CN101448314B - Method and system for realizing time synchronization between base stations and communication terminal - Google Patents

Abstract

The embodiment of the present invention discloses a method and system for realizing time synchronization between base stations and a communication terminal, which can be used in the situation where the slave base station cannot obtain the clock reference base station signal or when there is no communication terminal under the slave base station, without adding slave The receiver of the base station can also realize the time synchronization between the base stations without periodically interrupting the service. The method provided by the embodiment of the present invention includes: the slave base station sends a measurement report request for the clock reference base station determined to be tracked to the communication terminal working under the slave base station, and the measurement type carried in the request is the slave base station and the said slave base station The clock refers to the relative delay of the downlink preamble signal between the base stations, the reporting type is periodic reporting, and the reporting period is the period of air interface synchronization; the slave base station adjusts the clock of the slave base station according to the received measurement report result of the communication terminal . The technical solutions provided by the embodiments of the present invention can be used for time synchronization between base stations in the wireless communication field.

Description

Method and system for realizing time synchronization between base stations and communication terminal

technical field

The present invention relates to the field of wireless communication, in particular to a method and system for realizing time synchronization between base stations and a communication terminal.

Background technique

In modern wireless communications, a large number of requirements for indoor coverage and remote area coverage have emerged, and base stations have begun to be miniaturized and low-cost. In scenarios where indoor coverage is required, traditional synchronization acquisition mechanisms, such as the Global Positioning System (GPS, Global Positioning System), cannot solve the synchronization problem well.

The GPS global positioning system is divided into: space part - GPS satellite constellation, ground control part - ground monitoring system and user equipment part - GPS signal receiver. The GPS satellite constellation and the ground monitoring system work together to provide accurate time signals to the ground. After receiving the time signal of the satellite constellation, the GPS signal receiver outputs accurate and stable 1PPS pulses and absolute time to communication devices that need to be synchronized, such as base stations wait. Accurate and stable absolute time and 1PPS pulse are important conditions for realizing synchronization in a communication system.

However, GPS signals are sent through satellites. In indoor areas covered by buildings and in urban areas with dense buildings, GPS signals are blocked and attenuated, resulting in poor reception of GPS signals. In this way, synchronous communication equipment is required to be installed indoors It is impossible to achieve synchronization well by directly receiving GPS signals.

In the prior art, a method for synchronizing communication devices is to set a clock reference base station in a network area (generally select a base station that can receive GPS signals or obtain sufficient synchronization sources as a clock reference base station), The clock reference base station can be used as a clock reference. Generally, the base station (slave base station) receives the signal of the clock reference base station in the area, measures the frequency and phase deviation of the local station relative to the clock reference base station, and then calculates the transmission frequency and time of the local station according to the measured frequency and phase deviation. Adjust so that all base stations in a network area can achieve time synchronization with the clock reference base station.

In the process of realizing the present invention, the inventor found that the coverage area between the base stations of the same operator and the same technical system can only overlap in a small part, especially at the central position of the base station, that is, at the receiving antenna of the base station. Signals to other base stations, and in the scenario where coverage is required in remote areas, it is necessary to increase the receiver of the slave base station to receive the signal of the clock reference base station. Therefore, the time synchronization is obtained by receiving the signal of the clock reference base station in the area from the base station The method can only be used in rare cases; and synchronization is a continuous and periodic process that requires periodic interruption of business to achieve synchronization, which will affect the complexity of system implementation and normal business performance.

Contents of the invention

On the one hand, the embodiments of the present invention provide a method and system for realizing time synchronization between base stations, which can be implemented without adding receivers of the base station and periodically interrupting services when the base station cannot obtain the signal of the clock reference base station. Time synchronization between base stations can be realized.

In order to achieve the above object, the embodiments of the present invention are achieved through the following technical solutions:

A method for realizing time synchronization between base stations is provided, including:

Obtain the information of the surrounding clock reference base stations from the base station through the network management node, and determine the clock reference base stations that need to be tracked;

The slave base station sends a measurement report request for the determined clock reference base station to the communication terminal working under the slave base station, and the measurement type carried in the request is the downlink preamble between the slave base station and the clock reference base station The relative delay of the signal, the reporting type is periodic reporting, and the reporting period is the period of air interface synchronization;

The slave base station receives the measurement report result of the communication terminal, and adjusts the clock of the slave base station according to the measurement report result, and the measurement report result includes the downlink preamble signal between the slave base station and the clock reference base station. relative delay.

A system for realizing time synchronization between base stations is provided, including:

The secondary base station is used to send a measurement report request for the clock reference base station that needs to be tracked to the communication terminal working under the secondary base station, and the measurement type carried in the request is between the secondary base station and the clock reference base station The relative delay of the downlink preamble signal, the reporting type is periodic reporting, and the reporting period is the period of air interface synchronization; receiving the measurement reporting result of the communication terminal, and adjusting the clock of the slave base station according to the measurement reporting result, the The measurement report results include the relative delay of the downlink preamble signal between the slave base station and the clock reference base station;

A clock reference base station, used to provide a reference for time synchronization;

The communication terminal is configured to receive the measurement report request sent by the secondary base station to the clock reference base station, and measure the relative delay of the downlink preamble signal between the secondary base station and the clock reference base station by The period of air interface synchronization is reported to the secondary base station periodically.

