Time synchronization method, apparatus, device, storage medium, and computer program product

Abstract

The application provides a time synchronization method, device, equipment, storage medium and computer program product, which are applied to a BBU. The method comprises the following steps: acquiring a plurality of first time slot information corresponding to the BBU and a plurality of RRUs; acquiring a plurality of first adjacent station list information of the plurality of RRUs, and finding a first RRU serving as a sending end from the plurality of RRUs according to the plurality of first adjacent station list information; determining second time slot information corresponding to the first RRU from the plurality of first time slot information, and sending first synchronization information to the first RRU through the second time slot information; the first synchronization information at least comprises first time information when the BBU sends the first synchronization information; the first synchronization information is used for the first RRU to forward the first synchronization information to a second RRU; receiving second synchronization information sent by the second RRU, acquiring second time information when the second synchronization information is received; and performing time synchronization on the first RRU and the second RRU based on the first time information and the second time information, which can improve the synchronization precision between the RRUs.

Description

Technical Field

[0001] This application relates to the field of wireless technology, and in particular to a time synchronization method, apparatus, device, storage medium, and computer program product. Background Technology

[0002] Indoor 5G positioning primarily employs distributed base stations and a networking scheme with the same Baseband Unit (BBU). For synchronization of multiple Remote Radio Units (RRUs) under the same BBU, the BBU synchronizes with different RRUs via the Common Public Radio Interface (CPRI) to achieve relative synchronization between RRUs. However, due to the physical layer design, each basic frame period of the CPRI interface is 260.416667 nanoseconds (ns), resulting in an inherent 260ns latency. Furthermore, CPRI synchronization is incomplete for the transmission link; BBU-RRU synchronization only synchronizes a portion of the RRU modules, leading to synchronization errors between RRUs. Summary of the Invention

[0003] This application provides a time synchronization method, apparatus, device, storage medium, and computer program product that can improve the synchronization accuracy between RRUs.

[0004] To achieve the above objectives, the technical solution of this application embodiment is implemented as follows:

[0005] Firstly, this application proposes a time synchronization method applied to a BBU, the method comprising:

[0006] Obtain multiple first time slot information corresponding to the BBU and multiple RRUs;

[0007] Obtain multiple first neighbor station list information of the multiple RRUs, and find the first RRU as the sending end from the multiple RRUs according to the multiple first neighbor station list information;

[0008] The second time slot information corresponding to the first RRU is determined from the plurality of first time slot information, and the first synchronization information is sent to the first RRU through the second time slot information; the first synchronization information includes at least the first time information when the BBU sends the first synchronization information; the first synchronization information is used by the first RRU to forward the first synchronization information to the second RRU; the second RRU is the neighboring RRU of the first RRU in the plurality of RRUs.

[0009] Receive the second synchronization information sent by the second RRU, obtain the second time information when the second synchronization information is received, and synchronize the first RRU and the second RRU based on the first time information and the second time information.

[0010] Secondly, this application proposes a time synchronization device for use in a BBU, the device comprising:

[0011] The acquisition unit is used to acquire multiple first time slot information corresponding to the BBU and multiple radio remote units (RRUs);

[0012] The lookup unit is used to obtain multiple first neighbor station list information of the multiple RRUs, and to find the first RRU as the sending end from the multiple RRUs according to the multiple first neighbor station list information;

[0013] A sending unit is configured to determine the second time slot information corresponding to the first RRU from the plurality of first time slot information, and send first synchronization information to the first RRU through the second time slot information; the first synchronization information includes at least the first time information when the BBU sends the first synchronization information; the first synchronization information is used by the first RRU to forward the first synchronization information to the second RRU; the second RRU is the neighboring RRU of the first RRU among the plurality of RRUs.

[0014] The time synchronization unit is used to receive the second synchronization information sent by the second RRU, obtain the second time information when the second synchronization information is received, and perform time synchronization on the first RRU and the second RRU based on the first time information and the second time information.

[0015] Thirdly, this application proposes a time synchronization device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the steps of any of the methods described above.

[0016] Fourthly, this application proposes a storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of any of the methods described above.

[0017] Fifthly, this application proposes a computer program product, including a computer program that, when executed by a processor, implements the steps of any of the methods described above.

[0018] This application proposes a time synchronization method, apparatus, device, storage medium, and computer program product applied to a BBU. The method includes: acquiring multiple first time slot information corresponding to the BBU and multiple RRUs; acquiring multiple first neighbor list information of the multiple RRUs, and searching for a first RRU as the sending end from the multiple RRUs according to the multiple first neighbor list information; determining the second time slot information corresponding to the first RRU from the multiple first time slot information, and sending first synchronization information to the first RRU through the second time slot information; the first synchronization information includes at least first time information when the BBU sends the first synchronization information; the first synchronization information is used by the first RRU to forward the first synchronization information to a second RRU; the second RRU is a neighbor RRU of the first RRU among the multiple RRUs; receiving the second synchronization information sent by the second RRU, acquiring the second time information when the second synchronization information is received; and performing time synchronization between the first RRU and the second RRU based on the first time information and the second time information. Using the above implementation scheme, the BBU obtains multiple first neighbor list information of multiple RRUs, and searches for the first RRU as the transmitting end from multiple RRUs based on the multiple first neighbor list information. This allows the BBU to perform transmit and receive scheduling on multiple RRUs under the BBU, achieving synchronization with all base stations under the BBU. Furthermore, the BBU obtains multiple first time slot information between itself and multiple RRUs, determines the second time slot information corresponding to the first RRU as the transmitting end, and sends first synchronization information to the first RRU through the second time slot information. It also receives second synchronization information sent by the second RRU, which is the neighboring RRU of the first RRU. Based on the first time information when the BBU sends the first synchronization information and the second time information when it receives the second synchronization information, the BBU determines the time error information between the first RRU and the second RRU, thereby synchronizing the time between the first RRU and the second RRU and improving the synchronization accuracy between RRUs. Attached Figure Description

[0019] Figure 1 A schematic diagram of an exemplary distributed base station hardware architecture provided for an embodiment of this application;

[0020] Figure 2 A flowchart illustrating a time synchronization method provided in an embodiment of this application;

[0021] Figure 3 A schematic diagram illustrating an exemplary inter-station data interaction process provided in this application embodiment;

[0022] Figure 4A schematic diagram illustrating an exemplary configuration and adjustment of transmit and receive time slots provided for embodiments of this application;

[0023] Figure 5 A schematic diagram illustrating another exemplary configuration and adjustment of transmit and receive time slots provided for embodiments of this application;

[0024] Figure 6 A schematic diagram illustrating yet another exemplary configuration and adjustment of transmit and receive time slots provided in an embodiment of this application;

[0025] Figure 7 This is a schematic diagram illustrating an exemplary configuration of a transmitting end RRU and a receiving end RRU, provided for an embodiment of this application.

