is in a normal access state and whether the terminal's current time domain information configuration is consistent with the target time domain information. If the verification succeeds, the IMSI is determined to be the target IMSI. If the verification fails (e.g., the terminal has been offline or the time domain information configuration has changed), an exception handling mechanism is triggered, such as re-acquiring the mapping relationship or marking the time domain information as invalid.

[0108] S204: The BBU determines a target detection reference signal with the highest signal strength among a group of SRS signals corresponding to the target time domain information.

[0109] The BBU parses the set of SRS signals corresponding to the target time domain information and extracts the signal strength of each SRS signal. The signal strength is measured and uploaded by the pRRU after collecting the SRS signal, and is usually expressed in units such as decibel milliwatts (dBm).

[0110] The BBU compares the signal strengths of all the extracted SRS signals in the group and can use algorithms such as bubble sort or quick sort to sort the signal strengths of the SRS signals in the same group from high to low.

[0111] After sorting, the detection reference signal corresponding to the signal strength at the top is the SRS signal with the highest signal strength in the group. The BBU determines the SRS signal with the highest signal strength in the group as the target detection reference signal.

[0112] To improve accuracy, the BBU can verify signal strength and exclude outliers (e.g., signal strength significantly outside the normal range) to prevent abnormal data from influencing the judgment result. Through step 204, the BBU can accurately select the SRS signal with the highest signal strength from the set of SRS signals corresponding to the target time domain information, providing a reliable data foundation for subsequent related processing (such as determining the device location).

[0113] S205: The BBU determines the location information of the device corresponding to the device tag according to the device tag in the target detection reference signal.

[0114] The target sounding reference signal (SRS) (i.e., the SRS signal with the highest signal strength) includes a device tag that identifies the signal receiving device. The device indicated by this device tag is the device receiving the target sounding reference signal and is referred to as the target device. The BBU can query the address of the device corresponding to the device tag using a pre-stored mapping table of device tags and device locations.

[0115] In one possible implementation, the location information of the device corresponding to the device tag is determined according to the device tag in the target detection reference signal, including: parsing the target detection reference signal to determine the device tag; determining the target RF unit and the target RF antenna according to the device tag; and determining the location information of the target RF antenna.

[0116] The target RF antenna is the antenna in the target RF unit that receives the target sounding reference signal. The device identifier may include the RF unit number and the RF antenna number.

[0117] The radio frequency unit (pRRU) ID is used to identify the pRRU that receives SRS signals. Each pRRU is assigned a globally unique radio frequency unit (RFU) ID during deployment (for example, generated using the "area + equipment room + serial number" rule).

[0118] The RF antenna number is used to identify the specific antenna port on the pRRU that receives signals. The same pRRU may contain multiple RF antennas, and the RF antennas are numbered sequentially, such as ANT1-ANT4.

[0119] The BBU parses the device number from the target detection reference signal and combines them to form a complete device tag (such as "AreaA-RRU-005+Port1").

[0120] In a possible implementation, the method further includes: after the radio frequency unit and the radio frequency antenna are set up indoors, acquiring and recording location information of the radio frequency unit and the radio frequency antenna indoors.

[0121] During the deployment phase of the indoor positioning system, after the pRRUs and RF antennas are deployed, the installation location of each pRRU and RF antenna can be accurately measured using tools such as laser rangefinders. The collected location information is then associated with the corresponding device, creating a mapping table between device numbers and location information, which is stored in the BBU. This mapping table can use an indexed structure to support quick device lookup based on device tags.

[0122] As an example, the correspondence between the radio frequency unit, the radio frequency antenna and the location information may be as shown in Table 3.

[0123] Table 3 Mapping table of radio frequency unit, radio frequency antenna and location information

[0124]

[0125] S206: The BBU uses the location information as the location information of the terminal corresponding to the target IMSI.

[0126] When SRS signals propagate in space, their energy will attenuate due to factors such as increased distance, obstruction by obstacles (such as walls and furniture), and multipath effects. This is manifested as a decrease in signal strength as the propagation distance increases.

[0127] When the terminal is close to the device receiving the SRS signal (such as the pRRU or RF antenna), the SRS signal propagation path is short and obstructions are few, resulting in minimal energy loss and a higher signal strength measured by the device. At longer distances, the SRS signal must travel a longer path or penetrate more obstacles, significantly attenuating its energy and reducing the signal strength received by the receiving device. The SRS signal strength is correlated with the transmission distance.

[0128] The set of sounding reference signals corresponding to the target time domain information all originate from the same terminal and are collected by receiving devices at different locations. The target sounding reference signal with the highest signal strength means that the device receiving the target sounding reference signal experiences the least attenuation of the SRS signal collected by all devices collecting the terminal's signal. Therefore, the device receiving the target sounding reference signal is the closest to the terminal in terms of spatial distance.