From the above technical solutions provided by the embodiments of the present invention, it can be seen that the relative time delay of the downlink preamble signal between the slave base station and the clock reference base station that needs to be tracked is obtained from the base station through the assistance of the communication terminal. The clock of the slave base station is adjusted by the measurement report result of the communication terminal; since the communication terminal periodically reports the measurement report result of the communication terminal in the air interface synchronization period, the slave base station can adjust the clock of the slave base station without periodically interrupting the service after receiving the measurement report result of the communication terminal. Adjustments are made so that in the case that the base station slave cannot obtain the clock reference base station signal, the time synchronization between the base stations can be realized without adding receivers of the base station slave and without periodically interrupting services.

On the other hand, the embodiments of the present invention provide a method and system for realizing time synchronization between base stations, which can be implemented without adding receivers of the base station and periodically interrupting services when there is no communication terminal under the base station. Realize time synchronization between base stations.

In order to achieve the above object, the embodiments of the present invention are achieved through the following technical solutions:

A method for realizing time synchronization between base stations is provided, including:

The clock reference base station obtains the information of the surrounding secondary base stations through the network management node, and determines the secondary base stations that need to achieve time synchronization;

The clock reference base station sends a measurement report request for the determined secondary base station to the communication terminal working under the clock reference base station, and the measurement type carried in the request is the downlink preamble between the secondary base station and the current clock reference base station The relative delay of the Preamble signal, the reporting type is periodic reporting, and the reporting period is the period of air interface synchronization;

After receiving the measurement reporting result of the communication terminal, the clock reference base station forwards the measurement reporting result to the secondary base station, and the secondary base station adjusts the clock of the secondary base station according to the forwarded measurement reporting result, and the The measurement report results include the relative time delay of the downlink preamble signal between the slave base station and the clock reference base station.

A system for realizing time synchronization between base stations is provided, including:

The clock reference base station is used to send a measurement report request for the secondary base station determined to achieve time synchronization to the communication terminal working under the clock reference base station, and the measurement type carried in the request is the secondary base station and the local clock reference base station The relative delay of the downlink leading Preamble signal between, the reporting type is periodic reporting, and the reporting period is the period of air interface synchronization; receiving the measurement reporting result of the communication terminal, and forwarding the measurement reporting result to the secondary base station, The measurement report result includes the relative delay of the downlink preamble signal between the slave base station and the clock reference base station;

The slave base station is configured to receive the measurement report result forwarded by the clock reference base station, and adjust the clock of the slave base station according to the forwarded measurement report result;

The communication terminal is configured to receive the measurement report request to the secondary base station sent by the clock reference base station, and measure the relative time delay of the downlink preamble signal between the secondary base station and the clock reference base station by The cycle of air interface synchronization is reported to the clock reference base station.

From the above technical solutions provided by the embodiments of the present invention, it can be seen that through the communication terminal assistance, the clock reference base station first obtains the relative time delay of the downlink preamble signal between the slave base station and the clock reference base station that needs to realize time synchronization, and then Then the clock reference base station forwards the measurement reporting result of the communication terminal to the secondary base station, and the secondary base station adjusts the clock of the secondary base station according to the forwarded measurement reporting result; Periodic reporting, so after the slave base station receives the forwarded measurement report results, the clock of the slave base station can be adjusted without periodically interrupting the service, so that there is no need to increase the receiver of the slave base station when there is no communication terminal under the slave base station Time synchronization between base stations can also be realized without periodically interrupting services.

In yet another aspect, the embodiment of the present invention also provides a communication terminal, which can be used without adding a receiver of the base station and without the need to Interrupting business periodically can also realize time synchronization between base stations.

A communication terminal is provided, comprising:

The receiving unit is used to receive the downlink preamble signal of the clock reference base station and the slave base station;

a measuring unit, configured to measure the relative time delay of the downlink preamble signal received by the receiving unit between the clock reference base station and the slave base station;

The request receiving unit is used to receive the measurement report request sent by the base station, the measurement type carried in the request is the relative delay of the downlink preamble signal between the slave base station and the clock reference base station, and the report type is periodic report , the reporting period is the air interface synchronization period;

a reporting unit, configured to report the measurement result of the measurement unit to the base station at an air interface synchronization cycle according to the measurement report request received by the request receiving unit, the measurement result including the clock reference base station and the The relative delay of downlink preamble signals between base stations.