[0026] Figure 8 A schematic diagram illustrating another exemplary configuration of the transmitting end RRU and the receiving end RRU provided for embodiments of this application;

[0027] Figure 9 A schematic diagram illustrating yet another exemplary configuration of the transmitting end RRU and the receiving end RRU provided in this application embodiment;

[0028] Figure 10 A schematic diagram illustrating the relationship between an exemplary BBU and an RRU provided for embodiments of this application;

[0029] Figure 11 A schematic diagram illustrating the relationship between a BBU and an RRU, including a synchronization module, provided for embodiments of this application;

[0030] Figure 12 This is a schematic diagram of the structure of a time synchronization device provided in an embodiment of this application;

[0031] Figure 13 This is a schematic diagram of the structure of a time synchronization device provided in an embodiment of this application. Detailed Implementation

[0032] In order to gain a more detailed understanding of the features and technical content of the embodiments of this application, the implementation of the embodiments of this application will be described in detail below with reference to the accompanying drawings. The accompanying drawings are for reference and illustration only and are not intended to limit the embodiments of this application.

[0033] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing embodiments of this application only and is not intended to limit this application.

[0034] In the following description, references to "some embodiments" are made, which describe a subset of all possible embodiments. However, it is understood that "some embodiments" may be the same subset or different subsets of all possible embodiments and may be combined with each other without conflict. It should also be noted that the terms "first," "second," etc., used in the embodiments of this application are only used to distinguish similar objects and do not represent a specific ordering of objects. It is understood that "first," "second," etc., may be interchanged in a specific order or sequence where permitted, so that the embodiments of this application described herein can be implemented in an order other than that illustrated or described herein.

[0035] In 5G systems, time synchronization between base stations is a fundamental requirement for system operation. Synchronization in 5G systems can be mainly divided into inter-base station BBU synchronization, BBU and RRU synchronization, and base station and terminal synchronization. The required synchronization accuracy and equipment vary depending on the specific 5G service. Currently, inter-base station BBU synchronization uses the Global Positioning System (GPS) or the 1588V2 protocol; BBU and RRU synchronization uses the CPRI protocol; and base station and terminal synchronization uses reference signals such as the Sounding Reference Signal (SRS) for estimation.

[0036] Indoor positioning is a core 5G service, typically employing a distributed base station (BBU+RRU / Active Antenna Unit (AAU)) architecture and based on Uplink Time Difference of Arrival (UTDOA) technology for terminal location. This technology involves base stations measuring the uplink SRS arrival time from the terminal and reporting it to a location server. The location server then calculates the terminal's location based on the time differences measured by multiple base stations. Therefore, the synchronization accuracy between indoor positioning base stations directly impacts positioning accuracy. Currently, different RRUs within the same BBU primarily rely on the CPRI protocol between the BBU and RRUs for synchronization.

[0037] Indoor 5G positioning primarily employs distributed base stations and a network topology within the same BBU. For synchronization of multiple RRUs under the same BBU, the BBU synchronizes with different RRUs separately via the CPRI interface, thereby achieving relative synchronization between RRUs. This method has two significant drawbacks:

[0038] On the one hand, due to the physical layer design, the CPRI interface has a basic frame period of 260.416667ns, which results in a natural latency of 260ns. Since 5G systems have guard intervals and cyclic prefixes, this latency has virtually no impact on data transmission. However, when using 5G for positioning, considering the speed of light, the positioning error can reach approximately 76 meters, making accurate positioning impossible.

[0039] On the other hand, the synchronization of the CPRI interface is incomplete for the transmission link. Figure 1 A schematic diagram of an exemplary distributed base station hardware architecture provided for embodiments of this application; as shown Figure 1 As shown, the system includes a BBU, RRU1, and RRU2. RRU1 and RRU2 are under the same BBU. Synchronization between the BBU and RRU1 or RRU2 can only be synchronized up to the digital module; analog modules also exist. Therefore, there is error 1 between the BBU and RRU1, error 2 between the BBU and RRU2, and inter-station error 3 between the BBUs. Specifically, after the clock processing module of the RRU, there are modules such as radio frequency transceivers, local area networks (LANs), power amplifiers (PAs), and passive antennas. During the operation of these modules, additional time delay errors may be introduced due to factors such as temperature drift, manufacturing processes, and service life. These errors are fluctuating and unmeasurable. Therefore, this time delay also affects the synchronization accuracy between base stations, thus causing positioning errors.

[0040] Based on this, embodiments of this application provide a time synchronization method applied to a BBU. Figure 2 This is a flowchart illustrating a time synchronization method provided in an embodiment of this application; as shown below. Figure 2 As shown, the method includes:

[0041] S201. Obtain the first time slot information corresponding to the BBU and multiple RRUs.

[0042] It should be noted that multiple RRUs are different RRUs under the same BBU, and their specific number can be determined according to the actual situation, and is not limited here.

[0043] In this embodiment, the multiple first timeslot information can be understood as the first timeslot information corresponding to each RRU among the multiple RRUs and the BBU. This first timeslot information can be understood as dedicated transmit / receive timeslot information between the BBU and the RRUs. The process of obtaining the multiple first timeslot information corresponding to the BBU and the multiple RRUs specifically includes: upon receiving a first instruction sent by the network device, receiving multiple first pieces of information sent by the multiple RRUs; the multiple first pieces of information at least includes multiple timeslot allocation information of the multiple RRUs; and determining the multiple first timeslot information corresponding to the BBU and the multiple RRUs based on the multiple timeslot allocation information.

[0044] It should be noted that the first instruction sent by the network device can be understood as a location synchronization instruction. Specifically, when an indoor base station is used for positioning, the network device can send a location synchronization instruction to the BBU. The first information includes time slot allocation information, the physical location and identity (ID) information of the RRU, and the current cell frame structure information of the RRU. The BBU receives multiple pieces of the first information sent by multiple RRUs; this can be understood as the BBU receiving the first information sent by each RRU separately.

