Time synchronization method and system, electronic equipment, storage medium and program product

Abstract

The embodiment of the invention provides a time synchronization method and system, electronic equipment, a computer readable storage medium and a computer program product. The time synchronization system comprises an observation unit, a clock difference unit and an adjustment unit. The observation unit determines an asynchronous bidirectional code pseudo-range observed quantity between the first device and the second device. The clock difference unit determines a coarse clock difference between the first device and the second device based on the asynchronous bidirectional code pseudo-range observations. The adjusting unit adjusts the system time of the first device or the second device based on the rough clock difference, so that the system time of the first device and the system time of the second device are synchronized. And after the system time is synchronized, the observation unit determines the synchronous bidirectional code pseudo-range observed quantity between the devices at a preset time point. The clock difference unit determines the precise clock difference between the devices based on the synchronous bidirectional code pseudo-range observed quantity. The adjusting unit adjusts at least one of a frequency and a phase of a clock source of the first device or the second device based on the precise clock difference.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of time-frequency technology, and in particular to a time synchronization method, a time synchronization system, an electronic device, a computer-readable storage medium, and a computer program product. Background Art

[0002] Time synchronization refers to the process of exchanging local and remote time information, determining the time difference between the two, and reducing the time difference between the two by adjusting the clock. Time synchronization is of great significance to navigation, transportation, communication, electronics and other disciplines.

[0003] However, conventional high-precision time synchronization technologies are mostly applicable to static scenarios and are difficult to meet the needs of dynamic scenarios. In dynamic scenarios, changing geometric distance delays, multipath errors, and antenna group delays are the main factors affecting time synchronization accuracy.

[0004] Therefore, there is an urgent need for a high-precision time synchronization method and system suitable for dynamic scenes. Summary of the invention

[0005] The embodiments of the present application provide a time synchronization method and system, an electronic device, a computer-readable storage medium, and a computer program product that can at least partially solve the above-mentioned technical problems or other problems existing in the related technologies.

[0006] On the one hand, the present application provides a time synchronization system, which includes: an observation unit, which determines an asynchronous two-way code pseudorange observation amount between a first device and a second device; a clock difference unit, which determines a coarse clock difference between the first device and the second device based on the asynchronous two-way code pseudorange observation amount; and an adjustment unit, which adjusts the system time of the first device or the second device based on the coarse clock difference to synchronize the system time of the first device and the second device, wherein the clock difference unit is further configured to determine a synchronous two-way code pseudorange observation amount between the first device and the second device at a preset time point after the system time is synchronized; the clock difference unit is further configured to determine a precise clock difference between the first device and the second device based on the synchronous two-way code pseudorange observation amount; and the adjustment unit is further configured to adjust at least one of the frequency and phase of a clock source of the first device or the second device based on the precise clock difference.

[0007] In one embodiment of the present application, the time synchronization system also includes: an integrated receiving unit, which is arranged in the first device and the second device, wherein the integrated receiving unit is arranged in the first device and the second device, wherein the integrated receiving unit outputs second pulses to the inside and outside of the system based on the synchronized system time.

[0008] In one embodiment of the present application, the integrated receiving unit includes a time-division multiplexing transceiver integrated antenna structure, which realizes signal reception and transmission on the same frequency carrier through different time slots.

[0009] In one embodiment of the present application, the time-division multiplexing transceiver antenna includes: an antenna; a power amplifier connected to the antenna and amplifying the signal to be sent; a detector, which turns on the power amplifier in response to detecting the signal to be sent; and a low-noise amplifier connected to the antenna, amplifying the received signal and always keeping it in working state.

[0010] In one embodiment of the present application, the integrated receiving unit is further configured to: continuously generate a baseband signal in a silent state, wherein the silent state is a state in which no signal is transmitted.

[0011] In one embodiment of the present application, the system also includes a calibration unit for determining hardware delay, wherein the calibration unit is configured to determine an average value of misalignment of the second pulse within a predetermined time period after adjusting at least one of the frequency and phase of the clock source; and the adjustment unit is further configured to adjust the system time based on the hardware delay, wherein the hardware delay is the average value of the misalignment.

[0012] In one embodiment of the present application, the observation unit is further configured to: determine a first code pseudorange observation value obtained by the first device receiving a signal from the second device, and determine a second code pseudorange observation value obtained by the second device receiving a signal from the first device, wherein the asynchronous two-way code pseudorange observation value includes the first code pseudorange observation value and the second code pseudorange observation value; and the first device receiving the signal from the second device and the second device receiving the signal from the first device both include time hopping-direct sequence spread spectrum signals.

[0013] In one embodiment of the present application, the coarse clock error is proportional to the difference between the first code pseudorange observation value and the second code pseudorange observation value.

[0014] On the other hand, the present application provides a time synchronization method, which includes: determining an asynchronous two-way code pseudorange observation amount between a first device and a second device; determining a rough clock difference between the first device and the second device based on the asynchronous two-way code pseudorange observation amount; and adjusting the system time of the first device or the second device based on the rough clock difference to synchronize the system time of the first device and the second device; after the system time is synchronized, determining a synchronous two-way code pseudorange observation amount between the first device and the second device at a preset time point; determining a precise clock difference between the first device and the second device based on the synchronous two-way code pseudorange observation amount; and adjusting at least one of the frequency and phase of a clock source of the first device or the second device based on the precise clock difference.

[0015] In one embodiment of the present application, the time synchronization method further includes: utilizing time division multiplexing transceiver technology to realize signal reception and transmission through different time slots on the same frequency carrier.

[0016] In one embodiment of the present application, the time synchronization method further includes: continuously generating a baseband signal in a silent state, wherein the silent state is a state in which no signal is transmitted.

[0017] In one embodiment of the present application, the time synchronization method also includes: after adjusting at least one of the frequency and phase of the clock source, determining the average value of the misalignment amount of the second pulse within a predetermined time period; and adjusting the system time based on hardware delay, wherein the hardware delay is the average value of the misalignment amount.

[0018] In one embodiment of the present application, determining an asynchronous two-way code pseudorange observation amount between a first device and a second device includes: determining a first code pseudorange observation amount obtained by the first device receiving a signal from the second device, and determining a second code pseudorange observation amount obtained by the second device receiving a signal from the first device, wherein the asynchronous two-way code pseudorange observation amount includes the first code pseudorange observation amount and the second code pseudorange observation amount; the first device receiving the signal from the second device and the second device receiving the signal from the first device both include time hopping-direct sequence spread spectrum signals.

[0019] In one embodiment of the present application, the coarse clock error is proportional to the difference between the first code pseudorange observation value and the second code pseudorange observation value.

[0020] On the other hand, the present application provides an electronic device, which includes: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor can execute the time synchronization method provided by any embodiment of the other aspect of the present application.

[0021] On the other hand, the present application provides a computer-readable storage medium storing a computer program. When the computer program is executed by a processor, the time synchronization method provided in any embodiment of the present application is implemented.