The communication terminal provided by the embodiment of the present invention works under the clock reference base station or the slave base station, the downlink preamble signal of the clock reference base station and the slave base station can be received by the receiving unit, and the clock reference base station and the slave base station can be measured by the measuring unit The relative time delay between the downlink preamble Preamble signal, when the request receiving unit receives the measurement report request sent by the slave base station to the clock reference base station, the reporting unit will synchronize the measurement results of the measurement unit with the period of air interface synchronization Periodically report to the secondary base station, and the secondary base station adjusts the clock of the secondary base station according to the measurement report result of the communication terminal, so that when the secondary base station cannot obtain the clock reference base station signal, the communication terminal provided by the embodiment of the present invention Auxiliary, time synchronization between base stations can be achieved without adding receivers of the secondary base station and without periodically interrupting services; or when the request receiving unit receives the measurement report request for the secondary base station sent by the clock reference base station, The reporting unit reports the measurement results of the measurement unit to the clock reference base station in an air interface synchronization cycle, and then the clock reference base station forwards the measurement report results of the communication terminal to the secondary base station, and the secondary base station Adjust the clock of the secondary base station according to the forwarded measurement report results, so that when there is no communication terminal under the secondary base station, with the assistance of the communication terminal provided by the embodiment of the present invention, there is no need to increase the receiver of the secondary base station and no cycle Temporary interruption of business can also realize time synchronization between base stations.

Description of drawings

FIG. 1 is a flowchart of a method for realizing time synchronization between base stations provided by Embodiment 1 of the present invention;

FIG. 2 is a flowchart of a method for implementing time synchronization between base stations provided by Embodiment 2 of the present invention;

FIG. 3 is a schematic diagram of time offset and frequency offset adjustment performed by the base station according to the measured relative delay provided by the embodiment of the present invention;

FIG. 4 is a flowchart of a method for implementing time synchronization between base stations provided by Embodiment 3 of the present invention;

FIG. 5 is a flowchart of a method for realizing time synchronization between base stations provided by Embodiment 4 of the present invention;

FIG. 6 is a schematic diagram of a system composition for implementing time synchronization between base stations provided by Embodiment 5 of the present invention;

FIG. 7 is a schematic diagram of a system composition for implementing time synchronization between base stations provided by Embodiment 6 of the present invention;

FIG. 8 is a schematic structural diagram of a communication terminal provided by Embodiment 7 of the present invention;

FIG. 9 is a schematic diagram of a specific structure of a communication terminal provided by Embodiment 7 of the present invention.

Detailed ways

In order to make the purpose, technical solution, and advantages of the present invention clearer, the technical solution provided by the present invention will be further described in detail below with reference to the accompanying drawings and examples.

Embodiment one

Referring to FIG. 1, FIG. 1 is a flow chart of a method for realizing time synchronization between base stations provided by Embodiment 1 of the present invention, the method includes:

Step 11, the slave base station obtains the information of the surrounding clock reference base stations through the network management node, and determines the clock reference base stations that need to be tracked.

Step 12, the secondary base station sends a measurement report request for the determined clock reference base station to the communication terminal working under the secondary base station, and the measurement type carried in the request is the measurement report between the secondary base station and the clock reference base station The relative delay of the downlink Preamble signal (RelativeDalay), the reporting type is periodic reporting, and the reporting period is the air interface synchronization period.

Step 13: The slave base station receives the measurement report result of the communication terminal, and adjusts the clock of the slave base station according to the measurement report result.

In the method for realizing time synchronization between base stations provided by Embodiment 1 of the present invention, the relative delay of the downlink preamble signal between the slave base station and the clock reference base station to be tracked is obtained from the base station through the assistance of the communication terminal, and the slave base station is obtained from the base station Adjust the clock of the slave base station according to the measurement report result of the communication terminal; since the communication terminal periodically reports in the period of air interface synchronization, after the slave base station receives the measurement report result of the communication terminal, it does not need to periodically interrupt the service. The clock of the base station is adjusted, so that when the base station cannot obtain the clock reference signal of the base station, the time synchronization between the base stations can be realized without adding a receiver of the base station and without periodically interrupting the service.

Embodiment two

Referring to FIG. 2, FIG. 2 is a flowchart of a method for realizing time synchronization between base stations provided by Embodiment 2 of the present invention, including steps:

Step 21, the slave base station obtains the information of the surrounding clock reference base stations through the network management node, and determines the clock reference base stations that need to be tracked.

Step 22, the secondary base station sends a measurement report request for the determined clock reference base station to two or more communication terminals working under the secondary base station, and the measurement type carried in the request is the secondary base station and the clock reference base station The relative delay between the downlink preamble Preamble signals, the reporting type is periodic reporting, and the reporting period is the period of air interface synchronization; wherein the communication terminal receives the downlink carrier to interference + noise ratio (CINR) of the slave base station less than a set The communication terminal whose threshold is set, or the communication terminal whose distance to the slave base station is close to the distance to the clock reference base station.

Step 23: Receive the measurement report results of two or more communication terminals from the base station, average the measurement report results of the two or more communication terminals, and adjust the clock of the slave base station according to the average measurement report results.

