WO2014015649A1

WO2014015649A1 - Method, apparatus and system for time-synchronization

Info

Publication number: WO2014015649A1
Application number: PCT/CN2013/000833
Authority: WO
Inventors: 陈立俊; 刁穗东; 区洋; 邓单
Original assignee: 京信通信系统（中国）有限公司
Priority date: 2012-07-23
Filing date: 2013-07-11
Publication date: 2014-01-30
Also published as: CN103582108B; CN103582108A

Abstract

Disclosed are a method, apparatus and system for time-synchronization. The method comprises: within a set length of time, determining time delay vector parameter value which is corresponding with each received reference signal sent by a terminal and represents the variation of the reference signal; determining the credibility value that is used to measure the accuracy of each time delay vector parameter value based on the determined time delay vector parameter value; determining the time delay adjustment value based on the time delay vector parameter value and the credibility value, and sending the time delay adjustment value to the terminal. Using the technical solution provided by the embodiment of the present invention can better improve the accuracy of the time-synchronization between the base station and the terminal and improve the communication quality.

Description

Time synchronization method, device and system

Technical field

The present invention relates to the field of digital signal processing technologies, and in particular, to a time synchronization method, apparatus, and system. Background technique

At present, in the duplex communication mode of mobile communication, a frequency division duplex (FDD) mode and a time division duplex (TDD) mode are mainly included. Among them, in the mobile communication system of the TDD mode, the base station can receive and transmit data through one frequency channel. In practical applications, the TDD mode mainly controls the time when the data is transmitted in the same frequency channel and the time when the data is received, so that the base station can send data to the terminal within a specified time, and receive the data sent by the terminal in the second specified time, that is, the TDD mode. Time-separated control is used to control the data transmission in the same frequency channel to achieve the purpose of duplex communication.

Due to the above-mentioned duplex communication mode supported by the TDD mode, the terminal needs to transmit data to the base station within a specified time according to the distance of data transmission between itself and the base station. Otherwise, the time when the base station receives data through the frequency channel is missed, resulting in the terminal and the terminal. The communication of the base station failed. At present, the time for the base station to send data to the terminal can be controlled by the base station itself. However, for the terminal that sends data to the base station, it needs to adjust the direction to the base station according to the indication information sent by the base station after the communication path between the base station and the base station changes. The time at which data is sent to ensure successful communication between the terminal and the base station. In practical applications, based on the mobility of the terminal, after the base station and each terminal adopt initial synchronization, the base station can simultaneously receive the data sent by each terminal at a specified time, and if the location of the terminal changes, the terminal needs to calibrate itself to the base station in time. When the data is sent, the data is successfully sent to the base station, that is, the uplink synchronization is maintained with the base station.

At present, the terminal mainly controls the time for sending data to the base station by adjusting the configured timer. In an actual application, the terminal and the base station can agree on the format of the interactive data, for example, characterizing the data in a specified sequence, which is generally a sequence with strong autocorrelation, such as a ZC sequence. The base station performs a correlation operation on the received specified sequence according to the agreed original specified sequence to determine whether there is a difference between the time when the base station receives the specified sequence and the time when the specified sequence should be received, that is, the base station determines the delay adjustment value, and The delay adjustment value is sent to the terminal to instruct the terminal to perform time synchronization adjustment, that is, instruct the terminal to adjust the time for transmitting data to the base station.

However, in the prior art time synchronization method, when the base station determines the delay adjustment value according to the received specified sequence, there may be a problem that the accuracy is low. For example, the interference signal has a large interference intensity to the specified sequence sent by the terminal, and the result of the correlation operation performed by the base station on the specified sequence received is inaccurate, thereby determining the error delay information; or the terminal may move around. The building is relatively dense, resulting in a superposition of the sequence that arrives at the base station after reflection and the sequence of the normal arriving base station, so that the base station performs correlation operation on the specified sequence received and determines the channel estimation sequence. After the column, when determining the position of the peak according to the channel estimation sequence, it is found that there are multiple peaks, so that the interference base station judges the accuracy of receiving the specified sequence delay, and even causes the base station to determine the error delay adjustment value, and then adjusts the indication terminal. After the time of transmitting the data, the communication between the base station and the terminal fails.

In summary, the time synchronization method in the prior art has low accuracy, which makes the communication quality poor.

Summary of the invention

The embodiment of the invention provides a time synchronization method, device and system, which can better improve the accuracy of time synchronization between the base station and the terminal, and improve communication quality.

