WO2016184148A1

WO2016184148A1 - Clock switching method, apparatus and base station

Info

Publication number: WO2016184148A1
Application number: PCT/CN2016/070870
Authority: WO
Inventors: 董广明; 游洪波; 肖辉
Original assignee: 中兴通讯股份有限公司
Priority date: 2015-10-29
Filing date: 2016-01-14
Publication date: 2016-11-24
Also published as: CN106658626A; CN106658626B

Abstract

The embodiments of the present invention provide a clock switching method, an apparatus and a base station, and are used for solving the problem that switching of the existing system clock easily causes that the call of a user is dropped and/or the user is unable to access a network. The method comprises: obtaining a time offset value and a frequency offset value at the current time by a standby clock source; performing smoothing processing respectively on the time offset value and the frequency offset value at the current time to obtain a time offset value for adjusting and a frequency offset value for adjusting; adjusting the system clock according to the time offset value for adjusting and the frequency offset value for adjusting, and switching the current clock source to the standby clock source.

Description

Method, device and base station for clock switching

Technical field

The present invention relates to the field of mobile communications, and in particular, to a method, an apparatus, and a base station for clock switching.

Background technique

At present, in the LTE communication system, the reference clock source used includes GPS, air interface synchronization, and 1588. During the working process, there are some abnormal conditions that cause the current clock source to be unavailable. At this time, the system clock needs to be switched.

At present, the method of switching the system clock is likely to cause the user to drop the call or access the network, thereby affecting the user experience and resulting in poor user experience.

Summary of the invention

In view of this, the embodiment of the present invention is to provide a method, a device, and a base station for clock switching, which at least solves the problems existing in the prior art, and solves the problem that the switching of the existing system clock easily causes the user to drop the call and/or cannot access. Network problems.

The technical solution of the embodiment of the present invention is implemented as follows:

According to an aspect of the present invention, the present invention provides a method of clock switching, the method comprising:

Obtaining the time offset value and the frequency offset value of the current moment by using the alternate clock source;

Performing a smoothing process on the time offset value and the frequency offset value of the current time to obtain a time offset value for adjustment and a frequency offset value for adjustment;

The system clock is adjusted according to the time offset value for the adjustment and the frequency offset value for the adjustment, and the current clock source is switched to the standby clock source.

In an embodiment of the present invention, the time offset value and the frequency offset of the current moment are The values are respectively smoothed, and the steps of adjusting the time offset value and the frequency offset value are obtained, which specifically includes:

Obtaining the time offset value and the frequency offset value of the current moment by using the current clock source;

According to the offset value and the frequency offset value of the standby clock source, and the time offset value and the frequency offset value of the current clock source, the time-biased smoothing coefficient and the frequency-offset smoothing coefficient are calculated;

Determining a time offset value for adjustment according to the time offset smoothing coefficient and the time offset value of the current time; and determining a frequency offset value for adjusting according to the frequency offset smoothing coefficient and the frequency offset value of the current time .

In an embodiment of the present invention, the step of calculating a time-offset smoothing coefficient and a frequency offset smoothing coefficient according to the offset value and the frequency offset value of the standby clock source, and the time offset value and the frequency offset value of the current clock source are used. Specifically, including:

Obtaining time offset values and frequency offset values for several different moments;

And respectively smoothing the plurality of time offset values and frequency offset values to obtain the time offset smoothing coefficient and the frequency offset smoothing coefficient;

Wherein, the time deviation value is obtained by performing a difference processing between the time offset value acquired by the current clock source and the time offset value obtained by the standby clock source;

The frequency offset value is obtained by performing a difference processing between the frequency offset value acquired by the current clock source and the frequency offset value obtained by the standby clock source.

In an embodiment of the present invention, the method further includes:

Use GPS or 1588 clock as the current clock source, use the air interface synchronous clock as the backup clock source; when the GPS or 1588 clock loses lock, switch the system clock; or

The air interface synchronous clock is used as the current clock source, and GPS or 1588 clock is used as the backup clock source; when the GPS or 1588 clock is locked, the system clock is switched.