It should be noted that the Carrier to Interference + Noise Ratio (CINR, Carrier to Interference + Noise Ratio), expressed in decibels (dBs), is a measurement standard for signal effectiveness, where the carrier is an effective signal, and the interference can be noise or the same frequency interference or both. In order for the signal receiver (such as the base station) to be able to decode the signal, the signal must belong to a receivable CINR range, and in order to reduce the impact on the signal receiver (such as the base station), it is necessary to set a CINR threshold, the signal reception Or only receive signals sent by terminals whose CINR is smaller than a certain set threshold.

In order to reduce the impact of the communication terminal on the service of the secondary base station, optionally, the secondary base station sends the measurement report request to the communication terminal that receives the downlink carrier-to-interference + noise ratio (CINR) of the secondary base station is less than a set threshold. Or, optionally, the secondary base station sends the measurement report request to the communication terminal whose distance to the secondary base station is close to the distance to the clock reference base station.

The method for judging whether the distance between the terminal and the two base stations is close is as follows:

Suppose the terminal receives the received signal strength indicator RSSI (Received Signal Strength Indicator) of base station 1 as RSSI 1, and learns that the effective isotropic radiated power EIRP (Effective Isotropic Radiated Power) of base station 1 when sending is EIRP 1 in the neighbor cell broadcast message ; The terminal receives the received signal strength indication of base station 2 as RSSI 2, and knows in the neighbor cell broadcast message that the effective isotropic radiated power of base station 2 is EIRP 2; for this reason, the terminal calculates the path loss to base station 1 It is: L1=EIRP 1-RSSI 1, and the path loss to base station 2 is: L2=EIRP 2-RSSI 2. If L1≈L2, it can be judged that the distance from the terminal to base station 1 and the distance from the terminal to base station 2 are close.

The method for implementing time synchronization between base stations provided by the second embodiment of the present invention has two improvements compared with the first embodiment: one is to limit the communication terminal receiving the measurement report request, and only allow the downlink CINR of the slave base station to be less than A communication terminal with a set threshold or a communication terminal whose distance to the slave base station is close to the distance to the clock reference base station receives the measurement report request, and sends the measurement report result to the slave base station, which can reduce the need for the slave base station The impact on business; the second is to send the measurement report request to multiple communication terminals, and the slave base station adjusts the clock of the slave base station according to the average result of the measurement report of multiple communication terminals, which can reduce the measurement report of a certain communication terminal The resulting error improves the adjustment accuracy of the time synchronization between the slave base station and the clock reference base station.

It should be noted that the relative delay of the downlink preamble signal between the slave base station and the clock reference base station in the measurement report results is used as the phase detection value of the internal clock of the device to adjust the clock frequency and phase of the slave base station . Referring to Figure 3, a method for adjusting the clock of the slave base station according to the measurement report result may be:

Calculate the frequency difference between the slave base station and the clock reference base station according to the relative time delay of the downlink preamble signal between the slave base station and the clock reference base station;

The relative time delay is directly adjusted by the voltage-controlled crystal oscillator to adjust the time difference; at the same time, after the converted frequency difference is digital-to-analog converted into a voltage-controlled voltage, the voltage-controlled crystal oscillator is used to adjust the frequency difference;

The adjusted clock of the slave base station is output by the voltage-controlled crystal oscillator.

Embodiment three

Referring to FIG. 4, FIG. 4 is a flow chart of a method for realizing time synchronization between base stations provided by Embodiment 3 of the present invention. The method includes:

In step 41, the clock reference base station obtains the information of surrounding secondary base stations through the network management node, and determines the secondary base stations that need to realize time synchronization.

Step 42, the clock reference base station sends a measurement report request for the determined secondary base station to the communication terminal working under the clock reference base station, and the measurement type carried in the request is between the secondary base station and the current clock reference base station The relative delay of the downlink preamble signal, the reporting type is periodic reporting, and the reporting period is the period of air interface synchronization.

Step 43: After the clock reference base station receives the measurement reporting result of the communication terminal, it forwards the measurement reporting result to the secondary base station, and the secondary base station adjusts the clock of the secondary base station according to the forwarded measurement reporting result .

In the method for implementing time synchronization between base stations provided by Embodiment 3 of the present invention, the clock reference base station first obtains the relative time of the downlink preamble signal between the slave base station and the clock reference base station that needs to realize time synchronization through the assistance of the communication terminal. delay, and then the clock reference base station forwards the measurement reporting result of the communication terminal to the secondary base station, and the secondary base station adjusts the clock of the secondary base station according to the forwarded measurement reporting result; since the communication terminal synchronizes with the air interface Therefore, after the slave base station receives the forwarded measurement report results, it can adjust the clock of the slave base station without periodically interrupting the service, so that there is no need to increase the slave base station when there is no communication terminal under the slave base station The receiver can also achieve time synchronization between base stations without periodically interrupting the service.