A time synchronization method includes: determining, within a set duration, a delay carrier parameter value of a corresponding characteristic signal change of each reference signal sent by the terminal; according to the determined delay carrier parameter value, Determining a credibility value for measuring the accuracy of each delay carrier parameter value; determining a delay adjustment value according to the delay carrier parameter value and the credibility value, and transmitting the value to the terminal, where the terminal according to the The time delay adjustment value is used for time synchronization adjustment.

A time synchronization device, comprising: a delay carrier parameter value determining unit, configured to determine, within a set duration, a time delay carrier parameter value of a received corresponding characteristic signal change of each reference signal sent by the terminal; a credibility value determining unit, configured to determine, according to a delay carrier parameter value determined by the delay carrier parameter value determining unit, a credibility value used to measure the accuracy of each delay carrier parameter value; Determining, according to the delay carrier parameter value determining unit, the time delay carrier parameter value and the credibility value determined by the credibility value determining unit, determining a delay adjustment value, and sending the delay value to the terminal, where the terminal is configured according to the The delay adjustment value is time-synchronized.

A time synchronization system, comprising: a base station, the base station includes the time synchronization device; and a terminal, configured to determine, according to a preset rule, whether the delay adjustment value is received; if the delay adjustment value is received, according to the The delay adjustment value adjusts the time of sending the signal; if the delay adjustment value is not received, determining whether the preset reception duration is exceeded, and if yes, sending the out-of-synchronization status signal, and vice versa, continuing to receive the delay adjustment value.

Through the foregoing technical solution, determining a delay carrier parameter value corresponding to each reference signal sent by the terminal within a set duration, and determining, according to the delay carrier parameter value, a credibility for measuring the accuracy of each delay carrier parameter value The degree value is then determined according to the delay carrier parameter value and the confidence value, and sent to the terminal. By introducing the credibility value to constrain and optimize the correlation signal, the related signal related to time synchronization can be further processed to obtain a more stable and accurate delay adjustment value and sent to the terminal to improve time synchronization between the base station and the terminal. Accuracy and improve communication quality. DRAWINGS 1 is a flowchart of a time synchronization method according to Embodiment 1 of the present invention; FIG. 2 is a schematic structural diagram of a time synchronization apparatus according to Embodiment 2 of the present invention. detailed description

For the problem that the accuracy of the time synchronization between the base station and the terminal existing in the prior art is low and the communication quality is poor, the technical solution proposed by the embodiment of the present invention limits and optimizes the related signal by introducing a credibility value. The signal related to time synchronization can be further processed to obtain a stable and accurate delay adjustment value and sent to the terminal, so as to improve the accuracy of time synchronization between the base station and the terminal, and improve communication quality.

The main implementation principles, specific implementation manners, and the beneficial effects that can be achieved by the technical solutions of the embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

Embodiment 1

A first embodiment of the present invention provides a time synchronization method. As shown in FIG. 1, the specific processing flow is as follows: Step 11: Receive a reference signal sent by the terminal within a set duration.

The reference signal sent by the terminal to the base station may be a pilot signal or other communication signal including a reference signal. If it is another communication signal including the reference signal, the reference signal needs to be extracted from the communication signal.

Specifically, the reference signal sent by the terminal is a sequence with strong autocorrelation. In the first embodiment of the present invention, the reference signal sent by the terminal is a ZC sequence as an example for detailed description.

Step 12: Determine a delay carrier parameter value corresponding to the change of the characteristic signal of each reference signal sent by the terminal. The delay carrier parameter value may include, but is not limited to, a channel estimation sequence corresponding to the received reference signal, a power value corresponding to the received reference signal, an index number obtained from the received reference signal, and the like. In the above three delay carrier parameter values, the channel estimation sequence and the power value are both expressed in a sequence, but the index number is a specifically determined value. Corresponding time delay carrier parameter values that characterize signal changes:

The first mode: correlating each received reference signal from the terminal with a preset reference signal to obtain a channel estimation sequence, and using the channel estimation sequence as a delay corresponding to each reference signal sent by the terminal Carrier parameter value. For example, if the reference signal from the terminal is ^ ^{= = Ω} ό ^ '""; , where 0 _≤ Ρ _≤ ρ_1, which is the index number of the position of the element in the sequence in the sequence, and Q is the length of the reference signal from the terminal. The default reference signal is: :^ ⁰ ^ ¹ , " ² '" — ¹ , where 0 ≤ ≤ 2_1 , which is the index number of the position of the element in the sequence in the sequence, Q is the length of the preset reference signal , using Equation 1 for sequence and correlation operations: P-] _t

^{= C} m ⁼ Σ ^a (p+r)modP ' { ^a _P ) Equation 1 where <:„, = = ,«— is the channel estimation sequence obtained by the correlation operation, 0≤r≤R - 1 , r is each The index number of the position of the element in the sequence is the length of the channel estimation sequence obtained by the correlation operation, mod represents the division of the two numbers, and w is the index of the number of times the reference signal is sent within the set duration.