In an embodiment of the present invention, the method further includes:

When the GPS or 1588 clock is lost, the system clock is switched when

The time offset value for adjustment is specifically the time-averaged smoothing coefficient and the time-offset value of the current time. And the frequency offset value for adjustment is specifically the sum of the frequency offset smoothing coefficient and the frequency offset value of the current time.

In an embodiment of the present invention, the method further includes:

Locked by the GPS or 1588 clock, causing switching system clocks,

The time offset value for adjustment is specifically a difference between the time offset value of the current time and the time offset smoothing coefficient; and the frequency offset value used for the adjustment is specifically the frequency offset value of the current time and the frequency offset smoothing coefficient. Difference.

According to an aspect of the invention, the invention provides a device for clock switching, the device comprising:

The time-frequency offset obtaining module is configured to acquire a time offset value and a frequency offset value of the current moment through the standby clock source;

The smoothing module is configured to perform smoothing processing on the time offset value and the frequency offset value of the current time, respectively, to obtain a time offset value for adjustment and a frequency offset value for adjustment;

The switching module is configured to adjust the system clock according to the time offset value for the adjustment and the frequency offset value for the adjustment, and switch the system clock from the current clock source to the standby clock source.

In an embodiment of the present invention, the time-frequency offset obtaining module is further configured to acquire a time offset value and a frequency offset value of the current time by using a current clock source;

The smoothing module is specifically configured to calculate a time-offset smoothing coefficient and a frequency offset smoothing coefficient according to the offset value and the frequency offset value of the standby clock source, and the time offset value and the frequency offset value of the current clock source;

In an embodiment of the present invention, the smoothing module includes a smoothing coefficient determining module, and the smoothing coefficient determining module is configured to acquire time offset values and frequency offset values of the plurality of different moments;

The time-frequency offset obtaining module, the smoothing module, and the switching module, the smoothing coefficient determining module may use a central processing unit (CPU) and a digital signal processor (DSP, when performing processing). Digital Singnal Processor) or Field-Programmable Gate Array (FPGA) implementation.

According to an aspect of the present invention, the present invention provides a base station that performs clock switching using the clock switching apparatus of the present invention.

The beneficial effects of the present invention are as follows:

In the embodiment of the present invention, the time offset value and the frequency offset value of the current time source are obtained by performing smoothing processing on the standby clock source, thereby achieving the effect of clock smooth switching, improving the system clock performance, and effectively solving the problem that the user loses or fails when the system clock is switched. The problem of accessing the network.

DRAWINGS

1 is a main flowchart of a method for clock switching in an embodiment of the present invention;

2 is a detailed flowchart of a method for clock switching in an embodiment of the present invention;

FIG. 3 is a schematic structural diagram of a device for clock switching according to an embodiment of the present invention.

detailed description

In order to solve the problem that the switching of the existing system clock is easy to cause the user to drop the call and/or the network cannot be accessed, the present invention provides a method, an apparatus, and a base station for clock switching. The present invention further proceeds to the present invention with reference to the accompanying drawings and embodiments. Detailed description. It should be understood that the specifics described herein The examples are merely illustrative of the invention and are not intended to limit the invention.

Embodiment 1

As shown in FIG. 1 , an embodiment of the present invention provides a method for clock switching, where the method includes:

S101. Obtain a time offset value and a frequency offset value of the current moment by using a backup clock source.

S102: Smoothing the time offset value and the frequency offset value of the current time to obtain a time offset value for adjustment and a frequency offset value for adjustment;

S103. Adjust a system clock according to the time offset value for the adjustment and the frequency offset value for the adjustment, and switch the current clock source to the backup clock source.