[0022] On the other hand, the present application provides a computer program product, which stores a computer program. When the computer program is executed by a processor, it implements the time synchronization method provided in any implementation method of another aspect of the present application.

[0023] According to the time synchronization method and system, electronic device, computer-readable storage medium and computer program product provided by at least one embodiment of the present application, the observation unit can determine the two-way code pseudorange observation amount between different devices, the clock difference unit can determine the clock difference between the devices based on the two-way code pseudorange observation amount, and the adjustment unit can adjust the system time of the device based on the clock difference, thereby achieving "coarse synchronization" between the time of different devices in a dynamic scene. Furthermore, after coarse synchronization, the observation unit can re-determine the two-way code pseudorange observation amount between the above-mentioned devices at a preset time point, the clock difference unit can re-determine the clock difference between the devices based on the re-determined two-way code pseudorange observation amount, and the adjustment unit can adjust the clock source of the above-mentioned device based on the re-determined clock difference, thereby achieving "fine synchronization" between the time of different devices in a dynamic scene. Among them, coarse synchronization lays the foundation for simultaneous two-way observation, and simultaneous two-way observation can eliminate most errors and achieve high-precision time synchronization. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Other features, objects and advantages of the present application will become more apparent by reading the detailed description of non-limiting embodiments made with reference to the following drawings, in which:

[0025] Figure 1 is a structural diagram of a time synchronization system according to an embodiment of the present application;

[0026] Figure 2 This is an application scenario diagram of time synchronization according to an implementation mode of the present application;

[0027] Figure 3A is a schematic diagram of signals received and sent by a first device and a second device to a fifth device respectively according to an embodiment of the present application;

[0028] Figure 3B is a schematic diagram of a process of achieving system time synchronization between a first device and a second device according to an implementation mode of the present application;

[0029] Figure 4 is a structural schematic diagram of a receiving integrated unit according to an embodiment of the present application;

[0030] Figure 5 It is a structural schematic diagram of a time division multiplexing transceiver integrated antenna structure according to an embodiment of the present application;

[0031] Figure 6 is a structural diagram of a time synchronization system according to an embodiment of the present application;

[0032] Figure 7 is a schematic diagram of an experimental scenario of a time synchronization system according to an embodiment of the present application;

[0033] Figure 8 yes Figure 7 Comparison chart of the results of the experimental scenario;

[0034] Fig. 9 is a schematic diagram of an experimental scenario of a time synchronization system according to an embodiment of the present application;

[0035] Fig.10 yes Fig. 9 Comparison chart of the results of the experimental scenario;

[0036] Fig.11 is a schematic diagram of an experimental scenario of a time synchronization system according to an embodiment of the present application;

[0037] Fig.12 yes Fig.11 Comparison chart of the results of the experimental scenario;

[0038] Fig.13 is a schematic diagram of steps of a time synchronization method according to an embodiment of the present application; and

[0039] Fig.14 It is a structural diagram of a computer system suitable for implementing the electronic device of the embodiment of the present application. DETAILED DESCRIPTION

[0040] In order to better understand the present application, a more detailed description will be made of various aspects of the present application with reference to the accompanying drawings. It should be understood that these detailed descriptions are only descriptions of exemplary embodiments of the present application, and are not intended to limit the scope of the present application in any way. Throughout the specification, the same reference numerals refer to the same elements. The expression "and / or" includes any and all combinations of one or more of the associated listed items.

[0041] It should be noted that in this specification, the expressions first, second, third, etc. are only used to distinguish one feature from another feature area, and do not represent any limitation on the features, especially do not represent any order of precedence. Therefore, without departing from the teaching of this application, the first device discussed in this application may also be referred to as the second device, and vice versa.

[0042] In the drawings, the thickness, size and shape of the components have been slightly adjusted for ease of illustration. The drawings are for illustration only and are not drawn strictly to scale. As used herein, the terms "substantially," "approximately," and similar terms are used as terms of approximation, not as terms of degree, and are intended to account for the inherent deviations in measurements or calculations that would be recognized by one of ordinary skill in the art.

[0043] It should also be understood that expressions such as "include", "including", "have", "contain" and / or "comprising" are open rather than closed expressions in this specification, which indicate the presence of the stated features, elements and / or components, but do not exclude the presence of one or more other features, elements, components and / or combinations thereof. In addition, when expressions such as "at least one of..." appear after a list of listed features, they modify the entire list of features rather than just the individual elements in the list. In addition, when describing embodiments of the present application, "may" is used to mean "one or more embodiments of the present application". And, the term "exemplary" is intended to refer to an example or illustration.

[0044] Unless otherwise specified, all words (including engineering terms and scientific and technological terms) used in this article have the same meaning as those commonly understood by ordinary technicians in the field to which this application belongs. It should also be understood that, unless clearly stated in this application, words defined in common dictionaries should be interpreted as having the same meaning as their meaning in the context of the relevant technology, and should not be interpreted in an idealized or overly formal sense.

[0045] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. In addition, unless explicitly limited or contradictory to the context, the specific steps included in the method described in the present application are not necessarily limited to the order described, but can be performed in any order or in parallel. The present application will be described in detail below with reference to the accompanying drawings and in conjunction with the embodiments.

[0046] In addition, in the present application, when “connected” or “coupled” is used, it may indicate direct contact or indirect contact between corresponding components, unless otherwise clearly defined or inferred from the context.

[0047] Figure 1 FIG. 1 is a schematic diagram of the structure of a time synchronization system 1000 according to an embodiment of the present application. Figure 1As shown, the present application provides a time synchronization method system 1000, which includes: an observation unit 1100, a clock difference unit 1200 and an adjustment unit 1300. The observation unit 1100 can determine the asynchronous two-way code pseudorange observation amount between the first device and the second device. The clock difference unit 1200 can determine the rough clock difference between the first device and the second device based on the asynchronous two-way code pseudorange observation amount. The adjustment unit 1300 can adjust the system time of the first device or the second device based on the rough clock difference to synchronize the system time of the first device and the second device. In addition, the observation unit 1100 can determine the synchronous two-way code pseudorange observation amount between the first device and the second device at a preset time point after the system time is synchronized. The clock difference unit 1200 can determine the precise clock difference between the first device and the second device based on the synchronous two-way code pseudorange observation amount. The adjustment unit 1300 can adjust at least one of the frequency and phase of the clock source of the first device or the second device based on the precise clock difference.

[0048] The asynchronous two-way code pseudorange observation amount can be understood as the two-way code pseudorange observation amount determined when the observation time of the first device and the second device is not synchronized before the time synchronization. The synchronous two-way code pseudorange observation amount can be understood as the two-way code pseudorange observation amount determined when the observation time is synchronized after the first device and the second device are roughly synchronized in time and the system time of the two devices are synchronized. In addition, this content will be described in detail below.

