Wireless air interface accurate clock synchronization method without DPLL (Digital Phase Locked Loop) loop

Abstract

The invention relates to the technical field of wireless networks, and discloses a wireless air interface accurate clock synchronization method without a DPLL loop. Comprising the following steps: selecting a master node and a slave node in a wireless communication network, configuring communication parameters, sending a synchronization test signal to the slave node through a wireless air interface, calculating clock skew between the slave node and the master node, configuring clock adjustment parameters, performing clock synchronization adjustment on a local clock, and formulating a clock synchronization level of the wireless air interface. Compared with the prior art, the method has the advantages that the sending failure possibly occurring during single-channel transmission is avoided through a multi-channel signal sending mode, and the clock synchronization is adaptively adjusted by combining the frequency deviation and the phase deviation, so that the accurate and reasonable clock synchronization strategy of the clock synchronization is realized; inconvenience caused by multi-stage complex synchronization operation and calculation of a large amount of data is avoided, and the accuracy of clock synchronization of the wireless air interface in a wireless communication network is improved.

Description

Technical Field

[0001] The present invention relates to the field of wireless network technology, and more specifically, to a wireless air interface precise clock synchronization method without a DPLL loop. Background Art

[0002] In wireless communication systems, clock synchronization is the key to ensuring the reliability of wireless communication data transmission and system performance. If the clocks between the base station and the user equipment in the wireless communication system are not synchronized, or the clock error is too large, the wireless communication data in the wireless communication system cannot be accurately transmitted between the base station and the user equipment. Therefore, it is necessary to ensure the clock synchronization effect within the wireless air interface in the wireless communication system.

[0003] The patent application with reference publication number CN102118779A discloses a method for realizing clock synchronization based on wireless mode, including a synchronization node performing air interface signal detection, detecting a base station under test, comparing the air interface signal start flag received from the base station under test with the synchronization reference stored by the synchronization node, obtaining the time-frequency deviation between the base station under test and the synchronization node, the synchronization node accessing the base station under test, reporting the time-frequency deviation message to the base station under test, and the base station under test performing clock synchronization with the synchronization node according to the message; In the existing wireless air interface clock synchronization, a large amount of monitoring data in the wireless air interface is monitored in real time through the DPLL loop technology, and the calculation results are obtained after massive calculations, and the clock of the wireless air interface is synchronized with the final calculation results. For example, in the above-mentioned patent application, a single communication channel mode is selected, and real-time multi-point clock data detection and analysis operations are performed between the base station under test and the synchronization node through the communication channel to achieve the subsequent clock synchronization effect between the base station under test and the synchronization node. On the one hand, the security of the data transmission mode of a single channel is insufficient. When the channel fails, data transmission failure will occur, resulting in the inability to perform subsequent clock synchronization operations. On the other hand, through the real-time multi-point monitoring, calculation, and synchronization adjustment operations, it is necessary to continuously calculate a large amount of various types of data, which not only increases the calculation burden of the wireless communication system, but also increases the probability of errors in the calculation of clock synchronization data, thereby reducing the accuracy of the clock synchronization adjustment operation.

[0004] In view of this, the present invention proposes a wireless air interface precise clock synchronization method without a DPLL loop to solve the above problem. Summary of the invention

[0005] In order to overcome the above-mentioned defects of the prior art and to achieve the above-mentioned purpose, the present invention provides the following technical solution: a wireless air interface precise clock synchronization method without a DPLL loop, applied to a wireless communication system, comprising: S1: Based on the air interface communication criterion, a master node and a slave node are selected in the wireless communication network, and communication parameters of the wireless air interface are configured. The air interface communication criterion is: a wireless station with the highest stability coefficient is selected as the master node; S2: The master node constructs a synchronization test signal with a time stamp and sends the synchronization test signal to the slave node through the wireless air interface; S3: Based on the deviation calculation criterion, the clock deviation between the slave node and the master node is calculated, and it is determined whether to perform the clock synchronization operation. The deviation calculation criterion is: the first synchronization test signal that arrives at the slave node in the test channel is selected as the calculation signal; S4: If a clock synchronization operation is performed, the clock adjustment parameters of the slave node are configured, and the local clock of the slave node is adjusted for clock synchronization based on the clock adjustment specification. The clock adjustment specification is: when the adjustment unit is executed once, the frequency is adjusted once, and then the phase is adjusted once; S5: Analyze the synchronization performance of the adjusted master node and slave node, and determine the clock synchronization level of the wireless air interface.

[0006] Furthermore, the selection method of the master node and the slave node is: The communication status of each wireless station in the wireless communication network is queried one by one, and the wireless stations with normal communication status are recorded as valid stations, so as to obtain A valid stations; Query the maintenance events of A valid sites one by one through the database, record the end time of the maintenance of the wireless site in the maintenance event as the cycle start point, record the current time as the cycle end point, and record the period from the cycle start point to the cycle end point as the communication period, and obtain A communication periods; Count the number of times the clock sources of A valid sites trigger the safety detection system in the corresponding A communication periods one by one, and obtain A trigger values; The durations during which the clock sources of the effective sites in A communication periods do not trigger the safety detection system are respectively counted to obtain A duration values, and the A trigger values ​​and the A duration values ​​are respectively assigned corresponding proportional coefficients and then added to obtain A stability coefficients; Arrange the A stability coefficients in descending order, and record the valid site corresponding to the first stability coefficient as the master node; The communication coverage of the wireless air interface corresponding to the master node is queried, and the user equipment within the communication coverage is recorded as a slave node.

