WO2016165476A1

WO2016165476A1 - Clock synchronization method and system, end station and computer storage medium

Info

Publication number: WO2016165476A1
Application number: PCT/CN2016/074128
Authority: WO
Inventors: 石乔; 胡晓鹏; 尧小安
Original assignee: 中兴通讯股份有限公司
Priority date: 2015-08-03
Filing date: 2016-02-19
Publication date: 2016-10-20
Also published as: CN106413075A; CN106413075B

Abstract

Disclosed are a clock synchronization method and system, an end station and a computer storage medium, which are applied to the field of communications. The clock synchronization method comprises: an end station receiving a wireless signal forwarded by a primary station through a digital broadcast satellite, the wireless signal comprising primary station time information; the end station extracting the primary station time information from the wireless signal; and the end station conducting clock synchronization with the primary station according to the primary station time information.

Description

Method, system, end station and computer storage medium for clock synchronization

Technical field

The present invention relates to the field of communications, and in particular, to a clock synchronization method, system, end station, and computer storage medium.

Background technique

On a ship going offshore, it takes a long time to go to sea to maintain communication with the land. However, due to the limitation of the maritime environment, wired communication cannot be used, and communication between the ground and the ship terminal can only be realized by satellite forwarding. There are various base stations based on satellite communication. For example, a transceiver base station (BTS, Base Transceiver Station) or other type of base station.

The BTS base station is a base station based on the multi-frequency time division multiple access (MF-TDMA) mode. During the operation of the BTS base station, it is necessary to keep the clock of the end station and the clock synchronization or frequency synchronization of the primary station. If the frequency deviation between the end station and the main station is large, the frequency offset will be caused, the user will not be able to access, and even the call drop, call timeout and other faults may occur. At present, the clock synchronization of the BTS base station is realized by using a Global Positioning System (GPS) receiver, but the use of the GPS receiver for clock synchronization (frequency synchronization) has the following disadvantages: ensuring the normal use of the GPS receiver, receiving from above The signal of at least three satellites in the sky is a necessary condition. Of course, when you need to synchronize, the top of the head will not always be "a whole blue sky", so the lack of signal strength is one of the GPS injuries. Moreover, installing a GPS receiver at a BTS base station increases the cost.

Summary of the invention

In view of this, an embodiment of the present invention provides a method, a system, an end station, and a computer storage medium for clock synchronization, which solves the problem that a GPS receiver needs to be installed when performing clock synchronization through GPS. This leads to problems of high cost and poor signal strength.

To solve the above problem, an embodiment of the present invention provides a method for clock synchronization, where the method includes:

The end station receives a wireless signal forwarded by the primary station through the digital broadcast satellite, the wireless signal including the primary station time information;

The end station extracts the master station time information from the wireless signal;

The end station performs clock synchronization with the primary station according to the primary station time information.

In an embodiment of the invention, the primary station time information includes:

Sending, by the primary station, a transmission time of the wireless signal to the digital broadcast satellite,

or

The primary station time information includes: a transmission time and a transmission delay time at which the primary station transmits the wireless signal to the digital broadcast satellite.

In an embodiment of the present invention, when the primary station time information includes a sending time of the wireless signal sent by the primary station to the digital broadcast satellite, the end station extracts from the wireless signal The primary station time information includes: a sending time of the primary station sending the wireless signal to the digital broadcast satellite by the end station extracting the primary station time information from the wireless signal; The clock synchronization of the primary station time information with the primary station includes: the end station acquiring a transmission delay time; summing the transmission time and the transmission delay as a synchronization standard time; The local time is set to the synchronization standard time.

In an embodiment of the present invention, when the primary station time information includes a transmission time and a transmission delay time of the wireless signal sent by the primary station to the digital broadcast satellite, the end station is from the wireless Extracting the primary station time information from the signal includes: the end station extracting the primary station time information from the wireless signal, and transmitting, by the primary station, the transmission time and transmission of the wireless signal to the digital broadcast satellite Delay time; the end station performing clock synchronization with the primary station according to the primary station time information includes: adding the sum of the transmission time and the transmission delay as the same Step standard time; set the local time of the end station to the synchronization standard time.

