CN107493599B

CN107493599B - Method, device and system for realizing time synchronization between base station devices through baseband radio frequency interface

Info

Publication number: CN107493599B
Application number: CN201610408399.6A
Authority: CN
Inventors: 汪立林; 万娟; 余金清; 章伟
Original assignee: ZTE Corp
Current assignee: ZTE Corp
Priority date: 2016-06-12
Filing date: 2016-06-12
Publication date: 2021-04-02
Anticipated expiration: 2036-06-12
Also published as: CN107493599A

Abstract

The invention relates to a method, a device and a system for realizing time synchronization among base station equipment through a baseband radio frequency interface, wherein the method comprises the following steps: the first base station equipment providing the synchronization function acquires time synchronization information, and packages the time synchronization information to obtain a time information data packet. And the first base station equipment sends the time information data packet to the second base station equipment to be synchronized through a baseband radio frequency interface. The second base station receives the time information data packet through the baseband radio frequency interface. And the second base station recovers to obtain the time pulse signal according to the time information data packet and performs time synchronization according to the time pulse signal. Data interaction is carried out through the baseband radio frequency interface, even if the base station equipment installed indoors can receive time information data packets sent by other base station equipment through the baseband radio frequency interface to carry out time synchronization processing, GNSS receiving equipment does not need to be installed on the indoor base station equipment, the problem of application scene limitation of time synchronization among the base station equipment is solved, and the installation difficulty and the installation cost of the GNSS receiving equipment are reduced.

Description

Method, device and system for realizing time synchronization between base station devices through baseband radio frequency interface

Technical Field

The present invention relates to the field of mobile communication technologies, and in particular, to a method, an apparatus, and a system for implementing time synchronization between base station devices through a baseband radio frequency interface.

Background

Mobile communication systems all have Base Station (BS) time synchronization requirements to align clocks between Base stations. The conventional base station device is composed of a Radio Equipment Control (REC) and a Radio Equipment (RE), or is an integrated base station combining the REC and the RE.

In order to ensure the synchronization precision requirement between base stations, a GNSS (Global Navigation Satellite System) receiving device is installed at each base station to solve the problem. The installation and clock synchronization of the GNSS receiving equipment are usually completed on the REC side, while the REC equipment is usually indoor equipment, and the installation of the GNSS receiving equipment undoubtedly increases the engineering construction difficulty, resulting in high installation difficulty and installation cost of the GNSS receiving equipment.

Disclosure of Invention

Therefore, in order to solve the above problems, a method, an apparatus, and a system for implementing time synchronization between base station devices through a baseband radio frequency interface are provided, which can reduce the installation difficulty and installation cost of GNSS receiving devices.

A method for implementing time synchronization between base station devices through a baseband radio frequency interface, the method comprising:

receiving a time information data packet sent by base station equipment providing a synchronization function through a baseband radio frequency interface;

and recovering according to the time information data packet to obtain a time pulse signal, and carrying out time synchronization according to the time pulse signal.

An apparatus for implementing time synchronization between base station devices through a baseband radio frequency interface, comprising:

the time information receiving module is used for receiving a time information data packet sent by base station equipment providing a synchronization function through a baseband radio frequency interface;

and the time synchronization module is used for recovering to obtain a time pulse signal according to the time information data packet and carrying out time synchronization according to the time pulse signal.

According to the method and the device for realizing the time synchronization between the base station devices through the baseband radio frequency interface, the time information data packet sent by the base station device providing the synchronization function is received through the baseband radio frequency interface. And recovering the time pulse signal according to the time information data packet, and performing time synchronization according to the time pulse signal. And data interaction is carried out through a baseband radio frequency interface, so that time information data packets between base station equipment are received and transmitted to carry out time synchronization. Even if the indoor base station equipment can receive the time information data packets sent by other base station equipment through the baseband radio frequency interface to perform time synchronization processing, GNSS receiving equipment does not need to be installed on the indoor base station equipment, the problem of application scene limitation of time synchronization among the base station equipment is solved, and the installation difficulty and the installation cost of the GNSS receiving equipment are reduced.

the method comprises the steps that first base station equipment providing a synchronization function obtains time synchronization information, and the time synchronization information is packaged to obtain a time information data packet;

the first base station equipment sends the time information data packet to second base station equipment to be synchronized through a baseband radio frequency interface;

the second base station receives the time information data packet through the baseband radio frequency interface;

and the second base station recovers to obtain a time pulse signal according to the time information data packet and performs time synchronization according to the time pulse signal.

A system for achieving time synchronization between base station devices over a baseband radio frequency interface, the system comprising:

the first base station equipment with a synchronization function is used for acquiring time synchronization information and packaging the time synchronization information to obtain a time information data packet; sending the time information data packet to a second base station device to be synchronized through a baseband radio frequency interface;

and the second base station equipment to be synchronized is used for receiving the time information data packet through the baseband radio frequency interface, recovering to obtain a time pulse signal according to the time information data packet, and performing time synchronization according to the time pulse signal.

According to the method and the system for realizing the time synchronization between the base station devices through the baseband radio frequency interface, the first base station device with the synchronization function acquires the time synchronization information, packages the time synchronization information to obtain the time information data packet, and sends the time information data packet to the second base station device to be synchronized through the baseband radio frequency interface. And the second base station receives the time information data packet through the baseband radio frequency interface, recovers to obtain a time pulse signal according to the time information data packet, and performs time synchronization according to the time pulse signal. And data interaction is carried out through a baseband radio frequency interface, so that the receiving and sending of time information data packets between the first base station equipment and the second base station equipment are realized to carry out time synchronization. Even if the indoor base station equipment can receive the time information data packets sent by other base station equipment through the baseband radio frequency interface to perform time synchronization processing, GNSS receiving equipment does not need to be installed on the indoor base station equipment, the problem of application scene limitation of time synchronization among the base station equipment is solved, and the installation difficulty and the installation cost of the GNSS receiving equipment are reduced.

Drawings

Fig. 1 is a flowchart illustrating a method for implementing time synchronization between base station devices through a baseband rf interface according to an embodiment;

FIG. 2 is a diagram illustrating communications between base station devices over a baseband RF interface, according to an embodiment;

FIG. 3 is a diagram illustrating communications between base station devices over a baseband RF interface in another embodiment;

FIG. 4 is a diagram illustrating a format of a time information packet according to an embodiment;

fig. 5 is a flowchart illustrating that the second base station recovers the time pulse signal according to the time information packet and performs time synchronization according to the time pulse signal in an embodiment;

fig. 6 is a schematic structural diagram of a second base station device performing time synchronization according to a time pulse signal in an embodiment;

fig. 7 is a diagram illustrating a periodic time synchronization process of a second base station device in an embodiment;

fig. 8 is a schematic diagram illustrating a time synchronization process after the second base station device receives the time information packet in an embodiment;

fig. 9 is a flowchart of a method for implementing time synchronization between base station devices through a baseband radio frequency interface according to another embodiment;

FIG. 10 is a flowchart illustrating recovering a time pulse signal according to a time information packet and performing time synchronization according to the time pulse signal according to an embodiment;

fig. 11 is a schematic structural diagram of a system for implementing time synchronization between base station devices through a baseband radio frequency interface in an embodiment;

fig. 12 is a schematic structural diagram of an apparatus for implementing time synchronization between base station devices through a baseband radio frequency interface in an embodiment;

FIG. 13 is a block diagram of an embodiment of a time synchronization module;

FIG. 14 is a block diagram of an embodiment of a synchronization processing module.

