WO2013123784A1

WO2013123784A1 - Method and device for maintaining synchronization

Info

Publication number: WO2013123784A1
Application number: PCT/CN2012/084764
Authority: WO
Inventors: 钟显成; 倪伟
Original assignee: 大唐移动通信设备有限公司
Priority date: 2012-02-23
Filing date: 2012-11-16
Publication date: 2013-08-29
Also published as: CN102547970A

Abstract

Disclosed are a method and device for maintaining synchronization, so as to realize accurate synchronization between devices in a long-distance transmission scenario. The method comprises: between two devices that are to be synchronized and are distant from each other, a sender multiplexing at least two kinds of synchronization control signals, and sending an obtained multiplexed signal to a receiver through an optical fiber; the receiver receiving, through the optical fiber, the multiplexed signal transmitted by the sender, performing de-multiplexing to obtain at least two kinds of synchronization control signals, and maintaining synchronization with the sender according to the two kinds of synchronization control signals. In this way, the multiplexed synchronization control signal is transmitted between the devices through the optical fiber, so as to effectively avoid attenuation of the synchronization control signal, thereby increasing the transmission distance of the synchronization control signal. Therefore, the synchronization control signal can also be accurately transmitted between devices distant from each other, so as to accurately realize synchronization therebetween, thereby ensuring system transmission performance.

Description

Method and device for maintaining synchronization This application claims to be submitted to the Chinese Patent Office on February 23, 2012, the application number is 201210044766.0, and the invention name is

The priority of the Chinese Patent Application, which is incorporated herein by reference. TECHNICAL FIELD The present invention relates to the field of communications, and in particular, to a method and apparatus for maintaining synchronization. BACKGROUND OF THE INVENTION In the prior art, in a TDD (Time Division Duplex) communication system, in order to prevent mutual interference between a base station and a base station, strict synchronization is required. For the ground system, the most used ones are currently used. The satellite synchronization method is adopted, that is, each base station or the base station cluster of the same station is configured with a satellite synchronization unit to synchronize with other station base stations, and the synchronization precision can reach sub-microsecond level.

However, for underground systems (as shown in Figure 1) or large indoor distribution systems, the traditional satellite synchronization method is limited in these applications due to the attenuation characteristics of the analog high-frequency signal in the feeder and the transmission distance is very limited. It is difficult to meet the needs of applications such as underground systems (eg, mine coverage) and indoor distribution systems that are far apart. SUMMARY OF THE INVENTION Embodiments of the present invention provide a method and apparatus for maintaining synchronization, which are used to implement accurate synchronization between devices in a long-distance transmission scenario.

The specific technical solutions provided by the embodiments of the present invention are as follows:

A method of maintaining synchronization, including:

The transmitting end multiplexes at least two synchronous control signals;

The transmitting end transmits the obtained multiplexed signal to the receiving end through the optical fiber, so that the receiving end keeps synchronized with the transmitting end according to the received multiplexed signal.

A method of maintaining synchronization, including:

The receiving end receives the multiplexed signal transmitted by the transmitting end through the optical fiber,

The receiving end demultiplexes the multiplexed signal to obtain at least two synchronous control signals, and according to

The at least two synchronization control signals are synchronized with the transmitting end.

A device that maintains synchronization, including:

a processing unit, configured to multiplex at least two synchronization control signals; The communication unit is configured to transmit the obtained multiplexed signal to the receiving end through the optical fiber, so that the receiving end keeps synchronized with the transmitting end according to the received multiplexed signal.

A device that maintains synchronization, including:

a communication unit, configured to receive, by using an optical fiber, a multiplexed signal transmitted by the transmitting end,

And a processing unit, configured to demultiplex the multiplexed signal, obtain at least two synchronization control signals, and maintain synchronization with the transmitting end according to the at least two synchronization control signals.