Among them, in the LTE communication system, the clock source used includes GPS, air interface synchronization and 1588; generally, after the system is powered on, the GPS or 1588 clock is configured as the current clock source; the default air interface synchronization clock also runs at the same time as the backup clock source. . There are also special cases, such as GPS or 1588 clock loss, the air interface synchronization clock is also configured as the current clock source, GPS or 1588 clock as the backup clock source.

In the embodiment of the present invention, when the system clock is switched, the time offset value and the frequency offset value of the current time source are obtained by smoothing the backup clock source, thereby achieving the effect of clock smooth switching, improving the system clock performance, and effectively solving the system clock. The problem that the user dropped the call or failed to access the network when switching.

The step of smoothing the time offset value and the frequency offset value of the current time to obtain the time offset value for adjustment and the frequency offset value for adjustment are preferably implemented in the following manner:

S1011: Obtain a time offset value and a frequency offset value of the current time by using a current clock source;

S1012, calculating a time-biased smoothing coefficient and a frequency-offset smoothing coefficient according to the offset value and the frequency offset value of the standby clock source, and the time offset value and the frequency offset value of the current clock source;

S1013: Determine, according to the time-averaged smoothing coefficient and the time-offset value of the current time, a time-offset value for adjusting;

S1014: Determine a frequency offset value for adjustment according to the frequency offset smoothing coefficient and the frequency offset value of the current time.

In the prior art, there are many smoothing methods, some of which are simple to implement, but the smoothing effect is poor, and some methods have a good smoothing effect, but the implementation is complicated, and the computing power of the LTE system is high. In the embodiment of the present invention, the integrated smoothing effect and the performance of the LTE system are preferably obtained by using the foregoing manner to obtain the time offset value and the frequency offset value for adjustment. The method is simple to implement, and the calculation is fast without affecting the performance of the LTE system, and the clock is further improved. Smooth switching effect.

For the specific implementation of the S1012 step, refer to the following manner:

S10121: Obtain a time offset value and a frequency offset value at different times;

S10122: Perform smoothing processing on the plurality of time offset values and frequency offset values, respectively, to obtain the time offset smoothing coefficient and the frequency offset smoothing coefficient;

In the embodiment of the present invention, when the time-shifting smoothing coefficient and the frequency-offset smoothing coefficient are obtained, the effect of the smooth switching and the performance of the LTE system may be determined according to the need to determine the deviation value and the frequency offset value when performing the smoothing process respectively. The number is preferably selected within 100 seconds, for example, 50, 55, 60, 65 or 70 in 1 second.

At present, there are many reasons for causing the system clock to be switched. However, the inventors of the present invention have found that a large part of the reason is caused by the loss of the GPS or 1588 clock. Therefore, based on the discovery, the method of the embodiment of the present invention may further include:

The GPS or 1588 clock is used as the current clock source, and the air interface synchronous clock is used as the backup clock source; when the GPS or 1588 clock loses lock, the system clock is switched.

The inventor of the present invention may also find that, when the LTE system detects the GPS or the 1588 clock lock, the current clock source needs to be switched from the new clock to the GPS or the 1588 clock.

In order to make the embodiment of the present invention more clear, the following describes the method in the embodiment of the present invention by taking the system clock switching caused by GPS or 1588 clock loss of lock as an example. As shown in Figure 2, the detailed process is as follows:

Step 1: The LTE system is powered on, and the GPS or 1588 clock is used as the current clock source to configure the working system clock.

Step 2: The air interface is synchronized to the software clock. At the same time, it is used as the backup clock source. It can run synchronously in real time and perform periodic air interface synchronization.

Step 3: The local base station obtains the time-frequency offset value of the local base station by scanning the primary base station existing around and by GPS or 1588 (current clock source).

Step 4: The local base station obtains the time-frequency offset between the local base station and the primary base station by scanning the primary base station existing around the primary base station, and records the time-frequency offset value by using the air interface synchronization (the backup clock source). The time-frequency offset obtained by the air interface synchronization is not used as a reference value for adjusting the system clock, and only recording is performed.