[0129] Compared with the devices corresponding to other SRS signals in the group, the target device corresponding to the target detection reference signal is physically closer to the terminal because the location information of the target device can better reflect the actual location of the terminal.

[0130] The indoor positioning method provided in the embodiments of the present application obtains SRS signals uploaded by radio frequency units (RFUs), groups them using time domain information, and combines this information with a one-to-one mapping between IMSIs to achieve terminal identification. This method eliminates the need for GPS signals, thus avoiding the problem of insufficient positioning accuracy caused by GPS signal obstruction in indoor environments. Furthermore, positioning can be achieved using a single RFU (no need for at least three base stations), without the need for stringent time synchronization and periodic calibration between multiple base stations. This addresses the issues of UL-TDOA technology, such as the high base station requirements, complex synchronization maintenance, and limited applicability to indoor scenarios. Furthermore, by selecting the device marker corresponding to the SRS signal with the highest signal strength to determine location, it eliminates the need for a highly directional antenna array and strict antenna orientation calibration, reducing the requirements for the number of antennas and deployment engineering conditions. This overcomes the drawbacks of UL-AOA technology, which is difficult to deploy and is more suitable for outdoor scenarios. Furthermore, this method can be implemented using existing equipment, eliminating the need for equipment expansion and installation. This method enables efficient, convenient, and high-precision positioning in indoor environments.

[0131] The embodiment of the present application also provides a method for configuring time domain information for a terminal, specifically including:

[0132] When a terminal connects to or switches networks, the terminal's IMSI is obtained through the International Mobile Equipment Identity Software Version (IMEISV) field in the Next Generation Application Protocol (NGAP) message. Unique time domain information is configured for the terminal at the Media Access Control (MAC) layer, and a correspondence between the time domain information and the terminal's IMSI is established at the Radio Resource Control (RRC) layer. An RRC reconfiguration message is sent to the terminal via the radio frequency unit.

[0133] The RRC reconfiguration message includes the IMSI of the terminal and the time domain information allocated to the terminal.

[0134] When a terminal connects to the network (for example, for the first time) or switches networks (for example, from an outdoor macro base station to an indoor micro base station), the core network and the BBU exchange signaling using the NGAP protocol. The core network transmits the terminal's IMSI (International Mobile Subscriber Identity) to the BBU via the IMEISV field in the NGAP message.

[0135] The IMEISV field was originally used to identify the terminal device model and software version. Currently, the IMEISV field is not used in private networks. In the embodiments of this application, it is reused as a carrier for transmitting IMSIs, enabling secure transmission of terminal identity information from the core network to the base station. The IMEISV field in NGAP is 16 bits long and can accommodate an IMSI (up to 15 digits). Using the IMEISV field for IMSI transmission does not add new NGAP messages (adding new messages or fields requires upgrading the ASN.1 encoding tool, resulting in a sharp increase in technical complexity) nor does it affect existing logic.

[0136] The BBU's MAC layer schedules unused time domain resources for the terminal based on the current network resource occupancy (such as the allocated subframe number, number of timeslots, and number of symbols). This generates time domain information including the subframe number, number of timeslots, and number of symbols. When allocating time domain resources, the MAC layer must ensure uniqueness. This means that the time domain information of different terminals within the same network coverage area does not overlap to avoid signal conflicts.

[0137] After obtaining the terminal's IMSI and the time domain information assigned to it by the MAC layer, the BBU's RRC layer performs an association and binding operation. It maps the terminal's IMSI to the time domain information, forming a one-to-one mapping relationship. This mapping relationship can be stored in the RRC layer's local database to provide data support for subsequent IMSI queries using the time domain information.

[0138] After configuring the corresponding time domain information for the terminal, the terminal must also be informed of its assigned time domain information. The BBU generates an RRC reconfiguration message based on the terminal's IMSI and time domain information. The RRC reconfiguration message contains the terminal's IMSI (for terminal identity verification) and the allocated time domain information (for the terminal to send SRS signals based on the time domain information).

[0139] The BBU sends the RRC reconfiguration message to the terminal through the HUB and pRRU. After receiving the message, the terminal parses the RRC reconfiguration message and adjusts the transmission time of the SRS signal according to the configured time domain information (such as the specified subframe number, number of time slots and number of symbols), ensuring that the network side can accurately identify the SRS signal sent by the terminal through the time domain information.