[0045] It should be noted that Time Division Duplex (TDD) transmission schemes include uplink time slots, downlink time slots, and special time slots. The special time slots further include downlink pilot time slots, guard intervals (GAPs), and uplink pilot time slots. The uplink time slots and uplink pilot time slots are used for the terminal to send signals to the base station, while the downlink time slots and downlink pilot time slots are used for the base station to send signals to the terminal. The GAPs do not involve any interaction. To avoid inter-station interference and inter-time slot interference, the time slot order and allocation between base stations are kept consistent; that is, each base station is simultaneously in either receiving or transmitting mode.

[0046] In the embodiments of this application, the time slot allocation information can be understood as the number of GAPs in the current time slot allocation and the starting position of the current time slot allocation GAP in a specific time slot.

[0047] In this embodiment of the application, determining the multiple first time slot information corresponding to the BBU and multiple RRUs based on the time slot allocation information can be understood as obtaining the quantity information and location information corresponding to multiple protection intervals in the multiple time slot allocation information; and determining the multiple first time slot information based on the quantity information and location information corresponding to multiple protection intervals.

[0048] It should be noted that the quantity information corresponding to the protection interval can be understood as the number of GAPs configured in the current time slot; the location information corresponding to the protection interval can be understood as the starting position of the current time slot ratio GAP in the special time slot. Determining multiple first time slot information based on the quantity and location information corresponding to multiple protection intervals can be understood as determining the dedicated transmit / receive time slot information between the BBU and each RRU according to the number of GAPs in the current time slot ratio and the starting position of the current time slot ratio GAP in the special time slot.

[0049] In practical applications, the number of GAPs in the current time slot allocation can be denoted as N, and the starting position of the current time slot allocation GAP in the special time slot can be denoted as S. When the number of GAPs (N) is greater than or equal to 3, the number of GAPs N / 2 (rounded up) + S is used as the starting time slot (i.e., the first time slot information) for dedicated transceiver resources. When the number of GAPs (N) is less than 3, in order to reserve sufficient resources for the dedicated transceiver time slots and guard intervals, the normal time slots need to be silenced. Specifically, the number of GAPs N / 2 (rounded up) + S is used as the starting time slot for dedicated transceiver resources. If N = 1, the time slots of N / 2 (rounded up) + S plus ±1 become silent time slots, and the base station does not perform any uplink or downlink scheduling on the terminal in this time slot. If N = 2, the time slots of N / 2 (rounded up) + S plus -1 become silent time slots, and the base station does not perform any uplink or downlink scheduling on the terminal in this time slot.

[0050] The solution in this application embodiment determines the dedicated transmit and receive time slots between the BBU and each RRU through the time slot allocation information of each RRU. The use of the dedicated transmit and receive time slots for air interface data interaction between the BBU and each RRU can offset the impact of fluctuating latency caused by Cpri, passive modules of RRU, etc., and synchronously does not affect the existing network terminal services.

[0051] S202. Obtain the first neighbor list information of multiple RRUs, and find the first RRU as the sending end from multiple RRUs based on the first neighbor list information.

[0052] It should be noted that the first neighbor list information can be understood as the line-of-sight (LOS) path neighbor RRU list information of the RRU. The BBU obtains multiple first neighbor list information for multiple RRUs, which can be understood as the BBU maintaining the LOS path neighbor RRU list information for each of the multiple RRUs. The BBU adds a receive identifier R_f_x to each RRU, where X represents the current base station sequence number. The default value of the identifier R_f_x is 0. When data is received from an RRU in the maintenance table and successfully received, R_f_x is set to 1. This process continues until all RRU identifiers under that BBU are set to 1, at which point one round of data update is considered complete, and all identifiers are reset to 0.

[0053] In this embodiment of the application, the process of finding the first RRU as the sending end from multiple RRUs based on multiple first neighboring station list information specifically includes: finding the RRU corresponding to the second neighboring station list information with the most neighboring stations from multiple first neighboring station list information as the first RRU.

[0054] It should be noted that the second neighbor list information with the most neighboring stations can be understood as the RRU with the most LOS path neighboring stations. Finding the RRU corresponding to the second neighbor list information with the most neighboring stations from multiple first neighbor list information and designating it as the first RRU can be understood as designating the RRU with the most LOS path neighboring stations under the BBU as the sending RRU. Specifically, when the first RRU is found as the first sending RRU from multiple RRUs, the neighboring RRUs of the first RRU among the multiple RRUs (i.e., the second RRUs) are designated as the receiving RRUs. The second RRU can also be understood as any RRU in the second neighbor list information; the number of second RRUs can be one or more, and the specific number can be determined based on the actual situation.

[0055] In this embodiment of the application, after designating the RRU corresponding to the second neighboring station list information as the first RRU, the method further includes: if there are multiple third RRUs in addition to the second RRU among the multiple RRUs, obtaining multiple third neighboring station list information corresponding to the multiple third RRUs from the first neighboring station list information; if the target neighboring station information that appears most frequently is found from the multiple third neighboring station list information; then the RRU corresponding to the target neighboring station information is designated as the first RRU.

[0056] It should be noted that multiple third RRUs can be understood as the RRUs other than the second RRU that are not receiving data. That is, when the RRU with the most LOS path neighbors under the BBU is used as the transmitting RRU, the other RRUs besides the neighboring RRUs of that transmitting RRU (i.e., those used as receiving RRUs) are included. The third neighbor list information can be understood as the LOS neighbor RRU list information corresponding to the third RRU.

[0057] In this embodiment, if the target neighbor information that appears most frequently is found from multiple third neighbor list information, then the RRU corresponding to the target neighbor information is taken as the first RRU. This can be understood as obtaining the LOS path neighbor RRU list information for each third RRU, finding the neighbor RRU that appears most frequently, and taking that RRU as the sending RRU. In practical applications, this can be illustrated by taking an RRU that appears in multiple RRU neighbor lists as the sending RRU.

[0058] In this embodiment of the application, after designating the RRU corresponding to the target neighbor information as the first RRU, the method further includes: if a fourth neighbor list information that does not contain the target neighbor information is found from multiple third neighbor list information; then the fourth RRU corresponding to the fourth neighbor list information is determined from multiple third RRUs; and the neighbor RRU of the fourth RRU is designated as the first RRU.

[0059] It should be noted that the fourth list information can be understood as a list of information that does not contain target neighbor information. Alternatively, it can be illustrated as the fourth RRU corresponding to the fourth list information being an RRU that has not yet received data. Using the neighboring RRUs of the fourth RRU as the first RRU can be understood as arbitrarily selecting one RRU from the neighboring RRUs of the fourth RRU as the transmitting RRU; in this case, the fourth RRU becomes the receiving RRU.