[0007] Furthermore, the communication parameters include frequency band, channel bandwidth and modulation method; The configuration method of frequency band, channel bandwidth and modulation mode is: All communication logs of the wireless air interface during the communication period are queried one by one through the database, and the data with the keyword of frequency in the communication log is recorded as frequency data to obtain B frequency data; The signal-to-noise ratios of B frequency data are calculated one by one by the power ratio method formula, and the frequency data whose signal-to-noise ratio is greater than the calibrated signal-to-noise threshold is recorded as available data, thereby obtaining C available data; The power ratio method formula is: ; In the formula, For the The signal-to-noise ratio of the frequency data is =1,2,...,B, For the The signal power of the frequency data, For the The noise power of the frequency data; Query the communication frequencies in the C available data one by one, and record the frequencies between the minimum value of the communication frequency and the maximum value of the communication frequency as the frequency band; The difference between the maximum value of the communication frequency and the minimum value of the communication frequency is recorded as the channel bandwidth; When the channel bandwidth is greater than the calibrated modulation bandwidth value, the modulation mode is configured as frequency modulation; When the channel bandwidth is less than or equal to the calibrated modulation bandwidth value, the modulation mode is configured as amplitude modulation.

[0008] Furthermore, the method for constructing the synchronous test signal is: Query the current time data of the clock source in the master node, split the current time data into text part and numeric part through word segmentation technology, and record the numeric part as the timestamp; The node deployment data of the master node is queried through the attribute management system, the keyword groups in the node deployment data are identified using natural language processing technology, and the keyword groups are numbered in ascending order; The keyword group is split into keywords and key values ​​by using word segmentation technology, the keyword group with the keyword ID is recorded as ID phrase, the key value in the ID phrase is recorded as node ID, and the number of the ID phrase is recorded as a sequence number; A signal data packet with three test bits is constructed, and the timestamp, node ID and sequence number are sequentially imported into the three test bits to generate a synchronous test signal.

[0009] Furthermore, the method for sending the synchronization test signal is: The transmission status of all channels in the wireless air interface is queried one by one, and the channels with high-throughput transmission status are recorded as test channels, so as to obtain D test channels; Distribute the D test channels in parallel one by one, and connect the signal input ends and signal output ends of the D test channels to the master node and the slave node respectively; A basic wall is established between any two adjacent test channels, and a non-repeating frequency range within the frequency band is configured on the two adjacent basic walls to generate D-1 signal shielding walls; Set the preset duration as the synchronization period. The signal sending time; exist At the signal sending moment, the synchronization test signal on the master node is synchronously sent to the slave node through D test channels.

[0010] Furthermore, the calculation method of clock deviation is: Receive from the node one by one The synchronous test signals in the D test channels sent at the signal sending time are recorded, and the arrival time of all the synchronous test signals is recorded; In chronological order, the first synchronization test signal arriving at the slave node is recorded as the calculation signal, and the arrival time of the calculation signal is recorded as the receiving time. Receiving time; Analyze one by one Calculate the timestamp of the signal and obtain Send time, and Send time to The duration between the receiving times is recorded as the sub-deviation, and we can obtain Size deviation; The starting time when the calculation signal is parsed from the node and the ending time when the calculation signal is parsed are respectively found out, and the duration between the starting time and the ending time is recorded as the parsing duration; Remove the maximum and minimum values ​​of the sub-deviations and keep the remaining The individual deviations are subtracted from the analysis time one by one, and The differences are accumulated and averaged to obtain the clock deviation.

[0011] Furthermore, the method for determining whether to perform the clock synchronization operation is: When the clock deviation is equal to 0, it is determined that the clock synchronization operation is not performed; When the clock deviation is not equal to 0, it is determined to perform the clock synchronization operation.

[0012] Furthermore, the clock adjustment parameters include frequency deviation and phase deviation; The configuration method of frequency deviation and phase deviation is: The absolute value of the clock deviation is compared with the synchronization period to obtain the frequency deviation; The expression of frequency deviation is: ; In the formula, is the frequency deviation, is the clock deviation, is the synchronization cycle; Output a signal output waveform of the local clock, mark a complete signal cycle on the signal output waveform, and record the duration of the signal cycle as the cycle of the local clock; Generate a phase deviation based on the absolute value of the clock deviation and the period of the local clock; The expression of phase deviation is: ; In the formula, is the phase deviation, is the period of the local clock.

[0013] Furthermore, the method for adjusting clock synchronization is: A1: Combine the frequency deviation adjustment once and the phase deviation adjustment once to generate an adjustment unit, and use the single adjustment of one adjustment unit as the adjustment standard; A2: First, increase or decrease the control voltage of the local clock to force the frequency deviation of the local clock to decrease; A3: Then, insert or delete a quarter of the local clock cycle in the local clock signal, forcing the phase deviation of the local clock to decrease; A4: Repeat the above steps A2-A3 until the frequency deviation and phase deviation of the local clock are both 0, and then stop adjusting the clock synchronization of the local clock.

[0014] Further, the clock synchronization level includes a high synchronization level and a low synchronization level; The method for formulating high synchronization level and low synchronization level is: Calculate in real time the frequency deviation and phase deviation of the local clock after adjusting one adjustment unit, and record them as a first adjustment deviation and a second adjustment deviation respectively; The first adjustment deviation and the second adjustment deviation are respectively assigned corresponding proportional coefficients and then added to obtain an adjustment effective coefficient; When the adjustment effectiveness coefficient is greater than a preset adjustment effectiveness threshold, a low synchronization level is formulated; When the adjustment validity coefficient is less than or equal to a preset adjustment validity threshold, a high synchronization level is formulated.