[0140] This embodiment of the application transmits the IMSI via the NGAP protocol, allocates unique time domain resources at the MAC layer, and establishes a mapping relationship at the RRC layer, ultimately allowing the terminal and the BBU to reach a consensus on the mapping relationship between time domain information and IMSI. This provides a foundation for subsequent signal grouping and terminal positioning based on time domain information, allowing each terminal's SRS signal to be uniquely identified in the time domain, avoiding confusion between SRS signals from multiple terminals.

[0141] In a possible implementation, configuring unique time domain information for a terminal at a media access control (MAC) layer includes:

[0142] At the MAC layer, a target subframe number is selected from multiple subframe numbers; a target time slot number is selected from multiple time slot numbers corresponding to the target subframe number; an unoccupied symbol number is selected from multiple symbol numbers corresponding to the target time slot number as the target symbol number; and the target subframe number, target time slot number, and symbol number are used as time domain information of the terminal.

[0143] When the MAC layer configures unique time domain information for a terminal, it first selects a target subframe number from multiple subframe numbers, then selects a target time slot number from the multiple time slot numbers corresponding to the target subframe number. Next, it selects an unoccupied target symbol number from the multiple symbol numbers corresponding to the target time slot number. Finally, the target subframe number, target time slot number, and target symbol number are combined to form the terminal's unique time domain information. This process ensures the uniqueness of the time domain information allocated to the terminal by hierarchically screening time domain resources based on subframe number, time slot number, and symbol number, combined with checking the symbol occupancy status. This avoids conflicts in time domain resources between different terminals and lays the foundation for subsequent operations such as terminal identification and positioning based on time domain information.

[0144] To facilitate understanding of the indoor positioning method provided in the embodiment of the present application, Figure 4 The program is introduced again.

[0145] After the terminal accesses or switches to the BBU, the BBU obtains the terminal's IMSI through the core network. The BBU configures unique time domain information for the terminal based on the terminal's IMSI and sends the time domain information to the terminal via an RRC reconfiguration message.

[0146] The BBU obtains multiple SRS signals transmitted by the terminal through the pRRU, processes the multiple SRS signals, and determines the target detection reference signal with the highest signal strength by combining the IMSI and time domain information. The BBU uses the positioning service (the positioning service can run in the BBU) to determine the device tag corresponding to the target detection reference signal, and then uses the location information of the device corresponding to the device tag as the location information of the terminal.

[0147] In one possible implementation, to improve the effectiveness of the mapping between time domain information and IMSI, the BBU can also periodically and dynamically maintain this mapping. When a terminal undergoes handover, reconfiguration, or disconnects from the network, the RRC layer promptly updates the mapping. For example, after a terminal reconfigures its SRS resources, the RRC layer rebinds the new time domain information to the terminal's IMSI and overwrites the old mapping record. The BBU can also periodically synchronize information with the core network to verify the validity and status of the terminal's IMSI and ensure that there are no invalid or expired records in the mapping.

[0148] The present application also provides an indoor positioning system. Figure 1 As shown, the indoor positioning system includes a hub, a baseband processing unit and at least one radio frequency unit.

[0149] The hub is connected to the baseband processing unit and at least one radio frequency unit respectively.

[0150] The radio frequency unit is used to receive the sounding reference signal sent by the terminal and upload the sounding reference signal to the hub.

[0151] The hub is used to receive the sounding reference signal uploaded by the radio frequency unit and forward multiple sounding reference signals to the baseband processing unit.

[0152] The baseband processing unit is used to execute the indoor positioning method described in any of the above embodiments.

[0153] In one possible implementation, see Figure 5 , which is a schematic diagram of a control device provided in an embodiment of the present application.

[0154] The control device may include a memory 501 and a processor 502. Figure 5 As shown in FIG, the memory may be a random access memory (RAM), a flash memory, a read only memory (ROM), an EPROM memory, an Electronic Programmable ROM (EPROM), a register, a hard disk, a removable disk, etc.

[0155] The memory 501 can store computer instructions. When the computer instructions stored in the memory 501 are executed by the processor 502, the processor 502 can be used to perform the indoor positioning method. The memory 501 can also store data, such as the mapping relationship information involved in the above embodiments.

[0156] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented using software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the process or function according to the embodiment of the present application is generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions can be transmitted from one website, computer, server or data center to another website, computer, server or data center via a wired (e.g., coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) method. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that includes one or more available media integrated. The available medium can be a magnetic medium (e.g., a floppy disk, a hard disk, a tape), or a semiconductor medium (e.g., a solid-state drive (SSD)).

[0157] The present application also provides a readable storage medium for storing the methods provided in the above embodiments, such as a random access memory (RAM), flash memory, read-only memory (ROM), EPROM, electronic programmable ROM (EPROM), register, hard disk, removable disk, or any other form of storage medium known in the art.