Step 5: Smoothing the time-frequency offset obtained from the air interface synchronization, and smoothing the time-frequency offset obtained from the GPS or 1588 clock to obtain a time-frequency partial smoothing coefficient.

The specific implementation of this step can be as follows:

Step 51: The time offset value t ₂ obtained by the current clock source and the time offset value t ₁ obtained by the standby clock source are simultaneously subjected to difference processing, and the time deviation value Δt _{i is obtained} ;

Specifically, Δt _i = t _{2 -} t ₁ at the i-th time;

Step 52: Perform a difference processing between the frequency offset value obtained by the current clock source and the frequency offset value obtained by the standby clock source to obtain a frequency offset value Δf _i ;

Specifically, Δf _i = f ₂ -f ₁ at the i-th moment;

Step 53: Obtain a time offset value and a frequency offset value of the plurality of different moments; that is, take the time offset value and the frequency offset value of the n times in the preset time period; for example, 60 times in 1 second;

Step 54: Smoothing the plurality of time offset values and frequency offset values, respectively, to obtain the time-biased smoothing coefficient and the frequency-offset smoothing coefficient;

Specifically, the time-biased smoothing coefficient k _t is obtained by the following calculation method:

The frequency offset smoothing coefficient k _f is obtained by the following calculation method:

Where i=1, 2, 3, ..., n.

Step 6: When the GPS or 1588 clock is out of lock, the system immediately determines the time offset value T ₁ for adjustment according to the time-averaged smoothing coefficient and the time offset value T _{01 of} the current time; and the smoothing coefficient according to the frequency offset And the frequency offset value F _{01 of} the current time is determined, and the frequency offset value F _{1 for} adjustment is determined.

Specifically, T ₁ = k _t + T ₀₁ ; F ₁ = k _f + F ₀₁ .

That is to say, the time offset value for adjustment is specifically the sum of the time-averaged smoothing coefficient and the time-offset value of the current time; the frequency offset value used for the adjustment is specifically the frequency-offset smoothing coefficient and the current time The sum of the frequency offset values.

Then, the system clock is adjusted according to the time offset value for the adjustment and the frequency offset value for the adjustment, and the current clock source is switched to the standby clock source.

After the switchover is complete, the current clock source is the air interface synchronization clock, and the backup clock source is GPS or 1588 clock.

In order to make the embodiment of the present invention more clear, the following describes the method in the embodiment of the present invention by taking the clock switching caused by GPS or 1588 clock locking as an example. The detailed process is as follows:

In the detailed process, the first six steps are the same as the detailed process described above, and are not described here;

After the above step 6, the system detects whether the GPS or 1588 clock (the alternate clock source) is locked every 10 minutes, and after detecting the GPS or 1588 clock lock 2 times in succession, according to the time-averaged smoothing coefficient and the current moment a time offset value T ₀₂ , determining a time offset value T _{2 for} adjustment;

The value of the smoothing coefficient to the frequency deviation and frequency deviation of the current time F _02, determined by the offset value to adjust the frequency F _2.

Specifically, T ₂ = T ₀₂ - k _t ; F ₂ = F ₀₂ - k _f .

That is to say, the time offset value for adjustment is specifically the difference between the time offset value of the current time and the time offset smoothing coefficient;

The frequency offset value for adjustment is specifically the difference between the frequency offset value of the current time and the frequency offset smoothing coefficient.

Then, the system clock is adjusted according to the time offset value for the adjustment and the frequency offset value for the adjustment, and the current clock source is switched to the GPS or 1588 clock.

After the switchover is complete, the current clock source is GPS or 1588 clock, and the backup clock source is the air interface synchronization clock.