The second method: correlating each received reference signal from the terminal with a preset reference signal, and determining a power value of each element in the channel estimation sequence in a channel estimation sequence obtained by the correlation operation, The power value is used as a delay carrier parameter value corresponding to each reference signal sent by the terminal.

For the specific implementation manner of determining the channel estimation sequence, refer to the detailed description of the first mode above, and details are not described herein again. In the channel estimation sequence = = , ^ , 〜 obtained by the correlation operation, the power value of each element in the sequence is determined by Equation 2.

Equation 2 where 0 ≤ r ≤ i? - l, r is the index number of the position of the element corresponding to the power value in the sequence, the length of the channel estimation sequence obtained by the correlation operation, P is the power value, is the channel estimation sequence , ^w is the index of the number of times the reference signal is sent within the set duration.

The third way: correlate each received reference signal from the terminal with a preset reference signal. Determining, in the channel estimation sequence obtained by the correlation operation, a power value of each element in the channel estimation sequence, determining an index number of an element in the sequence corresponding to the maximum power value, and determining the index number as a terminal The delay carrier parameter value corresponding to each reference signal.

For a specific implementation manner of determining a channel estimation sequence and obtaining a power value of each element in the sequence according to the determined channel estimation sequence, refer to the foregoing first mode and the second mode for detailed description, and details are not described herein again. After determining the power value corresponding to each element in the channel estimation sequence, that is, among the calculated power values, the index number r of the position of the element corresponding to the maximum power value in the sequence is determined.

It should be noted that the determined index number is also equivalent to the delay adjustment value. In the technical solution proposed in the prior art, the determined index number is generally sent to the terminal as the final delay adjustment value. The terminal performs time synchronization adjustment according to the received delay adjustment value. This simple method of determining the delay adjustment value has low accuracy.

Step 13: Determine, according to the determined delay carrier parameter value, a credibility value used to measure the accuracy of each delay carrier parameter value.

Wherein, the credibility value for measuring the accuracy of each delay parameter value may be, but is not limited to, including an absolute credibility value and a relative credibility value. Specifically, the determination of the absolute credibility value may be, but is not limited to, determined by one or more of the following ways:

The first way: determining an absolute confidence value based on the channel estimation sequence.

Wherein, the absolute credibility value may be determined according to the channel estimation sequence by using, but not limited to, the following method: A: determining an absolute credibility value according to the following formula 3:

If SIR _m ≤ SNR _TH

0 if SIR , "' " > SNR. Equation 3 where TH is the preset signal-to-interference ratio in the communication system, "' is the signal-to-interference ratio corresponding to the channel estimation sequence. Preferably, the embodiment of the present invention will be Set to the minimum signal-to-interference ratio allowed by the communication system,

"' can be determined by the following formula 4:

Equation 4 where, for the channel estimation sequence, 0 ≤ r ≤ i? - 1 , r is the index number of the position of each element in the sequence, and the length of the channel estimation sequence obtained by the correlation operation.

B: Determine the absolute confidence value according to the following formula 5:

"1 if max {|C _m |} > Z _m

0 if max ilC !} <

Equation 5 where ^α "' is the absolute confidence value, ^C - is the channel estimation sequence, m ^ il ^ ' ll is the modulo value of the channel estimation sequence and takes the maximum value thereof, TM is the preset and the The trusted threshold corresponding to the channel estimation sequence, and w is the index of the number of times the reference signal is sent within the set duration.

The second way: determining the absolute confidence value according to the power value.

After determining the channel estimation sequence corresponding to each reference signal sent by the terminal, the channel estimation sequence can obtain the power value corresponding to each element in the channel estimation sequence, and all the power values constitute a power delay language. That is to say, the power delay is a sequence consisting of power values. Specifically, the power value is obtained by modulating each element in the channel estimation sequence and taking the square value thereof. For details, refer to Equation 2 above.

