Multi-node time-frequency signal synchronization system with self-adaptive regulation and control

Abstract

The invention relates to the field of time frequency, and provides a self-adaptive control multi-node time frequency signal synchronization system, which comprises a time frequency master node and a plurality of time frequency slave nodes, and is characterized in that the time frequency master node comprises a time frequency signal generation unit, a master time frequency signal transmission unit, a master time frequency signal monitoring unit and an optical fiber transmission unit; the time-frequency slave node comprises an optical receiving unit, a slave time-frequency signal transmission unit, a slave time-frequency signal monitoring unit and a time-frequency recovery unit. A time-frequency signal is transmitted to a time-frequency slave node from a time-frequency master node through an optical fiber link, signal recovery is carried out at the time-frequency slave node, the system is provided with a master time-frequency transmission link and a slave time-frequency transmission link which are online at the same time, and the master time-frequency signal monitoring unit and the slave time-frequency signal monitoring unit have high-precision time interval measurement capability. The master-slave time-frequency signal transmission unit has an optical fiber link transmission time delay self-adaptive compensation function. According to the invention, stability and reliability of time-frequency signal transmission among multiple distributed nodes in a hundred-kilometer wide area range can be effectively realized, and cross mutual backup of main and standby transmission links is supported.

Description

Technical Field

[0001] The present invention relates to the field of time and frequency, and is particularly applicable to the high-precision transmission of multi-node time and frequency signals in a wide area. Through the precise measurement and compensation control of the phase jitter of the time and frequency transmission link between the master and slave nodes of time and frequency, the adaptive regulation of the synchronization accuracy of time and frequency signals is realized. Background Art

[0002] The high-precision distributed multi-node time and frequency signal synchronization technology is one of the important common bases of the integrated comprehensive electronic information system and an important determinant of the performance of the electronic system. Satellite navigation ground remote control systems, space ground measurement and control systems, etc. all use high-performance and high-stability cesium atomic clocks or hydrogen atomic clocks as the time and frequency reference of the system, and it is necessary to transmit the time and frequency reference to each level of node equipment with high precision within the entire ground station range.

[0003] The high-precision distributed multi-node time and frequency signal synchronization technology is widely used in comprehensive electronic information systems such as integrated PNT systems, collaborative command and control systems, Beidou navigation systems, and space measurement and control systems. To ensure the normal operation of the electronic information system, it is required that the time and frequency signals of each node are accurate, stable, and reliable, and the quality of the time and frequency difference signals is monitored online and evaluated in real time. According to the specific requirements of different types of electronic information systems, it is necessary to transmit 10MHz frequency signals and 1PPS time signals between multiple nodes within a few hundred kilometers, and at the same time, it is necessary to ensure the uninterrupted and high-precision continuous transmission of time and frequency signals between the master and slave nodes.

[0004] However, in the actual working environment of the system, due to the influence of factors such as temperature changes and random vibrations in the node equipment and the working environment of the time and frequency transmission link, the synchronization accuracy of the time and frequency signals between the master and slave nodes will gradually deteriorate, thus affecting the overall efficiency of the electronic information system. Therefore, it is necessary to study the high-precision multi-node time and frequency signal synchronization technology and system to realize the adaptive regulation of the time and frequency signals between the master and slave nodes in a wide area, and to realize the high-precision, continuous, and stable transmission of the time and frequency signals between the master and slave nodes. Summary of the Invention

[0005] The object of the present invention is: aiming at the requirement of transmitting high-precision 10MHz frequency signals and 1PPS time signals between multiple nodes within a hundred kilometers in the electronic information system in a wide area, in order to eliminate the influence of factors such as temperature changes and random vibrations in the node equipment and the working environment of the time and frequency transmission link on the synchronization accuracy of the time and frequency signals, a multi-node time and frequency signal synchronization system with adaptive regulation is provided to realize the adaptive regulation of the time and frequency signals between the master and slave nodes in a wide area, and to realize the high-precision, continuous, and stable transmission of the time and frequency signals between the master and slave nodes.