[0060] The solution in this application embodiment, through the transmit and receive scheduling scheme of different RRUs under the same BBU, ensures that all RRUs under the same BBU can receive data sent from the LOS path neighbor station, and can realize data interaction of all RRUs. Moreover, it adopts one RRU for transmitting and multiple RRUs for receiving. This transmit and receive method can effectively offset the natural errors caused by the passive module, analog module and CPRI interface of the receiving RRU, so that the synchronization accuracy between RRUs is as close as possible to 10ns, and the corresponding positioning error is close to 3 meters, achieving sub-meter positioning.

[0061] S203. Determine the second time slot information corresponding to the first RRU from multiple first time slot information, and send the first synchronization information to the first RRU through the second time slot information; the first synchronization information includes at least the first time information when the BBU sends the first synchronization information; the first synchronization information is used by the first RRU to forward the first synchronization information to the second RRU; the second RRU is the neighboring station RRU of the first RRU among multiple RRUs.

[0062] It should be noted that determining the second time slot information corresponding to the first RRU from multiple first time slot information can be understood as determining the dedicated transmit / receive time slot information between the BBU and the first RRU from the dedicated transmit / receive time slot information between the BBU and each of the multiple RRUs.

[0063] It should be noted that the BBU contains a high-precision synchronization module. After the BBU determines the first RRU (i.e., the sending RRU), the synchronization module generates the first synchronization information and sends it to the first RRU via the second timeslot information. The method by which the BBU sends the first synchronization information to the first RRU can be determined according to the actual situation and is not limited here. As an example, the BBU can send the first synchronization information to the first RRU in the form of broadcast via the second timeslot information.

[0064] In this embodiment of the application, the first synchronization information can be understood as a synchronization sequence. The first synchronization information includes the first time information when the first synchronization information is sent. Specifically, the key fields that the first synchronization information should include are: the sending base station ID, the integer part of the timestamp, the fractional part of the timestamp, and the reserved field.

[0065] In this embodiment, the second RRU is the neighboring RRU of the first RRU among multiple RRUs. When the first RRU is a sending RRU, the second RRU is a receiving RRU. The first synchronization information is used by the first RRU to forward the first synchronization information to the second RRU. It can be understood that after the first RRU receives the first synchronization information sent by the BBU, it sends the first synchronization information to the receiving RRU (i.e., the second RRU).

[0066] S204. Receive the second synchronization information sent by the second RRU, obtain the second time information when the second synchronization information is received, and synchronize the time of the first RRU and the second RRU based on the first time information and the second time information.

[0067] It should be noted that obtaining the second time information when the second synchronization information is received can be understood as the BBU recording the time information when the second synchronization information enters the BBU. Specifically, the BBU records the second time information through the synchronization module.

[0068] In this embodiment of the application, the process of synchronizing the first RRU and the second RRU based on the first time information and the second time information specifically includes: obtaining the fifth neighboring station list information corresponding to the first RRU and the identification information contained in the second synchronization information; and synchronizing the first RRU and the second RRU based on the first time information and the second time information when the fifth neighboring station list information contains the identification information.

[0069] It should be noted that the fifth neighboring station list information can be understood as the LOS neighboring station RRU list information of the first RRU. The second identification information can be understood as the identification information of the second RRU, that is, the ID of the second RRU.

[0070] When the fifth neighboring station list information contains identification information, the first RRU and the second RRU are synchronized in time based on the first time information and the second time information. This can be understood as, when the ID of the second RRU is included in the LOS path neighboring station list information of the first RRU, the first RRU and the second RRU are synchronized in time based on the first time information and the second time information.

[0071] It should be noted that if the identification information is not included in the fifth neighboring station list information, no further processing will be performed, and the BBU will continue to wait for synchronization information sent by other RRUs.

[0072] In this embodiment of the application, the process of synchronizing the time of the first RRU and the second RRU based on the first time information and the second time information specifically includes: obtaining the distance information between the first RRU and the second RRU, and determining the error information based on the distance information, the first time information and the second time information; and synchronizing the time of the first RRU and the second RRU based on the error information.

[0073] It should be noted that the error information can be understood as the time delay error information between the first RRU and the second RRU. The process of determining the error information based on the distance information, the first time information, and the second time information can be understood as follows: dividing the distance information by the speed of light to obtain the air interface duration information between the first RRU and the second RRU; determining the difference information between the first time information and the second time information; this difference information is the transmission time difference information between the first RRU and the second RRU; and using the difference between the transmission time difference information and the air interface duration information as the time delay error information.

[0074] In the scheme of this application embodiment, the BBU obtains multiple first neighboring station list information of multiple RRUs, and searches for the first RRU as the sending end from multiple RRUs according to the multiple first neighboring station list information. It can perform transmit and receive scheduling on multiple RRUs under the BBU to achieve synchronization with all base stations under the BBU. Furthermore, the BBU obtains multiple first time slot information between itself and multiple RRUs, determines the second time slot information corresponding to the first RRU as the sending end, sends first synchronization information to the first RRU through the second time slot information, and receives second synchronization information sent by the neighboring RRU of the first RRU, i.e., the second RRU. Based on the first time information when the BBU sends the first synchronization information and the second time information when it receives the second synchronization information, it determines the time error information between the first RRU and the second RRU, and then performs time synchronization on the first RRU and the second RRU.

[0075] To facilitate understanding, an example is provided here. On one hand, for positioning base stations, specific time slots are reallocated to enable inter-station data exchange. Simultaneously, transmit and receive scheduling is performed on the RRUs under the BBU to achieve synchronization with all base stations under the BBU. On the other hand, a synchronization module is added to the BBU to generate and process synchronization interaction information, achieving high-precision synchronization between RRUs.

[0076] 1. Inter-station air interface data interaction scheme based on special time slots.

[0077] The TDD transmission scheme includes uplink time slots, downlink time slots, and special time slots. The special time slots further include downlink pilot time slots, gaps (GAPs), and uplink pilot time slots. The uplink time slots and uplink pilot time slots are used for terminals to send signals to the base station, while the downlink time slots and downlink pilot time slots are used for base stations to send signals to the terminal. The guard interval has no interactive behavior. To avoid inter-site interference and inter-slot interference, the time slot order and ratio between base stations are kept consistent, meaning that each base station is simultaneously in either receiving or transmitting mode. To achieve air interface data interaction between base stations, at least one base station needs to be in transmitting mode while other base stations are in receiving mode. In this embodiment, a gap (GAP) is used to achieve inter-site air interface data interaction.