In the embodiment of the present invention, between two devices that are far apart to be synchronized, the transmitting end multiplexes at least two types of synchronous control signals, and sends the obtained multiplexed signals to the receiving end through the optical fiber, and receives The terminal receives the multiplexed signal transmitted by the transmitting end through the optical fiber and performs demultiplexing to obtain at least two synchronous control signals, and then keeps synchronization with the transmitting end according to the at least two synchronous control signals. In this way, the synchronous control signals transmitted between the devices through the optical fiber can effectively avoid the attenuation of the synchronous control signal, prolong the transmission distance of the synchronous control signal, and enable the synchronous control to be transmitted accurately between the devices far apart. The signals are precisely synchronized with each other to ensure the transmission performance of the system. BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a diagram showing an example of a synchronization scenario in the prior art;

2 is a flow chart of synchronization of a transmitting end side according to an embodiment of the present invention;

3 is a schematic structural diagram of a multiplexed signal according to an embodiment of the present invention;

4 is a flowchart of synchronization of a receiving end side according to an embodiment of the present invention;

FIG. 5 is a schematic structural diagram of a device according to an embodiment of the present invention; FIG.

FIG. 6 is a diagram showing an example of a functional structure of a device in an embodiment of the present invention. In the embodiment of the present invention, the devices in the long-distance transmission application scenario are no longer based on the actual synchronization between the devices in the remote transmission application scenario (eg, the underground system, the indoor system, and the like). The satellite signals are kept in sync, but a unified clock source is used to maintain synchronization in a local range. Specifically, the transmitting end multiplexes at least two synchronous control signals, and sends the obtained multiplexed signals to the receiving end through the optical fiber. And the receiving end receives the multiplexed signal transmitted by the transmitting end through the optical fiber and performs demultiplexing, obtaining at least two synchronous control signals, and then maintaining synchronization with the transmitting end according to the at least two synchronous control signals.

Preferred embodiments of the invention are described in detail below.

Based on the foregoing embodiment, referring to FIG. 2, in the embodiment of the present invention, the sending end process of maintaining synchronization between devices is as follows: Step 200: The transmitting end multiplexes at least two synchronization control signals.

In the embodiment of the present invention, the synchronization control signal used by the transmitting end includes the following signals:

PP1 S (Pulse Per I S) signal, TOD (Time of Day) signal, status control signal, and status indication signal.

The specific execution process of step 200 is as follows:

Al, the sender determines the preset multiplexed clock.

In this embodiment, the function of the multiplexed clock is: sampling the input low-speed synchronous control signal, and referring to the clock used when converting between the low-speed synchronous control signal and the serial data stream;

A2. The transmitting end performs different sampling on at least two types of synchronous control signals according to the duration of the multiplexed clock multiplexed clock indication.

Preferably, when at least two synchronous control low speed and multiplexed clocks used by the transmitting end are in a synchronous relationship, the maximum supported rate of the at least two synchronous control signals is a multiplexed clock rate; and at least two types of synchronization used by the transmitting end When the control signal is in an asynchronous relationship with the multiplexed clock, the maximum supported rate of the at least two synchronous control signals is 1/5 of the multiplexed clock rate.

A3. In each frame of the multiplexed signal, the transmitting end arranges the sampling points corresponding to each of the synchronous control signals in the set order.

For example, after the low-speed PP1 S signal, the TOD signal, the state control signal, and the state indication signal are respectively sampled, they are multiplexed as shown in FIG. 3, so that multiple low-speed synchronous control signals are multiplexed. A high-speed serial data stream.

Step 210: The transmitting end transmits the obtained multiplexed signal to the receiving end through the optical fiber, so that the receiving end keeps synchronized with the transmitting end according to the received multiplexed signal.

In this embodiment, the synchronous control signals after the multiplexing are transmitted between the devices through the optical fiber can effectively avoid the attenuation of the synchronous control signals. Therefore, even if the devices are far apart, an accurate synchronous control signal can be obtained, thereby being accurate. Realize synchronization with each other.

Further, based on the foregoing embodiment, in order to improve the accuracy of the synchronization control signal, the transmitting end delays the synchronization control signal of one or any combination before the multiplexing of the at least two synchronous control signals. , Specifically:

B 1. The transmitting end performs delay measurement based on the delay compensation reference signal.

In this embodiment, the delay compensation reference signal used by the transmitting end may be an independent reference signal set in advance, or any one of the at least two types of synchronous control signals multiplexed.

On the other hand, in practical applications, when the transmitter performs the delay measurement, the obtained measured value represents the delay corresponding to the round-trip time between the transmitting end and the receiving end, so the measurement value is divided by 2 to be the final required. Measurement results.

B2. The measurement result of the transmitting end is respectively subjected to delay compensation for one or any combination of the at least two synchronous control signals. The instantaneous delay compensation operation can be performed independently for a single synchronous control signal or for a plurality of synchronous control signals.