[0015] The technical effects and advantages of the wireless air interface precise clock synchronization method without DPLL loop in the present invention are as follows: (1): The present invention selects a master node and a slave node in a wireless communication network through air interface communication criteria, and configures the communication parameters of the wireless air interface, and can select the best master node and slave node from multiple wireless sites to ensure that the master node and the slave node can maintain a high correlation and adaptability, and ensure that the master node and the slave node can maintain a normal and stable wireless communication effect in the wireless air interface; (2): The present invention constructs a synchronization test signal with a time mark through the master node, and sends the synchronization test signal to the slave node through the wireless air interface. The synchronization signal containing the time mark information can be synchronously sent to the slave node through a multi-channel manner, avoiding the transmission failure phenomenon that may occur during single channel transmission, thereby ensuring that the clock synchronization of the subsequent slave node can operate normally; (3): The present invention calculates the clock deviation between the slave node and the master node through the deviation calculation criterion, determines whether to perform the clock synchronization operation, configures the clock adjustment parameters of the slave node, and performs clock synchronization adjustment on the local clock of the slave node based on the clock adjustment specification. In the event of clock deviation, the local clock can be adaptively adjusted from two dimensions: frequency deviation and phase deviation. Combined with the restrictions of the clock adjustment specification, an accurate and reasonable clock synchronization strategy is implemented, avoiding the inconvenience caused by multi-level complex synchronization operations and large amounts of data calculation in the traditional DPLL loop algorithm, and greatly improving the accuracy of clock synchronization of the wireless air interface in the wireless communication network; (4): The present invention analyzes the synchronization performance of the adjusted master node and slave node and formulates the clock synchronization level of the wireless air interface. It can accurately analyze the clock synchronization performance of the wireless air interface after each clock synchronization adjustment, thereby providing accurate theoretical support for subsequent clock synchronization adjustments, further improving the accuracy of the clock synchronization adjustment, and avoiding the useless situation of repeated synchronization that may occur after the clock synchronization adjustment is completed. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 A flowchart of a wireless air interface precise clock synchronization method without a DPLL loop provided in the first embodiment of the present invention; Figure 2 A module diagram of a wireless air interface precise clock synchronization system without a DPLL loop provided in the second embodiment of the present invention. DETAILED DESCRIPTION

[0017] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0018] Example 1: Please refer to Figure 1 As shown, the wireless air interface precise clock synchronization method without a DPLL loop described in this embodiment is applied to a wireless communication system, including: S1: Based on the air interface communication criteria, a master node and a slave node are selected in the wireless communication network, and communication parameters of the wireless air interface are configured; The master node refers to the basic equipment in the wireless communication network that can provide a high-stability clock source for the wireless air interface, so that the master node can serve as the synchronization basis for the subsequent wireless air interface clock synchronization, and synchronize the local clocks on the attached nodes with the clock source on the master node as the standard; A slave node refers to a basic device that needs to perform clock synchronization in the wireless air interface of a wireless communication network, so that the slave node can perform clock synchronization processing based on the clock source on the master node.

[0019] In a wireless communication network, a master node is usually a wireless site that sends and receives wireless network signals. A master node is usually a user device that requires clock synchronization. Since each wireless site is configured with a clock source, and the clock sources in different wireless sites may be affected by factors such as service life, use environment, and human interference, the stability of the clock sources in each wireless site varies. In order to ensure that the master node has a clock source with high stability, it is necessary to select the best master node and slave node from multiple wireless sites based on air interface communication criteria to ensure that the master node and the slave node can maintain relevance and adaptability; The air interface communication criterion is: select the wireless site with the highest stability coefficient as the master node; this ensures that the clock source in the wireless site corresponding to the master node has the highest operating stability and the lowest probability of failure or shutdown, providing a stable and reliable time standard for subsequent clock synchronization; The selection method of the master node and the slave node is: The communication status of each wireless station in the wireless communication network is queried one by one, and the wireless stations with normal communication status are recorded as valid stations, and A valid stations are obtained; the communication status is used to indicate whether the wireless communication status of the wireless station in the wireless communication network is good or bad. Specifically, the communication status includes a normal state and an abnormal state; the normal state indicates that the wireless communication status of the wireless station is good, and the abnormal state indicates that the wireless communication status of the wireless station is poor; The maintenance events of A valid sites are queried one by one through the database, and the end time of the maintenance of the wireless site in the maintenance event is recorded as the start point of the cycle, the current time is recorded as the end point of the cycle, and the period between the start point of the cycle and the end point of the cycle is recorded as the communication period, and A communication periods are obtained; the maintenance event is a summary event of various data when the wireless site is manually or automatically operated and maintained, and each maintenance event corresponds to a maintenance start and end time; Count the number of times the clock sources of A valid sites trigger the safety detection system in the corresponding A communication periods one by one, and obtain A trigger values; The durations during which the clock sources of the valid sites in A communication periods do not trigger the safety detection system are respectively counted to obtain A duration values; Assign A trigger values ​​and A duration values ​​corresponding proportional coefficients respectively and add them together to obtain A stability coefficients; The expression of the stability coefficient is: ; In the formula, For the The stability factor of the effective site, =1,2,...,A, For the The trigger value for a valid site, For the The duration of the valid site, , are all proportional coefficients greater than 0, and ; Arrange the A stability coefficients in descending order, and record the valid site corresponding to the first stability coefficient as the master node; The communication coverage of the wireless air interface corresponding to the master node is queried, and the user equipment within the communication coverage is recorded as a slave node. The communication coverage refers to the effective coverage area of ​​the wireless network during normal communication of the wireless air interface, and is used as the basis for determining whether the user equipment is a slave node.