Specifically, the absolute confidence value may be determined according to the power value by using Equation 6 below: Formula 6

Where α „ is the absolute confidence value, _m is the preset threshold, and |C _m |—is the power value.

The third way: Determine the absolute credibility value according to the index number.

The index number is further determined after the power value is obtained. The reference signal sent by the terminal to the base station, for example, the ZC sequence, is subjected to correlation calculation to obtain a channel estimation sequence, and further obtains the power value of each element in the channel estimation sequence according to the channel estimation sequence, and selects the obtained maximum value of the power value in the sequence. The corresponding index number. Specifically, the absolute confidence value can be determined by the following formula 7:

Where α „ is the absolute confidence value, t _ra is the preset threshold value, and N is the index number corresponding to the maximum power value. Specifically, the determination of the relative confidence value may be, but not limited to, the following manner One or several of them are determined: The first way: Determine the relative confidence value according to the channel estimation sequence.

Specifically, the relative confidence value may be determined according to the channel estimation sequence by using, but not limited to, the following method: A: The relative confidence value may be determined according to Equation 8: where is the relative confidence value, The signal to interference ratio corresponding to the channel estimation sequence.

B: The relative confidence value can be determined according to formula 9: m = 丽{|c„, |} Equation 9 where ^" is the relative confidence value, which is the channel estimation sequence, "^^^^ is the The channel estimation sequence ^ takes the modulus value and takes the maximum value.

The second way: determining the relative confidence value according to the power value.

Specifically, the relative confidence value can be determined from the power value by the following formula 10:

B _m = max | |C _m | |

m ' ^{m |} Equation 10 where is the relative confidence value, is the channel estimation sequence, m^ fr^ ' } is the channel estimation sequence

^C w takes the modulus value and squares the obtained power value, and takes the maximum value of the power value.

A preferred implementation manner, after determining the absolute credibility value and the relative credibility value, the determined absolute credibility value and the relative credibility value may be correspondingly stored, specifically, as shown in Table 1. Shown as the first embodiment of the present invention A way to store an absolute confidence value corresponding to the corresponding delay carrier parameter value:

Table 1

As shown in Table 2, the method for storing the relative credibility value corresponding to the corresponding delay carrier parameter value according to the first embodiment of the present invention is as follows:

Table 2

As shown in Table 3, a method for storing the absolute credibility value and the relative credibility value corresponding to the corresponding delay carrier parameter value is proposed in the first embodiment of the present invention:

Step 14: Determine a delay adjustment value according to the time delay carrier parameter value and the credibility value, and send the delay adjustment value to the terminal. The delay adjustment value may be determined by using the following two methods:

The first method is: multiplying each determined credibility value by a delay carrier parameter value, summing the average value, and obtaining the result as a delay adjustment value.

Wherein, since the credibility value includes an absolute credibility value and a relative credibility value, the two may be used in combination, or may be used separately, specifically:

The delay adjustment value is determined by the absolute confidence value: Λ = ^ ~'∑a _m -t _m

""'Formula 10, where TA is the delay delay ^α " is the absolute confidence value, which is the power value.

Determine the delay by the relative confidence value: A' Formula 1 1

Where TA is the delay adjustment value, which is the relative confidence value, t„, is the power value.

In the prior art, the delay adjustment value is generally determined by combining all the obtained power values, that is, the delay adjustment value sent to the terminal is determined by the formula ∑4=Lyt _m , and the embodiment of the present invention is compared. A technical solution proposed herein, such as the formula 10 and the formula 1 1 , in the first embodiment of the present invention, when determining the delay adjustment value, the credibility value is further introduced, that is, the first embodiment of the present invention is proposed. In the technical solution, when determining the delay adjustment value, the reliability value is eliminated, and some of the lower accuracy values are eliminated, and then the combination is taken to obtain the average value, which improves the accuracy of determining the delay adjustment value.

The second method: summing each determined credibility value and the delay carrier parameter value, and determining the corresponding maximum number of values in the obtained sequence, and using the index number as the time Delay adjustment value.

The delay adjustment value is determined by the absolute confidence value: Equation 12

Where TA is the delay adjustment value, which is the absolute confidence value, and P is the power value.

The delay adjustment value is determined by the relative confidence value: Equation 13

Where TA is the delay adjustment value, which is the relative confidence value, and P is the power value. The delay adjustment value is determined together with the absolute confidence value and the relative confidence value: TA = arg max

Formula 14

Where TA is the delay adjustment value, a _m is the absolute confidence value, is the relative confidence value, and P is the power value. In the prior art, generally, all the obtained power values are combined to obtain a maximum value, and then the index value of the obtained maximum value in the sequence is determined, and the obtained index number is sent to the terminal as a delay adjustment value, that is, The formula J _m sets the delay adjustment value sent to the terminal, and compares the technique proposed in the first embodiment of the present invention.