Embodiment four

Referring to FIG. 5, FIG. 5 is a flowchart of a method for realizing time synchronization between base stations provided by Embodiment 4 of the present invention, including steps:

Step 51, the clock reference base station obtains the information of the surrounding secondary base stations through the network management node, and determines the secondary base stations that need to realize time synchronization.

Step 52, the clock reference base station sends a measurement reporting request for the determined secondary base station to two or more communication terminals working under the clock reference base station, and the measurement type carried in the request is the measurement type of the secondary base station and the local clock reference The relative time delay of the downlink leading Preamble signal between the base stations, the reporting type is periodic reporting, and the reporting period is the period of air interface synchronization; the communication terminal receives this clock reference base station's downlink carrier and interference + noise ratio (CINR) is less than one The communication terminal for which the threshold is set, or the communication terminal whose distance to the secondary base station is close to the distance to the clock reference base station.

Step 53, after the clock reference base station receives the measurement report results of more than two communication terminals, average the measurement report results of the two or more communication terminals, and forward the measurement report average results to the slave base station, The slave base station adjusts the clock of the slave base station according to the average result reported by the forwarded measurement.

The method for implementing time synchronization between base stations provided by Embodiment 4 of the present invention has two improvements compared with Embodiment 3: one is to limit the communication terminal receiving the measurement report request, and only allow the clock to refer to the downlink CINR of the base station A communication terminal that is less than a certain set threshold or a communication terminal whose distance to the slave base station is close to the distance to the clock reference base station receives the measurement report request, and sends the measurement report result to the clock reference base station, which can reduce the need for The influence of the clock reference base station business; the second is to send the measurement report request to a plurality of the communication terminals, and the clock reference base station averages the measurement report results of a plurality of the communication terminals, and then forwards the measurement report average to the slave base station As a result, the clock of the slave base station is adjusted by the slave base station, which can reduce the error caused by the measurement and reporting results of a certain communication terminal, and improve the adjustment accuracy of the time synchronization between the slave base station and the clock reference base station.

Embodiment five

Referring to FIG. 6, FIG. 6 is a schematic composition diagram of a system for implementing time synchronization between base stations provided by Embodiment 5 of the present invention, including:

The secondary base station 61 is used to send a measurement report request for the clock reference base station 62 that needs to be tracked to the communication terminal 63 working under the secondary base station, and the measurement type carried in the request is the primary secondary base station and the clock reference base station The relative time delay of the downlink leading Preamble signal between, the reporting type is periodic reporting, and the reporting period is the period of air interface synchronization; receiving the measurement reporting result of the communication terminal 63, and performing the clock of the slave base station according to the measurement reporting result Adjustment;

Clock reference base station 62, used to provide a reference for time synchronization;

The communication terminal 63 is configured to receive the measurement report request sent by the slave base station 61 to the clock reference base station 62, and to compare the measured downlink preamble signal relative to the clock reference base station between the slave base station and the clock reference base station. The time delay is reported to the secondary base station 61 in a period of air interface synchronization.

Preferably, the communication terminal 63 receives the downlink carrier to interference + noise ratio CINR of the secondary base station 61 is less than a set threshold; or the distance from the communication terminal to the secondary base station is close to the clock reference base station distance.

Preferably, the secondary base station is further configured to send the measurement report request to two or more communication terminals working under the secondary base station; the secondary base station averages the measurement reporting results of the two or more communication terminals , adjust the clock of the slave base station according to the average result.

In the system for implementing time synchronization between base stations provided in Embodiment 5, the relative time delay of the downlink preamble signal between the slave base station and the clock reference base station 62 to be tracked is obtained from the base station 61 through the assistance of the communication terminal 63. The slave base station adjusts the clock of the slave base station according to the measurement report result of the communication terminal 63; since the communication terminal 63 periodically reports in the air interface synchronization cycle, after the slave base station 61 receives the measurement report result of the communication terminal 63, there is no need to periodically The clock of the slave base station can be adjusted by interrupting the service, so that when the slave base station 61 cannot obtain the clock reference base station signal, the time synchronization between the base stations can be realized without adding receivers of the slave base station and without periodically interrupting the service.

Moreover, by limiting the communication terminal 63 that receives the measurement report request, only the communication terminal whose downlink CINR of the secondary base station is smaller than a certain threshold is allowed or the distance to the secondary base station is close to the distance to the clock reference base station The communication terminal receives the measurement report request, and sends the measurement report result to the secondary base station, which can reduce the impact on the service of the secondary base station 61; by sending the measurement report request to a plurality of communication terminals 63, the secondary base station 61 according to multiple The average result of the measurement report of the communication terminal adjusts the clock of the slave base station, which can reduce the error caused by the measurement report result of a certain communication terminal, and improve the adjustment accuracy of the time synchronization between the slave base station 61 and the clock reference base station 62 .