In an embodiment of the present invention, before setting the local time of the end station to the synchronization standard time, the method further includes: acquiring a receiving time of receiving the wireless signal; determining the receiving time and the synchronization standard Whether the time is the same; if different, the local time of the end station is set to the synchronization standard time.

In an embodiment of the present invention, the data format of the wireless signal is a data frame; the data frame includes a data header that serially describes the data bus; and the receiving time of receiving the wireless signal includes: The end station identifies the time at which the data header of the serial description data bus is output as the reception time.

In an embodiment of the invention, the data format of the wireless signal is a data frame; the data frame includes a data body of valid data on the data bus; and the end station extracts the data from the wireless signal The master station time information includes: parsing the master station time information from a data body of valid data on the data bus.

To solve the above problems, the present invention also provides a method for clock synchronization, the method comprising:

The wireless signal transmitted by the primary station through the digital broadcast satellite to the end station, the wireless signal including the primary station time information;

Receiving, by the end station, the wireless signal;

In order to solve the above problem, an embodiment of the present invention further provides an end station, where the end station includes a sending module, an extracting module, and a synchronization module;

The sending module is configured to receive a wireless signal that is forwarded by the primary station by using a digital broadcast satellite, where the wireless signal includes the primary station time information;

The extraction module is configured to extract the master station time information from the wireless signal;

The synchronization module is configured to perform the same clock with the primary station according to the primary station time information. step.

Sending, by the sending module, the sending time of the wireless signal to the digital broadcast satellite,

or

The primary station time information includes: the sending module sends a transmission time and a transmission delay time of the wireless signal to the digital broadcast satellite.

In an embodiment of the present invention, when the primary station time information includes a sending time of the wireless signal sent by the primary station to the digital broadcast satellite, the extracting module is further configured to receive the wireless signal Extracting to the primary station time information, the primary station transmitting a transmission time of the wireless signal to the digital broadcast satellite; the synchronization module is further configured to acquire a transmission delay time; delaying the transmission time and the transmission The sum of the sums is the synchronization standard time; the local time of the end station is set to the synchronization standard time.

In an embodiment of the present invention, when the primary station time information includes a sending time and a transmission delay time of the wireless signal sent by the primary station to the digital broadcast satellite, the extracting module is further configured to Extracting, by the wireless signal, the primary station time information, the primary station transmitting a transmission time and a transmission delay time of the wireless signal to the digital broadcast satellite; the synchronization module is further configured to send the transmission time and the location The sum of the transmission delays is added as the synchronization standard time; the local time of the end station is set to the synchronization standard time.

In an embodiment of the present invention, the synchronization module is further configured to: before receiving the local time of the end station as the synchronization standard time, acquire a receiving time of receiving the wireless signal; and determine the receiving Whether the time is the same as the synchronization standard time; if different, the local time of the end station is set to the synchronization standard time.

In order to solve the above problems, the present invention also provides a system for clock synchronization, the system comprising a primary station and an end station;

The primary station is configured to send a wireless signal forwarded by a digital broadcast satellite to the end station, The wireless signal includes the primary station time information;

The end station is configured to receive the wireless signal, extract the primary station time information from the wireless signal, and perform clock synchronization with the primary station according to the primary station time information.

Embodiments of the present invention provide a computer storage medium in which a computer program is stored, the computer program being used to perform the clock synchronization method described above.

The method, system, end station, and computer storage medium provided by the embodiment of the invention, the end station receives the wireless signal forwarded by the primary station through the digital broadcast satellite, the wireless signal includes the time information of the master station; the end station extracts the signal from the wireless signal The time information to the master station; the end station synchronizes with the master station according to the master station time information. Compared with the prior art, there is no need to synchronize by GPS, but the master station time information is directly carried in the wireless signal transmitted by the primary station, and the actual modulation encoder and the reception demodulation can be performed based on the network communication between the primary station and the end station. The decoder can realize the clock synchronization between the primary station and the end station, avoiding the need to install a GPS receiver, and can reduce the cost; further, the clock synchronization is directly performed between the primary station and the end station, and the signal strength is good, and the GPS satellite can be avoided. The problem of weak signal strength.