The scheme, as in the formula 12-14, the first embodiment of the present invention further introduces the credibility when determining the delay adjustment value. Value, that is, in the technical solution proposed by the first embodiment of the present invention, when determining the delay adjustment value, the reliability value is eliminated, and some low-accuracy values are eliminated, and then the merged average value is compared. The accuracy of determining the delay adjustment value is improved.

Step 15: After the determined delay adjustment value is sent to the terminal, the terminal determines whether the delay adjustment value is received according to a preset rule. If the determination result is yes, step 16 is performed, otherwise step 17 is performed.

Preferably, a timer can be set on the terminal side, and the timer can be set inside the terminal or outside the terminal, that is, the setting of the timer is not specifically limited.

Step 16: If the terminal receives the delay adjustment value, adjust the time of sending the signal according to the delay adjustment value, that is, perform time synchronization adjustment.

Preferably, when the terminal performs time synchronization adjustment according to the received delay adjustment value, the timer set on the terminal side is reset, that is, it is cleared and re-timed.

Step 17. If the delay adjustment value is not received, determine whether the preset reception duration is exceeded. If the determination result is yes, go to step 171, otherwise go to step 172.

Step 1 71: Determine that the preset receiving time exceeds the preset, and the terminal sends an out-of-synchronization status signal, where the out-of-step status signal is used to report the out-of-synchronization state.

Specifically, if it is determined that the preset duration is exceeded, the delay adjustment value has not been received, that is, the timer set on the terminal side times out, at this time, the timer operation of the timer is stopped, and the reception delay adjustment value is stopped. Sending an out-of-synchronization status signal and reporting the out-of-synchronization status to the base station or other out-of-synchronization state adjustment device

Step 172: Determine that the preset receiving duration is not exceeded, and the terminal continues to receive the delay adjustment value.

Specifically, if the timer set on the terminal side does not exceed the preset receiving duration, the terminal continues to receive the delay adjustment value according to the preset receiving duration.

Embodiment 2

Correspondingly, a second embodiment of the present invention provides a time synchronization device. It should be noted that the time synchronization device proposed in the second embodiment of the present invention can be installed as a standalone device on the base station side or as an integrated device. The module is disposed in the base station. In the second embodiment of the present invention, the time synchronization device is configured as an integrated module in the base station. The specific structure is as shown in FIG. 2, and includes:

The delay carrier parameter value determining unit 201 is configured to determine, in the set duration, a delay carrier parameter value of the received corresponding characteristic signal change of each reference signal sent by the terminal.

Specifically, the foregoing delay carrier parameter value determining unit 201 is specifically configured to perform correlation operation between each received reference signal from the terminal and a preset reference signal to obtain a channel estimation sequence, and use the channel estimation sequence as a terminal. The delay carrier parameter value corresponding to each reference signal sent; or each reference signal received from the terminal and the pre- The reference signal is subjected to a correlation operation, and in the channel estimation sequence obtained by the correlation operation, determining a power value of each element in the channel estimation sequence, and using the power value as a time corresponding to each reference signal sent by the terminal The carrier parameter value is extended; or each received reference signal from the terminal is correlated with a preset reference signal. In the sequence obtained by the correlation operation, determining the power value of each element in the sequence, determining an index number of the position of the element corresponding to the maximum power value in the sequence, and determining the index number as each sent to the terminal The delay carrier parameter value corresponding to the reference signal.

The credibility value determining unit 202 is configured to determine a credibility value for measuring the accuracy of each delay carrier parameter value according to the delay carrier parameter value determined by the delay carrier parameter value determining unit 201.

The credibility value includes an absolute credibility value. The credibility value determining unit 202 is specifically configured to determine an absolute credibility value according to the channel estimation sequence by one or more of the following manners. And determining an absolute credibility value according to the power value; determining an absolute credibility value according to the index number.

The credibility value includes a relative credibility value; the credibility value determining unit 202 is specifically configured to determine a relative credibility value in the channel estimation sequence; and/or determine a relative fidelity according to the power value. Reliability value.