Corresponding to the above embodiment, referring to FIG. 4, in the embodiment of the present invention, the process of receiving the synchronization between devices is as follows:

Step 400: The receiving end receives the multiplexed signal transmitted by the transmitting end through the optical fiber.

Step 410: The receiving end demultiplexes the received multiplexed signal, obtains at least two types of synchronization control signals, and maintains synchronization with the transmitting end according to the at least two types of synchronization control signals.

In this embodiment, the receiving end restores the high-speed serial data stream to a plurality of low-speed synchronous control signals through the demultiplexing operation, and the receiving end multiplexes the synchronous control signal obtained by the demultiplexing with the transmitting end. The synchronization control signal used is consistent in characteristics, that is, the synchronization control signal obtained by the receiving end includes: at least two of a PP1 S signal, a TOD signal, a state control signal, and a status indication signal.

Based on the foregoing embodiment, referring to FIG. 5, in the embodiment of the present invention, a device (for example, a base station) for maintaining synchronization includes a communication unit 50 and a processing unit 51, and further, a delay control unit 52 is further disposed, wherein ,

When acting as a sender,

The processing unit 51 is configured to multiplex the at least two synchronization control signals;

The communication unit 50 is configured to transmit the obtained multiplexed signal to the receiving end through the optical fiber, so that the receiving end keeps synchronization with the transmitting end according to the received multiplexed signal;

Further, the delay control unit 52 is configured to perform delay compensation on the at least two synchronization control signals before the processing unit 51 multiplexes the at least two synchronization control signals.

And as the receiver,

a communication unit 50, configured to receive, by using an optical fiber, a multiplexed signal transmitted by the transmitting end,

The processing unit 51 is configured to perform demultiplexing on the multiplexed signal, obtain at least two synchronization control signals, and maintain synchronization with the transmitting end according to the at least two synchronization control signals.

The specific logical implementation of the above communication unit 50, processing unit 51 and delay control unit 52 can be seen in FIG.

In summary, in the embodiment of the present invention, between two devices that are far apart to be synchronized, the transmitting end multiplexes at least two types of synchronous control signals, and sends the obtained multiplexed signals to the optical fiber through the optical fiber. The receiving end receives the multiplexed signal transmitted by the transmitting end through the optical fiber and performs demultiplexing to obtain at least two kinds of synchronous control signals, and then keeps synchronization with the transmitting end according to the at least two synchronous control signals. In this way, the synchronous control signals transmitted between the devices through the optical fiber can effectively avoid the attenuation of the synchronous control signal, prolong the transmission distance of the synchronous control signal, and enable the synchronous control to be transmitted accurately between the devices far apart. The signals are precisely synchronized with each other to ensure the transmission performance of the system.

In a practical application, the technical solution provided by the embodiment of the present invention can effectively solve two or more synchronization devices. For example, the synchronization problem of the base station when the distance is far apart can also effectively solve the problem of the synchronous transmission when the synchronization source and the synchronization device are far apart, and is not limited to one application scenario, and details are not described herein again.

Those skilled in the art will appreciate that embodiments of the present invention can be provided as a method, system, or computer program product. Accordingly, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment, or a combination of software and hardware. Moreover, the present invention can be embodied in the form of a computer program product embodied on one or more computer-usable storage interfaces (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer usable program code.

The present invention has been described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (system), and computer program products according to embodiments of the invention. It will be understood that each process and/or block of the flowchart illustrations and/or FIG. These computer program instructions can be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing device to produce a machine for the execution of instructions for execution by a processor of a computer or other programmable data processing device. Means for implementing the functions specified in one or more of the flow or in a block or blocks of the flow chart.

The computer program instructions can also be stored in a computer readable memory that can direct a computer or other programmable data processing device to operate in a particular manner, such that the instructions stored in the computer readable memory produce an article of manufacture comprising the instruction device. The apparatus implements the functions specified in one or more blocks of a flow or a flow and/or block diagram of the flowchart.

These computer program instructions can also be loaded onto a computer or other programmable data processing device such that a series of operational steps are performed on a computer or other programmable device to produce computer-implemented processing for execution on a computer or other programmable device. The instructions provide steps for implementing the functions specified in one or more of the flow or in a block or blocks of a flow diagram.