Detailed Description

In an embodiment, a method for implementing time synchronization between base station devices through a baseband radio frequency interface is shown in fig. 1, and the method includes:

step S102: the first base station equipment providing the synchronization function acquires time synchronization information, and packages the time synchronization information to obtain a time information data packet.

The first base station equipment is base station equipment providing a synchronization function, and obtains time synchronization information and encapsulates the time synchronization information to obtain a time information data packet. The first base station device may be a radio frequency device (RE) or a radio frequency control device (REC), and may specifically receive the time synchronization information output by the GNSS receiving device.

The type of the time synchronization information is not unique, and may be GNSS time synchronization information or 1588 time synchronization information. The GNSS time synchronization information is information directly output by GNSS receiving equipment, and the 1588 time synchronization information is time synchronization information conforming to IEEE1588 standard (which is entirely referred to as a precision clock synchronization protocol standard of a network measurement and control system), and specifically, the GNSS receiving equipment and the first base station equipment can be installed together, and the 1588 time synchronization information is obtained after 1588 networking of the first base station equipment. It is understood that the time synchronization information acquired by the first base station device is not limited to GNSS time synchronization information and 1588 time synchronization information.

After acquiring the time synchronization information, the first base station device encapsulates the time synchronization information to obtain a time information data packet. The packaging mode of the time synchronization information is not unique and can be selected according to actual conditions. And the time information data packet obtained by encapsulation is used for being sent to the base station equipment needing time synchronization so as to carry out time synchronization. The information included in the time information data packet may specifically include information such as current absolute time, time precision level, and link transmission delay. It is to be understood that the information contained in the time information packet is not limited to the above information.

Step S104: and the first base station equipment sends the time information data packet to the second base station equipment to be synchronized through a baseband radio frequency interface.

And the second base station equipment refers to base station equipment needing time synchronization, and after the first base station equipment packages the time information data packet, the time information data packet is sent to the second base station equipment to be synchronized through the baseband radio frequency interface so that the second base station equipment can perform time synchronization. The second base station device may specifically be an REC device. The transmission method and the transmission route of the time information data packet are not unique, for example, the transmission method may specifically be to transmit the time information data packet to the second base station device in a fragmented or complete manner, where the fragmented transmission refers to transmitting the time information data packet after dividing the time information data packet into a plurality of fragmented time information data packets. The transmission path may specifically be to transmit the time information data packet through ethernet, a common public radio interface, or the like.

And the first base station equipment sends the time information data packet to the second base station equipment through the baseband radio frequency interface. The time synchronization information can be packaged into a data frame of the baseband radio frequency interface to obtain and send a time information data packet, and the data transmission reliability is high. The baseband Radio Interface may specifically be a Common Public Radio Interface (CPRI), an Interface between the RRU and the BBU, a standard Interface of the chinese communication standardization association (china association), an OBSAI (Open Base Station Architecture), an ethernet, or the like. The first base station equipment encapsulates the received GNSS time synchronization information or 1588 time synchronization information to obtain a time information data packet, and sends the time information data packet to the second base station equipment through the baseband radio frequency interface.

Specifically, the time information data packet may be divided into time information data packets, and then carried to a corresponding data frame of the baseband radio frequency interface for transmission, or the time information data packet may be directly carried to a corresponding data frame of the baseband radio frequency interface for transmission. The specific form of encapsulating the time synchronization information into the data frame of the baseband radio frequency interface is different according to the type of the time synchronization information. And if the time synchronization information is GNSS time synchronization information, packaging the GNSS time synchronization information into a data frame of the baseband radio frequency interface to obtain a GNSS TOD (serial time interface protocol) frame. And if the time synchronization information is 1588 time synchronization information, encapsulating the 1588 time synchronization information into a data frame of the baseband radio frequency interface to obtain a 1588 frame.

In this embodiment, the first base station device may send the time information packet to the second base station device according to a preset amount of time ahead. Specifically, the first base station apparatus calculates in advance the time required for transmission and parsing of the time information packet as the amount of advance time. And sending the time information data packet according to the amount of the advance time, so that the second base station equipment can receive and analyze the time information data packet in advance. For example, if the time required for transmitting and analyzing the time information packet is calculated as a, the first base station apparatus transmits the time information packet at time B-a in order for the second base station apparatus to analyze the time information packet at time B.

By sending the time information data packet according to the preset time amount in advance, the influence of the transmission and analysis time of the data packet on the time synchronization operation is avoided, and the time synchronization accuracy is improved.

Step S106: the second base station device receives the time information data packet through the baseband radio frequency interface.

The specific form of the time information data packet received by the second base station device is not unique, and if the time information data packet is completely transmitted by the first base station device, the time information data packet is directly received by the second base station device; and if the first base station equipment transmits the time information data packet in a fragmentation mode, the second base station equipment restores the received time information data packet in a fragmentation mode into a complete time information data packet.

Step S108: and the second base station equipment recovers to obtain the time pulse signal according to the time information data packet and performs time synchronization according to the time pulse signal.

The specific form of the time pulse signal recovered by the second base station apparatus is not exclusive, and may be a 1PPS signal, or other signals. PPS (pulse Per second) indicates the number of pulses Per second, and serves to indicate the time of a whole second, and a 1PPS signal indicates a signal having a number of pulses Per second of 1. The 1PPS signal can indicate the time of the whole second through the rising edge of the PPS second pulse, so that the identification is convenient.

And after receiving the time information data packet, the second base station equipment recovers to obtain the time pulse signal according to the time information data packet. Specifically, taking the example that the time pulse signal is a 1PPS signal, the second base station device analyzes the time information data packet to obtain time information, where the time information specifically includes, but is not limited to, the current absolute time, the time precision level, and the link transmission delay. And the second base station equipment processes the current absolute time to generate an initial 1PPS signal, and calibrates the initial 1PPS signal according to the link transmission delay to obtain the 1PPS signal.

And after the second base station equipment recovers the time pulse signal according to the time information, the second base station equipment synchronizes the local time according to the time pulse signal, so that the time synchronization between the base station equipment to be synchronized and the base station equipment providing the synchronization function is realized.

It is understood that the first base station device may periodically acquire and encapsulate the time synchronization information, and send the time information packet to the second base station device. And the second base station equipment periodically recovers to obtain the time pulse signal according to the time information data packet and performs time synchronization according to the time pulse signal.

According to the method for realizing the time synchronization between the base station devices through the baseband radio frequency interface, data interaction is carried out through the baseband radio frequency interface, and the receiving and sending of the time information data packet between the first base station device and the second base station device are realized so as to carry out the time synchronization. Even if the indoor base station equipment can receive the time information data packets sent by other base station equipment through the baseband radio frequency interface to perform time synchronization processing, GNSS receiving equipment does not need to be installed on the indoor base station equipment, the problem of application scene limitation of time synchronization among the base station equipment is solved, and the installation difficulty and the installation cost of the GNSS receiving equipment are reduced. In addition, the time synchronization among the base station equipment is realized through the base band radio frequency interface, and the problems of safety and reliability caused by a single synchronization mode at the base station equipment side can be avoided.

In one embodiment, the first base station device may be an RE device and the second base station device may be an REC device. As shown in fig. 2, specifically, the second base station device includes REC 210, the first base station device includes RE 220 and/or RE 230, and both RE 220 and RE 230 communicate with REC 210 through a baseband radio frequency interface.