[0049] According to at least one embodiment of the present application, a time synchronization system is provided, which includes an observation unit, a clock difference unit and an adjustment unit. The observation unit can determine the two-way code pseudorange observation amount between different devices. The clock difference unit can determine the clock difference between the devices based on the two-way code pseudorange observation amount. The adjustment unit can adjust the system time of the device based on the clock difference, thereby achieving "coarse synchronization" between the times of different devices in dynamic scenes. Furthermore, after coarse synchronization, the observation unit can re-determine the two-way code pseudorange observation amount between the above-mentioned devices at a preset time point. The clock difference unit can re-determine the clock difference between the devices based on the re-determined two-way code pseudorange observation amount. The adjustment unit can adjust the clock source of the above-mentioned device based on the re-determined clock difference, thereby achieving "fine synchronization" between the times of different devices in dynamic scenes. Among them, coarse synchronization lays the foundation for simultaneous two-way observation, and simultaneous two-way observation can eliminate most errors and achieve high-precision time synchronization.

[0050] Figure 2 This is an application scenario diagram of time synchronization according to an implementation of the present application. Figure 3A It is a schematic diagram of signals received and sent by a first device 101 to a second device 102 , a third device 103 , a fourth device and a fifth device 105 according to one embodiment of the present application. Figure 3BIt is a schematic diagram of a process of achieving system time synchronization between a first device 101 and a second device 102 according to an embodiment of the present application.

[0051] Specifically, Figure 2 As shown, the dynamic application scenario applicable to the time synchronization method system 1000 may include multiple devices, such as a first device 101, a second device 102, a third device 103, a fourth device (not shown), and a fifth device 105, etc., and the multiple devices can receive and send signals to each other. Figure 2 The first device 101 is shown to receive and send signals to the second device 102, the third device 103, the fourth device, and the fifth device 105, respectively. Multiple devices are constantly moving, and the geometric distance between each other is constantly changing. In complex scenarios, it is difficult to obtain the accurate coordinates and speeds of each device in real time. In addition, when multiple devices are far apart from each other, the atmospheric delay between the transceiver antennas of multiple devices is difficult to accurately estimate using a model. In dynamic application scenarios, multiple devices can be connected using wireless signals. Compared with wired signal connection, wireless signal connection is free from the limitations of cables and is more flexible and convenient to use. However, in the case of wireless signal connection, the channel environment between multiple devices is complex, and multipath error is one of the important factors affecting the time synchronization accuracy of multiple devices. In dynamic application scenarios, multipath error is a constantly changing quantity and is difficult to handle in a modeling manner. In addition, when multiple devices are moving, the signal angles of the devices entering and exiting the antenna are constantly changing, resulting in changes in the antenna group delay. Although the antenna group delay changes in the decimeter order, its order of magnitude is smaller than the multipath error. However, in sub-nanosecond high-precision time synchronization, the antenna group delay variation error is also one of the important factors affecting the time synchronization accuracy of multiple devices.

[0052] refer to Figure 1-Figure 3B, taking the first device 101 receiving and sending signals with the second device 102, the third device 103, the fourth device and the fifth device 105 as an example, the second device 102, the third device 103, the fourth device and the fifth device 105 can perform two-way observation with the first device 101. For example, in the signal sent by the first device 101, the interval between the signal pulses can be pseudo-random. The first device 101 can receive signals from itself and other devices, and the signals sent by multiple devices are distinguished by color blocks of different grayscales. It should be noted that any one of the first device 101 to the fifth device 105 can be any one of the multiple devices connected by wireless signals in a dynamic application scenario, and this application does not limit this. Optionally, multiple devices connected by wireless signals in a dynamic application scenario can have an observation unit 1100, a clock difference unit 1200 and an adjustment unit 1300, or some of the multiple devices connected by wireless signals in a dynamic application scenario have an observation unit 1100, a clock difference unit 1200 and an adjustment unit 1300, but this application does not limit this. Taking the first device 101 and the second device 102 as an example, when the devices are just started, the device clocks run independently and the time systems of the two are not synchronized. In the absence of an external reference, there may be a second-level difference in the observation extraction time between the devices. In this case, the asynchronous two-way code pseudorange observation between the first device 101 and the second device 102 can be obtained.

[0053] In order to achieve simultaneous extraction of observations between devices, it is first necessary to synchronize the system time of each device, or to perform coarse synchronization of the time of different devices. Then, based on the coarse synchronization, fine synchronization of the time of different devices can be achieved. Figure 3B The process of implementing time synchronization between the first device 101 and the second device 102 is shown, wherein Clock1 and Clock2 are clocks of the first device 101 and the second device 102 respectively.

[0054] Figure 3B .a indicates the initial stage without time synchronization, combined with Figure 1 , Figure 2 and Figure 3B .a, the observation unit 1100 may determine an asynchronous two-way code pseudorange observation amount between the first device 101 and the second device 102. The clock difference unit 1200 may determine a coarse clock difference δt between the first device 101 and the second device 102 based on the asynchronous two-way code pseudorange observation amount.

[0055] For example, the first device 101 receives a signal sent by the second device 102 at time T1′ at time T2, and the signal propagation takes τ; the second device 102 receives a signal sent by the first device 101 at time T1 at time T2′, and the signal propagation takes τ′, where the rough clock difference between the first device 101 and the second device 102 is δt. This can be expressed as formula (1):

[0056]

[0057] Since the first device 101 and the second device 102 are both in motion and the observed quantity extraction time is different, the two-way propagation delay is different. In other words, τ≠τ′. However, considering that the signal propagates at the speed of light, the signal propagation time is very short, and the geometric distance difference caused by movement in such a short time is not large. In other words, |τ-τ′|<<δt. Therefore, when estimating the rough clock error δt, τ≈τ′ can be set. According to formula (1), the rough clock error δt can be determined as:

[0058]

[0059] in, is a first code pseudorange observation value obtained by the first device 101 receiving a signal from the second device 102; is the second code pseudorange observation value obtained by the second device 102 receiving the signal of the first device 101; c is the speed of light.

[0060] Therefore, the coarse clock error δt can be combined with the first code pseudorange observation The second code pseudo-range observation is proportional to the difference between them.

[0061] Optionally, in order to avoid the near-far effect, the signal received by the first device 101 from the second device 102 and the signal received by the second device 102 from the first device 101 may both include a time-hopping Direct Sequence Spread Spectrum (TH-DSSS) signal.

[0062] Combination Figure 1 , Figure 2 and Figure 3B .b, the adjustment unit 1300 can adjust the system time of the first device or the second device based on the rough clock difference, so that the system time of the first device and the second device are synchronized, or in other words, the rough synchronization of the time of the two devices is achieved. For example, the system time of the second device 102 can be gradually adjusted and modified to be close to the system time of the first device 101. The system time synchronization of the two devices can be achieved by iterating once. Optionally, the system time can be understood as the receiving unit time or the transmitting unit time.