[0020] It should be noted that the number of user devices corresponding to the slave node can be multiple or one. Since all slave nodes are based on the clock source on the master node when performing clock synchronization, the clock synchronization operations of all slave nodes are consistent; therefore, in this embodiment, the number of slave nodes is limited to one, that is, the clock synchronization operation between one slave node and one master node can replace the clock synchronization operation between different numbers of slave nodes and the master node.

[0021] The wireless air interface refers to a virtual logical port in a wireless communication network that implements wireless communication between a slave node and a master node. In order to ensure the normal operation of the wireless air interface, it is necessary to set and configure relevant parameters of the wireless air interface, so that the set and configured parameters are called communication parameters; Communication parameters include frequency band, channel bandwidth and modulation mode; frequency band refers to the range of transmission frequencies of wireless signals in wireless communication networks, channel bandwidth refers to the difference between the maximum frequency and the minimum frequency of the transmission channel of wireless signals in wireless communication networks, and modulation mode refers to the method of converting digital signals into analog signals in wireless communication networks; The configuration method of frequency band, channel bandwidth and modulation mode is: All communication logs of the wireless air interface during the communication period are queried one by one through the database, and the data with the keyword of frequency in the communication log is recorded as frequency data to obtain B frequency data; the communication log is used to summarize all the communication data in the wireless air interface, and the keyword is the text that can intermittently express the true meaning of different data in the communication log identified by natural language processing technology, so that complex and large amounts of communication data can be accurately identified; The signal-to-noise ratio of B frequency data is calculated one by one through the power ratio method formula, and the frequency data with a signal-to-noise ratio greater than the calibrated signal-to-noise threshold is recorded as available data, and C available data are obtained; the calibrated signal-to-noise threshold refers to the minimum value of the signal-to-noise ratio identified as available data, which can provide a numerical basis for the accurate identification of frequency data; The power ratio method formula is: ; In the formula, For the The signal-to-noise ratio of the frequency data is =1,2,...,B, For the The signal power of the frequency data, For the The noise power of the frequency data; Query the communication frequencies in the C available data one by one, and record the frequencies between the minimum value of the communication frequency and the maximum value of the communication frequency as the frequency band; The difference between the maximum value of the communication frequency and the minimum value of the communication frequency is recorded as the channel bandwidth; Compare the channel bandwidth with the calibrated modulation bandwidth value. When the channel bandwidth is greater than the calibrated modulation bandwidth value, it means that the wireless air interface requires a larger bandwidth for communication, and the modulation mode is configured as frequency modulation. When the channel bandwidth is less than or equal to the calibrated modulation bandwidth value, it means that the wireless air interface requires a smaller bandwidth for communication, and the modulation mode is configured as amplitude modulation.

[0022] S2: The master node constructs a synchronization test signal with a time stamp and sends the synchronization test signal to the slave node through the wireless air interface; The synchronization test signal refers to a signal constructed by the master node and containing relevant data such as a specific time mark and used for clock synchronization of the slave node, so that the synchronization test signal can be used as a signal sent by the master node to the slave node and can also be used as a basis for subsequent clock synchronization of the slave node; The time tag is used to mark the time information in the synchronization test signal as a whole to achieve the relative independence of each synchronization test signal. The time tag includes a timestamp, a node ID, and a sequence number. The method for constructing the synchronous test signal is: Query the current time data of the clock source in the master node, split the current time data into text part and numeric part through word segmentation technology, and record the numeric part as the timestamp; The node deployment data of the master node is queried through the attribute management system, and the keyword groups in the node deployment data are identified using natural language processing technology, and the keyword groups are numbered in ascending order. The node deployment data refers to the overall representation of the location, number and other information of the master node when the network node is deployed in the wireless air interface, and the keyword group is the precise representation of the node deployment data. The keyword group is split into keywords and key values ​​by using word segmentation technology, the keyword group with the keyword ID is recorded as ID phrase, the key value in the ID phrase is recorded as node ID, and the number of the ID phrase is recorded as a sequence number; A signal data packet with three test bits is constructed, and the timestamp, node ID and sequence number are sequentially imported into the three test bits to generate a synchronous test signal. A signal data packet refers to a blank synchronous test signal without any substantial content. The test bit is the smallest unit that constitutes the signal data packet and provides an accurate position limit for the import of the timestamp, node ID and sequence number.

[0023] After the synchronization test signal is constructed, the synchronization test signal at this time only stays on the master node. In order to perform clock synchronization operation on the wireless air interface, it is necessary to send the synchronization test signal from the master node to the slave node, and through the transmission operation of the synchronization test signal between the master node and the slave node, the local clock of the slave node is provided with the relevant basis for clock synchronization; When sending the synchronization test signal from the master node to the slave node, in order to ensure that the synchronization test signal can be correctly and completely sent to the slave node and to ensure that the synchronization test signal received by the slave node contains complete information required for clock synchronization, it is necessary to transmit the synchronization test signal through multiple channels in the wireless air interface; The method of sending the synchronous test signal is: The transmission status of all channels in the wireless air interface is queried one by one, and the channels with high-throughput transmission status are recorded as test channels to obtain D test channels; the transmission status is used to indicate the signal transmission status of the channels in the wireless air interface. Specifically, the transmission status includes high-throughput and low-throughput. High-throughput indicates that the channel has a better signal transmission status, and low-throughput indicates that the channel has a worse signal transmission status; Distribute the D test channels in parallel one by one, and connect the signal input ends and signal output ends of the D test channels to the master node and the slave node respectively; A basic wall is established between any two adjacent test channels, and a non-repeating frequency range within the frequency band is configured on the two adjacent basic walls to generate D-1 signal shielding walls; a basic wall refers to a blank signal shielding wall without any substantial content and data. By configuring a non-repeating frequency range on the two adjacent basic walls, it can be ensured that there will be no frequency interference between the test channels located on both sides of any basic wall, thereby improving the stability of synchronous test signal transmission in each test channel; Set the preset duration as the synchronization period. The preset duration is used to indicate the duration corresponding to the synchronization period, so as to ensure that the synchronization test signal can be sent regularly according to a certain sending interval; exist At the signal sending moment, the synchronization test signal on the master node is synchronously sent to the slave node through D test channels.