[0006] The technical solution adopted by the present invention is as follows:

[0007] An adaptive regulation multi-node time-frequency signal synchronization system is used to achieve the adaptive regulation of time signals and frequency signals between multiple nodes, and to achieve high-precision and high-stability adaptive synchronization of time-frequency signals within a wide area, forming a strong coherent time-frequency service. It includes a time-frequency master node and multiple time-frequency slave nodes. The time-frequency master node includes a time-frequency signal generation unit, a master time-frequency signal transmission unit, a master time-frequency signal monitoring unit, and an optical fiber transmission unit. The time-frequency slave node includes an optical reception unit, a slave time-frequency signal transmission unit, a slave time-frequency signal monitoring unit, and a time-frequency recovery unit;

[0008] The time-frequency signal generation unit is used to generate 10 MHz and 1PPS signals, transmit the 10 MHz signal to the master time-frequency signal transmission unit, and transmit the 10 MHz and 1PPS signals to the master time-frequency signal monitoring unit;

[0009] The master time-frequency signal transmission unit is paired with the slave time-frequency signal transmission unit; it is used to perform frequency conversion on the 10 MHz frequency signal transmitted by the time-frequency signal generation unit to generate a reference frequency signal, convert the reference frequency signal into an optical signal consistent with the optical transmission unit channel, and transmit it to the time-frequency slave node through the optical fiber link of the optical transmission unit; at the same time, use the 10 MHz time-frequency signal returned by the time-frequency slave node to compare the phase with the locally generated reference frequency signal to obtain the phase jitter of the time-frequency signal optical fiber transmission link, and use the obtained phase jitter to pre-compensate the phase jitter of the time-frequency signal transmission link, so as to achieve phase locking of the 10 MHz frequency signal between the master and slave nodes, that is, to achieve coherence of the frequency signal between the master and slave nodes;

[0010] The slave time-frequency signal transmission unit is paired with the master time-frequency signal transmission unit; it is used to receive the optical signal transmitted by the time-frequency master node through the optical fiber link through the optical reception unit, perform optoelectronic conversion, then demodulate the reference frequency signal transmitted by the time-frequency master node, perform frequency conversion on the reference frequency signal to generate a 10 MHz frequency signal, perform equal-phase splitting on the 10 MHz frequency signal, one path is output to the time-frequency recovery unit, and one path is returned to the time-frequency master node through the optical fiber link of the optical reception unit;

[0011] The master time-frequency signal monitoring unit is used in pair with the slave time-frequency signal monitoring unit; it is used to generate a data frame based on the 1PPS signal output by the time-frequency signal generating unit as the time reference, generate the local pseudo-code spread-spectrum signal t1 of the time-frequency master node through BPSK modulation, and at the same time generate the intermediate-frequency signal f1 based on the 10MHz signal output by the time-frequency signal generating unit as the frequency reference. Modulate the local pseudo-code spread-spectrum signal t1 through digital modulation to modulate the 1PPS time information of the master node carried thereon onto the intermediate-frequency signal f1 to generate the master node measurement signal F1, which is converted into an optical signal by the optical transmission unit and then transmitted to the optical receiving unit of the time-frequency slave node through the optical fiber link; it is also used to receive the slave node measurement signal F2 transmitted by the slave time-frequency signal monitoring unit through the optical transmission unit, and generate the observation quantity T 从主 , and transmit the observation quantity T 从主 to the slave time-frequency signal monitoring unit through the optical transmission unit and the optical receiving unit, or receive the observation quantity T transmitted by the slave time-frequency signal monitoring unit 主从 , generate the phase difference of the time-frequency signals of the master and slave time-frequency nodes, and transmit it to the time-frequency recovery unit through the optical transmission unit, the optical receiving unit and the slave time-frequency signal monitoring unit;

[0012] The slave time-frequency signal monitoring unit is used in pair with the master time-frequency signal monitoring unit; it is used to generate a data frame based on the 1PPS signal output by the time-frequency recovery unit as the time reference, generate the local pseudo-code spread-spectrum signal t2 of the slave node through BPSK modulation, and at the same time generate the intermediate-frequency signal f2 based on the 10MHz signal output by the time-frequency recovery unit of the slave node as the frequency reference; modulate the local pseudo-code spread-spectrum signal t2 of the slave node through digital modulation to modulate the 1PPS time information of the slave node carried thereon onto the intermediate-frequency signal f2 to generate the slave node measurement signal F2, which is converted into an optical signal by the optical receiving unit and then transmitted to the optical transmission unit of the time-frequency master node through the optical fiber link; it is also used to receive the master node measurement signal F1 of the master time-frequency signal monitoring unit through the optical receiving unit, and generate the observation quantity T 主从 , and transmit the observation quantity T 主从 to the master time-frequency signal monitoring unit through the optical transmission unit and the optical receiving unit, or receive the observation quantity T transmitted by the master time-frequency signal monitoring unit 从主 , generate the phase difference of the time-frequency signals of the master and slave time-frequency nodes, and transmit it to the time-frequency recovery unit;