Specifically, the credibility value determining unit 202 specifically determines the absolute credibility value according to the channel estimation sequence according to the following method:

Where ^ is the preset signal-to-interference ratio in the communication system, which is the signal-to-interference ratio corresponding to the channel estimation sequence; or

1 if max {|C _ra |} >

a _n

If max C _m < _:

The absolute confidence value is determined according to the formula, wherein ^α TM is an absolute confidence value, which is a channel estimation sequence, and ^max i′ ^e ^ is a modulo value of the channel estimation sequence ^e “′ and takes the maximum value thereof, X TM is a preset trusted threshold corresponding to the channel estimation sequence, and ^m is an index of the number of times the reference signal is sent within the set duration.

Specifically, the credibility value determining unit 202 specifically determines the absolute credibility value according to the power value by using the following method:

Where is the absolute confidence value, t _ra is the preset threshold, and t _m is the power value.

Specifically, the above-mentioned credibility value determining unit 202 specifically adopts the following formula, and determines an absolute credibility value according to the index number: 1 if N≤t„

0 if N > t _n

Wherein, α „ is an absolute credibility value, t _m is a preset threshold value, and N is an index number corresponding to the maximum power value. Specifically, the credibility value determining unit 202 specifically adopts the following method. Determining a relative confidence value according to the channel estimation sequence: determining a relative confidence value according to the formula "', wherein ^" is a relative confidence value, which is a signal to interference ratio corresponding to the channel estimation sequence; or according to the formula ^" - max fl^^ determines a relative confidence value, where "is a relative confidence value, is a channel estimation sequence, max fd} is a modulus value of the channel estimation sequence and takes the maximum value thereof. Specifically, The credibility value determining unit 202 specifically determines the relative credibility value according to the power value by using the following formula: β = 匪C,

, where the relative confidence value is the channel estimation sequence,

Is a power value obtained by modulating and squaring the channel estimation sequence, and taking a maximum value of the power values.

The sending unit 203 is configured to determine, according to the delay carrier parameter value determined by the delay carrier parameter value determining unit 201 and the credibility value determined by the credibility value determining unit 202, determine a delay adjustment value, and send To the terminal, where the terminal performs time synchronization adjustment according to the delay adjustment value.

Specifically, the sending unit 203 is specifically configured to: after multiplying each determined credibility value by a delay carrier parameter value, summing the average value, and obtaining the result as a real-time delay adjustment value; or determining Each credibility value is multiplied by a delay carrier parameter value, and then summed to determine a corresponding index number of the obtained maximum sum value in the obtained sequence, and the index number is used as a delay adjustment value.

Correspondingly, the embodiment of the present invention further provides a time synchronization system, including a base station and a terminal:

The base station includes the foregoing time synchronization device, and is mainly configured to receive a signal sent by the terminal and send a delay adjustment value to the terminal.

a terminal, configured to determine, according to a preset rule, whether the delay adjustment value is received; if the delay adjustment value is received, adjusting a time of sending a signal according to the delay adjustment value; if the delay is not received Adjust the value to determine whether the preset receiving duration is exceeded. If yes, send the out-of-synchronization status signal, and vice versa, continue to receive the delay adjustment value.

It should be understood that the units included in the above apparatus are only logical divisions according to the functions implemented by the apparatus, and in actual applications, superposition or splitting of the above units may be performed. And the function implemented by the device provided by the embodiment corresponds to the time synchronization method flow provided by the foregoing embodiment, and the more detailed processing flow implemented by the device is described in detail in the foregoing method embodiment. , will not be described in detail here. The technical solution proposed by the embodiment of the present invention introduces a credibility value in the synchronization process between the base station and the terminal to constrain and optimize the correlation signal, so as to improve the stability and accuracy of the time synchronization. The credibility value includes the analysis of any variation characteristics of the measured channel quality and the delay carrier parameter value measured within a certain window time, and the accuracy of the determined delay adjustment value is better improved, thereby realizing The accuracy of time synchronization between the base station and the terminal improves communication quality and obtains stable and accurate system synchronization performance.

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

Claims

Rights request

A time synchronization method, comprising:

Determining a time delay carrier parameter value of the corresponding characteristic signal change of each received reference signal sent by the terminal within a set duration;

Determining a credibility value for measuring the accuracy of each delay carrier parameter value based on the determined delay carrier parameter value;

And determining, according to the delay carrier parameter value and the credibility value, a delay adjustment value, and sending the delay adjustment value to the terminal, where the terminal performs time synchronization adjustment according to the delay adjustment value.