[0024] It should be noted that by synchronously sending synchronous test signals through multiple test channels, the multi-channel transmission effect of the synchronous test signal can be achieved, avoiding the phenomenon of transmission failure during single channel transmission, thereby ensuring that the clock synchronization of subsequent slave nodes can operate normally.

[0025] S3: Based on the deviation calculation criterion, the clock deviation between the slave node and the master node is calculated, and it is determined whether to perform the clock synchronization operation; Clock deviation refers to the delay deviation value between the time information in the synchronization test signal sent by the slave node and the time information in the synchronization test signal received by the slave node. It can be used to numerically represent the clock delay phenomenon between the master node and the slave node, and also serves as the numerical basis for subsequent clock synchronization of the slave node. After the synchronization test signal is sent from the test channel, the slave node will receive synchronization test signals sent from multiple test channels. At this time, the time point at which the synchronization test signal in each test channel reaches the slave node may be inconsistent. The slave node can determine whether there is a clock deviation between the slave node and the master node based on the reception time of the synchronization test signal sent by each test channel. When calculating the clock deviation, it is necessary to ensure the accuracy of the clock deviation calculation under the constraints of the deviation calculation criteria to avoid the negative impact of unreasonable or interfering time information on the calculation of the clock deviation; The deviation calculation criterion is: select the first synchronous test signal that arrives at the slave node in the test channel as the calculation signal; it can not only select the unique signal transmission duration of the synchronous test signal from multiple test channels, reduce the impact of multiple channels on the clock synchronization accuracy when transmitting synchronously, but also reduce the calculation burden brought by a large amount of similar data participating in the calculation; The clock deviation is calculated as: Receive from the node one by one The synchronous test signals in the D test channels sent at the signal sending time are recorded, and the arrival time of all the synchronous test signals is recorded; In chronological order, the first synchronization test signal arriving at the slave node is recorded as the calculation signal, and the arrival time of the calculation signal is recorded as the receiving time. Receiving time; Analyze one by one Calculate the timestamp of the signal and obtain Send time, and Send time to The duration between the receiving times is recorded as the sub-deviation, and we can obtain Size deviation; The starting time when the calculation signal is parsed from the node and the ending time when the calculation signal is parsed are respectively found out, and the duration between the starting time and the ending time is recorded as the parsing duration; Remove the maximum and minimum values ​​of the sub-deviations and keep the remaining The individual deviations are subtracted from the analysis time one by one, and The differences are accumulated and averaged to obtain the clock deviation. The expression of clock deviation is: ; In the formula, is the clock deviation, For the The sub-deviations of the calculated signal, The parsing duration.

[0026] After calculating the clock deviation between the master node and the slave node, it is necessary to determine whether there is a delay in the transmission time of the synchronization test signal between the master node and the slave node according to the size of the clock deviation, and issue a warning in a timely and accurate manner when a transmission delay occurs, and perform the corresponding clock synchronization operation at the same time; In this embodiment, when it is determined that a transmission delay of the synchronization test signal occurs between the master node and the slave node, it is necessary to perform a clock synchronization operation of the local clock. At this time, the clock synchronization operation can synchronize and adjust the local clock of the slave node according to the size of the clock deviation, so that the time of the master node and the slave node can maintain the same time reference; The method for determining whether to perform clock synchronization operation is as follows: When the clock deviation is equal to 0, it means that there is no delay in the transmission of the synchronization test signal between the master node and the slave node. At this time, the time base between the master node and the slave node is consistent, and it is determined that the clock synchronization operation is not performed; When the clock deviation is not equal to 0, it indicates that there is a delay in the transmission of the synchronization test signal between the master node and the slave node. At this time, the time references between the master node and the slave node are inconsistent, and it is determined to perform a clock synchronization operation.

[0027] It should be noted that when the clock deviation is not equal to 0, the clock deviation may be less than 0 or greater than 0. When the clock deviation is less than 0, it means that the internal clock source of the master node lags behind the local clock of the slave node on the timeline. At this time, the local clock of the slave node is too fast and the timeline of the local clock of the slave node needs to be adjusted backward. When the clock deviation is greater than 0, it means that the internal clock source of the master node is ahead of the local clock of the slave node on the timeline. At this time, the local clock of the slave node is too slow and the timeline of the local clock source of the slave node needs to be adjusted forward.

[0028] S4: If a clock synchronization operation is performed, a clock adjustment parameter of the slave node is configured, and based on the clock adjustment specification, a clock synchronization adjustment is performed on the local clock of the slave node; The clock adjustment parameter refers to the corresponding parameter for adjusting the local clock of the slave node when performing the clock synchronization operation, so as to ensure that the local clock of the slave node can be adjusted by the clock adjustment parameter to ensure that the slave node and the master node are in the same time base; The clock adjustment parameters include frequency deviation and phase deviation; the frequency deviation refers to the frequency difference between the local clock of the slave node and the clock source of the master node, which can be used as the frequency adjustment object in the clock synchronization adjustment; the phase deviation refers to the phase difference between the local clock of the slave node and the clock source of the master node, which can be used as the phase adjustment object in the clock synchronization adjustment; The configuration method of frequency deviation and phase deviation is: The absolute value of the clock deviation is compared with the synchronization period to obtain the frequency deviation; The expression of frequency deviation is: ; In the formula, is the frequency deviation, is the synchronization cycle; Output a signal output waveform of the local clock, mark a complete signal cycle on the signal output waveform, and record the duration of the signal cycle as the cycle of the local clock; Generate a phase deviation based on the absolute value of the clock deviation and the period of the local clock; The expression of phase deviation is: ; In the formula, is the phase deviation, is the period of the local clock.