The RE 220 is connected to the GNSS receiving apparatus, receives and encapsulates GNSS time synchronization information output by the GNSS receiving apparatus, obtains a time information data packet, and sends the time information data packet to the REC 210 through the baseband radio frequency interface. The REC 240 receives GNSS time synchronization information output by GNSS receiving equipment, transmits 1588 time synchronization information to the RE 230 through a 1588 networking interface, and the RE 230 encapsulates the received 1588 time synchronization information to obtain a time information data packet and sends the time information data packet to the REC 210 through a baseband radio frequency interface.

In another embodiment, the first base station device may be a REC device and the second base station device may also be a REC device. As shown in fig. 3, specifically, the second base station device includes REC 310, the first base station device includes REC 320 and/or REC 330, and REC 320 and REC 330 both communicate with REC 310 through the baseband radio frequency interface.

The REC 320 is connected to the GNSS receiving apparatus, receives and encapsulates GNSS time synchronization information output by the GNSS receiving apparatus, obtains a time information data packet, and sends the time information data packet to the REC 310 through the baseband radio frequency interface. The REC 340 receives GNSS time synchronization information output by the GNSS receiving equipment, 1588 time synchronization information is transmitted to the REC 330 through a 1588 networking interface, and the REC 330 packages the received 1588 time synchronization information to obtain a time information data packet and transmits the time information data packet to the REC 310 through a baseband radio frequency interface.

Embodiments of time synchronization information and communication between the first base station devices being different types of base station devices are given above. It is understood that the specific manner of communication between base station devices through the baseband radio frequency interface includes, but is not limited to, the above embodiments.

In one embodiment, as shown in fig. 4, the format of the time information packet includes a frame header, a message length field, a message payload, and a frame check sequence field. The header may be composed of SYNC CHAR (synchronization character) of fixed bytes, and the header may be composed of a preset number of bytes, which respectively define the message classification and the message ID. The message length is also composed of a preset number of bytes, and the calculation range of the message length comprises the message payload. The message payload consists of a plurality of bytes and is used for carrying message contents, and in the embodiment, the message payload specifically carries absolute time, time precision level, link transmission delay and the like. The frame check sequence field is used for checking the correctness of the time information data packet. It is to be understood that the format of the time information packet is not limited to the above-described form.

In one embodiment, as shown in fig. 5, step S108 includes steps S502 to S508.

Step S502: and the second base station equipment acquires the time information quality of the baseband radio frequency interface according to the time information data packet.

The specific way of obtaining the quality of the time information of the baseband radio frequency interface is not unique, and the quality of the time information can be obtained through a higher time precision level, and can also be obtained by combining the higher time precision level, the integrity of a time information data packet and the correctness of the time information data packet. In this embodiment, the quality of the time information of the baseband radio frequency interface is determined by the higher level of the time precision, the integrity of the time information data packet, and the correctness of the time information data packet.

Step S504: and the second base station equipment recovers to obtain the time pulse signal according to the time information data packet.

The specific manner of recovering the time pulse signal according to the time information data packet is described in step S108, and is not described herein again.

Step S506: and judging whether to allow the initiation of time synchronization according to the quality of the time information of the baseband radio frequency interface and the time pulse signal.

Judging whether the standard for allowing the initiation of time synchronization is not unique, after determining the time information quality of the baseband radio frequency interface and the time pulse signal, judging that the time information quality of the baseband radio frequency interface meets the preset grade according to the time information quality of the baseband radio frequency interface, and judging that the initiation of time synchronization is allowed under the condition that the time pulse signal is detected to be normal; if the initiation of the time synchronization is allowed, go to step S508; if the initiation of time synchronization is not allowed, it may be ended without proceeding to step S508.

Step S508: time synchronization is performed according to the time pulse signal.

Specifically, whether the local clock frequency needs to be adjusted or not can be further determined according to the time-to-second pulse signal and by combining the local time pulse signal, and if so, the local clock frequency is adjusted, so that the time of the second base station device is synchronized with the time of the first base station device.

In this embodiment, before performing time synchronization, the quality of the time information of the baseband radio frequency interface is further obtained according to the time information data packet, and the time pulse signal is recovered. And judging whether to allow the initiation of time synchronization according to the quality of the time information of the baseband radio frequency interface and the time pulse signal, thereby avoiding the influence on the accuracy of the time synchronization caused by unqualified quality of the time information data packet.

Further, in one embodiment, step S506 includes: the second base station equipment checks the integrity and the correctness of the time information data packet according to the time information data packet, acquires a superior time precision level according to the time information data packet and detects whether the time pulse signal is normal or not; and if the integrity and the correctness are verified, the upper-level time precision level reaches the preset precision level, and the time second impact signal is normal, judging that the time synchronization is allowed to be initiated.

The format of the time information data packet is detected to determine the integrity of the time information data packet, for example, keyword information may be extracted from a data frame received through the baseband radio frequency interface, and whether the received keywords of the previous preset number or the keywords of the previous preset bytes meet a preset standard is determined, if so, the integrity of the time information data packet is verified, so as to determine the integrity of the time information data packet. And if the time information data packet is of a preset definition type, determining the integrity of the time information data packet.

The method for checking the correctness of the time information data packet is not unique, and in this embodiment, the correctness of the time information data packet may be obtained through CRC (Cyclic Redundancy Check). Specifically, the message payload and the frame check sequence are extracted, CRC check calculation is performed, whether the calculation result is a preset fixed sequence is detected, and if yes, the correctness check of the time information data packet is passed, so that the correctness check of the time information data packet is confirmed.

The mode of obtaining the superior time precision level according to the time information data packet is not unique, the specific standard of the preset precision level is not unique, and the superior time precision level can be determined according to parameters carried in the message payload of the time information data packet. Parameters carried in message payload can include cycle number, pulse per second state, clock source working state, monitoring alarm, link delay and the like, each parameter has multiple attributes, and when the parameters are different attributes, different combination modes can be obtained among the parameters. Corresponding precision levels can be preset for different combination modes, and after the attributes of all parameters in message payload are obtained, the superior time precision level of the time information data packet can be determined.

The specific way of detecting whether the time pulse signal is normal is not unique according to the specific type of the time pulse signal. Taking the time pulse signal as the 1PPS signal as an example, when the 1PPS signal is recovered according to the time information data packet, whether a pulse can be recovered within 1 second is detected, and if so, the 1PPS signal can be considered to be normal.

When the integrity and the correctness are checked to be passed and the upper-level time precision level reaches the preset precision level, the time information quality of the baseband radio frequency interface can be considered to be passed, otherwise, the quality of the time information data packet is unqualified, and the time information data packet can be discarded. And if the quality of the time information of the baseband radio frequency interface is passed and the time pulse signal is normal, judging that the time synchronization is allowed to be initiated.

In addition, if the quality of the time information of the baseband radio frequency interface does not pass, the step S502 may be returned to obtain the quality of the time information of the baseband radio frequency interface for the next time of receiving the time information data packet, recover to obtain the time pulse signal, and then judge whether to allow the initiation of the time synchronization again.

In the embodiment, whether the time synchronization is allowed to be initiated or not is comprehensively judged according to the integrity and the correctness of the time information data packet, the upper-level time precision level and the time pulse signal, so that the influence on the accuracy of the time synchronization caused by unqualified quality of the time information data packet is avoided.