Although the preferred embodiment of the invention has been described, it will be apparent to those of ordinary skill in the art that <RTIgt; Therefore, the appended claims are intended to be construed as including the preferred embodiments and the modifications

It is apparent that those skilled in the art can make various modifications and variations to the embodiments of the present invention without departing from the spirit and scope of the embodiments of the present invention. Thus, it is intended that the present invention cover the modifications and modifications of the inventions

Claims

Rights request

A method for maintaining synchronization, characterized in that it comprises:

The transmitting end multiplexes at least two synchronous control signals;

2. The method according to claim 1, wherein the synchronization control signal comprises:

1 second timing pulse PP1 S signal, time information TOD signal, status control signal and status indication signal.

The method according to claim 1 or 2, wherein the transmitting end multiplexes the at least two synchronization control signals, including:

The transmitting end determines a preset multiplexed clock;

Transmitting, by the transmitting end, the at least two synchronization control signals respectively according to the multiplexed clock;

The transmitting end arranges the sampling points corresponding to each of the synchronous control signals in the set order in each frame of the multiplexed signal.

The method according to claim 3, wherein when the at least two synchronous control low speed and the multiplexed clock used by the transmitting end are in a synchronous relationship, the highest supported rate of the at least two synchronous control signals is multiplexed Clock rate; when the at least two synchronization control signals used by the transmitting end are in an asynchronous relationship with the multiplexed clock, the at least two synchronous control signals support a maximum rate of 1/5 of the multiplexed clock rate.

The method according to claim 1 or 2, wherein the transmitting end performs delay compensation on the at least two types of synchronization control signals before multiplexing the at least two types of synchronization control signals.

The method according to claim 5, wherein the transmitting end delays the at least two synchronization control signals, including:

The transmitting end performs delay measurement based on the delay compensation reference signal;

The transmitting end separately performs delay compensation on one or any combination of the at least two synchronization control signals according to the measurement result.

The method according to claim 6, wherein the delay compensation reference signal used by the transmitting end is a preset independent reference signal, or is any of the at least two synchronous control signals. One.

8. A method of maintaining synchronization, characterized by comprising:

The receiving end receives the multiplexed signal transmitted by the transmitting end through the optical fiber;

The receiving end demultiplexes the multiplexed signal to obtain at least two synchronization control signals, and keeps synchronization with the transmitting end according to the at least two synchronization control signals.

9. The method according to claim 8, wherein the synchronization control signal comprises:

10. A device for maintaining synchronization, characterized by comprising:

a processing unit, configured to multiplex at least two synchronization control signals;

The communication unit is configured to transmit the obtained multiplexed signal to the receiving end through the optical fiber, so that the receiving end is synchronized with the transmitting end according to the received multiplexed signal.

The apparatus according to claim 10, wherein the synchronization control signal used by the processing unit comprises:

PP1 S signal, TOD signal, status control signal and status indication signal.

The device according to claim 10 or 11, wherein, when the processing unit multiplexes at least two types of synchronization control signals, determining a preset multiplexed clock, and based on the multiplexed clock, The at least two synchronization control signals are respectively sampled, and in each frame of the multiplexed signal, the sample points corresponding to each of the synchronization control signals are sequentially arranged in a set order.

The device according to claim 12, wherein when the at least two synchronous control low speed and the multiplexed clock used by the processing unit are in a synchronous relationship, the maximum supported rate of the at least two synchronous control signals is The multiplexed clock rate; when the at least two types of synchronization control signals used by the processing unit are in an asynchronous relationship with the multiplexed clock, the maximum supported rate of the at least two types of synchronization control signals is 1/5 of the multiplexed clock rate.

The device according to claim 10 or 11, further comprising:

And a delay control unit, configured to perform delay compensation on the at least two synchronization control signals before the processing unit multiplexes the at least two synchronization control signals.

The device according to claim 14, wherein when the delay control unit delays the at least two synchronization control signals, the transmitting end performs delay measurement based on the delay compensation reference signal, and Delay compensation is performed on one or any combination of the at least two synchronization control signals according to the measurement result.

The device according to claim 15, wherein the delay compensation reference signal used by the delay compensation unit is a preset independent reference signal, or is in the at least two synchronous control signals. Any of them.

17. A device for maintaining synchronization, characterized by comprising:

a communication unit, configured to receive, by using an optical fiber, a multiplexed signal transmitted by the transmitting end;

18. The apparatus according to claim 17, wherein the synchronization control signal used by the processing unit comprises:

PP1 S signal, TOD signal, status control signal and status indication signal.