[0029] After the frequency deviation and phase deviation of the slave node are configured, the local clock of the slave node can be adjusted for clock synchronization based on the frequency deviation and phase deviation, so that the local clock can maintain consistency with the clock source in time, thereby ensuring the high accuracy of the wireless signal transmission time in the wireless air interface of the wireless communication network and improving the communication quality of the wireless communication network; When adjusting the local clock for clock synchronization, it is necessary to follow the clock adjustment specification to ensure that the local clock can be adjusted for clock synchronization in an orderly and stable manner. The clock adjustment specification is: when the adjustment unit is executed once, the frequency is adjusted once, and then the phase is adjusted once; this ensures that each clock synchronization adjustment can make a combined adjustment to the frequency and phase of the local clock, avoiding the limitation and unreasonable phenomenon of the clock synchronization adjustment of the local clock caused by adjusting only the frequency or the phase in a single adjustment operation; The method of adjusting clock synchronization is: A1: Combine the frequency deviation adjustment once and the phase deviation adjustment once to generate an adjustment unit, and use the single adjustment of one adjustment unit as the adjustment standard; A2: First, increase or decrease the control voltage of the local clock to force the frequency deviation of the local clock to decrease; A3: Then, insert or delete a quarter of the local clock cycle in the local clock signal, forcing the phase deviation of the local clock to decrease; A4: Repeat the above steps A2-A3 until the frequency deviation and phase deviation of the local clock are both 0, and then stop adjusting the clock synchronization of the local clock.

[0030] It should be noted that when the frequency deviation and phase deviation are both 0, it means that the clock deviation at this time is 0, then the clock source of the master node and the local clock of the slave node are the same time reference on the timeline, and the master node and the slave node can perform high-precision and delay-free wireless signal communication operations in the wireless air interface, ensuring the high communication quality of the wireless communication network.

[0031] S5: Analyze the synchronization performance of the adjusted master node and slave node, and formulate the clock synchronization level of the wireless air interface; After the clock source of the master node and the local clock of the slave node are adjusted for clock synchronization, it is necessary to analyze the synchronization performance of the clock source of the master node and the local clock of the slave node to accurately obtain the accuracy of the clock source of the master node and the local clock of the slave node in time consistency, and use it as a result of the time consistency between the wireless station and the user equipment in the wireless air interface of the wireless communication network; The clock synchronization level is used to specifically indicate the time consistency between the wireless station and the user equipment in the wireless air interface of the wireless communication network, and serves as a conclusion for the subsequent judgment of the quality of the wireless air interface communication in the wireless communication network; The clock synchronization level includes a high synchronization level and a low synchronization level; a high synchronization level means that the time consistency of the wireless air interface in the wireless communication network is high, and a low synchronization level means that the time consistency of the wireless air interface in the wireless communication network is low; The method for formulating high synchronization level and low synchronization level is: Calculate in real time the frequency deviation and phase deviation of the local clock after adjusting one adjustment unit, and record them as a first adjustment deviation and a second adjustment deviation respectively; The first adjustment deviation and the second adjustment deviation are respectively assigned corresponding proportional coefficients and then added to obtain an adjustment effective coefficient; The expression for adjusting the effective coefficient is: ; In the formula, To adjust the effective coefficient, is the first adjustment deviation, is the second adjustment deviation, , are all proportional coefficients greater than 0, and ; The adjustment effectiveness coefficient is compared with the preset adjustment effectiveness threshold. When the adjustment effectiveness coefficient is greater than the preset adjustment effectiveness threshold, it means that the effect of the clock synchronization adjustment operation of the local clock is not obvious, and the time consistency of the wireless air interface in the wireless communication network is low, so a low synchronization level is formulated; the preset adjustment effectiveness threshold is used to adjust the minimum value of the adjustment effectiveness coefficient when the time consistency of the wireless air interface after the clock synchronization adjustment is high, so as to judge the effect of each clock synchronization adjustment and serve as the numerical basis for each clock synchronization adjustment; When the adjustment effectiveness coefficient is less than or equal to the preset adjustment effectiveness threshold, it means that the local clock performs a significant effect of the clock synchronization adjustment operation, and the time consistency of the wireless air interface in the wireless communication network is high, and a high synchronization level is set.