[0063] Therefore, after the system time of the first device 101 and the second device 102 are synchronized, the two-way code pseudorange observations obtained are synchronized two-way code pseudorange observations. The two-way propagation delays of synchronized two-way code pseudoranges are substantially the same, and thus can be offset in the process of determining the precise clock error.

[0064] Combination Figure 1 , Figure 2 , Figure 3B .b and Figure 3B .c. On the basis of coarse synchronization, precise synchronization of the time of different devices can be achieved, thereby eliminating various delays and errors between the time of different devices in dynamic scenes and achieving high-precision time synchronization.

[0065] Specifically, the observation unit 1100 may repeat the above process at a preset time point after the system time is synchronized to determine the synchronous two-way code pseudorange observation amount between the first device 101 and the second device 102. The clock difference unit 1200 may adopt a similar method as described above to determine the precise clock difference between the first device 101 and the second device 102 based on the synchronous two-way code pseudorange observation amount. The adjustment unit 1300 may adjust at least one of the frequency and phase of the clock source of the first device 101 or the second device 102 based on the precise clock difference. As an option, an error of less than 1 microsecond (us) is used as the decision threshold, and the device enters a normal working state (such as Figure 3B .c), in other words, it achieves fine synchronization of time between different devices.

[0066] Optionally, the pre-set time point may be an integer time point shown by the device after the system time synchronization of different devices is achieved, for example, an integer of 100 milliseconds, an integer of a second, or an integer of a minute. In addition, the clock source may include a crystal oscillator or an atomic clock.

[0067] In addition, in order to avoid the near-far effect, in the process of synchronizing the two-way code pseudorange observation amount, the signal received by the first device 101 from the second device 102 and the signal received by the second device 102 from the first device 101 can both include a time hopping-direct sequence spread spectrum signal. In addition, the precise clock error can be proportional to the difference between the two-way code pseudorange observation amounts.

[0068] Optionally, considering that the geometric distance delay difference may cause some signal collisions, a protection timing may be set at the end of the signals sent by multiple devices. For example, a protection timing may be set at the end of a signal sent by the second device 102 and received by the first device 101, and a signal sent by the first device 102 and received by the second device 102. Optionally, the protection timing may be equal to the time each device sends a signal or be a part of the time the signal is sent, for example, the protection timing may be 0.2 milliseconds (ms).

[0069] In addition, multiple devices may include a silent state and a signal transmission state, wherein the silent state may be understood as a non-signal transmission state. The signal transmission state is only a portion of the time, and the device is in a non-signal transmission state for most of the rest of the time. When the device remains in the silent state, the receiving unit of the device or the receiving integrated unit described below can continuously generate a baseband signal to ensure the coherence of the signal.

[0070] Taking the use of UWB (Ultra-wideband) signals for two-way ranging to achieve sub-nanosecond time synchronization as an example, the transmission distance of UWB signals is only in the hundreds of meters, and can only be used in a small range. In addition, in the process of using UWB signals for two-way ranging to achieve time synchronization, some devices need to send a request first, and the corresponding device then returns a response, so the receiving signal and the sending signal are asynchronous, so the UWB node is required to remain stationary to ensure that the round-trip distance is as equal as possible.

[0071] Unlike UWB, which only captures and extracts observations when the signal is valid, in some embodiments of the present application, when the device remains in a silent state, the receiving unit or the receiving integrated unit of the device can continuously generate baseband signals to ensure the coherence of the signal. Using the coherence characteristics of the signal, the receiving unit or the receiving integrated unit can extract observations at any time.

[0072] Figure 4 It is a structural schematic diagram of a receiving integrated unit 2400 according to an embodiment of the present application.

[0073] like Figure 4 As shown, in some embodiments of the present application, in order to optimize the high-precision time synchronization result and further solve the above technical problems, the time synchronization method system 1000 may also include an integrated receiving unit 2400. The integrated receiving unit 2400 may be set in multiple devices connected to each other via wireless signals. Figure 2 , Figure 3B .c and Figure 4 As shown, taking the first device 101 and the second device 102 as examples, the integrated receiving unit 2400 can be respectively arranged in the first device 101 and the second device 102, and the integrated receiving unit 2400 can output pulse-per-second (PPS) to the system and the outside of the system based on the synchronized system time. Optionally, the system time can be understood as the time when the integrated receiving unit 2400 sends a signal and the time when the integrated receiving unit 2400 receives a signal. In other words, after the device enters the normal working state, the system time of the device can no longer be adjusted and modified, but the crystal oscillator frequency can be adjusted to enter the precise synchronization and keep the time synchronization of each device.

[0074] Specifically, the integrated receiving unit 2400 may include a time unit 2401, a sending unit 2402, and a receiving unit 2403. The time unit 2401 may output a PPS to the outside every second, and the PPS is also transmitted to the receiving unit 2403 to trigger the extraction of the observed quantity. The receiving unit 2403 may adjust the frequency of the clock source of the device according to the precise clock difference between the device (e.g., the second device 102) and the reference device (e.g., the first device 101) to achieve time synchronization between the device and the reference device.

[0075] In addition, in some embodiments, the integrated receiving unit 2400 may also include a time-division multiplexing integrated transceiver antenna structure 2404. The time-division multiplexing integrated transceiver antenna structure 2404 can receive and send signals on the same frequency carrier through different time slots.

[0076] In dynamic application scenarios, the geometric distances of the two one-way measurements are likely to be inconsistent, so distance delay correction is required based on the geometric relationship of the antennas. In addition, due to differences in antenna manufacturing, the group delay changes of the receiving and transmitting antennas may be different, and the angle at which the signal enters the receiving antenna is inconsistent with the angle at which the signal leaves the transmitting antenna, which leads to inconsistent group delays of the receiving and transmitting antennas, and the antenna group delay difference cannot be eliminated through bidirectional differentials. In addition, the propagation paths of the signals measured in the two one-way measurements are inconsistent, which may lead to inconsistent multipath errors, and multipath errors cannot be eliminated through bidirectional differentials.

[0077] Figure 5 It is a structural diagram of a time-division multiplexing transceiver integrated antenna structure 2404 according to an embodiment of the present application.

[0078] like Figure 4 and Figure 5 As shown, in order to solve these technical problems, in some implementations, a time division multiplexing transceiver integrated antenna structure 2404 can be used to realize signal reception and transmission.

[0079] Specifically, the time-division multiplexing transceiver integrated antenna structure 2404 can perform different functions at different time intervals. The time-division multiplexing transceiver integrated antenna structure 2404 may include a power amplifier 201, an antenna 202, a low noise amplifier 203, and a detector (not shown). The power amplifier 201 is connected to the antenna 202 and amplifies the signal to be sent. The low noise amplifier 203 is also connected to the antenna 202 and amplifies the received signal. In addition, the low noise amplifier 203 can always remain in an operating state, and the power amplifier 201 can be turned on by the detector. In other words, the detector can turn on the power amplifier 201 in response to detecting the signal to be sent.