In one embodiment, step S508 includes step 1 through step 4.

Step 1: and if the second base station equipment judges that the time synchronization is allowed to be initiated, the time pulse signal is used as a reference pulse signal.

When the initiation of the time synchronization is allowed, the time pulse signal is directly used as a reference pulse signal for performing subsequent synchronization processing.

Step 2: and acquiring a local time pulse signal, and performing phase comparison on the reference time pulse signal and the local time pulse signal to obtain a phase deviation value.

Specifically, a local time pulse signal can be acquired through a local crystal oscillator, and a phase deviation value is obtained by performing phase comparison on the recovered reference time pulse signal and the local time pulse signal.

And step 3: and judging whether the phase deviation value is greater than or equal to a preset adjustment threshold value.

The specific value of the adjustment threshold value can be adjusted according to the actual situation. And determining whether to initiate frequency adjustment of the local clock according to the phase deviation value. If the phase deviation value is smaller than the adjustment threshold value, not initiating the frequency adjustment of the local clock; otherwise, step 4 is carried out, and the frequency adjustment of the local clock is initiated.

And 4, step 4: and adjusting the clock frequency of the local crystal oscillator according to the reference time pulse signal and the local time pulse signal to synchronize the phases of the local time pulse signal and the reference time pulse signal.

If the local clock frequency adjustment needs to be initiated, the phase deviation value of the reference time pulse signal and the local time pulse signal can be repeatedly calculated, and the clock frequency of the local crystal oscillator is adjusted until the phase deviation value is smaller than the adjustment threshold value, so that the phase synchronization of the local time pulse signal and the reference time pulse signal is realized.

The specific structure of the second base station device is different, and the specific manner of performing time synchronization according to the time pulse signal is also different. In one embodiment, as shown in fig. 6, the second base station apparatus includes a phase detector 602, a low pass filter 604, a local crystal 606, a frequency divider 608, and a phase locked loop 610. The phase detector 602 is coupled to the low pass filter 604, the frequency divider 608, and the phase locked loop 610, the local crystal 606 is coupled to the low pass filter 604 and the frequency divider 608, and the frequency divider 608 is coupled to the phase locked loop 610. In this embodiment, the local Crystal Oscillator 606 is an OCXO (Oven Controlled Crystal Oscillator).

Taking the time pulse signal as a 1PPS signal as an example, the second base station device performs time synchronization according to the time pulse signal, specifically: divider 608 receives the crystal signal from local crystal 606 and outputs a local 1PPS signal to phase detector 602. Phase locked loop 610 outputs a high frequency clock signal to phase detector 602. The phase detector 602 performs phase detection on the received 1PPS signal and the local 1PPS signal to obtain a phase detection value, generates a corresponding signal according to the phase detection value, and sends the signal to the low-pass filter 604, and the low-pass filter 604 attenuates a high-frequency error component at the output end of the phase detector 602, so as to improve the anti-interference performance. The low pass filter 604 adjusts the voltage-controlled voltage output to the local oscillator 606 to adjust the clock frequency of the local oscillator 606.

In one embodiment, when the first base station device periodically acquires the time synchronization information and encapsulates the acquired time information data packet to send to the second base station device, the second base station device periodically performs the time synchronization operation. As shown in fig. 7, the second base station device periodically recovers to obtain the time pulse signal according to the time information data packet, and performs time synchronization according to the time pulse signal, which specifically includes the following steps:

step S702: and periodically acquiring time information data packets from the baseband radio frequency interface.

Step S704: and periodically calculating the phase deviation value of the reference time pulse signal and the local time pulse signal.

Step S706: judging whether the local clock frequency needs to be adjusted or not according to the phase deviation value; if yes, go to step S708; if not, the process is ended and no adjustment is performed.

Step S708: and adjusting the frequency of the local clock according to the phase deviation value to complete time synchronization, wherein the phase of the local time pulse signal is synchronous with that of the reference time pulse signal.

In this embodiment, the second base station device may continuously obtain the time information data packet from the baseband radio frequency interface, and continuously calculate a phase deviation value between the reference time pulse signal and the local time pulse signal, and when it is determined that the local clock frequency needs to be adjusted according to the phase deviation value, adjust the local clock frequency according to the phase deviation value, so as to finally implement time synchronization between the second base station device and the first base station device.

In an embodiment, as shown in fig. 8, after receiving the time information data packet, the second base station device first obtains the quality of the time information of the baseband radio frequency interface and recovers to obtain the time pulse signal, and performs time synchronization according to the time pulse signal when the time synchronization is allowed to be initiated. The method specifically comprises the following steps:

step S802: and receiving the time information data packet.

Step S804: and acquiring the time information quality of the baseband radio frequency interface according to the integrity and the CRC check correctness of the time information data packet and the precision level of the upper-level time information.

Step S806: and generating an initial time pulse signal according to the time information data packet, and calibrating the initial time pulse signal according to the link transmission delay to obtain the time pulse signal.

Step S808: and judging whether to allow the initiation of phase adjustment according to the quality of the time information of the baseband radio frequency interface and the time pulse. If yes, the phase adjustment enabling is initiated, and step S810 is executed.

Step S810: using the time pulse signal as a reference pulse signal, and calculating a phase deviation value between the reference time pulse signal and the local time pulse signal

Step S812: judging whether the phase deviation value is greater than or equal to a preset adjustment threshold value or not; if yes, go to step S814; if not, the frequency adjustment of the local clock is not initiated.

Step S814: and adjusting the clock frequency of the local crystal oscillator according to the phase deviation value so as to synchronize the phases of the local time pulse signal and the reference time pulse signal.

To facilitate a further understanding of the above-described methods, several specific examples are provided below for illustration.

In a first embodiment, the time synchronization information is GNSS time synchronization information, and the first base station device encapsulates the GNSS time synchronization information into a corresponding data frame sent by the baseband radio frequency interface.

The first base station device encapsulates the GNSS time synchronization information to obtain a GNSS TOD frame, where the GNSS TOD frame is defined as follows:

frame head: may consist of 2 fixed bytes of SYNC CHAR. Such as fixed values of 0x43 (representing the "C" characters in ASCII code) and 0x4D (representing the "M" characters in ASCII code).

Message header: may consist of 4 bytes, defining a message classification and a message ID, respectively. If a fixed value of 0x8001 is used to indicate that the current message is a GNSS TOD message; the number of the current message as one message period is expressed by using unsigned numbers 0-65535.

Message length field: may consist of 4 bytes. The range of message length field calculations contains the message payload.

Message payload: the message content consists of several bytes (20 bytes is taken as an example in this embodiment).

Frame check sequence field: may be composed of 1 byte, 2 bytes or 4 bytes (2 bytes is taken as an example in this embodiment).

When the frame check sequence field is 1 byte, the polynomial of the frame check sequence is g (x) ═ x8+ x5+ x4+ 1.

The check sequence may be calculated using CRC16 when the frame check sequence field is 2 bytes.

The check sequence may be calculated using CRC32 when the frame check sequence field is 4 bytes.

In this embodiment, the GNSS TOD frame format totals 32 bytes. The message payload is 20 bytes and contains information such as absolute time, time precision level, link delay and the like. The message payload definition is shown in table 1.