[0032] In this embodiment, a master node and a slave node are selected in a wireless communication network through air interface communication criteria, and communication parameters of the wireless air interface are configured, so that the best master node and slave node can be selected from multiple wireless sites to ensure that the master node and the slave node can maintain high relevance and adaptability, and ensure that the master node and the slave node can maintain normal and stable wireless communication effects in the wireless air interface; A synchronization test signal with a time stamp is constructed through the master node, and the synchronization test signal is sent to the slave node through the wireless air interface. The synchronization signal containing the time stamp information can be synchronously sent to the slave node through multiple channels, avoiding the transmission failure that may occur during single channel transmission, thereby ensuring that the clock synchronization of the subsequent slave node can operate normally; Through the deviation calculation criteria, the clock deviation between the slave node and the master node is calculated, and it is determined whether to perform the clock synchronization operation, the clock adjustment parameters of the slave node are configured, and the local clock of the slave node is adjusted for clock synchronization based on the clock adjustment specification. In the event of clock deviation, the local clock can be adaptively adjusted for clock synchronization from two dimensions: frequency deviation and phase deviation. Combined with the restrictions of the clock adjustment specification, an accurate and reasonable clock synchronization strategy is implemented, avoiding the inconvenience caused by multi-level complex synchronization operations and large amounts of data calculations in the traditional DPLL loop algorithm, and greatly improving the accuracy of clock synchronization of wireless air interfaces in wireless communication networks. By analyzing the synchronization performance of the adjusted master node and slave node and formulating the clock synchronization level of the wireless air interface, the clock synchronization performance of the wireless air interface after each clock synchronization adjustment can be accurately analyzed, thereby providing accurate theoretical support for subsequent clock synchronization adjustments, further improving the accuracy of clock synchronization adjustments, and avoiding the useless situation of repeated synchronization that may occur after the clock synchronization adjustment is completed.

[0033] Example 2: Please refer to Figure 2 As shown, the part not described in detail in this embodiment is described in the first embodiment, and a wireless air interface precise clock synchronization system without a DPLL loop is provided, which is applied to a wireless communication system and is used to implement a wireless air interface precise clock synchronization method without a DPLL loop, including a node selection module, a signal sending module, a deviation calculation module, a clock synchronization module and a synchronization analysis module, wherein each module is connected via a wired or wireless network; A node selection module is used to select a master node and a slave node in a wireless communication network based on air interface communication criteria, and configure communication parameters of the wireless air interface; A signal sending module is used for the master node to construct a synchronous test signal with a time mark and send the synchronous test signal to the slave node through the wireless air interface; The deviation calculation module is used to calculate the clock deviation between the slave node and the master node based on the deviation calculation criterion, and determine whether to perform the clock synchronization operation; The clock synchronization module is used to configure the clock adjustment parameters of the slave node and perform clock synchronization adjustment on the local clock of the slave node based on the clock adjustment specification; The synchronization analysis module is used to analyze the synchronization performance of the adjusted master node and slave node and formulate the clock synchronization level of the wireless air interface; Among them, the master node is usually a wireless station that sends and receives wireless network signals. The master node is usually a user device that needs clock synchronization. The communication parameters include frequency band, channel bandwidth and modulation mode. The clock adjustment parameters include frequency deviation and phase deviation. The clock synchronization level includes high synchronization level and low synchronization level. The air interface communication criterion is: select the wireless station with the first stability coefficient as the master node; The deviation calculation criterion is: select the first synchronous test signal arriving at the slave node in the test channel as the calculation signal; The clock adjustment specification is: when the adjustment unit is executed once, the frequency is adjusted once, and then the phase is adjusted once.

[0034] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A wireless air interface precise clock synchronization method without DPLL loop, applied to wireless communication system, characterized in that: include: S1: Based on the air interface communication criterion, a master node and a slave node are selected in the wireless communication network, and communication parameters of the wireless air interface are configured. The air interface communication criterion is: a wireless station with the highest stability coefficient is selected as the master node; S2: The master node constructs a synchronization test signal with a time stamp and sends the synchronization test signal to the slave node through the wireless air interface; S3: Based on the deviation calculation criterion, the clock deviation between the slave node and the master node is calculated, and it is determined whether to perform the clock synchronization operation. The deviation calculation criterion is: the first synchronization test signal that arrives at the slave node in the test channel is selected as the calculation signal; S4: If a clock synchronization operation is performed, the clock adjustment parameters of the slave node are configured, and the local clock of the slave node is adjusted for clock synchronization based on the clock adjustment specification. The clock adjustment specification is: when the adjustment unit is executed once, the frequency is adjusted once, and then the phase is adjusted once; S5: Analyze the synchronization performance of the adjusted master node and slave node, and determine the clock synchronization level of the wireless air interface.

2. A wireless air interface precise clock synchronization method without DPLL loop according to claim 1, characterized in that: The selection method of the master node and the slave node is: The communication status of each wireless station in the wireless communication network is queried one by one, and the wireless stations with normal communication status are recorded as valid stations, so as to obtain A valid stations; Query the maintenance events of A valid sites one by one through the database, record the end time of the maintenance of the wireless site in the maintenance event as the cycle start point, record the current time as the cycle end point, and record the period from the cycle start point to the cycle end point as the communication period, and obtain A communication periods; Count the number of times the clock sources of A valid sites trigger the safety detection system in the corresponding A communication periods one by one, and obtain A trigger values; The durations during which the clock sources of the effective sites in A communication periods do not trigger the safety detection system are respectively counted to obtain A duration values, and the A trigger values ​​and the A duration values ​​are respectively assigned corresponding proportional coefficients and then added to obtain A stability coefficients; Arrange the A stability coefficients in descending order, and record the valid site corresponding to the first stability coefficient as the master node; The communication coverage of the wireless air interface corresponding to the master node is queried, and the user equipment within the communication coverage is recorded as a slave node.