Embodiment 2

As shown in FIG. 3, an embodiment of the present invention provides a device for clock switching, where the device includes:

The time-frequency offset obtaining module 30 is configured to acquire a time offset value and a frequency offset value of the current moment by using a backup clock source;

The smoothing module 32 is configured to perform smoothing processing on the time offset value and the frequency offset value of the current time, respectively, to obtain a time offset value for adjustment and a frequency offset value for adjustment;

The switching module 34 is configured to adjust the system clock according to the time offset value for the adjustment and the frequency offset value for the adjustment, and switch the current clock source to the backup clock source.

The time-frequency offset obtaining module 30 is further configured to obtain a time offset value and a frequency offset value of the current time by using the current clock source; the smoothing module 32 is specifically configured to be based on the offset value and the frequency offset value of the standby clock source, and the current The time offset value and the frequency offset value of the clock source are calculated, and the time-averaged smoothing coefficient and the frequency-offset smoothing coefficient are calculated;

Specifically, the smoothing module includes a smoothing coefficient determining module and a time-frequency offset determining module;

The smoothing coefficient determining module is configured to acquire time offset values and frequency offset values of the plurality of different moments; and smoothing the plurality of time offset values and the frequency offset values respectively to obtain the time skew smoothing coefficient and the frequency offset Smoothing factor

The time-frequency offset value determining module is configured to determine a time-offset value for adjustment according to the time-shifted smoothing coefficient and the time-offset value of the current time; and the frequency-offset value according to the frequency-offset smoothing coefficient and the current time , determine the frequency offset value for adjustment.

The device in the embodiment of the present invention may further include a triggering module configured to use the GPS or 1588 clock as the current clock source in the LTE system, and use the air interface synchronous clock as the backup clock source; when the GPS or 1588 clock loses lock, trigger the switch. The module switches the system clock; or

When the LTE system uses the air interface synchronous clock as the current clock source, the GPS or 1588 clock is used as the backup clock source; when the GPS or 1588 clock is locked, the switching module is triggered to switch the system clock.

Wherein, when the GPS or 1588 clock is lost, the system clock is switched when

The time offset value for adjustment is specifically a sum of the time-averaged smoothing coefficient and the time-offset value of the current time; and the frequency offset value used for the adjustment is specifically the frequency-offset smoothing coefficient and the frequency offset value of the current time Sum.

Locked by the GPS or 1588 clock, causing switching system clocks,

The embodiment of the present invention is an embodiment of the device corresponding to the first embodiment. For the specific configuration, refer to the first embodiment, and details are not described herein again. In the embodiment of the present invention, when the device performs the system clock switching, the backup clock source obtains the time offset value and the frequency offset value of the current time to smooth the clock, thereby achieving the effect of clock smooth switching, improving the system clock performance, and effectively solving the problem. The problem that the user dropped the call or failed to access the network when the system clock was switched.

Embodiment 3

An embodiment of the present invention provides a base station, where the base station includes the apparatus in Embodiment 2. In the embodiment of the present invention, when the system clock is switched, the base station obtains the time offset value and the frequency offset value of the current time by the backup clock source, thereby achieving the effect of clock smooth switching, improving the system clock performance, and effectively It solves the problem that the user drops the call or cannot access the network when the system clock is switched.

Although the preferred embodiments of the present invention have been disclosed above for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible. Therefore, the scope of the present invention should not be limited to the embodiments described above.

Industrial applicability

Claims

A method of clock switching, the method comprising:

Obtaining the time offset value and the frequency offset value of the current moment by using the alternate clock source;

Performing a smoothing process on the time offset value and the frequency offset value of the current time to obtain a time offset value for adjustment and a frequency offset value for adjustment;

Adjusting the system clock according to the time offset value for the adjustment and the frequency offset value for the adjustment, and switching the system clock from the current clock source to the standby clock source.
The method according to claim 1, wherein the step of smoothing the time offset value and the frequency offset value of the current time to obtain a time offset value and a frequency offset value for adjustment, specifically comprising:

Obtaining the time offset value and the frequency offset value of the current moment by using the current clock source;

According to the offset value and the frequency offset value of the standby clock source, and the time offset value and the frequency offset value of the current clock source, the time-biased smoothing coefficient and the frequency-offset smoothing coefficient are calculated;