[0158] The "first" and "second" (if any) in the names mentioned in the embodiments of this application are only used as name identifiers and do not represent the first or second in order.

[0159] It should be noted that the various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from the other embodiments. Similar or identical parts between the various embodiments can be referred to in conjunction with each other. The methods disclosed in the embodiments are described briefly because they correspond to the product embodiments disclosed in the embodiments. For relevant details, refer to the description of the product embodiments.

[0160] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present application. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application is not limited to the embodiments shown herein, but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An indoor positioning method, characterized in that: The method comprises: Acquire multiple sounding reference signals uploaded by at least one radio frequency unit; the sounding reference signals are signals sent by the terminal; Grouping the plurality of sounding reference signals according to the time domain information in each of the sounding reference signals to obtain a plurality of groups of sounding reference signals; the time domain information in the same group of sounding reference signals is the same; Determining a target IMSI corresponding to the target time domain information by using a one-to-one mapping relationship between the time domain information and the international mobile subscriber identity (IMSI) of the terminal; the target time domain information is any one of the multiple time domain information; Determine a target detection reference signal with the highest signal strength among a group of detection reference signals corresponding to the target time domain information; Determining, based on the device tag in the target detection reference signal, the location information of the device corresponding to the device tag; The location information is used as the location information of the terminal corresponding to the target IMSI.

2. The method according to claim 1, characterized in that The radio frequency unit includes a plurality of radio frequency antennas; the plurality of radio frequency antennas of the radio frequency unit are arranged at different positions; The determining, according to the device tag in the target detection reference signal, the location information of the device corresponding to the device tag includes: parsing the target detection reference signal to determine the device tag; Determining a target radio frequency unit and a target radio frequency antenna according to the device tag; the target radio frequency antenna is an antenna in the target radio frequency unit that receives the target detection reference signal; Determine the location information of the target radio frequency antenna.

3. The method according to claim 1, characterized in that The receiving a plurality of sounding reference signals uploaded by at least one radio frequency unit includes: Receive multiple sounding reference signals sent by a hub HUB; the HUB is used to receive at least one sounding reference signal uploaded by each radio frequency unit.

4. The method according to claim 1, wherein The method further comprises: When the terminal connects to or switches networks, obtaining the IMSI of the terminal through the International Mobile Station Equipment Identity and Software Version Number IMEISV field in the application protocol NGAP message; Configuring unique time domain information for the terminal at a media access control (MAC) layer, and establishing a correspondence between the time domain information and the IMSI of the terminal at a radio resource control (RRC) layer; An RRC reconfiguration message is sent to the terminal through the radio frequency unit, where the RRC reconfiguration message includes the IMSI of the terminal and time domain information allocated to the terminal.

5. The method according to claim 4, characterized in that The configuring unique time domain information for the terminal at a media access control (MAC) layer includes: A target subframe number is selected from a plurality of subframe numbers at the MAC layer; a target time slot number is selected from a plurality of time slot numbers corresponding to the target subframe number; an unoccupied number of symbols is selected as a target number of symbols from a plurality of symbol numbers corresponding to the target time slot number; and the target subframe number, the target time slot number, and the number of symbols are used as time domain information of the terminal.

6. The method according to claim 1, characterized in that The obtaining of multiple sounding reference signals uploaded by at least one radio frequency unit includes: A management plane message is received by packaging each of the sounding reference signals through a management plane; the management plane message includes a subframe number, a time slot number, a symbol number, a radio frequency unit number, a radio frequency antenna number, and a signal strength.

7. The method according to claim 1, characterized in that The method further comprises: After the radio frequency unit and the radio frequency antenna are set up indoors, position information of the radio frequency unit and the radio frequency antenna indoors is acquired and recorded.

8. An indoor positioning system, characterized in that: The indoor positioning system includes a hub, a baseband processing unit and at least one radio frequency unit; the hub is connected to the baseband processing unit and at least one radio frequency unit respectively; The radio frequency unit is configured to receive a sounding reference signal sent by a terminal and upload the sounding reference signal to the hub; The hub is configured to receive the sounding reference signal uploaded by the radio frequency unit and forward a plurality of the sounding reference signals to the baseband processing unit; The baseband processing unit is used to execute the indoor positioning method according to any one of claims 1 to 7.

9. A control device, characterized in that: It includes a processor and a memory, the memory is used to store programs, instructions or codes, and the processor is used to execute the programs, instructions or codes in the memory to complete the indoor positioning method according to any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that A computer program is stored, and the computer program is loaded by a processor to execute the indoor positioning method according to any one of claims 1 to 7.

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