[0013] The optical transmission unit has the functions of optical signal transmission and reception, and is used in pair with the optical receiving unit to realize the transmission of optical signals between the time-frequency master node and the time-frequency slave node;

[0014] The optical receiving unit has the functions of optical signal transmission and reception, and is used in pair with the optical transmission unit to realize the transmission of optical signals between the time-frequency master node and the time-frequency slave node;

[0015] The time-frequency recovery unit is used to receive the 10 MHz signal output from the time-frequency signal transmission unit, generate the 10 MHz frequency signal and 1PPS time signal from the time-frequency node, and output them to the slave time-frequency signal monitoring unit, and receive in real time the phase difference of the time-frequency signals of the master and slave time-frequency nodes reported by the slave time-frequency signal monitoring unit, denoted as Δt 主从 , and adjust the time difference of the slave node time-frequency signal in real time according to the phase difference Δt 主从 until Δt 主从 is less than the set threshold; among them, the time-frequency recovery unit consists of a 10 MHz generation branch and a 1PPS signal generation branch, and the generated 10 MHz signal and 1PPS signal are homologous signals.

[0016] Further, the transmission process of the 10 MHz reference frequency signal from the master time-frequency signal transmission unit of the time-frequency master node to the slave time-frequency signal transmission unit of the time-frequency slave node is as follows:

[0017] The 10 MHz reference frequency signal with a frequency of and a phase of f ref = ω ref / 2π is transmitted from the master node to the time-frequency slave node and then denoted as where is the additional phase introduced by the time-frequency signal transmission, is the additional phase introduced by the optical fiber transmission link. The time-frequency signal transmission includes the master time-frequency signal transmission unit, the optical transmission unit, the optical reception unit, and the slave time-frequency signal transmission unit;

[0018] The processing process of the time-frequency signal transmission unit after receiving the 10 MHz frequency signal is as follows:

[0019] After the slave time-frequency signal transmission unit receives the 10 MHz frequency signal, it is transmitted in reverse to the master time-frequency signal transmission unit by the same optical fiber link in a partial decimation manner and then denoted as

[0020] The master time-frequency signal transmission unit compares the phase of the 10 MHz time-frequency signal returned by the time-frequency slave node with the reference signal to obtain the phase jitter of the time-frequency signal optical fiber transmission link; and uses the obtained phase jitter to pre-compensate the phase jitter of the time-frequency signal transmission link. The processing process is as follows:

[0021] The master time-frequency signal transmission unit compares the phase of the 10 MHz reference frequency signal V ref with the signal V returned by the time-frequency slave node return to obtain a phase difference of and makes

[0022] Further, the process of calculating the phase difference between the master and slave time-frequency signals by the master time-frequency signal monitoring unit and the slave time-frequency signal monitoring unit is as follows:

[0023] Let the time when the master time-frequency signal monitoring unit transmits the master node measurement signal F1 to the time-frequency slave node be T 主 , and the time when the slave time-frequency signal monitoring device receives the master node measurement signal F1 be T 从收 , and the time when the slave time-frequency signal monitoring unit transmits the slave node measurement signal F2 to the time-frequency master node be T 主 + ΔT 主从 , and the time when the master time-frequency signal monitoring unit receives the slave node measurement signal F2 be T 主收 ; where ΔT 主从 is the theoretical phase difference;

[0024] Let the time of the time-frequency master node be T 主 , and the time of the time-frequency slave node be T 从 , then the clock difference between the two places is Δt 主从 = T 主 - T 从 ;

[0026] The observable quantity generated by the slave time-frequency signal monitoring unit is T 主从 = T 主 - T 主收 ; The observable quantity generated by the master time-frequency signal monitoring unit is T 从主 = T 从 - T 从收 ; where, when the optical fiber length between the master and slave nodes is L and the light speed in the optical fiber is c,

[0027] Since the optical fiber transmission paths between the master and slave time-frequency nodes are the same, the difference in the transmission paths between the two places caused by the synchronous clock difference ΔT 主从 is ignored, and the difference between the measured values at the two places is the phase difference Δt 主从 between the master and slave nodes;