[0078] For different RRUs under the same BBU, their receiving and transmitting states in the GAP time slot can be controlled by the BBU. For ease of understanding... Figure 3 This application provides an exemplary flowchart of inter-station data interaction; as shown in the embodiments. Figure 3 As shown, the specific steps are as follows:

[0079] 1. Inter-station data interaction judgment.

[0080] It should be noted that when an indoor base station is used for positioning, a positioning synchronization command can be sent to the BBU via the network. After receiving the command, the BBU will determine whether the currently accessed RRU needs to be synchronized and obtain key information such as the RRU's physical location and ID, the current cell frame structure, and time slot allocation.

[0081] 2. Configure dedicated time slots for sending and receiving.

[0082] It should be noted that for TDD systems, a guard interval is mandatory to isolate uplink and downlink signals. According to the 3rd Generation Partnership Project (3GPP) protocol, this guard interval must be at least one Orthogonal Frequency Division Multiplexing (OFDM) symbol in the time domain (e.g., for 2.6G, the special time slot ratio is DDDDDDGGGGUUUU). The length of the guard interval generally depends on the coverage area of ​​the base station. For 5G signals using a 30 kHz subcarrier spacing, the flight distance per symbol is 10 kilometers (km). However, for indoor positioning, the spacing between RRUs is typically 20 meters, which is far less than the transmission time of one symbol. Therefore, to use special time slots for air interface data exchange between base stations, at least one OFDM symbol should be reserved for communication in the time domain, and at least one preceding and following time slot should be reserved as a guard interval.

[0083] The specific definition of the configuration and adjustment of transmit and receive time slots is: the number of gaps in the current time slot allocation: N, and the starting position of the gap in the current time slot allocation in the special time slot: S.

[0084] Case 1: When the number of gaps (N) is greater than or equal to 3, sufficient resources can be allocated to dedicated time slots for transmission and reception. The number of gaps N / 2 (rounded up) + S is used as the starting time slot for dedicated transmission and reception resources. Figure 4 A schematic diagram illustrating an exemplary configuration and adjustment of transmit and receive time slots provided for embodiments of this application; as shown Figure 4 As shown, Figure 4 In the middle (a), the special time slot allocation is N=4 and S=6. Then the starting time slot of the adjusted dedicated transmission and reception resources is 8. Figure 4 In (b), the adjusted allocation of special time slots is shown, where TR is the starting time slot for dedicated transmission and reception resources.

[0085] Case 2: When the number of GAPs (N) is less than 3, in order to reserve sufficient resources for the dedicated time slots for transmission and reception and the protection interval, the normal time slots need to be silenced. The specific operation is as follows: take the number of GAPs N / 2 (rounded up) + S as the starting time slot for the dedicated time slots for transmission and reception.

[0086] If N=1, then the ±1 time slot of the GAP number N / 2 (rounded up) + S becomes a silent time slot, and the base station does not perform any uplink or downlink scheduling on the terminal in this time slot. Figure 5 A schematic diagram illustrating another exemplary configuration and adjustment of transmit / receive time slots provided for embodiments of this application; as shown. Figure 5 As shown, Figure 5 In the middle (a), the special time slot allocation is N=1 and S=7. Then the starting time slot of the adjusted dedicated transmission and reception resources is 8. Figure 5 In (b), the ratio of special time slots is adjusted. TR is the starting time slot of dedicated resources for sending and receiving, and the ±1 time slot of TR is the sleep time slot.

[0087] If N=2, then the -1 time slot of the GAP number N / 2 (rounded up)+S becomes a silent time slot, and the base station does not perform any uplink or downlink scheduling on the terminal in this time slot. Figure 6 A schematic diagram illustrating yet another exemplary configuration and adjustment of transmit and receive time slots provided in an embodiment of this application; as shown Figure 6 , Figure 6 In the middle (a), the special time slot allocation is N=2 and S=7. Then the starting time slot of the adjusted dedicated transmission and reception resources is 8. Figure 6 In (b), the ratio of special time slots is adjusted. TR is the starting time slot of dedicated transmission and reception resources. The -1 time slot of TR is the sleep time slot, in which the base station does not perform any uplink or downlink scheduling on the terminal.

[0088] 3. Configure transceiver base stations.

[0089] It should be noted that the process protection for configuring the transceiver base station determines whether to switch transceivers, i.e., whether to switch the transmitting RRU or the receiving RRU. When multiple RRUs exist under the same BBU, all RRUs need to be scheduled to ensure that the base station is in either receiving or transmitting state at the same time.

[0090] Base station transceiver scheduling scheme: Air interface data exchange between base stations used for inter-site synchronization should ensure the existence of a LOS path between RRUs. However, in indoor deployments, even though RRUs are connected to the same BBU, there are still cases where two RRUs lack a LOS path. Therefore, base station configuration and scheduling are required to ensure that each base station can receive signals from base stations with LOS paths.

[0091] The specific process is as follows: The BBU maintains a LOS path RRU list for each RRU, and considers reception successful only when data is received from an RRU in the list. Table 1 shows the LOS path RRU list maintained by the BBU for each RRU.

[0092] Table 1

[0093] RRU_id RRUx LOS_RRU_list RRUa, RRUb, RRUc...

[0094] In Table 1, RRU_id represents the identifier of the RRU, x in RRUx represents the current base station sequence number, and LOS_RRU_list represents the LOS path RRU list of this RRU.

[0095] The BBU adds a receive identifier R_f_x to each RRU, where X represents the current base station sequence number. The default value of the identifier R_f_x is 0. When data is received from an RRU in the maintenance table and successfully received, R_f_x is set to 1. When all RRU identifiers under this BBU are set to 1, it is considered that one round of data update is completed, and all identifiers are reset to 0.

[0096] To ensure that all RRUs under the BBU complete receiving, the transmitting end should be configured according to the following steps:

[0097] (1) Use the RRU with the most LOS path neighbor stations under the BBU as the sending end.

[0098] (2) Use the RRU that appears in multiple RRU neighbor lists as the sending end.

[0099] (3) Select any RRU in the list of unreceived RRU neighboring stations as the sending end.