DRAWINGS

1 is a flowchart of a method for clock synchronization provided by Embodiment 1 of the present invention;

2-1 is a flowchart of a method for clock synchronization provided by Embodiment 2 of the present invention;

2-2 is a schematic structural diagram of a frame of a frame in a method for clock synchronization according to Embodiment 2 of the present invention;

2-3 is a schematic diagram of connection between a tuner and a demodulator chip on an end station in a method for clock synchronization according to Embodiment 2 of the present invention;

2-4 is a flowchart of parsing data signals on an end station in a method for clock synchronization provided by Embodiment 2 of the present invention;

2-5 are schematic diagrams showing the time sequence of serially describing a data bus output signal in a clock synchronization method according to Embodiment 2 of the present invention;

2-6 are schematic diagrams showing a time sequence of a data bus output signal in a clock synchronization method according to Embodiment 2 of the present invention;

2-7 are flowcharts showing a synchronous clock sequence formed in a clock synchronization method according to Embodiment 2 of the present invention;

3 is a schematic structural diagram of an end station according to Embodiment 3 of the present invention;

FIG. 4 is a schematic structural diagram of a system for clock synchronization according to Embodiment 3 of the present invention.

detailed description

The technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings in the embodiments of the present invention. It is a partial embodiment of the invention, and not all of the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative efforts are within the scope of the present invention.

Embodiment 1:

The method for clock synchronization in the embodiment of the present application is as shown in FIG. 1 , and the method includes:

S101: The end station receives the wireless signal forwarded by the primary station through the digital broadcast satellite, and the wireless signal includes the primary station time information.

In this step, the digital broadcasting satellite here mainly refers to DVB-S2 (second generation DVB System for satellite broadcasting and unicasting) which is DVB-S (Digital Video Broadcasting System for satellite broadcasting) and makes bandwidth utilization more efficient. For transmitting satellites, the wireless signals here mainly refer to wireless signals that transmit high-quality video and advanced services through satellites. The master station time information here refers to all the time that can be used for clock synchronization of the end stations. Preferably, the primary station time information includes the time at which the primary station transmits the wireless signal. The time when the wireless signal is about to be transmitted is carried in the wireless signal, where the end station can perform clock synchronization according to the time. Specifically, since there is a certain delay time between the end station and the primary station, the end station has to know the delay time between the terminal and the primary station after receiving the wireless signal. Generally speaking, the delay time is a relatively fixed value, and the end station can obtain a synchronization time according to the time of transmitting the wireless signal and the delay time, and synchronize the local clock according to the synchronization time. Further, in order to facilitate the clock synchronization of the end station directly, the time information of the main station further includes the delay time of the wireless signal reaching the end station, that is, the time and the delay time of transmitting the wireless signal are directly carried in the wireless signal, so that the end station directly obtains the information. Subsequent clock synchronization. The wireless signal here refers to various signals capable of carrying the time information of the primary station, and the data format of the specific wireless data signal may be a data message, a data packet, a data frame, and the like.

S102: The end station extracts the master station time information from the wireless signal.

In this step, since the primary station time information is carried in the wireless signal, the wireless signal processing is performed to obtain the corresponding primary station time information, and the corresponding primary station time information is obtained. Specifically, since the ground primary station accesses the Internet through the gateway, on the primary station, the original data message is encapsulated into a DVB-S2 format, modulated by a modulator to a frequency point corresponding to the satellite, and the primary station generates a radio frequency signal through the antenna. The signal is sent to the satellite transponder, and the signal is amplified by the transponder and forwarded to the end station on the ship; the end station receives the radio frequency signal and converts it into a baseband signal, and then demodulates and decodes to recover the original data. In an embodiment, the end station receives the wireless signal forwarded by the primary station through the digital broadcast satellite, including: the end station receiving the primary station transmits the radio frequency signal corresponding to the wireless signal through the digital broadcast satellite; and the end station performs the signal conversion processing on the radio frequency signal. Corresponding digital orthogonal signal; the end station demodulates and decodes the digital orthogonal signal to obtain a corresponding wireless signal. The wireless signal includes a data body of valid data on the data bus; the data body of the valid data on the data bus includes the master station time information; and the end station parses the wireless signal to obtain the master station time information including: the data body from the valid data on the bus Analyze the master station time information.