[0028] We get T 主从 - T 从主 = 2(T 主 - T 从 ) = 2Δt 主从 , and the phase difference between the time-frequency signals of the master and slave time-frequency nodes is

[0029] Further, the master time-frequency signal transmission unit, the master time-frequency signal monitoring unit, the slave time-frequency signal transmission unit, the slave time-frequency signal monitoring unit, and the time-frequency recovery unit all adopt a dual A / B hot standby design; the slave time-frequency signal monitoring unit is also used for time interval measurement, and by receiving the 1PPS signals generated by the two time-frequency recovery units in the time-frequency slave node, the real-time monitoring of the phase difference is carried out.

[0030] The advantages of the present invention compared with the prior art are as follows:

[0031] (1) The present invention can effectively realize the transmission of 10MHz frequency signals and 1PPS time signals between distributed multi-nodes within a wide area of 100 kilometers, and perform online compensation for the time delay jitter of the time-frequency signal transmission link, providing unified time-frequency services for each node.

[0032] (2) The present invention can effectively monitor and evaluate the quality of time-frequency difference signals between distributed multi-nodes within a wide area of 100 kilometers online in real time.

[0033] (3) The present invention can effectively realize the stability and reliability of time-frequency signal transmission between distributed multi-nodes within a wide area of 100 kilometers, and support cross-backup of the primary and standby transmission links.

[0034] (4) The present invention can effectively realize the precise adaptive regulation of time-frequency signals of distributed multi-nodes within a wide area of 100 kilometers, and ensure the high-precision time synchronization index between each node. Description of the Drawings

[0035] Figure 1 It is a schematic structural diagram of a multi-node time-frequency signal synchronization system with adaptive regulation according to the present invention.

[0036] Figure 2 It is a schematic structural diagram of the time-frequency signal transmitted from the time-frequency master node to the time-frequency slave node according to the present invention. Detailed Embodiments

[0037] The present invention will be further described in detail below with reference to the drawings.

[0038] As Figure 1 shown, a multi-node time-frequency signal synchronization system with adaptive regulation is used to realize the adaptive regulation of time signals and frequency signals between multi-nodes, achieve high-precision and high-stability adaptive synchronization of time-frequency signals within a wide area, and form a strong coherent time-frequency service; it includes a time-frequency master node and multiple time-frequency slave nodes 1-n. The time-frequency master node includes a time-frequency signal generation unit, a master time-frequency signal transmission unit, a master time-frequency signal monitoring unit, and an optical fiber transmission unit. The time-frequency slave node includes an optical receiving unit, a slave time-frequency signal transmission unit, a slave time-frequency signal monitoring unit, and a time-frequency recovery unit.

[0039] The time-frequency signal generation unit is used to generate 10 MHz and 1PPS signals, transmit the 10 MHz signal to the main time-frequency signal transmission unit, and transmit the 10 MHz and 1PPS signals to the main time-frequency signal monitoring unit.

[0040] The main time-frequency signal transmission unit is used in pair with the slave time-frequency signal transmission unit; it is used to perform frequency conversion on the 10 MHz frequency signal transmitted by the time-frequency signal generation unit to generate a reference frequency signal, convert the reference frequency signal into an optical signal consistent with the optical transmission unit channel, and transmit it to the time-frequency slave node through the optical transmission unit via the optical fiber link; at the same time, it uses the 10 MHz time-frequency signal returned by the time-frequency slave node to compare the phase with the locally generated reference frequency signal to obtain the phase jitter of the time-frequency signal optical fiber transmission link, and uses the obtained phase jitter to pre-compensate the phase jitter of the time-frequency signal transmission link, so as to realize the phase locking of the 10 MHz frequency signal between the master and slave nodes, that is, to realize the coherence of the frequency signal between the master and slave nodes.

[0041] The slave time-frequency signal transmission unit is used in pair with the main time-frequency signal transmission unit; it is used to receive the optical signal transmitted by the time-frequency master node through the optical receiving unit via the optical fiber link, perform optoelectronic conversion, then demodulate the reference frequency signal transmitted by the time-frequency master node, perform frequency conversion on the reference frequency signal to generate a 10 MHz frequency signal, perform equal-phase splitting on the 10 MHz frequency signal, output one path to the time-frequency recovery unit, and transmit one path back to the time-frequency master node through the optical receiving unit via the optical fiber link.