Embodiment six

Referring to FIG. 7, FIG. 7 is a schematic diagram of the system composition for implementing time synchronization between base stations provided by Embodiment 6 of the present invention, including:

The clock reference base station 71 is used to send a measurement reporting request to the secondary base station 72 determined to achieve time synchronization to the communication terminal 73 working under the clock reference base station, and the measurement type carried in the request is the secondary base station and the local The clock refers to the relative time delay of the downlink preamble Preamble signal between the base stations, the report type is periodic report, and the report period is the cycle of air interface synchronization; the measurement report result of the communication terminal 73 is received, and the measurement report result is forwarded to the The slave base station 72;

The slave base station 72 is configured to receive the measurement report result forwarded by the clock reference base station 71, and adjust the clock of the slave base station according to the forwarded measurement report result;

The communication terminal 73 is configured to receive the measurement report request to the slave base station 72 sent by the clock reference base station 71, and to measure the relative relationship between the measured downlink preamble Preamble signal between the slave base station and the clock reference base station. The time delay is reported to the clock reference base station 71 in a period of air interface synchronization.

Preferably, the downlink carrier-to-interference + noise ratio (CINR) of the clock reference base station received by the communication terminal 73 is less than a set threshold; or the distance from the communication terminal to the secondary base station is close to that of the clock reference distance to the base station.

Preferably, the clock reference base station 71 is also used to send the measurement report request to two or more communication terminals working under the clock reference base station; average the measurement report results of the two or more communication terminals , and forward the measurement report average result to the secondary base station 72;

The secondary base station 72 is further configured to adjust the clock of the secondary base station according to the average result of the forwarded measurement report.

In the system for implementing time synchronization between base stations provided in Embodiment 6, through the assistance of the communication terminal 73, the clock reference base station 71 first obtains the downlink preamble signal between the slave base station 72 that needs to realize time synchronization and the clock reference base station. relative time delay, then the clock reference base station forwards the measurement reporting result of the communication terminal 73 to the secondary base station 72, and the secondary base station 72 adjusts the clock of the secondary base station according to the forwarded measurement reporting result; because The communication terminal periodically reports in the period of air interface synchronization, so after the slave base station receives the forwarded measurement report result, it can adjust the clock of the slave base station without periodically interrupting the service, so that there is no communication terminal 73 under the slave base station In this way, the time synchronization between base stations can be realized without increasing the receiver of the secondary base station and without periodically interrupting the service.

Moreover, by limiting the communication terminal 73 receiving the measurement report request, only communication terminals whose downlink CINR of the clock reference base station is smaller than a certain threshold or whose distance to the slave base station is close to the distance to the clock reference base station are allowed. The distance communication terminal receives the measurement report request, and sends the measurement report result to the clock reference base station 71, which can reduce the impact on the clock reference base station 71 business; by sending the measurement report request to multiple communication terminals, the clock reference base station 71 After averaging the measurement report results of a plurality of communication terminals, forward the measurement report average result to the secondary base station 72, and the secondary base station 72 adjusts the clock of the secondary base station, which can reduce the measurement of a certain communication terminal Errors caused by the reported results improve the adjustment accuracy of the time synchronization between the slave base station 72 and the clock reference base station 71 .

Embodiment seven

Referring to FIG. 8, FIG. 8 is a schematic structural diagram of a communication terminal provided by Embodiment 7 of the present invention, including:

A receiving unit 81, configured to receive clock reference base stations and downlink preamble signals from the base station;

A measuring unit 82, configured to measure the relative time delay of the downlink preamble signal received by the receiving unit 81 between the clock reference base station and the slave base station;

The request receiving unit 83 is configured to receive the measurement report request sent by the base station, the measurement type carried in the request is the relative delay of the downlink preamble signal between the slave base station and the clock reference base station, and the report type is periodic Reporting, the reporting period is the period of air interface synchronization;

The reporting unit 84 is configured to report the measurement result of the measuring unit 82 to the base station in an air interface synchronization cycle according to the measurement reporting request received by the request receiving unit 83 .

Further, referring to FIG. 9, the request receiving unit 83 further includes:

Request receiving module A 831, configured to receive the measurement report request sent by the slave base station to the clock reference base station;

Request receiving module B 832, configured to receive the measurement reporting request sent by the clock reference base station to the slave base station;

Corresponding to the request receiving unit 83, the reporting unit 84 further includes:

The reporting module A 841 is configured to report the measurement result of the measurement unit to the secondary base station in an air interface synchronization cycle according to the measurement reporting request received by the request receiving module A 831;

The reporting module B 842 is configured to report the measurement result of the measurement unit to the clock reference base station in an air interface synchronization cycle according to the measurement reporting request received by the request receiving module B 832.

The communication terminal may be a Worldwide Interoperability for Microwave Access wimax (Worldwide Interoperability for Microwave Access) terminal, the measurement report request may be an SCN-REQ message, and the measurement report result may be an SCN-REPORT message.