2. The method according to claim 1, wherein the received delay carrier parameter value of the corresponding characterization signal change of each reference signal sent by the terminal is determined within a set duration, and includes:

Correlating each received reference signal from the terminal with a preset reference signal to obtain a channel estimation sequence, and using the channel estimation sequence as a delay carrier parameter value corresponding to each reference signal sent by the terminal; or Correlating each received reference signal from the terminal with a preset reference signal, and determining, in the channel estimation sequence obtained by the correlation operation, a power value of each element in the channel estimation sequence, and using the power value as a delay carrier parameter value corresponding to each reference signal sent by the terminal; or

Correlating each received reference signal from the terminal with a preset reference signal, determining a power value of each element in the sequence in the sequence obtained by the correlation operation, and determining an element corresponding to the maximum power value in the sequence The index number of the middle position, and the determined index number is used as the delay carrier parameter value corresponding to each reference signal sent by the terminal.

The method according to claim 2, wherein the credibility value comprises an absolute credibility value; and the determining, according to the determined delay carrier parameter value, determining the delay carrier parameter The method of credibility value of value accuracy includes at least one of the following ways:

Determining an absolute confidence value according to the channel estimation sequence;

Determining an absolute confidence value based on the power value;

An absolute confidence value is determined based on the index number.

The method according to claim 2, wherein the credibility value includes a relative credibility value; and the determining, according to the determined delay carrier parameter value, determining the delay carrier parameter The value of the credibility of the value accuracy, including:

Determining a relative confidence value based on the sequence of channel estimates; and/or

A relative confidence value is determined based on the power value.

5. The method according to claim 3, wherein the channel estimation sequence is used according to the following method Determine the absolute confidence value:

Il if SIR _m ≤ SNR _TH

Determine the absolute confidence value according to the formula "' ° ^if ^ ^ ^TM, where the signal-to-interference ratio preset in the communication system is the signal-to-interference ratio corresponding to the channel estimation sequence; or according to the formula

Determine the absolute credibility value, where "„' is the absolute credibility value,

^ is a channel estimation sequence, max fl^'li is a modulus value of the channel estimation sequence and takes the maximum value thereof, and XTM is a preset trusted threshold corresponding to the channel estimation sequence, ^m It is the index of the number of times the reference signal is sent within the set duration.

6. The method according to claim 3, wherein the absolute confidence value is determined according to the power value by using the following method:

Where ^α "' is the absolute confidence value, ^y TM is the preset threshold, and l "'l is the power value.

7. The method according to claim 3, wherein the absolute confidence value is determined according to the index number by using the following formula:

Where ^α » 'is the absolute confidence value, ^ is the preset threshold, and Ν is the index number corresponding to the maximum power value.

8. The method according to claim 4, wherein the relative confidence value is determined according to the channel estimation sequence by using the following method:

The relative confidence value is determined according to the formula, where ^" is the relative confidence value, which is the signal-to-interference ratio corresponding to the channel estimation sequence; or the relative confidence value is determined according to the formula ^Ai = ^maX fl ^Cm 1}, where ^" Is a relative confidence value, ^C - is a channel estimation sequence, and ^max { 1} is a modulo value of the channel estimation sequence and takes the maximum value thereof.

9. The method according to claim 4, wherein the relative confidence value is determined according to the power value by using the following formula: /?, „ = max {|C _m | ² } where is the relative confidence value, ^c - ' is the channel estimation sequence, and ^max I } is the channel estimation sequence

^C "' takes the modulo value and squares the resulting power value and takes the maximum of the power values.

The method according to claim 1, wherein the determining the delay adjustment value according to the delay carrier parameter value and the credibility value comprises:

And multiplying each determined credibility value by a delay carrier parameter value, summing the average value, and obtaining the result as a delay adjustment value; or

The determined each credibility value is multiplied by the delay carrier parameter value, and then summed to determine a corresponding index number of the obtained maximum sum value in the obtained sequence, and the index number is used as a delay adjustment value.

The method according to claim 1, wherein after the determined delay adjustment value is sent to the terminal, the method further includes:

The terminal determines, according to a preset rule, whether the delay adjustment value is received;

And if the delay adjustment value is received, adjusting a time of sending the signal according to the delay adjustment value;

If the delay adjustment value is not received, it is determined whether the preset reception duration is exceeded, and if yes, the out-of-synchronization status signal is sent, and otherwise, the delay adjustment value is continuously received.