[0042] The main time-frequency signal monitoring unit is used in pair with the slave time-frequency signal monitoring unit; it is used to generate a data frame based on the 1PPS signal output by the time-frequency signal generation unit as the time reference, generate the local pseudo-code spread spectrum signal t1 of the time-frequency master node through BPSK modulation, and at the same time generate an intermediate frequency signal f1 based on the 10 MHz signal output by the time-frequency signal generation unit as the frequency reference, modulate the local pseudo-code spread spectrum signal t1 through digital modulation to modulate the 1PPS time information of the master node carried on the intermediate frequency signal f1 to generate the master node measurement signal F1, which is converted into an optical signal by the optical transmission unit and then transmitted to the optical receiving unit of the time-frequency slave node via the optical fiber link; it is also used to receive the slave node measurement signal F2 transmitted by the slave time-frequency signal monitoring unit through the optical transmission unit, generate the observation quantity T 从主 and transmit the observation quantity T 从主 to the slave time-frequency signal monitoring unit through the optical transmission unit and the optical receiving unit, or receive the observation quantity T transmitted by the slave time-frequency signal monitoring unit 主从 to generate the phase difference of the time-frequency signals of the master and slave time-frequency nodes, and transmit it to the time-frequency recovery unit through the optical transmission unit, the optical receiving unit and the slave time-frequency signal monitoring unit.

[0043] The slave time-frequency signal monitoring unit is used in pair with the master time-frequency signal monitoring unit; it is used to generate data frames based on the 1PPS signal output by the time-frequency recovery unit as the time reference, and generate the local pseudo-code spread-spectrum signal t2 of the slave node through BPSK modulation. At the same time, it generates the intermediate-frequency signal f2 based on the 10MHz signal output by the time-frequency recovery unit of the slave node as the frequency reference; it modulates the 1PPS time information of the slave node carried by the local pseudo-code spread-spectrum signal t2 of the slave node onto the intermediate-frequency signal f2 through digital modulation to generate the measurement signal F2 of the slave node, which is converted into an optical signal by the optical receiving unit and then transmitted to the optical transmission unit of the time-frequency master node through the optical fiber link; it is also used to receive the measurement signal F1 of the master node of the master time-frequency signal monitoring unit through the optical receiving unit to generate the observation quantity T 主从 , and transmit the observation quantity T 主从 to the master time-frequency signal monitoring unit through the optical transmission unit and the optical receiving unit, or receive the observation quantity T transmitted by the master time-frequency signal monitoring unit 从主 , generate the phase difference of the time-frequency signals of the master and slave time-frequency nodes, and transmit it to the time-frequency recovery unit; the slave time-frequency signal monitoring unit is also used for time interval measurement, and monitors the phase difference in real time by receiving the 1PPS signals generated by two time-frequency recovery units in the time-frequency slave node

[0044] The optical transmission unit has the functions of optical signal transmission and reception, and is used in pair with the optical receiving unit to realize the transmission of optical signals between the time-frequency master node and the time-frequency slave node

[0045] The optical receiving unit has the functions of optical signal transmission and reception, and is used in pair with the optical transmission unit to realize the transmission of optical signals between the time-frequency master node and the time-frequency slave node

[0046] The time-frequency recovery unit is used to receive the 10MHz signal output by the slave time-frequency signal transmission unit, generate the 10MHz frequency signal and 1PPS time signal of the slave time-frequency node, and output them to the slave time-frequency signal monitoring unit, and receive in real time the phase difference of the time-frequency signals of the master and slave time-frequency nodes reported by the slave time-frequency signal monitoring unit, denoted as Δt 主从 , and adjust the time difference of the time-frequency signal of the slave node in real time according to the phase difference Δt 主从 until Δt 主从 is less than the set threshold; among them, the time-frequency recovery unit consists of a 10MHz generation branch and a 1PPS signal generation branch, and the generated 10MHz signal and 1PPS signal are homologous signals

[0047] As Figure 2 shown, the transmission process of the 10MHz reference frequency signal from the master time-frequency signal transmission unit of the time-frequency master node to the slave time-frequency signal transmission unit of the time-frequency slave node in the embodiment of the present invention is as follows:

[0048] The frequency is and the phase is fref = ω ref The 10 MHz reference frequency signal of / 2π After being transmitted from the master node to the time - frequency slave node, it is denoted as Wherein is the additional phase introduced by the time - frequency signal transmission, is the additional phase introduced by the optical fiber transmission link. The time - frequency signal transmission includes a master time - frequency signal transmission unit, an optical transmission unit, an optical reception unit, and a slave time - frequency signal transmission unit;

[0049] The processing process after the time - frequency signal transmission unit receives the 10 MHz frequency signal is as follows:

[0050] After the slave time - frequency signal transmission unit receives the 10 MHz frequency signal, it is reversely transmitted to the master time - frequency signal transmission unit by the same optical fiber link in a partial decimation manner and then denoted as

[0051] The master time - frequency signal transmission unit uses the 10 MHz time - frequency signal returned by the time - frequency slave node to compare the phase with the reference signal to obtain the phase jitter of the time - frequency signal optical fiber transmission link; and uses the obtained phase jitter to pre - compensate the phase jitter of the time - frequency signal transmission link. The processing process is as follows:

[0052] The master time - frequency signal transmission unit performs phase comparison on the 10 MHz reference frequency signal V ref and the signal V returned by the time - frequency slave node return to obtain a phase difference of and makes

[0053] Wherein, in the embodiment of the present invention, the calculation process of the phase difference between the time - frequency signals of the master time - frequency signal monitoring unit and the slave time - frequency signal monitoring unit for the master - slave time - frequency nodes is as follows:

[0054] Let the time when the master time - frequency signal monitoring unit transmits the master node measurement signal F1 to the time - frequency slave node be T 主 , and the time when the slave time - frequency signal monitoring device receives the master node measurement signal F1 be T 从收 , and the time when the slave time - frequency signal monitoring unit transmits the slave node measurement signal F2 to the time - frequency master node be T 主 + ΔT 主从 , and the time when the master time - frequency signal monitoring unit receives the slave node measurement signal F2 be T 主收 ; wherein, ΔT 主从 is the theoretical phase difference;

[0055] Let the time of the time - frequency master node be T 主 , and the time of the time - frequency slave node be T从 Then the clock difference between the two places is Δt 主从 = T 主 - T 从 ;

[0057] The observable quantity generated by the time-frequency signal monitoring unit is T 主从 = T 主 - T 主收 ; The observable quantity generated by the master time-frequency signal monitoring unit is T 从主 = T 从 - T 从收 ; Wherein, when the optical fiber length between the master and slave nodes is L and the light speed in the optical fiber is c,

[0058] If the optical fiber transmission paths between the master and slave time-frequency nodes are the same, the synchronous clock difference ΔT 主从 causing different transmission paths between the two places is ignored, and the difference between the measured values of the two places is the phase difference Δt between the master and slave nodes 主从 ;

[0059] Obtain T 主从 - T 从主 = 2(T 主 - T 从 ) = 2Δt 主从 , the phase difference of the time-frequency signals of the master and slave time-frequency nodes is

[0060] To ensure the continuous and highly reliable output of the time-frequency signal of the slave node, the master time-frequency signal transmission unit, the master time-frequency signal monitoring unit and the optical fiber transmission unit of the time-frequency master node, as well as the slave time-frequency signal transmission unit, the slave time-frequency signal monitoring unit and the time-frequency recovery unit of the time-frequency slave node all adopt the A / B dual-set hot standby design.