S103: The end station performs clock synchronization with the primary station according to the time information of the primary station.

In this step, specifically, the local clock of the end station is clock-synchronized directly according to the time information of the main station; that is, the clock of the main station is synchronized regardless of whether the local clock is faulty. In this way, there may be a large number of synchronization operations, in order to reduce the processing of the part, preferably, Therefore, it is first determined whether the local clock of the end station is the same as the clock of the main station, and if not, the clock is synchronized. That is to say, the local clock is clocked only if the master clock is not synchronized. In a specific implementation, determining whether the local clock of the end station is the same as the clock of the primary station comprises: obtaining a receiving time of receiving the wireless signal; determining whether the local clock is the same as the clock of the primary station according to the time information of the primary station and the receiving time. Further, since the terminal station performs relevant processing after receiving the wireless signal in the normal processing process to obtain the specific master station time information, there is a certain delay in the processing, and the delay time is difficult to determine, in order to The receiving time of the specific receiving wireless signal is accurately determined, and the determining error is reduced. In a specific implementation, the wireless signal includes a data header that serially describes the data bus; and the receiving time of acquiring the received wireless signal includes: identifying the output string of the end station The line describes the time of the data head of the data bus as the reception time. That is, since the end station can recognize the data header of the output serial description data bus immediately after receiving the wireless signal, there is no subsequent processing, so that the time of receiving the wireless signal can be well determined, and of course, other wireless signals can be determined. The way of time can also be achieved.

Further, in order to ensure that the clock between the primary station and the end station is synchronized at the same time, that is, the primary station will continuously forward the wireless signal through the digital broadcast satellite to the end station, preferably, let the primary station pass the digital broadcast according to the preset period. The wireless signal continuously forwarded by the satellite is sent to the end station. Here, in order to reduce the overhead of the physical layer, the purpose of the network synchronization can be achieved, and the primary station transmits the wireless signal with the time information of the primary station with a preset period of 80 milliseconds; The end station periodically obtains the wireless signals. In order to facilitate subsequent time synchronization of the primary station time information corresponding to the wireless signals, preferably, a synchronous clock sequence is formed. In a specific embodiment, a synchronous clock is formed according to how many wireless signals are formed. The sequence may be each wireless signal further comprising a data body that serially describes the data body of the data bus and valid data on the data bus; the data body of the serial description data bus includes a first physical frame counter; data of valid data on the data bus The main body includes a second physical frame counter and master station time information; according to how many wireless signals Forming synchronous clock sequence comprising: forming a first physical frame queues according to the respective wireless signal counter; find the corresponding physical frame in accordance with each of the first counter Each second physical frame counter; the data body of the valid data on the corresponding data bus is found according to each second physical frame counter, and each master time information is extracted from the data body of the valid data on the data bus to form a synchronous clock sequence. For example, if the wireless signal is a data frame, before the end station receives the demodulation decoding, the arriving frame header portion (SOF, Start of Frame) is detected, and then the main station time information (NCR, Network Clock Reference) is parsed from the frame data portion. Knowing the synchronization timestamp of the primary station, the SOF sequence corresponding to the NCR information received in the cycle forms a stable synchronous clock sequence, and then we can process the synchronization like a normal base station, and send the synchronous clock sequence to the phase-locked loop. By performing calibration, it is possible to replace the GPS and achieve clock synchronization with the primary station.

In a specific embodiment, the primary station time information includes: a transmission time at which the primary station transmits a wireless signal to the digital broadcast satellite; or the primary station time information includes: a transmission time and a transmission delay time at which the primary station transmits the wireless signal to the digital broadcast satellite.

When the primary station time information includes the transmission time of the primary station transmitting the wireless signal to the digital broadcast satellite, the end station extracts the primary station time information from the wireless signal, including: the end station extracts from the wireless signal to the primary station time information, the primary station to the digital The transmission time of the wireless signal transmitted by the broadcasting satellite; the clock synchronization of the terminal station with the primary station according to the time information of the primary station includes: the end station acquires the transmission delay time; the sum of the transmission time and the transmission delay is used as the synchronization standard time; The local time is set to synchronize the standard time.