[0080] In the signal transmission state, after the signal is detected, the power amplifier 201 can be enabled to amplify the signal and send it out through the antenna 202. After the transmission is completed, the power amplifier is disabled and the device enters the silent state. At this time, the antenna 202 is converted to the receiving state. Since the low noise amplifier 203 always keeps the working state, the signal received by the antenna 202 can be amplified by the low noise amplifier 203 and then received and processed.

[0081] refer to Figure 3A and Figure 5 , we can find from the signal format that the time slice for sending and receiving is only 0.2 milliseconds. It is precisely because of such a short switching time that the signal is sent and received at the same time from a larger time scale. This pair of simultaneously extracted observations can be regarded as approximately symmetrical, which can further eliminate the delays and errors mentioned above.

[0082] Figure 6 It is a structural diagram of a time synchronization system 1000 according to an embodiment of the present application.

[0083] like Figure 6 As shown, in some embodiments of the present application, the time synchronization system 1000 further includes a calibration unit 1400 for determining hardware delay. The calibration unit 1400 may determine an average value of the misalignment amount of the PPS within a predetermined time period after adjusting at least one of the frequency and phase of the clock source. The adjustment unit 1300 may adjust the system time based on the hardware delay, wherein the hardware delay is the above-mentioned average value of the misalignment amount.

[0084] Specifically, due to imperfect manufacturing, the hardware of each device has certain differences, resulting in inconsistent hardware delays. In order to achieve synchronous PPS output of multiple devices, the hardware delay differences can be corrected.

[0085] Hardware delays may include hardware delays of the sending unit and the receiving unit, such as antennas, cables, electronic units, etc. These delays can be measured in advance and deducted. As an option, it is not necessary to accurately measure the delay of each hardware, and the above hardware delays can be measured as a whole. In addition, ignoring the effects of temperature and aging, hardware delays do not change with system restarts, so hardware delays are usually stable, so they can be calibrated in advance and written into the device parameters for the next time synchronization.

[0086] In other words, the system time synchronization (coarse time synchronization) can be performed first, and then the fine time synchronization can be completed. After that, the PPS misalignment amount is statistically recorded within a predetermined time, and the average value of the PPS misalignment amount within the predetermined time period is determined. By writing the average value of the PPS misalignment amount within the predetermined time period into, for example, a configuration file, the error caused by inconsistent hardware delays is eliminated, and PPS alignment is achieved.

[0087] For example, during time synchronization, after using asynchronous two-way code pseudorange observations and synchronous two-way code pseudorange observations to determine a portion of the time difference, the above steps are used to determine another portion of the hardware delay difference to achieve PPS alignment.

[0088] The code pseudorange and carrier phase observation equations can be expressed using formula (3):

[0089]

[0090] Among them, the subscript i represents the receiving device, and the superscript j represents the transmitting device; and Respectively represent the code pseudorange and carrier phase observation, in meters; is the geometric distance from the receiving device to the transmitting device, where the receiving device and the transmitting device can be any two of the multiple devices in the dynamic scene; c is the speed of light; δt i and δt j are the clock differences of the receiving device and the transmitting device respectively; τ i and τ j are the hardware delays of the receiving device and the transmitting device respectively; b i and b j are the phase deviations of the receiving device and the transmitting device respectively; λ is the carrier wavelength; N is the carrier phase ambiguity; GDV i and GDV j PCV is the delay variation of the antenna of the receiving device and the antenna group of the transmitting device respectively; i and PCV j are the phase center changes of the receiving antenna and the transmitting antenna respectively; and are the multipath errors of code pseudorange and carrier phase respectively; and are the observation noise of code pseudorange and carrier phase respectively.

[0091] Optionally, the hardware delay can be calibrated in a static and short distance scenario, so that the round-trip distance is completely consistent and the signal-to-noise ratio is high. The shortest distance between devices during hardware delay calibration can be tens of meters. After the PPS of the two devices are connected to the same frequency meter, the two-way code pseudo-range differential method can be used for time synchronization, which is expressed as formula (4):

[0092]

[0093] Among them, τ j and τ j Respectively represent the hardware delay of the receiving unit and sending unit of the device.

[0094] The clock difference between the receiving unit and the sending unit of the same device is equal. In other words, δt j ≡δt j ,δt i ≡δt i In addition, since the device remains stationary and the distance is short, the geometric distance can be completely offset; and the antenna group delay and multipath error can be eliminated by two-way differential code pseudorange observation, so formula (4) can be simplified to:

[0095]

[0096] After adjusting the frequency of the device's clock source, Therefore, after ignoring the noise, it can be simplified to:

[0097] (τ j -τ i )-(τ i -τ j )+2c(δt j -δt i )=0 (6)

[0098] (τ j -τ i )-(τ i -τ j )=-2c(δt j -δt i ) (7)

[0099] Due to the difference in hardware delay, (τ j -τ i )-(τ i -τ j ) is not zero. Therefore, 2c(δt j -δt i ) is also not zero. In addition, as described above, the hardware delay does not change with system restart, so the hardware delay is usually stable. The difference in hardware delay is a constant, and the pulse misalignment observed from the frequency meter is caused by the inconsistent hardware delay. In other words, the hardware delay is the average misalignment of the PPS in a predetermined time period.

[0100] PPS offset =(τ j -τ i )-(τ i -τ j )≠0 (8)

[0101] Among them, PPS offset is the average value of the misalignment of PPS within a predetermined time period.

[0102] After deducting the average value of the non-alignment amount of the PPS within a predetermined time period, the objective function can be set to zero to achieve PPS alignment.

[0103]

[0104] 2c(δt j -δt i )=0 (10)

[0105] Therefore, according to at least one embodiment of the present application, the time synchronization system includes an observation unit, a clock difference unit and an adjustment unit. The observation unit can determine the two-way code pseudorange observation amount between different devices. The clock difference unit can determine the clock difference between the devices based on the two-way code pseudorange observation amount. The adjustment unit can adjust the system time of the device based on the clock difference to achieve "coarse synchronization" between the times of different devices in dynamic scenes. Further, after coarse synchronization, the observation unit can determine the two-way code pseudorange observation amount between the above-mentioned devices again at a preset time point. The clock difference unit can determine the clock difference between the devices again based on the re-determined two-way code pseudorange observation amount. The adjustment unit can adjust the clock source of the above-mentioned device based on the re-determined clock difference, thereby achieving "fine synchronization" between the times of different devices in dynamic scenes. This eliminates various delays and errors between the times of different devices in dynamic scenes and achieves high-precision time synchronization.

[0106] In some embodiments of the present application, the effect of eliminating antenna group delay variation and multipath error can be determined by code-subtraction carrier observation. In other words, the effect of time synchronization system 1000 and the time synchronization method described below can be determined by code-subtraction carrier observation.