12. A time synchronization device, comprising:

a delay carrier parameter value determining unit, configured to determine, within a set duration, a time delay carrier parameter value of the received corresponding characteristic signal change of each reference signal sent by the terminal within a set duration;

a credibility value determining unit, configured to determine a credibility value for measuring the accuracy of each delay carrier parameter value according to the delay carrier parameter value determined by the delay carrier parameter value determining unit;

a sending unit, configured to determine, according to the delay carrier parameter parameter determined by the delay carrier parameter value determining unit, a credibility value determined by the credibility value determining unit, and determine a delay adjustment value and send the value to the terminal, The terminal performs time synchronization adjustment according to the delay adjustment value.

The apparatus according to claim 12, wherein the delay carrier parameter value determining unit is configured to perform correlation operation between each received reference signal from the terminal and a preset reference signal to obtain a channel. Estimating a sequence, using the channel estimation sequence as a delay carrier parameter value corresponding to each reference signal sent by the terminal; or correlating each received reference signal from the terminal with a preset reference signal, Determining, in the channel estimation sequence obtained by the correlation operation, a power value of each element in the channel estimation sequence, using the power value as a delay carrier parameter value corresponding to each reference signal sent by the terminal; or Each reference signal from the terminal is correlated with a preset reference signal, and in the sequence obtained by the correlation operation, the power value of each element in the sequence is determined. The index number of the position of the element corresponding to the maximum power value in the sequence, and the determined index number is used as the delay carrier parameter value corresponding to each reference signal sent by the terminal.

The device according to claim 13, wherein the credibility value includes an absolute credibility value; the credibility value determining unit is specifically configured to determine by one of the following manners The credibility value is: determining an absolute credibility value according to the channel estimation sequence; determining an absolute credibility value according to the power value; determining an absolute credibility value according to the index number.

The device according to claim 13, wherein the credibility value includes a relative credibility value, and the credibility value determining unit is specifically configured to determine a relative credibility value according to the channel estimation sequence. And/or determine a relative confidence value based on the power value.

The device according to claim 14, wherein the credibility value determining unit specifically determines the absolute credibility value according to the channel estimation sequence by using the following method:

Jl if SIR _m ≤SNR _TH

a _m = <

The absolute confidence value is determined according to the formula "' I ^{0 if} ^TM" ⁵⁷ ^TM, where ^ is the preset signal-to-interference ratio in the communication system, "' is the signal-to-interference ratio corresponding to the channel estimation sequence; or a _m ―

According to the formula"

Determining the absolute confidence value, where is the absolute confidence value, ^c "' is the channel estimation sequence, ^max fl ^m B is the modulo value of the channel estimation sequence and taking the maximum value thereof, ^χ TM is preset The trusted threshold corresponding to the channel estimation sequence, ^m is an index of the number of times the reference signal is sent within the set duration.

The device according to claim 14, wherein the credibility value determining unit specifically determines the absolute credibility value according to the power value by using the following method:

(1 if t _m ≤ t _TH

0 if t _m > t _TH where is the absolute confidence value, ^ is the preset threshold and is the power value.

The device according to claim 14, wherein the credibility value determining unit specifically adopts the following formula, and determines an absolute credibility value according to the index number:

1 if N≤t _TH

If N > TH where ^α TM is the absolute confidence value, ^ is the preset threshold, and Ν is the index number corresponding to the maximum power value.

The device according to claim 15, wherein the credibility value determining unit specifically adopts a method, determining a relative credibility value according to the channel estimation sequence: determining a relative credibility value according to a formula A' ^{= OT?} "', where is a relative credibility value, "' is a signal corresponding to the channel estimation sequence Interference ratio; or determine a relative confidence value according to the formula ^' m ^"^, where is a relative confidence value, is a channel estimation sequence, ^max fl ^e "^ is a modulo value of the channel estimation sequence and takes The maximum value.

The apparatus according to claim 15, wherein the credibility value determining unit specifically adopts the following formula, and determines a relative credibility value according to the power value:

/?„, = max{|C _m | ² } where ^" is the relative confidence value, which is the channel estimation sequence, ma^^"'' } is the channel estimation sequence

The method according to claim 12, wherein the sending unit is specifically configured to: after multiplying each determined credibility value by a delay carrier parameter value, summing the average value, Obtaining the result as a delay adjustment value; or summing each determined credibility value and the delay carrier parameter value, and determining the corresponding maximum index of the obtained index value in the obtained sequence, The index number is used as the delay adjustment value.

22. A time synchronization system, comprising:

a base station, the base station comprising the time synchronization device of any one of claims 12-21;