When the primary station time information includes the transmission time and the transmission delay time of the wireless signal transmitted by the primary station to the digital broadcast satellite, the end station extracts the primary station time information from the wireless signal, including: the end station extracts the primary station time information from the wireless signal. The sending time and the transmission delay time of the wireless signal sent by the primary station to the digital broadcasting satellite; the clock synchronization of the terminal station with the primary station according to the time information of the primary station includes: adding the sum of the transmission time and the transmission delay as the synchronization standard time; The local time is set to synchronize the standard time.

In a specific embodiment, before setting the local time of the end station to the synchronization standard time The method further includes: obtaining a receiving time of receiving the wireless signal; determining whether the receiving time is the same as the synchronization standard time; if different, setting the local time of the end station to the synchronous standard time.

In a specific implementation, the data format of the wireless signal is a data frame; the data frame includes a data header serially describing the data bus; and the receiving time of acquiring the received wireless signal includes: identifying the end station and outputting the data header of the serial description data bus Time as the receiving time.

In a specific implementation, the data format of the wireless signal is a data frame; the data frame includes a data body of valid data on the data bus; and the end station extracts the time information from the wireless signal to the master station including: valid data from the data bus The data body is parsed to obtain the master station time information.

Embodiment 2:

The method for clock synchronization in the embodiment of the present application is as shown in FIG. 2-1, and the method includes:

S201: The wireless signal periodically forwarded by the primary station through the digital broadcast satellite, the wireless signal including the primary station time information.

In this step, specifically, taking the data frame as an example, the DVB-S2 frame modulated and encapsulated on the primary station is shown in Figure 2-2, and the header portion can be divided into an SOF segment and a PLSC (Physical Layer Signaling Code). , physical layer signal coding) segment, where XFECFRAME (complex Forward Error Correction Frame) represents the data portion. The frame header consists of 90 symbols, in which SOF occupies 26 symbols and is converted to hexadecimal 18D2E82HEX. This piece of data information is fixed in the DVB-S2 protocol for DVB-S2 protocol frame format. In this feature, we can encapsulate the Network Clock Reference (NCR) in the XFECFRAME on the primary station and periodically transmit the data frame carrying the NCR. The network clock reference here is a specific example of the time information of the master station, and of course other clock information is also available.

S202: The end station receives the wireless signal, and parses the time information of the primary station according to the digital signal, and forms a synchronous clock sequence.

S203: The end station synchronizes with the clock of the primary station according to the synchronous clock sequence.

In the above step S202, specifically, on the receiving end station, we use a separate tuner (Tuner) and a demodulation chip (Demod), as shown in Figure 2-3, for the tuner and demodulation on the end station. The connection of the chip is shown in Figure 2-3. DiSEqc 2.0 represents the digital satellite device control version 2.0, "SDAT1, SCLT" represents the I2C data and clock port connected to the tuner and demodulator, and AGCRF1 represents the RF automatic gain indication. (I1N, I1P) represents the same direction signal, "Q1N, Q1P" represents the quadrature signal, "XTAL1" represents the clock pin (input), D71 represents the output frame data (bit 0 - bit 7), and CLOCKOUT1 represents the output frame clock, STROUT1 indicates the start of the output frame, DPN1 indicates the data valid indication, ERROR1 indicates the error indication, CLOCKOUT27 indicates the output clock, "SDA, SCL" indicates the I2C data and clock port connected to the controller, and SDD1 indicates the serial data description bus. Output, DISEQCIN1 represents the digital satellite device control input, and DISEQCOUT1 represents the digital satellite device control output. It is recommended to use STMicroelectronics' STV6111B plus STV0910ADB chipset. The external controllers uController and Tuner and Demod communicate according to the I2C (Inter-Integrated Circuit) protocol. Tuner is responsible for moving the RF signal received by the antenna to near zero frequency, and then sending the analog quadrature IQ (Inphase and Quadrature) signal to Demod. The processing flow of the entire Demod is shown in Figure 2-4. The method for parsing the wireless signal on the end station in the clock synchronization method is specifically to parse and match the serial description data SDD (Serial data description) bus SOF and The flow of valid data on the data bus. Within Demod, the analog IQ signal is sampled, quantized into a digital IQ signal by an analog-to-digital converter (ADC), then demodulated, decoded, and finally transmitted. The management module Transport stream manager outputs the original data frame on the data bus. The data bus includes the output timing CLKOUT, the data STROUT of the valid data on the data bus, the D/P, the data body DATA of the valid data on the data bus, etc., wherein the data The specific data sequence of the data header STROUT_SOF containing valid data on the data bus in the data STROUT on the bus is shown in Figure 2-5.