TABLE 1

Wherein, U1 is an unsigned character type, and is composed of 1 byte. I1 is a signed character type consisting of 1 byte. U2 is an unsigned character type consisting of 2 bytes. U4 is an unsigned character type consisting of 4 bytes.

The first base station device divides the data of 32 bytes in total of the GNSS TOD frames into 16 subframes, each subframe being 2 bytes. And sending data through a baseband radio frequency interface, and sending out the 16 sub-frames with 2 bytes loaded in corresponding data frames of the baseband radio frequency interface for 16 times. The absolute time carried in the message payload is kept consistent with the local sending time.

The second base station equipment receives the data frame, extracts the keyword information from the GNSS TOD filling position of the data frame, and determines the integrity and CRC check correctness of the time information data packet according to the extracted keyword information, specifically comprising the following steps:

1) and judging whether the first time receiving key is 0x434d (namely the frame header defined by the sending end), if not, discarding the current information, and if so, waiting for next time receiving data.

2) And judging whether the keyword received for the second time is 0x8001 (namely the current field is the message TOD message type), if not, discarding the current information, and if so, waiting for receiving data for the next time.

3) Reading the third received data, recording the ID number of the current TOD message, and judging whether the received TOD message is interrupted or not and the interruption amount according to the continuity of the ID number.

4) And reading the fourth and fifth received data and recording the current message length field. And determines the length (i.e., the number of times) of the received message according to the message length field.

5) And counting the message length according to the message length field and collecting the payload of the received message. If the message length field is 0x14, it indicates that the current message length is 20 bytes. The GNSS TOD messages are collected 10 times (2 bytes each) next.

6) And after receiving the message payload, receiving a frame check sequence field. And (3) carrying out CRC16 check calculation again for 1 time on the 20byte message payload and the frame check sequence, wherein the calculated fixed sequence (x 15-x 0:0001110100001111) is the current collected complete message, and otherwise, discarding the current message.

7) And checking the correct message, and respectively extracting information such as absolute time, time precision level, link time delay and the like encapsulated in the GNSS TOD message from the current message corresponding to the message payload definition.

Further, the second base station device determines whether synchronization needs to be initiated according to information such as the quality of the time information of the baseband radio frequency interface encapsulated by the extracted GNSS TOD message. If the quality of the time information obtained by the analysis of the baseband radio frequency interface is poor, synchronization is not initiated; the quality of time information obtained by analyzing the baseband radio frequency interface is good, and then synchronization can be started.

If the initiation of synchronization is allowed, the second base station device initiates synchronization enabling. And the second base station equipment performs phase discrimination on the recovered 1PPS signal and the local 1PPS signal, extracts a phase deviation value, and reports the phase deviation value obtained by phase discrimination.

The second base station apparatus determines whether the phase deviation value is smaller than a phase adjustment deviation threshold value. If so, it is not necessary to adjust a local clock crystal such as an OCXO (rubidium clock or the like). Otherwise, the frequency of the local clock is adjusted by adjusting the voltage-controlled voltage of the local clock crystal and the like. And repeatedly calculating the phase deviation value and adjusting the frequency of the local clock until synchronization is finished.

The clock frequency synchronization between the base station equipment to be synchronized and the base station equipment providing the synchronization function is finally achieved through the encapsulation of the GNSS TOD information by the first base station equipment, the sending of the baseband radio frequency interface, the analysis of the GNSS TOD information by the second base station equipment and the processing of the synchronization mechanism, so that the time synchronization function is achieved.

In a second embodiment, the time synchronization information is GNSS time synchronization information, and the first base station device encapsulates the GNSS time synchronization information into a data frame sent by the baseband radio frequency interface.

The GNSS TOD frame is obtained by encapsulating the GNSS time synchronization information, and the definition thereof is similar to that of the first embodiment and is not described herein again.

The first base station device sends data through a baseband radio frequency interface, and directly loads the data of 32 bytes in total of the GNSS TOD frames in a corresponding data frame of the baseband radio frequency interface to send the data. The absolute time carried in the message payload is kept consistent with the local sending time.

1) it is determined whether the key of the first 2 bytes of the received message is 0x434d (i.e., the sender-defined header), otherwise the current information is discarded.

2) And judging whether the 3 rd and 4 th byte keywords of the received message are 0x8001 (namely the current field is the type of the TOD message of the message), and if not, discarding the current information.

3) Reading the 5 th and 6 th byte data of the received message, recording the ID number of the current TOD message, and judging whether the received TOD message has interruption or not and the interruption amount according to the continuity of the ID number.

4) Reading the 7 th, 8 th, 9 th and 10 th byte data of the received message, and recording the length field of the current message. And judging the length of the received message according to the message length field.

5) And counting the message length according to the message length field and collecting the payload of the received message. If the message length field is 0x14, it indicates that the current message length is 20 bytes. The payload length of the current GNSS TOD message is 20 bytes.

6) The 2byte data after the message payload is the frame check sequence field. And (4) carrying out CRC16 check calculation again for 1 time on the 20byte message payload and the frame check sequence, obtaining a fixed sequence (x 15-x 0:0001110100001111) which is correct for checking the current collected message, and otherwise, discarding the current message.

Further, the second base station device determines whether synchronization needs to be initiated according to information such as the quality of the time information of the baseband radio frequency interface encapsulated by the extracted GNSS TOD message. If the quality of the time information of the baseband radio frequency interface obtained by analysis is poor, synchronization is not initiated; the baseband radio frequency interface time information obtained by analysis has good quality, and then synchronization can be started.

If the initiation of synchronization is allowed, the second base station device initiates synchronization enabling. The specific process is similar to that in the first embodiment, and is not described herein again.

In the third embodiment, the time synchronization information is 1588 synchronization information, and the first base station device encapsulates the 1588 synchronization information into a corresponding data frame sent by the baseband radio frequency interface.

The first base station equipment encapsulates the 1588 synchronization information to obtain a 1588 frame, the 1588 frame can be directly encapsulated into a message payload, and since the baseband radio frequency interface link delay is relatively definite, the link delay can be filled in the message payload according to the same format of the GNSS TOD message. Because the link delay does not need to be calculated through interaction, only several messages such as sync, followup, announce and the like need to be supported for the 1588 frame. And respectively representing several message types of 1588 messages, such as sync, followup, announce and the like, of the current message by using fixed numerical values of 0x 8002-0 x8004 in the message classification of the message header.

In this embodiment, the format of the 1588 frame is consistent with that of the 1588 protocol, and the definition of the message payload is shown in table 2.

TABLE 2

Wherein 1588header definition description is shown in table 3.

TABLE 3

1588 timestamp totals 10 bytes, containing 6 bytes of second bit information and 4 bytes of nanosecond bit information. 1588 the clock precision is 20 bytes in total, and only exists in the announce message. The link delay and the baseband radio frequency interface clock quality are consistent with the message encapsulation definition of the GNSS TOD.

The first base station device divides data of 60 bytes (sync message, followup message, where the message payload is 48 bytes) or 80 bytes (announce message, where the message payload is 68 bytes) in total of the 1588 frames into 30 or 40 subframes, and each subframe is 2 bytes. And sending data through a baseband radio frequency interface, and sending the 30 or 40 sub-frames of 2 bytes in a data frame of the baseband radio frequency interface in a way of being carried by 30 times or 40 times. The absolute time carried in the message payload is kept consistent with the local sending time.