Claims

1. An adaptive regulation multi-node time-frequency signal synchronization system, which is used to realize the adaptive regulation of time signals and frequency signals between multiple nodes, achieve high-precision and high-stability adaptive synchronization of time-frequency signals within a wide area, and form a strong coherent time-frequency service; it is characterized in that, It includes a time-frequency master node and multiple time-frequency slave nodes. The time-frequency master node includes a time-frequency signal generation unit, a master time-frequency signal transmission unit, a master time-frequency signal monitoring unit, and an optical fiber transmission unit. The time-frequency slave node includes an optical reception unit, a slave time-frequency signal transmission unit, a slave time-frequency signal monitoring unit, and a time-frequency recovery unit; The time-frequency signal generation unit is used to generate 10 MHz and 1PPS signals, transmit the 10 MHz signal to the master time-frequency signal transmission unit, and transmit the 10 MHz and 1PPS signals to the master time-frequency signal monitoring unit; The master time-frequency signal transmission unit is used in pair with the slave time-frequency signal transmission unit; it is used to perform frequency conversion on the 10 MHz frequency signal transmitted by the time-frequency signal generation unit to generate a reference frequency signal, convert the reference frequency signal into an optical signal consistent with the optical transmission unit channel, and transmit it to the time-frequency slave node through the optical fiber link via the optical transmission unit; at the same time, it compares the phase of the 10 MHz time-frequency signal returned by the time-frequency slave node with the locally generated reference frequency signal to obtain the phase jitter of the time-frequency signal optical fiber transmission link, and uses the obtained phase jitter to pre-compensate the phase jitter of the time-frequency signal transmission link, so as to achieve phase locking of the 10 MHz frequency signal between the master and slave nodes, that is, to achieve coherence of the frequency signal between the master and slave nodes; The slave time-frequency signal transmission unit is used in pair with the master time-frequency signal transmission unit; it is used to receive the optical signal transmitted by the time-frequency master node through the optical fiber link via the optical reception unit, perform optoelectronic conversion, then demodulate the reference frequency signal transmitted by the time-frequency master node, perform frequency conversion on the reference frequency signal to generate a 10 MHz frequency signal, perform equal-phase splitting on the 10 MHz frequency signal, output one path to the time-frequency recovery unit, and transmit one path back to the time-frequency master node through the optical fiber link via the optical reception unit; The master time-frequency signal monitoring unit is used in pair with the slave time-frequency signal monitoring unit; It is used to generate a data frame based on the 1PPS signal output by the time-frequency signal generation unit as the time reference, generate a local pseudo-code spread spectrum signal t1 of the time-frequency master node through BPSK modulation, and generate an intermediate frequency signal f1 based on the 10MHz signal output by the time-frequency signal generation unit as the frequency reference. Modulate the local pseudo-code spread spectrum signal t1 through digital modulation to modulate the 1PPS time information of the master node carried thereon to the intermediate frequency signal f1 to generate a master node measurement signal F1, which is converted into an optical signal by the optical transmission unit and then transmitted to the optical receiving unit of the time-frequency slave node through the optical fiber link; it is also used to receive the slave node measurement signal F2 transmitted from the time-frequency signal monitoring unit through the optical transmission unit, and generate an observable quantity T 从主 , and transmit the observable quantity T 从主 to the time-frequency signal monitoring unit through the optical transmission unit and the optical receiving unit, or receive the observable quantity T transmitted from the time-frequency signal monitoring unit 主从 , generate the phase difference of the time-frequency signals of the master and slave time-frequency nodes, and transmit it to the time-frequency recovery unit through the optical transmission unit, the optical receiving unit and the time-frequency signal monitoring unit; The slave time-frequency signal monitoring unit is used in pair with the master time-frequency signal monitoring unit; It is used to generate a data frame based on the 1PPS signal output by the time-frequency recovery unit as the time reference, and generate the local pseudo-code spread-spectrum signal t2 of the slave node through BPSK modulation. At the same time, it generates an intermediate-frequency signal f2 based on the 10MHz signal output by the time-frequency recovery unit of the slave node as the frequency reference; modulate the local pseudo-code spread-spectrum signal t2 of the slave node through digital modulation to modulate the 1PPS time information of the slave node carried thereon onto the intermediate-frequency signal f2 to generate the measurement signal F2 of the slave node, which is converted into an optical signal by the optical receiving unit and then transmitted to the optical transmission unit of the time-frequency master node through an optical fiber link; it is also used to receive the master node measurement signal F1 of the master time-frequency signal monitoring unit through the optical receiving unit to generate an observation quantity T 主从 , and transmit the observation quantity T 主从 to the master time-frequency signal monitoring unit through the optical transmission unit and the optical receiving unit, or receive the observation quantity T transmitted by the master time-frequency signal monitoring unit 从主 to generate the phase difference of the time-frequency signals of the master and slave time-frequency nodes and transmit it to the time-frequency recovery unit; The optical transmission unit has the functions of optical signal emission and reception, and is used in pair with the optical reception unit to realize the transmission of optical signals between the time-frequency master node and the time-frequency slave node; The optical reception unit has the functions of optical signal emission and reception, and is used in pair with the optical transmission unit to realize the transmission of optical signals between the time-frequency master node and the time-frequency slave node; The time-frequency recovery unit is used to receive the 10 MHz signal output from the time-frequency signal transmission unit, generate a 10 MHz frequency signal and a 1PPS time signal from the time-frequency node, and output them to the slave time-frequency signal monitoring unit, and also receive in real time the phase difference of the master-slave time-frequency node time-frequency signals reported by the slave time-frequency signal monitoring unit, denoted as Δt 主从 , and adjust the time difference of the slave node time-frequency signal in real time according to the phase difference Δt 主从 until Δt 主从 is less than the set threshold; among them, the time-frequency recovery unit consists of a 10 MHz generation branch and a 1PPS signal generation branch, and the generated 10 MHz signal and 1PPS signal are homologous signals.