In order to properly enable Demod to output SOF, we can configure the general input in Figure 2-3. Output GPIO (General Purpose Input Output) switching matrix, select fixed GPIO pin as SDD bus output, SDD bus output serial description data bus data header SDD_SOF, Symbol Clock and serial description data bus data body SD_data, SDD bus The output signal timing is shown in Figure 2-6.

Since the wireless signal is transmitted from the primary station to the satellite, from the satellite to the end station, there is a propagation delay in the intermediate process. In addition, during the processing of the receiving end, the inner processing of Tuner and Demod will also bring the delay of hardware operation. We hope that all delays add up to a fixed value, so that the end station does not introduce too much error.

Comparing Figure 2-5 with Figure 2-6, it is important to note that the data bus STROUT also has a STROUT_SOF that identifies the start frame, which indicates that the entire DVB-S2 data frame is demodulated and decoded for output, while the SDD bus The upper SOF is the DVB-S2 data header that is identified and output, without subsequent demodulation and decoding processes. We know that DVB-S2 supports bit rate ranging from 1/4 to 9/10. It supports QPSK, 8PSK, 16PSK and 32APSK demodulation methods. The time between different bit rate and demodulation method changes. If we use SOF on STROUT as the timing synchronization clock source, because the physical frame length is different at different code rates, the processing delay caused by different demodulation methods is not fixed, so the arrival time is not a fixed value, so the clock synchronization must be Use the SOF output on the SDD bus.

At the transmitting end of the primary station, the SOF and the data XFECFRAME on a single frame are one-to-one correspondence, but at the receiving end of the end station, the data header SDD_SOF of the serial description data bus is output on the SDD bus, and the data is output on the data bus DATA. The SOF and data output timing of the same frame are also biased. The SOF always precedes the data. In order to ensure that the SOF and the data are not misaligned, we find that both the SD_data and the data bus Data have a counter PLFRAME_counter indicating which physical frame the current physical frame belongs to. These two fields are extracted and then compared to determine whether the data headers SDD_SOF and DATA of the serial description data bus are the same frame, as shown in Figure 2-7, including:

Step S2021: opening two large enough buffers to continuously charge SDD_SOF, SD_data, and STROUT and DATA on the data bus;

Specifically, Buffer0 reads SOF and SD_data on the SDD bus; Buffer1 reads STROUT_SOF and DATA on the data bus.

Step S2022: Obtain the precise time when the frame arrives from the timestamp of the SDD_SOF, and extract the counter PLFRAME_couter1 of the first physical frame in the SD_data, which is in the queue;

Step S2023: After the data bus detects the STROUT_SOF, the data is fetched from the DATA, and the counter PLFRAME_couter2 of the second physical frame included in the DATA is extracted;

Step S2024: Compare PLFRAME_couter2 with PLFRAME_couter1 in the queue. If the size is equal, it is judged to be the same frame. If there is a difference between the two PLFRAME_couters, the corresponding step size is moved in the queue according to the difference, and the corresponding SDD_SOF of the current data in the queue is found.

Embodiment 3:

An embodiment of the present application provides an end station 300. As shown in FIG. 3, the end station 300 includes a sending module 301, an extracting module 302, and a synchronization module 303.

The sending module 301 is configured to receive a wireless signal that is forwarded by the primary station by using a digital broadcast satellite, where the wireless signal includes primary station time information;

The extraction module 302 is configured to extract the master station time information from the wireless signal;

The synchronization module 303 is configured to perform clock synchronization with the primary station based on the primary station time information.

The master station time information includes: a sending time of the sending module sending the wireless signal to the digital broadcasting satellite, or the master station time information includes: a sending time and a transmission delay time of the sending module sending the wireless signal to the digital broadcasting satellite.