The second base station equipment receives the data frame, extracts the keyword information from the 1588 message filling position of the data frame, and determines the integrity and the CRC check correctness of the time information data packet according to the extracted keyword information, and the method specifically comprises the following steps:

2) And judging whether the keyword received for the second time is 0x8001 (namely the current field is the message type of the message 1588), if not, discarding the current information, and if so, waiting for next data reception.

3) Reading the third received data, recording the third received data as the ID number of the current 1588 message, and judging whether the received 1588 message has interruption or not and the interruption amount according to the continuity of the ID number.

5) And counting the message length according to the message length field and collecting the payload of the received message. If the message length field is 0x30, it indicates that the current message payload length is 48 bytes. Collecting 1588 messages for the next 24 times (2 bytes each); if the message length field is 0x44 as described above, it indicates that the current message payload length is 68 bytes. The next 34 times (2 bytes each) the 1588 message is collected.

6) And after receiving the message payload, receiving a frame check sequence field. And (3) carrying out CRC16 check calculation again for 1 time on the message payload and the frame check sequence of 48 bytes or 68 bytes to obtain a fixed sequence (x 15-x 0:0001110100001111), namely, the fixed sequence is the current collected complete message, otherwise, the current message is discarded.

7) And checking the correct message, and respectively extracting information such as absolute time, time precision level (only announce message), link delay and the like encapsulated in the 1588 time message from the currently acquired complete message corresponding to the message payload definition.

Further, the second base station device determines whether synchronization needs to be initiated according to information such as the quality of the extracted baseband radio frequency interface time information encapsulated by the 1588 message. If the quality of the time information of the baseband radio frequency interface obtained by analysis is poor, synchronization is not initiated; the baseband radio frequency interface time information obtained by analysis has good quality, and then synchronization can be started.

The clock frequency synchronization between the base station equipment to be synchronized and the base station equipment providing the synchronization function is finally achieved through the encapsulation of the 1588 information by the first base station equipment, the sending of the baseband radio frequency interface, the analysis of the 1588 information by the second base station equipment and the processing of the synchronization mechanism, and thus the time synchronization function is achieved.

In the fourth embodiment, the time synchronization information is 1588 synchronization information, and the first base station device encapsulates the 1588 synchronization information into a data frame sent by the baseband radio frequency interface.

The first base station device encapsulates the 1588 synchronization information to obtain 1588 frames, and the 1588 frames can be directly encapsulated into a message payload. The format of 1588 frame is specific to the type in the third embodiment, and is not described herein again.

The first base station device sends out data bearing of 60 bytes (sync message, followup message, where the message payload is 48 bytes) or 80 bytes (announce message, where the message payload is 68 bytes) in total of 1588 frames in a data frame of the baseband radio frequency interface. The absolute time carried in the message payload is kept consistent with the local sending time.

2) Judging whether the 3 rd and 4 th byte keywords of the received message are 0x 8002-0 x8004 (namely the current field is the message type of the message 1588), and if not, discarding the current information.

3) Reading the 5 th byte data and the 6 th byte data of the received message, recording the data as the ID number of the current 1588 message, and recording and judging whether the received TOD message has interruption and the interruption amount according to the continuity of the ID number.

4) Reading the 7 th, 8 th, 9 th and 10 th byte data of the received message, and recording the length field of the current message. And judging the length of the received message according to the length field.

5) Counting the message length according to the message length field, and collecting the payload of the received message; when the message length field is 0x30, it indicates that the current message length is 48 bytes. The length of the payload of the current 1588 message is 48 bytes; when the message length field is 0x44, as described above, it indicates that the current message length is 68 bytes. The payload length of the current 1588 message is 68 bytes.

6) The 2byte data after the message payload is the frame check sequence field. And (3) carrying out CRC16 check calculation again for 1 time on the 48 or 68byte message payload and the frame check sequence, wherein the calculated fixed sequence (x 15-x 0:0001110100001111) is correct for checking the current collected message, otherwise, the current message is discarded.

7) And checking the correct message, and respectively extracting information such as absolute time, time precision level (only announce message), link delay and the like encapsulated in the 1588 message from the current message corresponding to the message payload definition of the sending end.

In an embodiment, the method for implementing time synchronization between base station devices through a baseband radio frequency interface is exemplified by being applied to a base station device to be synchronized. As shown in fig. 9, the method comprises the following steps:

step S902: and receiving a time information data packet sent by the base station equipment providing the synchronization function through a baseband radio frequency interface.

Step S904: and recovering the time pulse signal according to the time information data packet, and performing time synchronization according to the time pulse signal.

According to the method for realizing the time synchronization between the base station devices through the baseband radio frequency interface, data interaction is carried out through the baseband radio frequency interface, and the time information data packets between the base station devices are received and sent to carry out the time synchronization. Even if the indoor base station equipment can receive the time information data packets sent by other base station equipment through the baseband radio frequency interface to perform time synchronization processing, GNSS receiving equipment does not need to be installed on the indoor base station equipment, the problem of application scene limitation of time synchronization among the base station equipment is solved, and the installation difficulty and the installation cost of the GNSS receiving equipment are reduced.

In one embodiment, the time synchronization information in the time information data packet is GNSS time synchronization information or 1588 time synchronization information.

In one embodiment, as shown in fig. 10, step S904 includes steps S1002 to S1008.

Step S1002: and acquiring the time information quality of the baseband radio frequency interface according to the time information data packet.

Step S1004: and recovering the time pulse signal according to the time information data packet.

Step S1006: and judging whether to allow the initiation of time synchronization according to the quality of the time information of the baseband radio frequency interface and the time pulse signal. If yes, go to step S1008.

Step S1008: time synchronization is performed according to the time pulse signal.

Specifically, in this embodiment, the base station device with synchronization may determine, according to the quality of the time information of the baseband radio frequency interface, that the quality of the time information of the baseband radio frequency interface meets the preset level, and determine that the time synchronization is allowed to be initiated when it is detected that the time pulse signal is normal.

Further, in one embodiment, step S1006 includes: and checking the integrity and the correctness of the time information data packet according to the time information data packet, acquiring the upper time precision level according to the time information data packet, and detecting whether the time pulse signal is normal or not. And if the integrity and the correctness are verified, the upper-level time precision level reaches the preset precision level, and the time pulse signal is normal, judging that the time synchronization is allowed to be initiated.

In one embodiment, step S1008 includes the steps of: if the time synchronization is allowed to be initiated, the time pulse signal is used as a reference pulse signal; acquiring a local time pulse signal, and performing phase comparison on the reference time pulse signal and the local time pulse signal to obtain a phase deviation value; judging whether the phase deviation value is greater than or equal to a preset adjustment threshold value or not; if so, adjusting the clock frequency of the local crystal oscillator according to the reference time pulse signal and the local time pulse signal to synchronize the phases of the local time pulse signal and the reference time pulse signal.

The system for implementing time synchronization between base station devices through a baseband radio frequency interface in one embodiment, as shown in fig. 11, includes a first base station device 112 providing a synchronization function and a second base station device 114 to be synchronized.

The first base station device 112 is configured to obtain time synchronization information, and encapsulate the time synchronization information to obtain a time information data packet; and sending the time information data packet to the second base station equipment to be synchronized through the baseband radio frequency interface.

The second base station device 114 is configured to receive the time information data packet through the baseband radio frequency interface, recover the time pulse signal according to the time information data packet, and perform time synchronization according to the time pulse signal.