[0107] Specifically, the code minus carrier observation (Code Minus Carrier, CMC) is the differential observation obtained by subtracting the carrier phase observation from the code pseudorange observation. CMC can be expressed by formula (11):

[0108]

[0109] Refer to formula (11), B i -B j -λ(N+b i -b j ) can be regarded as a constant when no cycle slip occurs. The changes are small, on the millimeter level. The variation is large, ranging from meters to tens of meters. It is the main error term of CMC. The fluctuation of CMC can reflect the fluctuation of code pseudorange error, among which GDV i and GDV jIt is mainly affected by the signal entry and exit angle, and its magnitude is in the decimeter level. This error can be ignored because it is smaller than the multipath error and it is difficult to separate them. The magnitude of can reach meters or even tens of meters, which is the main factor affecting the accuracy of code pseudorange and is difficult to be modeled and eliminated. It is about centimeter to decimeter level and is mainly affected by the signal-to-noise ratio.

[0110] In addition, the antenna group delay changes with the signal entry and exit angles, and acts on the code pseudorange. The change in CMC fluctuations can be used to reflect the change in antenna group delay. Antenna group delay can be modeled as a function of the azimuth angle and the zenith angle. During the movement, the angle of the signal entering and exiting the antenna changes with the carrier's attitude, resulting in changes in group delay. Antenna group delay changes can reach decimeters or even meters, which is equivalent to several nanoseconds in time. Therefore, antenna group delay changes are an important error source that affects high-precision time synchronization.

[0111] Figure 7 It is a schematic diagram of an experimental scenario of a time synchronization system 1000 according to an embodiment of the present application. Figure 8 yes Figure 7 Comparison chart of results for the experimental scenarios. Fig. 9 It is a schematic diagram of an experimental scenario of a time synchronization system 1000 according to an embodiment of the present application. Fig.10 yes Fig. 9 Comparison chart of results for the experimental scenarios. Fig.11 It is a schematic diagram of an experimental scenario of a time synchronization system 1000 according to an embodiment of the present application. Fig.12 yes Fig.11 Comparison chart of results for the experimental scenarios.

[0112] exist Figure 7 In the experimental scenario shown, the antennas of the two devices (first device 1 and second device 2) remain stationary throughout the process. During the 86th to 176th seconds, the antenna is walked around the antenna with a reflector to artificially introduce multipath, and the antenna remains stationary at other times. Figure 8 are the corresponding CMC observations and two-way code pseudorange differential observations. "CMC (1->2)" means that the second device 2 receives the CMC observations of the first device 1, and "CMC (2->1)" means that the first device 1 receives the CMC observations of the second device 2. In the scenario where multipath is not artificially introduced, the CMC observations have no obvious fluctuations except for the observation noise. In the scenario where multipath is artificially introduced, the CMC observations have a fluctuation of about 0.5m (e.g. Figure 8 In addition, the two-way code pseudorange differential observations do not fluctuate significantly when multipath is artificially introduced (e.g. Figure 8.c), which shows that bidirectional differential can eliminate multipath errors, so that the time synchronization process is not affected by multipath errors.

[0113] exist Fig. 9 In the experimental scenario shown, the antenna of the first device 1 is mounted on a stationary tripod, and the antenna of the second device 2 is mounted on a mechanical arm (eg, Fig. 9 ). During the 160-250s period, the robot arm is used to rotate the antenna of the second device 2 clockwise for one circle in place, and the position is ensured to be almost unchanged, which can be considered that the multipath error is almost unchanged. During the 310-400s period, the robot arm is used to rotate the antenna of the second device 2 counterclockwise for one circle in place, and the antenna is restored to its original state. The antenna remains stationary in other time periods. Fig.10 is the corresponding CMC observation and two-way code pseudorange differential observation. Fig.10 As shown in Figure .a, when the antenna is stationary, CMC (1—>2) has no obvious fluctuation except for the observation noise. When the antenna rotates clockwise and counterclockwise, there is a fluctuation of about 0.5m. This is mainly because when the antenna rotates, the incident angle of the signal changes, which causes the antenna group delay to change, thus affecting the code pseudorange observation. Fig.10 As shown in .b, “CMC(2—>1)” and “CMC(1—>2)” have similar performance. Fig.10 .c shows the two-way code pseudorange differential observation between the first device 1 and the second device 2. The two-way differential observation has no obvious fluctuation when the antenna rotates, indicating that the two-way differential can eliminate the delay variation of the antenna group.

[0114] exist Fig.11 In the experimental scenario shown, the first device 1 and the fourth device 4 are the starting device and the ending device, respectively outputting PPS to the frequency meter to verify the time synchronization accuracy. The second device 2 and the third device 3 are transfer devices that transmit time information. In other words, the time information is transmitted from the first device 1 to the fourth device 4 through the second device 2 and the third device 3. Fig.12 The PPS deviation output by the first device 1 and the fourth device 4 is shown, and its accuracy can reach 0.157ns, indicating that the time synchronization accuracy of the system has reached the sub-nanosecond level, achieving high-precision time synchronization in dynamic scenes.

[0115] Fig.13 It is a schematic diagram of the steps of a time synchronization method according to an embodiment of the present application.

[0116] like Fig.13 As shown, some embodiments of the present application further provide a time synchronization method 2000, and the time synchronization method 2000 includes:

[0117] S1, determine an asynchronous two-way code pseudorange observation amount between a first device and a second device.

[0118] S2, determining a coarse clock difference between the first device and the second device based on the asynchronous two-way code pseudorange observation.

[0119] S3: Based on the rough clock difference, adjust the system time of the first device or the second device to synchronize the system time of the first device with the system time of the second device.

[0120] S4, after the system time is synchronized, at a preset time point, determining a synchronous two-way code pseudorange observation value between the first device and the second device.

[0121] S5, determining a precise clock difference between the first device and the second device based on the synchronous two-way code pseudorange observation.

[0122] S6. Adjust at least one of the frequency and phase of a clock source of the first device or the second device based on the precise clock difference.

[0123] The specific steps of the above-mentioned time synchronization method 2000 will be described in detail below.

[0124] refer to Figure 4 and Fig.13 In some embodiments of the present application, the clock source may include a crystal oscillator or an atomic clock.

[0125] In addition, if Figure 5 and Fig.13 As shown, time division multiplexing transceiver technology can be used to receive and send signals through different time slots on the same frequency carrier. For example, the time division multiplexing transceiver integrated antenna structure 2404 is used to receive and send signals, where the time division multiplexing transceiver integrated antenna structure 2404 can perform different functions in different time intervals.

[0126] In addition, refer to Figure 3A and Fig.13 , multiple devices may include a silent state and a signal transmission state, wherein the silent state can be understood as a non-signal transmission state. The signal transmission state is only a part of the time, and the device is in a non-signal transmission state for most of the rest of the time. When the device remains in the silent state, the receiving unit or the receiving integrated unit of the device can continuously generate a baseband signal to ensure the coherence of the signal. Using the coherence characteristics of the signal, the receiving unit or the receiving integrated unit can extract the observed value at any time.