3. A wireless air interface precise clock synchronization method without DPLL loop according to claim 2, characterized in that: Communication parameters include frequency band, channel bandwidth and modulation method; The configuration method of frequency band, channel bandwidth and modulation mode is: All communication logs of the wireless air interface during the communication period are queried one by one through the database, and the data with the keyword of frequency in the communication log is recorded as frequency data to obtain B frequency data; The signal-to-noise ratios of B frequency data are calculated one by one by the power ratio method formula, and the frequency data whose signal-to-noise ratio is greater than the calibrated signal-to-noise threshold is recorded as available data, thereby obtaining C available data; The power ratio method formula is: ； In the formula, For the The signal-to-noise ratio of the frequency data is =1,2,...,B, For the The signal power of the frequency data, For the The noise power of the frequency data; Query the communication frequencies in the C available data one by one, and record the frequencies between the minimum value of the communication frequency and the maximum value of the communication frequency as the frequency band; The difference between the maximum value of the communication frequency and the minimum value of the communication frequency is recorded as the channel bandwidth; When the channel bandwidth is greater than the calibrated modulation bandwidth value, the modulation mode is configured as frequency modulation; When the channel bandwidth is less than or equal to the calibrated modulation bandwidth value, the modulation mode is configured as amplitude modulation.

4. A wireless air interface precise clock synchronization method without DPLL loop according to claim 3, characterized in that: The method for constructing the synchronous test signal is: Query the current time data of the clock source in the master node, split the current time data into text part and numeric part through word segmentation technology, and record the numeric part as the timestamp; The node deployment data of the master node is queried through the attribute management system, the keyword groups in the node deployment data are identified using natural language processing technology, and the keyword groups are numbered in ascending order; The keyword group is split into keywords and key values ​​by using word segmentation technology, the keyword group with the keyword ID is recorded as ID phrase, the key value in the ID phrase is recorded as node ID, and the number of the ID phrase is recorded as a sequence number; A signal data packet with three test bits is constructed, and the timestamp, node ID and sequence number are sequentially imported into the three test bits to generate a synchronous test signal.

5. A wireless air interface precise clock synchronization method without DPLL loop according to claim 4, characterized in that: The method of sending the synchronous test signal is: The transmission status of all channels in the wireless air interface is queried one by one, and the channels with high-throughput transmission status are recorded as test channels, so as to obtain D test channels; Distribute the D test channels in parallel one by one, and connect the signal input ends and signal output ends of the D test channels to the master node and the slave node respectively; A basic wall is established between any two adjacent test channels, and a non-repeating frequency range within the frequency band is configured on the two adjacent basic walls to generate D-1 signal shielding walls; Set the preset duration as the synchronization period. The signal sending time; exist At the signal sending moment, the synchronization test signal on the master node is synchronously sent to the slave node through D test channels.

6. A wireless air interface precise clock synchronization method without DPLL loop according to claim 5, characterized in that: The clock deviation is calculated as: Receive from the node one by one The synchronous test signals in the D test channels sent at the signal sending time are recorded, and the arrival time of all the synchronous test signals is recorded; In chronological order, the first synchronization test signal arriving at the slave node is recorded as the calculation signal, and the arrival time of the calculation signal is recorded as the receiving time. Receiving time; Analyze one by one Calculate the timestamp of the signal and obtain Send time, and Send time to The duration between the receiving times is recorded as the sub-deviation, and we can obtain Size deviation; The starting time when the calculation signal is parsed from the node and the ending time when the calculation signal is parsed are respectively found out, and the duration between the starting time and the ending time is recorded as the parsing duration; Remove the maximum and minimum values ​​of the sub-deviations and keep the remaining The individual deviations are subtracted from the analysis time one by one, and The differences are accumulated and averaged to obtain the clock deviation.

7. A wireless air interface precise clock synchronization method without DPLL loop according to claim 6, characterized in that: The method for determining whether to perform clock synchronization operation is as follows: When the clock deviation is equal to 0, it is determined that the clock synchronization operation is not performed; When the clock deviation is not equal to 0, it is determined to perform the clock synchronization operation.

8. A wireless air interface precise clock synchronization method without DPLL loop according to claim 7, characterized in that: Clock adjustment parameters include frequency deviation and phase deviation; The configuration method of frequency deviation and phase deviation is: The absolute value of the clock deviation is compared with the synchronization period to obtain the frequency deviation; The expression of frequency deviation is: ； In the formula, is the frequency deviation, is the clock deviation, is the synchronization cycle; Output a signal output waveform of the local clock, mark a complete signal cycle on the signal output waveform, and record the duration of the signal cycle as the cycle of the local clock; Generate a phase deviation based on the absolute value of the clock deviation and the period of the local clock; The expression of phase deviation is: ； In the formula, is the phase deviation, is the period of the local clock.

9. A wireless air interface precise clock synchronization method without DPLL loop according to claim 8, characterized in that: The method of adjusting clock synchronization is: A1: Combine the frequency deviation adjustment once and the phase deviation adjustment once to generate an adjustment unit, and use the single adjustment of one adjustment unit as the adjustment standard; A2: First, increase or decrease the control voltage of the local clock to force the frequency deviation of the local clock to decrease; A3: Then, insert or delete a quarter of the local clock cycle in the local clock signal, forcing the phase deviation of the local clock to decrease; A4: Repeat the above steps A2-A3 until the frequency deviation and phase deviation of the local clock are both 0, and then stop adjusting the clock synchronization of the local clock.

10. A wireless air interface precise clock synchronization method without DPLL loop according to claim 9, characterized in that: The clock synchronization level includes a high synchronization level and a low synchronization level; The method for formulating high synchronization level and low synchronization level is: Calculate in real time the frequency deviation and phase deviation of the local clock after adjusting one adjustment unit, and record them as a first adjustment deviation and a second adjustment deviation respectively; The first adjustment deviation and the second adjustment deviation are respectively assigned corresponding proportional coefficients and then added to obtain an adjustment effective coefficient; When the adjustment effectiveness coefficient is greater than a preset adjustment effectiveness threshold, a low synchronization level is formulated; When the adjustment validity coefficient is less than or equal to a preset adjustment validity threshold, a high synchronization level is formulated.

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