[0100] To facilitate understanding, an example is provided here. Under the BBU, there are RRU1, RRU2, RRU3, RRU4, RRU5, and RRU6. The above scheme is used to complete the receiving operation of all RRUs. Figure 7 A schematic diagram illustrating the configuration of a transmitting end RRU and a receiving end RRU is provided for embodiments of this application; as shown Figure 7 As shown, the neighboring RRUs of RRU1 are RRU2 and RRU3, the neighboring RRUs of RRU2 are RRU1 and RRU3, the neighboring RRUs of RRU3 are RRU1, RRU2 and RRU4, the neighboring RRUs of RRU4 are RRU3 and RRU5, the neighboring RRU of RRU5 is RRU4, and the neighboring RRU of RRU6 is RRU5. Among them, RRU3 has the most LOS path neighbors. RRU3 is used as the transmitter, and RRU1, RRU2 and RRU4 are used as receivers. Then, RRU1's R_f_1 is marked as 1, RRU2's R_f_2 is marked as 1, and RRU4's R_f_4 is marked as 1.

[0101] Figure 8 A schematic diagram illustrating another exemplary configuration of the transmitting end RRU and the receiving end RRU provided in this application embodiment; as shown Figure 8 As shown, the neighboring RRUs of RRU1 are RRU2 and RRU3, the neighboring RRUs of RRU2 are RRU1 and RRU3, the neighboring RRUs of RRU3 are RRU1, RRU2 and RRU4, the neighboring RRUs of RRU4 are RRU3 and RRU5, the neighboring RRU of RRU5 is RRU4, and the neighboring RRU of RRU6 is RRU5. Among them, the terminals that do not receive include RRU3, RRU5 and RRU6. RRU3 and RRU5 share the same LOS path neighbor RRU4, so RRU4 is used as the transmitting end. At this time, RRU3 and RRU5 are used as the receiving ends. The R_f_3 label of RRU3 is set to 1 and the R_f_5 label of RRU5 is set to 1.

[0102] Figure 9 This is another exemplary schematic diagram of configuring the transmitting end RRU and the receiving end RRU provided in the embodiments of this application; as shown... Figure 9 As shown, the neighboring RRUs of RRU1 are RRU2 and RRU3, the neighboring RRUs of RRU2 are RRU1 and RRU3, the neighboring RRUs of RRU3 are RRU1, RRU2 and RRU4, the neighboring RRUs of RRU4 are RRU3 and RRU5, the neighboring RRU of RRU5 is RRU4, and the neighboring RRU of RRU6 is RRU5. Among them, only RRU6 is not receiving signals. RRU6 has a LOS path neighbor RRU5, so RRU5 is used as the transmitter. In addition, RRU4 has completed receiving and will not process the received signal. RRU6's R_f_6 is marked as 1.

[0103] 2. A high-precision synchronization solution based on air interface data interaction.

[0104] The air interface synchronization scheme uses one RRU for transmission and multiple RRUs for reception. This transmission and reception method can effectively offset the natural errors caused by the passive module, analog module and Cpri interface of the receiving RRU, so that the synchronization accuracy between RRUs is as close as possible to 10ns, and the corresponding positioning error is close to 3 meters, achieving sub-meter positioning. Figure 10 An exemplary diagram illustrating the relationship between a BBU and an RRU is provided for embodiments of this application, as shown below. Figure 10 As shown, the BBU includes RRU1, RRU2 and RRU3. RRU1 is the transmitter, and RRU2 and RRU3 are the receivers. RRU1, RRU2 and RRU3 all include digital modules and analog modules. There is an error 1 between BBU and RRU2 and an error 2 between BBU and RRU3.

[0105] To implement the above solution, a high-precision synchronization module needs to be added to the BBU. Its main functions include, but are not limited to: generating picosecond-level synchronization time; generating / parsing the timestamp sequence of the sending end; recording the time information of the receiving end; and adding identification information such as RRUid.

[0106] In a BBU, the synchronization module can be either a virtual module or a physical module. Its specific implementation depends on the base station manufacturer's hardware capabilities and circuit design. Figure 11 An exemplary diagram illustrating the relationship between a BBU and an RRU, including a synchronization module, is provided for embodiments of this application. Figure 11 As shown, there is a synchronization model within the BBU, and RR1 and RRU2 exist under the same BBU.

[0107] Synchronization process: (1) The BBU determines the sending end RRU, the synchronization module generates a synchronization sequence, and broadcasts the sequence in a special transmit / receive time slot. The synchronization sequence mainly records the time t1 when the data leaves the BBU. The synchronization sequence should contain key fields. Table 2 is a table of key fields contained in the synchronization sequence, as shown in Table 2:

[0108] Table 2

[0109] Fields size Sending base station ID 8bit timestamp integer part 64bit decimal part of timestamp 64bit Reserved fields 64bit

[0110] (2) The receiving RRU receives the synchronization sequence sent by the transmitting RRU, demodulates it and transmits it to the BBU. When the data enters the BBU, the synchronization module records the arrival time t2_x, where x indicates which RRU received it.

[0111] (3) Check the LOS path neighbor list of the received RRU to see if it contains the sending base station ID. If it exists, proceed to the next step. If it does not exist, do not proceed with the subsequent processing and wait for information sent by other sending base stations.

[0112] (4) The BBU calculates the time difference between the two stations by using the actual position between the RRUs, t1, and t2, and achieves relative synchronization between the two stations.

[0113] For ease of understanding, an example is provided here. Defined as follows: RRU1, 2, and 3 are under the same BBU, with RRU1 as the transmitter and RRU2 and RRU3 as receivers. The distance between RRU1 and RRU2 is 6.3 meters, and the distance between RRU1 and RRU3 is 7.2 meters.

[0114] The BBU time synchronization module generates a synchronization sequence for RRU1. Assume the current picosecond-level time of the generated synchronization sequence is 13,842.145,689,231,221 seconds (s). The information contained in the sequence is shown in Table 3, which contains the actual information of the current synchronization sequence. Table 3 is as follows:

[0115] Table 3

[0116]

[0117] When RRU2 and RRU3 receive data and transmit it to the BBU, the time synchronization module records the arrival time. Assume the current time recorded by the time synchronization module is: 13,842.145,689,252,356s (picosecond level) generated by RRU2, and 13,842.145,689,255,478s (picosecond level) generated by RRU3.

[0118] Transmission time difference from RRU1 to RRU2:

[0119] 13,842.145,689,252,356-13,842.145,689,231,221=2.1135*10^-8s.