The communication terminal provided by the embodiment of the present invention works under the clock reference base station or the slave base station, and can receive the downlink preamble signal of the clock reference base station and the slave base station through the receiving unit 81, and can measure the clock reference base station through the measurement unit 82 The relative time delay with the downlink preamble Preamble signal between the secondary base station, when the request receiving unit 83 receives the measurement report request to the clock reference base station sent by the secondary base station, the measurement unit 82 will be reported by the reporting unit 84 The results are reported to the secondary base station in the cycle of air interface synchronization, and the secondary base station adjusts the clock of the secondary base station according to the measurement report results of the communication terminal, so that when the secondary base station cannot obtain the clock reference base station signal, it is implemented by the present invention The assistance of the communication terminal provided by the example, the time synchronization between the base stations can also be realized without increasing the receiver of the slave base station and without periodically interrupting the service; or when the request receiving unit 83 receives the clock reference sent by the base station When the measurement report request of the base station, the measurement result of the measurement unit 82 is reported to the clock reference base station by the reporting unit 84 in an air interface synchronization period, and then the clock reference base station forwards the measurement report result of the communication terminal to the clock reference base station. The secondary base station, the secondary base station adjusts the clock of the secondary base station according to the forwarded measurement report results, so that when there is no communication terminal under the secondary base station, the assistance of the communication terminal provided by the embodiment of the present invention does not need Adding the receiver of the slave base station can also realize the time synchronization between the base stations without periodically interrupting the business.

In summary, the technical solution provided by the embodiment of the present invention utilizes a communication terminal-assisted method to send a measurement report request to the communication terminal through the clock reference base station or the slave base station, and the communication between the slave base station and the clock reference base station The relative delay of the downlink preamble signal is measured and reported periodically with the air interface synchronization cycle. In the case that the slave base station cannot obtain the clock reference base station signal, or when there is no communication terminal under the slave base station, there is no need to increase the slave The receiver of the base station can realize the time synchronization between the base stations without periodically interrupting the business, so it has a wide range of applications, has little impact on the business of the base station, and does not require special development and measurement of the physical layer, so the implementation is simple.

It should be noted that the method in the embodiment of the present invention can be implemented in the form of a software function module, and when the software function module is sold or used as an independent product, it can also be stored in a computer-readable storage medium. The storage medium mentioned above may be a read-only memory, a magnetic disk or an optical disk, and the like.

Each functional unit in the embodiment of the present invention may be integrated into one processing module, each unit may exist separately physically, or two or more units may be integrated into one module. The above-mentioned integrated modules can be implemented in the form of hardware or in the form of software function modules. If the integrated modules are realized in the form of software function modules and sold or used as independent products, they can also be stored in a computer-readable storage medium. The storage medium mentioned above may be a read-only memory, a magnetic disk or an optical disk, and the like.

The method and system for realizing time synchronization between base stations and the communication terminal provided by the embodiment of the present invention have been introduced in detail above. The description of the embodiment is only used to help understand the method and idea of the present invention; anyone familiar with the technical field Within the technical scope disclosed in the present invention, changes or substitutions can be easily conceived, and all should be covered within the protection scope of the present invention.

Claims (16)