It is understood that the first base station apparatus 112 may periodically acquire and encapsulate the time synchronization information, and send the time information packet to the second base station apparatus 114. The second base station apparatus 114 periodically recovers the time pulse signal from the time information packet and performs time synchronization based on the time pulse signal.

According to the system for realizing time synchronization between the base station devices through the baseband radio frequency interface, data interaction is carried out through the baseband radio frequency interface, and the receiving and sending of the time information data packet between the first base station device and the second base station device are realized so as to carry out time synchronization. Even if the indoor base station equipment can receive the time information data packets sent by other base station equipment through the baseband radio frequency interface to perform time synchronization processing, GNSS receiving equipment does not need to be installed on the indoor base station equipment, the problem of application scene limitation of time synchronization among the base station equipment is solved, and the installation difficulty and the installation cost of the GNSS receiving equipment are reduced. In addition, the time synchronization among the base station equipment is realized through the base band radio frequency interface, and the problems of safety and reliability caused by a single synchronization mode at the base station equipment side can be avoided.

In one embodiment, the second base station device 114 is configured to obtain the time information quality of the baseband radio frequency interface according to the time information data packet; and recovering the time pulse signal according to the time information data packet. Judging whether to allow to initiate time synchronization according to the quality of the time information of the baseband radio frequency interface and the time pulse signal; if yes, time synchronization is carried out according to the time pulse signal.

Further, in one embodiment, the second base station device 114 is configured to check the integrity and correctness of the time information data packet according to the time information data packet, and obtain an upper time precision level according to the time information data packet; and detecting whether the time pulse signal is normal. And if the integrity and the correctness are verified, the upper-level time precision level reaches the preset precision level, and the time pulse signal is normal, judging that the time synchronization is allowed to be initiated.

In one embodiment, the second base station apparatus 114 is further configured to use the time pulse signal as a reference pulse signal if it is determined that the initiation of the time synchronization is allowed; and acquiring a local time pulse signal, and performing phase comparison on the reference time pulse signal and the local time pulse signal to obtain a phase deviation value. Judging whether the phase deviation value is greater than or equal to a preset adjustment threshold value or not; if so, adjusting the clock frequency of the local crystal oscillator according to the reference time pulse signal and the local time pulse signal to synchronize the phases of the local time pulse signal and the reference time pulse signal.

In one embodiment, second base station equipment 114 may be REC equipment.

The apparatus for implementing time synchronization between base station devices through a baseband radio frequency interface in one embodiment, as shown in fig. 12, includes a time information receiving module 122 and a time synchronization module 124. Wherein:

the time information receiving module 122 is configured to receive a time information data packet sent by a base station device providing a synchronization function through a baseband radio frequency interface.

The time synchronization module 124 is configured to obtain a time pulse signal according to the time information data packet, and perform time synchronization according to the time pulse signal.

The device for realizing time synchronization between the base station devices through the baseband radio frequency interface carries out data interaction through the baseband radio frequency interface, and realizes the receiving and sending of time information data packets between the base station devices so as to carry out time synchronization. Even if the indoor base station equipment can receive the time information data packets sent by other base station equipment through the baseband radio frequency interface to perform time synchronization processing, GNSS receiving equipment does not need to be installed on the indoor base station equipment, the problem of application scene limitation of time synchronization among the base station equipment is solved, and the installation difficulty and the installation cost of the GNSS receiving equipment are reduced.

In one embodiment, as shown in fig. 13, the time synchronization module 124 includes a time information quality acquisition module 132, a signal recovery module 134, a synchronization judgment module 136, and a synchronization processing module 138. Wherein:

the time information quality obtaining module 132 is configured to obtain the quality of the time information of the baseband radio frequency interface according to the time information data packet.

The signal recovery module 134 is configured to recover the time pulse signal according to the time information data packet.

The synchronization determining module 136 is configured to determine whether to allow initiating time synchronization according to the quality of the time information of the baseband radio frequency interface and the time pulse signal.

The synchronization processing module 138 is configured to perform time synchronization according to the time pulse signal when the synchronization judging module 136 determines that the time synchronization is allowed to be initiated.

Further, in one embodiment, the synchronization determining module 136 is configured to check the integrity and correctness of the time information data packet according to the time information data packet, and obtain a higher time precision level according to the time information data packet; and detecting whether the time pulse signal is normal. And if the integrity and the correctness are verified, the upper-level time precision level reaches the preset precision level, and the time pulse signal is normal, judging that the time synchronization is allowed to be initiated.

In one embodiment, as shown in fig. 14, the synchronization processing module 138 includes a phase calculation module 142, a phase determination module 144, and a phase synchronization module 146. Wherein:

the phase calculation module 142 is configured to take the time pulse signal as a reference pulse signal if it is determined that the initiation of time synchronization is allowed; and acquiring a local time pulse signal, and performing phase comparison on the reference time pulse signal and the local time pulse signal to obtain a phase deviation value.

The phase determining module 144 is configured to determine whether the phase deviation value is greater than or equal to a preset adjustment threshold.

The phase synchronization module 146 is configured to adjust a clock frequency of the local crystal oscillator according to the reference time pulse signal and the local time pulse signal when the phase deviation value is greater than or equal to the preset adjustment threshold value, so that the phases of the local time pulse signal and the reference time pulse signal are synchronized.

It will be understood by those skilled in the art that all or part of the processes in the methods of the embodiments described above may be implemented by hardware related to instructions of a computer program, which may be stored in a computer readable storage medium, for example, in the storage medium of a computer system, and executed by at least one processor in the computer system, so as to implement the processes of the embodiments including the methods described above. The storage medium may be a magnetic disk, an optical disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), or the like.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims

1. A method for implementing time synchronization between base station devices through a baseband radio frequency interface, the method comprising:

a second base station device of the base station receives a time information data packet which is sent by a first base station device of the base station and provides a synchronization function according to a preset advance time quantum and contains current absolute time and link transmission time delay through a baseband radio frequency interface;

and the second base station equipment of the base station recovers to obtain a time pulse signal according to the time information data packet containing the current absolute time and the link transmission delay, and performs time synchronization according to the time pulse signal to synchronize the phase of the local time pulse signal and the phase of the time pulse signal.

2. The method of claim 1, wherein the recovering a time pulse signal according to the time information packet including the current absolute time and the link transmission delay and performing time synchronization according to the time pulse signal comprises:

acquiring the time information quality of a baseband radio frequency interface according to the time information data packet;

recovering to obtain a time pulse signal according to the current absolute time and the link transmission delay in the time information data packet;

judging whether to allow to initiate time synchronization according to the quality of the time information of the baseband radio frequency interface and the time pulse signal;

and if so, performing time synchronization according to the time pulse signal.

3. The method of claim 2, wherein the determining whether to allow the initiation of time synchronization according to the quality of the baseband radio frequency interface time information and the time pulse signal comprises:

checking the integrity and correctness of the time information data packet according to the time information data packet, and acquiring a superior time precision level according to the time information data packet;

detecting whether the time pulse signal is normal or not;

and if the integrity and the correctness are verified, the upper-level time precision level reaches a preset precision level, and the time pulse signal is normal, judging that the time synchronization is allowed to be initiated.