[0120] Air interface time from RRU1 to RRU2:

[0121] 6.3 / (3*10^8)=2.1*10^-8s.

[0122] Therefore, the time delay error from RRU1 to RRU2 is: E12 = 2.1135 * 10^-8 - 2.1 * 10^-8 = 0.135 * 10^-9.

[0123] Transmission time difference from RRU1 to RRU3:

[0124] 13,842.145,689,255,478-13,842.145,689,231,221=2.4257*10^-8s.

[0125] Air interface time from RRU1 to RRU2:

[0126] 7.2 / (3*10^8)=2.4*10^-8s.

[0127] Therefore, the time delay error from RRU1 to RRU2 is: E13 = 2.4257 * 10^-8 - 2.4 * 10^-8 = 0.257 * 10^-9.

[0128] Subsequently, when positioning via RRU2 and 3, the E12 and E13 errors should be considered in the calculation.

[0129] This application provides a time synchronization device. Figure 12 This is a schematic diagram of the structure of a time synchronization device provided in an embodiment of this application; as shown below. Figure 12 As shown, the time synchronization device 1200, applied to a BBU, includes:

[0130] Acquisition unit 1201 is used to acquire multiple first time slot information corresponding to the BBU and multiple radio remote units (RRUs);

[0131] The lookup unit 1202 is used to obtain multiple first neighbor station list information of the multiple RRUs, and to find the first RRU as the sending end from the multiple RRUs according to the multiple first neighbor station list information;

[0132] The sending unit 1203 is configured to determine the second time slot information corresponding to the first RRU from the plurality of first time slot information, and send first synchronization information to the first RRU through the second time slot information; the first synchronization information includes at least the first time information when the BBU sends the first synchronization information; the first synchronization information is used by the first RRU to forward the first synchronization information to the second RRU; the second RRU is the neighboring RRU of the first RRU among the plurality of RRUs;

[0133] The time synchronization unit 1204 is used to receive the second synchronization information sent by the second RRU, obtain the second time information when the second synchronization information is received, and perform time synchronization on the first RRU and the second RRU based on the first time information and the second time information.

[0134] Optionally, the acquisition unit 1201 is further configured to receive multiple first information sent by the multiple RRUs upon receiving a first instruction sent by the network device; the multiple first information includes at least multiple time slot allocation information of the multiple RRUs; and determine multiple first time slot information corresponding to the BBU and the multiple RRUs based on the multiple time slot allocation information.

[0135] Optionally, the acquisition unit 1201 is further configured to acquire the quantity and location information corresponding to the multiple protection interval time slots in the multiple time slot allocation information; and determine the multiple first time slot information based on the quantity and location information corresponding to the multiple protection interval time slots.

[0136] Optionally, the lookup unit 1202 is further configured to find the second neighboring station list information with the largest number of neighboring stations from the plurality of first neighboring station list information, and use the RRU corresponding to the second neighboring station list information as the first RRU.

[0137] Optionally, after setting the RRU corresponding to the second neighboring station list information as the first RRU, the search unit 1202 is further configured to, when there are multiple third RRUs in addition to the second RRU among the multiple RRUs, obtain multiple third neighboring station list information corresponding to the multiple third RRUs from the first neighboring station list information; if the target neighboring station information with the most occurrences is found from the multiple third neighboring station list information, then the RRU corresponding to the target neighboring station information is set as the first RRU.

[0138] Optionally, after setting the RRU corresponding to the target neighbor information as the first RRU, the lookup unit 1202 is further configured to: if a fourth neighbor list information that does not contain the target neighbor information is found from the plurality of third neighbor list information; then determine the fourth RRU corresponding to the fourth neighbor information from the plurality of third RRUs; and set the neighbor RRU of the fourth RRU as the first RRU.

[0139] Optionally, the time synchronization unit 1204 is further configured to acquire the fifth neighboring station list information corresponding to the first RRU and the identification information contained in the second synchronization information; if the identification information is contained in the fifth neighboring station list information, the first RRU and the second RRU are time-synchronized based on the first time information and the second time information.

[0140] This application also provides a time synchronization device. Figure 13 This is a schematic diagram of the structure of a time synchronization device provided in an embodiment of this application; as shown below. Figure 13 As shown, the time synchronization device 1300 includes a processor 1301 and a memory 1303. Optionally, the time synchronization device 1300 may also include a communication bus 1302.

[0141] In specific embodiments, the processor 1301 can be at least one of the following: Application Specific Integrated Circuit (ASIC), Digital Signal Processor (DSP), Digital Signal Processing Device (DSPD), Programmable Logic Device (PLD), Field Programmable Gate Array (FPGA), CPU, controller, microcontroller, and microprocessor. It is understood that for different devices, the electronic device used to implement the above processor function can also be other types, and this embodiment does not specifically limit it.

[0142] In this embodiment, the communication bus 1302 is used to establish communication between the processor 1301 and the memory 1303; when the processor 1301 executes the running program stored in the memory 1303, it implements the following time synchronization method:

[0143] The system acquires multiple first time slot information corresponding to the BBU and multiple remote radio units (RRUs); acquires multiple first neighbor list information of the multiple RRUs, and searches for a first RRU as the transmitting end from the multiple RRUs according to the multiple first neighbor list information; determines the second time slot information corresponding to the first RRU from the multiple first time slot information, and sends first synchronization information to the first RRU through the second time slot information; the first synchronization information includes at least the first time information when the BBU sends the first synchronization information; the first synchronization information is used by the first RRU to forward the first synchronization information to a second RRU; the second RRU is a neighbor RRU of the first RRU among the multiple RRUs; receives the second synchronization information sent by the second RRU, acquires the second time information when the second synchronization information is received; and performs time synchronization between the first RRU and the second RRU based on the first time information and the second time information.

[0144] Furthermore, the processor 1301 is also configured to receive multiple first pieces of information sent by the plurality of RRUs upon receiving a first instruction sent by the network device; the plurality of first pieces of information includes at least multiple time slot allocation information of the plurality of RRUs; and determine multiple first time slot information corresponding to the BBU and the plurality of RRUs based on the multiple time slot allocation information.

[0145] Furthermore, the processor 1301 is also used to acquire the quantity and location information of the multiple protection interval time slots in the multiple time slot allocation information; and to determine the multiple first time slot information based on the quantity and location information of the multiple protection interval time slots.

[0146] Furthermore, the processor 1301 is also configured to find the second neighboring station list information with the largest number of neighboring stations from the plurality of first neighboring station list information, and use the RRU corresponding to the second neighboring station list information as the first RRU.