Determining a time offset value for adjustment according to the time offset smoothing coefficient and the time offset value of the current time; and determining a frequency offset value for adjusting according to the frequency offset smoothing coefficient and the frequency offset value of the current time .
The method according to claim 2, wherein said calculating a time-skew smoothing coefficient and a frequency-offset smoothing coefficient according to a bias value and a frequency offset value of the standby clock source, and a time offset value and a frequency offset value of the current clock source The steps specifically include:

Obtaining time offset values and frequency offset values for several different moments;

And respectively smoothing the plurality of time offset values and frequency offset values to obtain the time offset smoothing coefficient and the frequency offset smoothing coefficient;

Wherein, the time deviation value is obtained by performing a difference processing between the time offset value acquired by the current clock source and the time offset value obtained by the standby clock source;

The frequency offset value is the frequency offset value obtained by simultaneously engraving the current clock source and the frequency acquired by the alternate clock source. The partial value is obtained by the difference processing.
The method of any of claims 1-3, wherein the method further comprises:

Use GPS or 1588 clock as the current clock source, use the air interface synchronous clock as the backup clock source; when the GPS or 1588 clock loses lock, switch the system clock; or

The air interface synchronous clock is used as the current clock source, and GPS or 1588 clock is used as the backup clock source; when the GPS or 1588 clock is locked, the system clock is switched.
The method of claim 4 wherein the method further comprises:

When the GPS or 1588 clock is lost, the system clock is switched when

The time offset value for adjustment is specifically a sum of the time-averaged smoothing coefficient and the time-offset value of the current time; and the frequency offset value used for the adjustment is specifically the frequency-offset smoothing coefficient and the frequency offset value of the current time Sum.
The method of claim 4 wherein the method further comprises:

Locked by the GPS or 1588 clock, causing switching system clocks,

The time offset value for adjustment is specifically a difference between the time offset value of the current time and the time offset smoothing coefficient; and the frequency offset value used for the adjustment is specifically the frequency offset value of the current time and the frequency offset smoothing coefficient. Difference.
A device for clock switching, the device comprising:

The time-frequency offset obtaining module is configured to acquire a time offset value and a frequency offset value of the current moment through the standby clock source;

The smoothing module is configured to perform smoothing processing on the time offset value and the frequency offset value of the current time, respectively, to obtain a time offset value for adjustment and a frequency offset value for adjustment;

The switching module is configured to adjust the system clock according to the time offset value for the adjustment and the frequency offset value for the adjustment, and switch the system clock from the current clock source to the standby clock source.
The apparatus according to claim 7, wherein the time-frequency offset obtaining module is further configured to acquire a time offset value and a frequency offset value of the current moment by using a current clock source;

The smoothing module is specifically configured to calculate a time-offset smoothing coefficient and a frequency offset smoothing coefficient according to the offset value and the frequency offset value of the standby clock source, and the time offset value and the frequency offset value of the current clock source;

Determining a time offset value for adjustment according to the time offset smoothing coefficient and the time offset value of the current time; and determining a frequency offset value for adjusting according to the frequency offset smoothing coefficient and the frequency offset value of the current time .
The apparatus of claim 8, wherein the smoothing module comprises a smoothing coefficient determining module, the smoothing coefficient determining module configured to acquire time offset values and frequency offset values of the plurality of different moments;

And respectively smoothing the plurality of time offset values and frequency offset values to obtain the time offset smoothing coefficient and the frequency offset smoothing coefficient;

Wherein, the time deviation value is obtained by performing a difference processing between the time offset value acquired by the current clock source and the time offset value obtained by the standby clock source;

The frequency offset value is obtained by performing a difference processing between the frequency offset value acquired by the current clock source and the frequency offset value obtained by the standby clock source.
A base station that performs clock switching using the apparatus for clock switching according to any one of claims 7-9.