4. The method of claim 2, wherein the time synchronizing according to the time pulse signal comprises:

if the time synchronization is allowed to be initiated, taking the time pulse signal as a reference time pulse signal;

acquiring the local time pulse signal, and performing phase comparison on the reference time pulse signal and the local time pulse signal to obtain a phase deviation value;

judging whether the phase deviation value is greater than or equal to a preset adjustment threshold value or not;

if so, adjusting the clock frequency of a local crystal oscillator according to the reference time pulse signal and the local time pulse signal to synchronize the phases of the local time pulse signal and the reference time pulse signal.

5. The method of claim 1, wherein the time synchronization information in the time information packet is GNSS time synchronization information or 1588 time synchronization information.

6. A method for implementing time synchronization between base station devices through a baseband radio frequency interface, the method comprising:

a first base station device of a base station, which provides a synchronization function, acquires time synchronization information including current absolute time and link transmission delay, and packages the time synchronization information including the current absolute time and the link transmission delay to obtain a time information data packet including the current absolute time and the link transmission delay;

the first base station equipment of the base station sends the time information data packet containing the current absolute time and the link transmission delay to second base station equipment to be synchronized of the base station through a baseband radio frequency interface according to preset advance time quantum;

the second base station equipment of the base station receives the time information data packet which is sent by the first base station equipment of the base station and provides the synchronization function according to the preset advance time quantum and contains the current absolute time and the link transmission time delay through the baseband radio frequency interface;

7. The method of claim 6, wherein the second base station device recovers to obtain a time pulse signal according to the time information packet including the current absolute time and the link transmission delay, and performs time synchronization according to the time pulse signal, and the method includes:

the second base station equipment acquires the time information quality of the baseband radio frequency interface according to the time information data packet;

the second base station equipment recovers to obtain a time pulse signal according to the current absolute time and the link transmission delay in the time information data packet;

and if so, performing time synchronization according to the time pulse signal.

8. The method of claim 7, wherein the determining whether to allow the initiation of time synchronization according to the quality of the baseband radio frequency interface time information and the time pulse signal comprises:

the second base station equipment checks the integrity and the correctness of the time information data packet according to the time information data packet and acquires a superior time precision level according to the time information data packet;

detecting whether the time pulse signal is normal or not;

9. The method of claim 7, wherein the time synchronizing according to the time pulse signal comprises:

if the second base station equipment determines that the time synchronization is allowed to be initiated, taking the time pulse signal as a reference time pulse signal;

10. The method of claim 6, wherein the time synchronization information is GNSS Global navigation satellite System time synchronization information or 1588 time synchronization information.

11. The method of claim 6, wherein the second base station equipment is REC radio frequency control equipment.

12. An apparatus for implementing time synchronization between base station devices through a baseband radio frequency interface, the apparatus being applied to a second base station device of a base station, the apparatus comprising:

the time information receiving module is used for receiving a time information data packet which is sent by first base station equipment of the base station and provides a synchronization function according to preset advance time quantity and contains current absolute time and link transmission delay through a baseband radio frequency interface;

and the time synchronization module is used for recovering the time pulse signal according to the time information data packet containing the current absolute time and the link transmission delay, and carrying out time synchronization according to the time pulse signal so as to synchronize the phase of the local time pulse signal with the phase of the time pulse signal.

13. The apparatus of claim 12, wherein the time synchronization module comprises:

the time information quality acquisition module is used for acquiring the time information quality of the baseband radio frequency interface according to the time information data packet;

the signal recovery module is used for recovering and obtaining a time pulse signal according to the current absolute time and the link transmission delay in the time information data packet;

a synchronization judging module for judging whether to allow to initiate time synchronization according to the quality of the time information of the baseband radio frequency interface and the time pulse signal;

and the synchronization processing module is used for carrying out time synchronization according to the time pulse signal when the synchronization judging module judges that the time synchronization is allowed to be initiated.

14. The apparatus according to claim 13, wherein the synchronization determining module is configured to check integrity and correctness of the time information packet according to the time information packet, and obtain a higher time precision level according to the time information packet; detecting whether the time pulse signal is normal or not; and if the integrity and the correctness are verified, the upper-level time precision level reaches a preset precision level, and the time pulse signal is normal, judging that the time synchronization is allowed to be initiated.

15. The apparatus of claim 13, wherein the synchronization processing module comprises:

the phase calculation module is used for taking the time pulse signal as a reference time pulse signal if the time synchronization is allowed to be initiated; acquiring the local time pulse signal, and performing phase comparison on the reference time pulse signal and the local time pulse signal to obtain a phase deviation value;

the phase judgment module is used for judging whether the phase deviation value is greater than or equal to a preset adjustment threshold value or not;

and the phase synchronization module is used for adjusting the clock frequency of the local crystal oscillator according to the reference time pulse signal and the local time pulse signal when the phase deviation value is greater than or equal to a preset adjustment threshold value, so that the phases of the local time pulse signal and the reference time pulse signal are synchronized.

16. The apparatus of claim 12, wherein the time synchronization information in the time information packet is GNSS time synchronization information or 1588 time synchronization information.

17. A system for implementing time synchronization between base station devices through a baseband radio frequency interface, the system comprising a first base station device of a base station providing a synchronization function and a second base station device of the base station to be synchronized, wherein:

the first base station equipment of the base station, which provides a synchronization function, is configured to acquire time synchronization information including current absolute time and link transmission delay, and package the time synchronization information including the current absolute time and the link transmission delay to obtain a time information data packet including the current absolute time and the link transmission delay; according to a preset amount of time in advance, sending the time information data packet containing the current absolute time and the link transmission delay to the second base station equipment to be synchronized of the base station through a baseband radio frequency interface;

the second base station device to be synchronized of the base station is configured to receive, through the baseband radio frequency interface, the time information data packet including the current absolute time and the link transmission delay, which is sent by the first base station device providing the synchronization function of the base station according to a preset amount of advance time, recover the time pulse signal according to the time information data packet including the current absolute time and the link transmission delay, and perform time synchronization according to the time pulse signal, so that the phase of the local time pulse signal is synchronized with the phase of the time pulse signal.

18. The system according to claim 17, wherein said second base station device is configured to obtain a quality of time information of a baseband radio frequency interface according to said time information data packet; recovering to obtain a time pulse signal according to the current absolute time and the link transmission delay in the time information data packet; judging whether to allow to initiate time synchronization according to the quality of the time information of the baseband radio frequency interface and the time pulse signal; and if so, performing time synchronization according to the time pulse signal.

19. The system according to claim 18, wherein the second base station device is configured to check integrity and correctness of the time information packet according to the time information packet, and obtain an upper time precision level according to the time information packet; detecting whether the time pulse signal is normal or not; and if the integrity and the correctness are verified, the upper-level time precision level reaches a preset precision level, and the time pulse signal is normal, judging that the time synchronization is allowed to be initiated.

20. The system according to claim 18, wherein the second base station device is further configured to use the time pulse signal as a reference time pulse signal if it is determined that the initiation of time synchronization is allowed; acquiring the local time pulse signal, and performing phase comparison on the reference time pulse signal and the local time pulse signal to obtain a phase deviation value; judging whether the phase deviation value is greater than or equal to a preset adjustment threshold value or not; if so, adjusting the clock frequency of a local crystal oscillator according to the reference time pulse signal and the local time pulse signal to synchronize the phases of the local time pulse signal and the reference time pulse signal.

21. The system of claim 17, wherein the time synchronization information is GNSS time synchronization information or 1588 time synchronization information.

22. The system in claim 17, wherein the second base station device is a REC radio frequency control device.