[0147] Furthermore, after taking the RRU corresponding to the second neighboring station list information as the first RRU, the processor 1301 is further configured to, when there are multiple third RRUs in addition to the second RRU among the multiple RRUs, obtain multiple third neighboring station list information corresponding to the multiple third RRUs from the first neighboring station list information; if the target neighboring station information that appears most frequently is found from the multiple third neighboring station list information, then take the RRU corresponding to the target neighboring station information as the first RRU.

[0148] Furthermore, after setting the RRU corresponding to the target neighbor information as the first RRU, the processor 1301 is further configured to: if a fourth neighbor list information that does not contain the target neighbor information is found from the plurality of third neighbor list information; determine the fourth RRU corresponding to the fourth neighbor information from the plurality of third RRUs; and set the neighbor RRU of the fourth RRU as the first RRU.

[0149] Furthermore, the processor 1301 is also configured to acquire the fifth neighboring station list information corresponding to the first RRU and the identification information contained in the second synchronization information respectively; when the identification information is contained in the fifth neighboring station list information, the processor synchronizes the first RRU and the second RRU based on the first time information and the second time information.

[0150] This application provides a storage medium storing a computer program thereon. The computer-readable storage medium stores one or more programs, which can be executed by one or more processors. The computer program implements the time synchronization method described above.

[0151] Based on the above embodiments, this application provides a computer program product, including a computer program that can be executed by one or more processors, and the computer program implements the time synchronization method described above.

[0152] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0153] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods of the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of this disclosure, in essence, or the part that contributes to the related technology, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk), and includes several instructions to cause an image display device (which may be a mobile phone, computer, server, air conditioner, or network device, etc.) to execute the methods described in the various embodiments of this disclosure.

[0154] The above description is merely a preferred embodiment of this application and is not intended to limit the scope of protection of this application.

Claims

1. A time synchronization method, characterized in that, Applied to a baseband processing unit (BBU), the method includes: Obtain multiple first time slot information corresponding to the BBU and multiple radio remote units (RRUs); Obtain multiple first neighbor station list information of the multiple RRUs, and find the first RRU as the sending end from the multiple RRUs according to the multiple first neighbor station list information; The second time slot information corresponding to the first RRU is determined from the plurality of first time slot information, and the first synchronization information is sent to the first RRU through the second time slot information; the first synchronization information includes at least the first time information when the BBU sends the first synchronization information; the first synchronization information is used by the first RRU to forward the first synchronization information to the second RRU; the second RRU is the neighboring RRU of the first RRU in the plurality of RRUs. Receive the second synchronization information sent by the second RRU, obtain the second time information when the second synchronization information is received, and synchronize the first RRU and the second RRU based on the first time information and the second time information.

2. The method according to claim 1, characterized in that, The step of obtaining multiple first time slot information corresponding to the BBU and multiple RRUs includes: Upon receiving a first instruction from a network device, the system receives multiple first pieces of information sent by the plurality of RRUs; the plurality of first pieces of information includes at least multiple time slot allocation information of the plurality of RRUs. Based on the multiple time slot allocation information, the corresponding multiple first time slot information between the BBU and the multiple RRUs is determined.

3. The method according to claim 2, characterized in that, The step of determining the corresponding first time slot information between the BBU and the multiple RRUs based on the multiple time slot allocation information includes: Obtain the quantity and location information of multiple protection interval time slots from the multiple time slot allocation information; The information of the multiple first time slots is determined based on the quantity and location information corresponding to the multiple protection interval time slots.

4. The method according to claim 1, characterized in that, The step of searching for the first RRU as the sending end from the plurality of RRUs based on the plurality of first neighbor station list information includes: Find the second neighboring station list information with the most neighboring stations from the plurality of first neighboring station list information, and take the RRU corresponding to the second neighboring station list information as the first RRU.

5. The method according to claim 4, characterized in that, After using the RRU corresponding to the second neighboring station list information as the first RRU, the method further includes: If there are multiple third RRUs in addition to the second RRU among the multiple RRUs, obtain the multiple third neighbor list information corresponding to the multiple third RRUs from the first neighbor list information; If the target neighbor information that appears most frequently is found from the multiple third neighbor list information, then the RRU corresponding to the target neighbor information is taken as the first RRU.

6. The method according to claim 5, characterized in that, After using the RRU corresponding to the target neighbor information as the first RRU, the method further includes: If a fourth neighboring station list that does not contain the target neighboring station information is found from the plurality of third neighboring station list information, then the fourth RRU corresponding to the fourth neighboring station information is determined from the plurality of third RRUs, and the neighboring RRU of the fourth RRU is taken as the first RRU.

7. The method according to claim 1, characterized in that, The step of synchronizing the time of the first RRU and the second RRU based on the first time information and the second time information includes: The fifth neighbor station list information corresponding to the first RRU and the identification information contained in the second synchronization information are obtained respectively. If the identification information is included in the fifth neighboring station list information, the first RRU and the second RRU are synchronized in time based on the first time information and the second time information.

8. A time synchronization device, characterized in that, Applied to a BBU, the device includes: The acquisition unit is used to acquire multiple first time slot information corresponding to the BBU and multiple radio remote units (RRUs); The lookup unit is used to obtain multiple first neighbor station list information of the multiple RRUs, and to find the first RRU as the sending end from the multiple RRUs according to the multiple first neighbor station list information; A sending unit is configured to determine the second time slot information corresponding to the first RRU from the plurality of first time slot information, and send first synchronization information to the first RRU through the second time slot information; the first synchronization information includes at least the first time information when the BBU sends the first synchronization information; the first synchronization information is used by the first RRU to forward the first synchronization information to the second RRU; the second RRU is the neighboring RRU of the first RRU among the plurality of RRUs. The time synchronization unit is used to receive the second synchronization information sent by the second RRU, obtain the second time information when the second synchronization information is received, and perform time synchronization on the first RRU and the second RRU based on the first time information and the second time information.

9. A time synchronization device, characterized in that, The method includes a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor, when executing the program, implements the steps of the method according to any one of claims 1 to 7.

10. A storage medium having a computer program stored thereon, characterized in that, When executed by a processor, the computer program implements the steps of the method according to any one of claims 1 to 7.

11. A computer program product, comprising a computer program, characterized in that, When executed by a processor, the computer program implements the steps of the method according to any one of claims 1 to 7.

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