[0127] Optionally, in some embodiments, after adjusting at least one of the frequency and phase of the clock source, an average misalignment value of the second pulse within a predetermined time period can be determined, and the system time can be adjusted based on the hardware delay, where the hardware delay is the average misalignment value.

[0128] Due to imperfect manufacturing, the hardware of each device has certain differences, resulting in inconsistent hardware delays. In order to achieve synchronous PPS output of multiple devices, the hardware delay differences can be corrected.

[0129] After the precise time synchronization is completed, the PPS misalignment amount can be statistically recorded within the predetermined time, and the average value of the PPS misalignment amount within the predetermined time period can be determined. Afterwards, the average value of the PPS misalignment amount within the predetermined time period is written into, for example, a configuration file. During the time synchronization process, after determining a part of the minute difference using the asynchronous two-way code pseudorange observation amount and the synchronous two-way code pseudorange observation amount, the above steps are used to determine the difference of the other part of the hardware delay to achieve PPS alignment.

[0130] In addition, in order to avoid the near-far effect, step S1 of determining the asynchronous two-way code pseudorange observation value between the first device and the second device may include: determining, through two one-way measurements, a first code pseudorange observation value obtained by the first device receiving a signal from the second device, and determining a second code pseudorange observation value obtained by the second device receiving a signal from the first device, wherein the signal received by the first device from the second device and the signal received by the second device from the first device may both include time hopping-direct sequence spread spectrum signals.

[0131] In addition, in step S4, after system time synchronization, at a preset time point, in the process of determining the synchronous two-way code pseudorange observation value between the first device and the second device, the first device receiving the signal of the second device and the second device receiving the signal of the first device may also include a time hopping-direct sequence spread spectrum signal.

[0132] Optionally, the preset time point may be an integer time point displayed by the device after system time synchronization of different devices is achieved.

[0133] Optionally, the coarse clock error is proportional to the difference between the first code pseudorange observation and the second code pseudorange observation. Similarly, the precise clock error is also proportional to the difference between the synchronous two-way code pseudorange observations determined in step S4.

[0134] In some implementations of the present application, considering that geometric distance delay differences may cause partial signal collisions, protection timing may be set at the end of signals sent by multiple devices.

[0135] Therefore, the time synchronization method provided in the present application has the same beneficial effects as the above-mentioned time synchronization system because it adopts the time synchronization system provided by at least one embodiment of the present application, and will not be described in detail here.

[0136] Fig.14 It is a structural diagram of a computer system suitable for implementing the electronic device of the embodiment of the present application.

[0137] refer to Fig.14 , which shows a schematic diagram of the structure of an electronic device 600 suitable for implementing the embodiments of the present application. The terminal device in the embodiments of the present application may include but is not limited to mobile terminals such as mobile phones, laptop computers, digital broadcast receivers, PDAs (personal digital assistants), PADs (tablet computers), PMPs (portable multimedia players), vehicle-mounted terminals (such as vehicle-mounted navigation terminals), etc., and fixed terminals such as digital TVs, desktop computers, etc. Fig.14 The electronic device shown is only an example and should not bring any limitation to the functions and scope of use of the embodiments of the present application.

[0138] like Fig.14 As shown, the electronic device 600 may include a processing device (e.g., a central processing unit, a graphics processing unit, etc.) 601, which can perform various appropriate actions and processes according to a program stored in a read-only memory (ROM) 602 or a program loaded from a storage device 608 into a random access memory (RAM) 603. In the RAM 603, various programs and data required for the operation of the electronic device 600 are also stored. The processing device 601, the ROM 602, and the RAM 603 are connected to each other via a bus 604. An input / output (I / O) interface 605 is also connected to the bus 604.

[0139] Typically, the following devices may be connected to the I / O interface 605: an input device 606 including, for example, a touch screen, a touch pad, a keyboard, a mouse, a camera, a microphone, an accelerometer, a gyroscope, etc.; an output device 607 including, for example, a liquid crystal display (LCD), a speaker, a vibrator, etc.; a storage device 608 including, for example, a magnetic tape, a hard disk, etc.; and a communication device 609. The communication device 609 may allow the electronic device 600 to communicate with other devices wirelessly or by wire to exchange data. Although Fig.14 The electronic device 600 is shown with various devices, but it should be understood that it is not required to implement or possess all the devices shown. More or fewer devices may be implemented or possessed instead. Fig.14 Each block shown in the figure may represent one device, or may represent multiple devices as required.

[0140] In addition, according to the embodiment of the present application, the process described above with reference to the flowchart can be implemented as a computer software program. For example, the embodiment of the present application includes a computer program product, which includes a computer program carried on a computer-readable medium, and the computer program includes a program code for executing the method shown in the flowchart. In such an embodiment, the computer program can be downloaded and installed from the network through a communication device 609, or installed from a storage device 608, or installed from a ROM 602. When the computer program is executed by the processing device 601, the above functions defined in the method of the embodiment of the present application are executed. It should be noted that the computer-readable medium of the embodiment of the present application can be a computer-readable signal medium or a computer-readable storage medium or any combination of the above two. The computer-readable storage medium can be, for example, but not limited to, a system, device or device of electricity, magnetism, light, electromagnetic, infrared, or semiconductor, or any combination of the above. More specific examples of computer-readable storage media may include, but are not limited to, an electrical connection with one or more conductors, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. In an embodiment of the present application, a computer-readable storage medium may be any tangible medium containing or storing a program that can be used by or in combination with an instruction execution system, an apparatus, or a device. In an embodiment of the present application, a computer-readable signal medium may include a data signal propagated in a baseband or as part of a carrier wave, in which a computer-readable program code is carried. Such propagated data signals may take a variety of forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination of the above. A computer-readable signal medium may also be any computer-readable medium other than a computer-readable storage medium, which may send, propagate, or transmit a program for use by or in combination with an instruction execution system, an apparatus, or a device. The program code embodied on the computer readable medium may be transmitted using any appropriate medium, including but not limited to: wire, optical cable, RF (radio frequency), etc., or any suitable combination of the foregoing.

[0141] The computer-readable medium may be included in the electronic device; or it may exist independently without being assembled into the electronic device. The computer-readable medium carries one or more programs. When the one or more programs are executed by the electronic device, the electronic device: determines the asynchronous two-way code pseudorange observation between the first device and the second device; determines the rough clock difference between the first device and the second device based on the asynchronous two-way code pseudorange observation; adjusts the system time of the first device or the second device based on the rough clock difference to synchronize the system time of the first device and the second device; determines the synchronous two-way code pseudorange observation between the first device and the second device at a preset time point after the system time is synchronized; determines the precise clock difference between the first device and the second device based on the synchronous two-way code pseudorange observation; adjusts at least one of the frequency and phase of the clock source of the first device or the second device based on the precise clock difference.