In a specific sub-embodiment, when the primary station time information includes a transmission time at which the primary station transmits a wireless signal to the digital broadcast satellite,

The extraction module 302 is further configured to extract, from the wireless signal, a transmission time of the primary station time information primary station transmitting the wireless signal to the digital broadcast satellite;

The synchronization module 303 is further configured to acquire a transmission delay time; the sum of the transmission time and the transmission delay is used as the synchronization standard time; and the local time of the end station is set to the synchronization standard time.

In a specific sub-embodiment, when the primary station time information includes a transmission time and a transmission delay time at which the primary station transmits a wireless signal to the digital broadcast satellite,

The extraction module 302 is further configured to extract, from the wireless signal, a transmission time and a transmission delay time of the primary station time information primary station transmitting the wireless signal to the digital broadcast satellite; the synchronization module 303 is further configured to transmit the transmission time and the transmission delay phase Add the sum as the synchronization standard time; set the local time of the end station to the synchronous standard time.

In another embodiment, the synchronization module 303 is further configured to acquire a receiving time of receiving the wireless signal before setting the local time of the end station to the synchronization standard time; determining whether the receiving time is the same as the synchronization standard time; if different, The local time of the end station is set to synchronize the standard time.

In an actual application, the sending module 301, the extracting module 302, and the synchronizing module 303 may be a Central Processing Unit (CPU) or a Micro Processor Unit (MPU) on the device to which the end station or the end station belongs. , digital signal processor (DSP, Digital Signal Processor), or Field Programmable Gate Array (FPGA) implementation.

The embodiment of the present application further provides a system for clock synchronization, where the system includes a primary station 400 and an end station 300;

The primary station 400 is configured to send the wireless signal forwarded by the digital broadcast satellite to the end station 300, and the wireless signal includes primary station time information;

The end station 300 is configured to receive a wireless signal, extract master station time information from the wireless signal, and perform clock synchronization with the primary station based on the primary station time information.

The embodiment of the invention further describes a computer storage medium, wherein the computer storage medium stores computer executable instructions, and the computer executable instructions are used to execute the method of clock synchronization described in Embodiment 1 or Embodiment 2.

One of ordinary skill in the art will appreciate that all or a portion of the above steps may be accomplished by a program that instructs the associated hardware, such as a read-only memory, a magnetic disk, or an optical disk. Alternatively, all or part of the steps of the above embodiments may also be implemented using one or more integrated circuits. Correspondingly, each module/unit in the foregoing embodiment may be implemented in the form of hardware or in the form of a software function module. The invention is not limited to any specific form of combination of hardware and software.

The above embodiments are only intended to illustrate the technical solutions of the present invention and are not to be construed as limiting the invention. It should be understood by those skilled in the art that the present invention may be modified or equivalently substituted without departing from the spirit and scope of the invention.

Industrial applicability

In the embodiment of the present invention, the end station receives the wireless signal forwarded by the primary station through the digital broadcast satellite, and the wireless signal includes the time information of the primary station; the end station extracts the time information of the primary station from the wireless signal; the end station according to the time information of the primary station and the primary station The station performs clock synchronization; thus, the problem of high cost and poor signal strength caused by the need to install a GPS receiver for clock synchronization through GPS is solved.

Claims

A method of clock synchronization, the method comprising:

The end station receives a wireless signal forwarded by the primary station through the digital broadcast satellite, the wireless signal including the primary station time information;

The end station extracts the master station time information from the wireless signal;

The end station performs clock synchronization with the primary station according to the primary station time information.
The method of clock synchronization according to claim 1, wherein said master station time information comprises:

Sending, by the primary station, a transmission time of the wireless signal to the digital broadcast satellite,

or

The primary station time information includes: a transmission time and a transmission delay time at which the primary station transmits the wireless signal to the digital broadcast satellite.
The method of clock synchronization according to claim 2, wherein when said primary station time information includes a transmission time at which said primary station transmits said wireless signal to said digital broadcast satellite,