1. A method for realizing time synchronization between base stations, characterized in that, comprising: Obtain the information of the surrounding clock reference base stations from the base station through the network management node, and determine the clock reference base stations that need to be tracked; The slave base station sends a measurement report request for the determined clock reference base station to the communication terminal working under the slave base station, and the measurement type carried in the request is the downlink preamble between the slave base station and the clock reference base station The relative delay of the signal, the reporting type is periodic reporting, and the reporting period is the period of air interface synchronization; The slave base station receives the measurement report result of the communication terminal, and adjusts the clock of the slave base station according to the measurement report result, and the measurement report result includes the downlink preamble signal between the slave base station and the clock reference base station. relative delay. 2. The method according to claim 1, wherein the communication terminal is a communication terminal receiving a downlink carrier-to-interference+noise ratio (CINR) of the slave base station that is smaller than a set threshold. 3. The method according to claim 1, wherein the communication terminal is a communication terminal whose distance to the current slave base station is close to the distance to the clock reference base station. 4. The method according to claim 2 or 3, characterized in that the method further comprises: sending the measurement report request from the base station to two or more communication terminals working under the base station; The slave base station averages the measurement report results of two or more communication terminals, and adjusts the clock of the slave base station according to the average result. 5. A method for realizing time synchronization between base stations, comprising: The clock reference base station obtains the information of the surrounding secondary base stations through the network management node, and determines the secondary base stations that need to achieve time synchronization; The clock reference base station sends a measurement report request for the determined secondary base station to the communication terminal working under the clock reference base station, and the measurement type carried in the request is the downlink preamble between the secondary base station and the current clock reference base station The relative delay of the Preamble signal, the reporting type is periodic reporting, and the reporting period is the period of air interface synchronization; After receiving the measurement reporting result of the communication terminal, the clock reference base station forwards the measurement reporting result to the secondary base station, and the secondary base station adjusts the clock of the secondary base station according to the forwarded measurement reporting result, and the The measurement report results include the relative time delay of the downlink preamble signal between the slave base station and the clock reference base station. 6. The method according to claim 5, wherein the communication terminal is a communication terminal that receives a downlink carrier-to-interference+noise ratio (CINR) of the clock reference base station that is smaller than a set threshold. 7. The method according to claim 5, wherein the communication terminal is a communication terminal whose distance to the secondary base station is close to the distance to the reference base station of the current clock. 8. The method according to claim 6 or 7, further comprising: The clock reference base station sends the measurement report request to two or more communication terminals working under the clock reference base station; After the clock reference base station averages the measurement report results of more than two communication terminals, the measurement report average result is forwarded to the secondary base station, and the secondary base station reports the average result according to the forwarded measurement report to the secondary base station. The clock is adjusted. 9. A system for realizing time synchronization between base stations, comprising: The secondary base station is used to send a measurement report request for the clock reference base station that needs to be tracked to the communication terminal working under the secondary base station, and the measurement type carried in the request is between the secondary base station and the clock reference base station The relative delay of the downlink preamble signal, the reporting type is periodic reporting, and the reporting period is the period of air interface synchronization; receiving the measurement reporting result of the communication terminal, and adjusting the clock of the slave base station according to the measurement reporting result, the The measurement report results include the relative delay of the downlink preamble signal between the slave base station and the clock reference base station; A clock reference base station, used to provide a reference for time synchronization; The communication terminal is configured to receive the measurement report request sent by the secondary base station to the clock reference base station, and measure the relative delay of the downlink preamble signal between the secondary base station and the clock reference base station by The period of air interface synchronization is reported to the secondary base station periodically. 10. The system according to claim 9, wherein the downlink carrier-to-interference+noise ratio (CINR) received by the communication terminal from the base station is less than a set threshold; The distance of the base station is close to the distance to the clock reference base station. 11. The system of claim 10, wherein: The secondary base station is further configured to send the measurement report request to two or more communication terminals working under the secondary base station; average the measurement report results of the two or more communication terminals, and calculate the secondary The clock of the base station is adjusted. 12. A system for realizing time synchronization between base stations, characterized in that it comprises: The clock reference base station is used to send a measurement report request for the secondary base station determined to achieve time synchronization to the communication terminal working under the clock reference base station, and the measurement type carried in the request is the secondary base station and the local clock reference base station The relative delay of the downlink leading Preamble signal between, the reporting type is periodic reporting, and the reporting period is the period of air interface synchronization; receiving the measurement reporting result of the communication terminal, and forwarding the measurement reporting result to the secondary base station, The measurement reporting result includes the relative delay of the downlink preamble signal between the slave base station and the clock reference base station; The slave base station is configured to receive the measurement report result forwarded by the clock reference base station, and adjust the clock of the slave base station according to the forwarded measurement report result; The communication terminal is configured to receive the measurement report request to the secondary base station sent by the clock reference base station, and measure the relative time delay of the downlink preamble signal between the secondary base station and the clock reference base station by The cycle of air interface synchronization is reported to the clock reference base station. 13. The system according to claim 12, wherein the downlink carrier-to-interference+noise ratio (CINR) received by the communication terminal from the clock reference base station is less than a set threshold; The distance from the base station is close to the distance to the clock reference base station. 14. The system of claim 13, wherein: The clock reference base station is also used to send the measurement report request to two or more communication terminals working under the clock reference base station; average the measurement report results of the two or more communication terminals, and combine the The average result of the measurement report is forwarded to the secondary base station; The secondary base station is further configured to adjust the clock of the secondary base station according to the average result of the forwarded measurement report. 15. A communication terminal, characterized in that it comprises: The receiving unit is used to receive the downlink preamble signal of the clock reference base station and the slave base station; a measuring unit, configured to measure the relative time delay of the downlink preamble signal received by the receiving unit between the clock reference base station and the slave base station; The request receiving unit is used to receive the measurement report request sent by the base station, the measurement type carried in the request is the relative delay of the downlink preamble signal between the slave base station and the clock reference base station, and the report type is periodic report , the reporting period is the air interface synchronization period; a reporting unit, configured to report the measurement result of the measurement unit to the base station at an air interface synchronization cycle according to the measurement report request received by the request receiving unit, the measurement result including the clock reference base station and the The relative delay of downlink preamble signals between base stations. 16. The communication terminal according to claim 15, characterized in that, The request receiving unit further includes: A request receiving module A, configured to receive the measurement report request sent by the slave base station to the clock reference base station; A request receiving module B, configured to receive a measurement report request sent by the clock reference base station to the slave base station; Corresponding to the request receiving unit, the reporting unit further includes: The reporting module A is configured to report the measurement result of the measurement unit to the secondary base station in an air interface synchronization cycle according to the measurement reporting request received by the request receiving module A; The reporting module B is configured to report the measurement result of the measurement unit to the clock reference base station at an air interface synchronization cycle according to the measurement report request received by the request receiving module B.

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