[0142] The computer program code for the operation of the embodiments of the present application can be written in one or more programming languages ​​or a combination thereof, and the programming language includes an object-oriented programming language, such as Java, Smalltalk, C++, and also includes a conventional procedural programming language, such as "C" language or similar programming language. The program code can be executed entirely on the user's computer, partially on the user's computer, as an independent software package, partially on the user's computer and partially on the remote computer, or completely on the remote computer or server. In the case of a remote computer, the remote computer can be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or can be connected to an external computer (e.g., using an Internet service provider to connect through the Internet).

[0143] The flow chart and block diagram in the accompanying drawings illustrate the possible architecture, function and operation of the system, method and computer program product according to various embodiments of the present application. In this regard, each square box in the flow chart or block diagram can represent a module, a program segment or a part of a code, and the module, the program segment or a part of the code contains one or more executable instructions for realizing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the square box can also occur in a sequence different from that marked in the accompanying drawings. For example, two square boxes represented in succession can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each square box in the block diagram and / or flow chart, and the combination of the square boxes in the block diagram and / or flow chart can be implemented with a dedicated hardware-based system that performs a specified function or operation, or can be implemented with a combination of dedicated hardware and computer instructions.

[0144] The units involved in the embodiments described in the present application may be implemented by software or hardware. The units described may also be set in a processor, for example, it may be described as: a processor includes an observation unit, an estimation unit, and a time synchronization unit. The names of these units do not constitute a limitation on the units themselves in some cases, for example, the time synchronization unit may also be described as a "time synchronization object position information unit".

[0145] The above description is only a preferred embodiment of the present application and an explanation of the technical principles used. Those skilled in the art should understand that the scope of the invention involved in the embodiments of the present application is not limited to the technical solutions formed by a specific combination of the above technical features, but should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the above invention concept. For example, the above features are replaced with (but not limited to) technical features with similar functions disclosed in the embodiments of the present application.

Claims

1. A time synchronization system, characterized in that: The system comprises: An observation unit, determining an asynchronous two-way code pseudorange observation amount between the first device and the second device; a clock difference unit, which determines a coarse clock difference between the first device and the second device based on the asynchronous two-way code pseudorange observation; and an adjusting unit, adapted to adjust the system time of the first device or the second device based on the rough clock difference so that the system time of the first device and the system time of the second device are synchronized, The observation unit is further configured to determine, at a preset time point after the system time is synchronized, an observation amount of a synchronized two-way code pseudorange between the first device and the second device; The clock error unit is further configured to determine a precise clock error between the first device and the second device based on the synchronous two-way code pseudorange observation; and The adjustment unit is further configured to adjust at least one of a frequency and a phase of a clock source of the first device or the second device based on the precise clock difference.

2. The system according to claim 1, wherein: The system further comprises: a receiving integrated unit, arranged in the first device and the second device, The integrated receiving unit outputs second pulses to the inside and outside of the system based on the synchronized system time.

3. The system according to claim 2, wherein: The integrated receiving unit includes a time division multiplexing integrated transmitting and receiving antenna structure, The time division multiplexing transceiver integrated antenna structure realizes signal reception and transmission on the same frequency carrier through different time slots.

4. The system according to claim 3, wherein: The time division multiplexing transceiver integrated antenna comprises: antenna; A power amplifier connected to the antenna and amplifying the signal to be transmitted; a detector, in response to detecting the signal to be transmitted, turning on the power amplifier; and The low noise amplifier is connected to the antenna, amplifies the received signal, and always keeps working.

5. The system according to claim 2, wherein: The receiving integrated unit is further configured as follows: The baseband signal is continuously generated in a silent state, wherein the silent state is a state in which a signal is not transmitted.

6. The system according to claim 2, wherein: The system further comprises a calibration unit for determining a hardware delay, The calibration unit is configured to determine an average value of the misalignment amount of the second pulse within a predetermined time period after adjusting at least one of the frequency and the phase of the clock source; and The adjustment unit is further configured to adjust the system time based on the hardware delay, wherein the hardware delay is an average value of the misalignment amount.

7. The system according to claim 1, wherein: The observation unit is further configured to: determining a first code pseudorange observation value obtained by the first device receiving a signal from the second device, and determining a second code pseudorange observation value obtained by the second device receiving a signal from the first device, The asynchronous two-way code pseudorange observation amount includes the first code pseudorange observation amount and the second code pseudorange observation amount; and The signal received by the first device from the second device and the signal received by the second device from the first device both include a time hopping-direct sequence spread spectrum signal.

8. The system according to claim 7, wherein: The coarse clock error is proportional to a difference between the first code pseudorange observation value and the second code pseudorange observation value.

9. A time synchronization method, characterized in that: The method comprises: Determine an asynchronous two-way code pseudorange observation between the first device and the second device; Determine a coarse clock difference between the first device and the second device based on the asynchronous two-way code pseudorange observation; Based on the rough clock difference, adjust the system time of the first device or the second device to synchronize the system time of the first device with the system time of the second device; After the system time is synchronized, at a preset time point, determining a synchronous two-way code pseudorange observation amount between the first device and the second device; Determining a precise clock difference between the first device and the second device based on the synchronous two-way code pseudorange observation; and Based on the precise clock difference, at least one of the frequency and the phase of a clock source of the first device or the second device is adjusted.

10. The method according to claim 9, wherein: The method further comprises: By using time division multiplexing transceiver technology, signals can be received and sent through different time slots on the same frequency carrier.

11. The method according to claim 9, wherein: The method further comprises: The baseband signal is continuously generated in a silent state, wherein the silent state is a state in which no signal is transmitted.

12. The method according to claim 9, wherein: The method further comprises: After adjusting at least one of the frequency and the phase of the clock source, determining an average value of misalignment of the emitted second pulses within a predetermined time period; and The system time is adjusted based on a hardware delay, wherein the hardware delay is an average value of the misalignment amount.

13. The method according to claim 9, wherein: Determining an asynchronous two-way code pseudorange observation amount between a first device and a second device includes: determining a first code pseudorange observation value obtained by the first device receiving a signal from the second device, and determining a second code pseudorange observation value obtained by the second device receiving a signal from the first device, The asynchronous two-way code pseudorange observation amount includes the first code pseudorange observation amount and the second code pseudorange observation amount; and The signal received by the first device from the second device and the signal received by the second device from the first device both include a time hopping-direct sequence spread spectrum signal.

14. The method according to claim 13, wherein: The coarse clock error is proportional to a difference between the first code pseudorange observation value and the second code pseudorange observation value.

15. An electronic device, characterized in that: include: at least one processor; as well as, A memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, the instructions being executed by the at least one processor so that the at least one processor can execute the time synchronization method described in any one of claims 9 to 14.

16. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the time synchronization method according to any one of claims 9 to 14 is implemented.

17. A computer program product storing a computer program, characterized in that: When the computer program is executed by a processor, the time synchronization method according to any one of claims 9 to 14 is implemented.

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