2. The adaptive control multi-node time-frequency signal synchronization system according to claim 1, characterized in that: The process of transmitting the 10 MHz reference frequency signal from the master time-frequency signal transmission unit of the time-frequency master node to the slave time-frequency signal transmission unit of the time-frequency slave node is as follows: A reference frequency signal of 10 MHz with a frequency of and a phase of f ref = ω ref / 2π is transmitted from the master node to the time-frequency slave node and then denoted as where is the additional phase introduced by the time-frequency signal transmission, is the additional phase introduced by the optical fiber transmission link. The time-frequency signal transmission includes a master time-frequency signal transmission unit, an optical transmission unit, an optical reception unit, and a slave time-frequency signal transmission unit; ​ The processing process after the time-frequency signal transmission unit receives the 10 MHz frequency signal is as follows: After receiving a 10 MHz frequency signal from the time-frequency signal transmission unit, it is transmitted in reverse to the main time-frequency signal transmission unit through the same optical fiber link by means of partial decimation and then recorded as The master time-frequency signal transmission unit compares the phase of the 10 MHz time-frequency signal returned by the time-frequency slave node with the reference signal to obtain the phase jitter of the time-frequency signal optical fiber transmission link; and uses the obtained phase jitter to pre-compensate the phase jitter of the time-frequency signal transmission link, and the processing process is as follows: The main time-frequency signal transmission unit pairs the 10 MHz reference frequency signal V ref with the time-frequency slave node return signal V return to perform phase comparison to obtain a phase difference of and makes it through the phase correction method 3. An adaptive regulation multi-node time-frequency signal synchronization system according to claim 1, characterized in that The process of calculating the phase difference of the time-frequency signals of the master and slave time-frequency nodes by the master time-frequency signal monitoring unit and the slave time-frequency signal monitoring unit is as follows: Let the time when the master time-frequency signal monitoring unit transmits the master node measurement signal F1 to the time-frequency slave node be T 主 , and the time when the slave time-frequency signal monitoring device receives the master node measurement signal F1 be T 从收 , and the time when the slave time-frequency signal monitoring unit transmits the slave node measurement signal F2 to the time-frequency master node be T 主 +ΔT 主从 , and the time when the master time-frequency signal monitoring unit receives the slave node measurement signal F2 be T 主收 ; where, ΔT 主从 is the theoretical phase difference Set the time of the time-frequency master node as T 主 , and the time of the time-frequency slave node as T 从 . Then the clock difference between the two places is Δt 主从 = T 主 - T 从 ; The observable quantity generated by the time-frequency signal monitoring unit is T 主从 = T 主 - T 主收 ; The observable quantity generated by the master time-frequency signal monitoring unit is T 从主 = T 从 - T 从收 ; Wherein, when the optical fiber length between the master and slave nodes is L and the speed of light in the optical fiber is c If the optical fiber transmission paths between the master and slave time-frequency nodes are the same, the synchronous clock difference ΔT is ignored. 主从 The difference in the transmission paths between the two locations caused by this is ignored, and the difference between the measured values at the two locations is the phase difference Δt between the master and slave nodes. 主从 ; Get T 主从 -T 从主 = 2(T 主 -T 从 ) = 2Δt 主从 , the phase difference of the time-frequency signals of the master and slave time-frequency nodes is 4. An adaptive regulation multi-node time-frequency signal synchronization system according to claim 1, characterized in that The master time-frequency signal transmission unit, the master time-frequency signal monitoring unit, the slave time-frequency signal transmission unit, the slave time-frequency signal monitoring unit, and the time-frequency recovery unit all adopt a dual A / B hot standby design; the slave time-frequency signal monitoring unit is also used for time interval measurement, and by receiving the 1PPS signals generated by the two time-frequency recovery units in the time-frequency slave node, it conducts real-time monitoring of the phase difference.

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