Extracting, by the end station, the primary station time information from the wireless signal comprises: the end station extracting, from the wireless signal, the primary station time information, the primary station transmitting to the digital broadcast satellite Determining a transmission time of the wireless signal; the end station performing clock synchronization with the primary station according to the primary station time information includes: the end station acquiring a transmission delay time; adding the transmission time and the transmission delay And as the synchronization standard time; setting the local time of the end station to the synchronization standard time.
The method of clock synchronization according to claim 2, wherein when said primary station time information includes a transmission time and a transmission delay time at which said primary station transmits said wireless signal to said digital broadcast satellite,

Extracting, by the end station, the primary station time information from the wireless signal comprises: the end station extracting, from the wireless signal, the primary station time information, the primary station to the digital broadcast satellite Transmitting a transmission time and a transmission delay time of the wireless signal; and the end station performing clock synchronization with the primary station according to the primary station time information comprises: synchronizing the sum of the transmission time and the transmission delay as a synchronization Standard time; the local time of the end station is set to the synchronization standard time.
The method of clock synchronization according to claim 3 or 4, further comprising: before setting the local time of the end station to the synchronization standard time:

Obtaining a receiving time for receiving the wireless signal; determining whether the receiving time is the same as the synchronization standard time; if different, setting a local time of the end station to the synchronization standard time.
The method of clock synchronization according to claim 5, wherein said data format of said wireless signal is a data frame; said data frame comprises a data header of a serial description data bus;

The obtaining the receiving time of receiving the wireless signal comprises: determining, by the end station, a time when the data header of the serial description data bus is output as the receiving time.
The method of clock synchronization according to claim 1, wherein said data format of said wireless signal is a data frame; said data frame comprises a data body of valid data on a data bus;

The extracting, by the end station, the master station time information from the wireless signal comprises: parsing the master station time information from a data body of valid data on the data bus.
A method of clock synchronization, the method comprising:

The wireless signal transmitted by the primary station through the digital broadcast satellite to the end station, the wireless signal including the primary station time information;

Receiving, by the end station, the wireless signal;

The end station extracts the master station time information from the wireless signal;

The end station performs clock synchronization with the primary station according to the primary station time information.
An end station, the end station includes a sending module, an extracting module, and a synchronization module, wherein

The sending module is configured to receive a wireless signal that the primary station forwards through the digital broadcast satellite, The wireless signal includes the primary station time information;

The extracting module is configured to extract the master station time information from the wireless signal;

The synchronization module is configured to perform clock synchronization with the primary station according to the primary station time information.
The end station of claim 9 wherein said primary station time information comprises:

Sending, by the sending module, the sending time of the wireless signal to the digital broadcast satellite,

or

The primary station time information includes: the sending module sends a transmission time and a transmission delay time of the wireless signal to the digital broadcast satellite.
The end station according to claim 10, wherein when said primary station time information includes a transmission time at which said primary station transmits said wireless signal to said digital broadcast satellite,

The extraction module is further configured to extract, from the wireless signal, the primary station time information, the primary station sends a transmission time of the wireless signal to the digital broadcast satellite; the synchronization module is further configured to acquire a transmission delay Time; summing the transmission time and the transmission delay as a synchronization standard time; setting the local time of the end station to the synchronization standard time.
The end station according to claim 10, wherein when said primary station time information includes a transmission time and a transmission delay time at which said primary station transmits said wireless signal to said digital broadcast satellite,

The extraction module is further configured to extract, from the wireless signal, the primary station time information, the primary station sends a transmission time and a transmission delay time of the wireless signal to the digital broadcast satellite; the synchronization module is further configured The sum of the transmission time and the transmission delay is used as a synchronization standard time; the local time of the end station is set as the synchronization standard time.
The terminal according to claim 3 or 4, wherein the synchronization module is further configured to acquire a reception time for receiving the wireless signal before setting a local time of the end station to the synchronization standard time; Whether the reception time is the same as the synchronization standard time; if different, the local time of the end station is set to the synchronization standard time.
A clock synchronization system, the system comprising a primary station and an end station:

The primary station is configured to send the wireless signal forwarded by the digital broadcast satellite to the end station, and the wireless signal includes the primary station time information;

The end station is configured to receive the wireless signal, extract the primary station time information from the wireless signal, and perform clock synchronization with the primary station according to the primary station time information.
A computer storage medium having stored therein computer executable instructions for performing the method of any one of claims 1 to 7, or the method of claim 8.