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

Abstract

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, wherein the time synchronization system includes: an observation unit, a clock difference unit, and an adjustment unit. The observation unit determines an asynchronous two-way code pseudorange observation amount 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 two-way code pseudorange observation amount. The adjustment unit 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. After the system time is synchronized, the observation unit determines a synchronous two-way code pseudorange observation amount between the above-mentioned devices at a preset time point. The clock difference unit determines a precise clock difference between the above-mentioned devices based on the synchronous two-way code pseudorange observation amount. The adjustment unit 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.

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 is the process of exchanging local and remote time information to determine the time difference between them and then adjusting the clocks to minimize this difference. Time synchronization is crucial for navigation, transportation, communications, electronics, and other disciplines.

[0003] However, conventional high-precision time synchronization technologies are mostly suitable for 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 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, so that the system time of the first device and the second device are synchronized, 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 further 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 misalignment amount 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 misalignment amount.

[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 both the signal received by the first device from the second device and the signal received by the second device from the first device include a time-hopping-direct sequence spread spectrum signal.

[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 coarse 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 coarse clock difference to synchronize the system time of the first device and the second device; after the system time is synchronized, at a predetermined 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 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 further includes: determining an average misalignment value of the second pulse within a predetermined time period after adjusting at least one of the frequency and phase of the clock source; and adjusting the system time based on hardware delay, wherein the hardware delay is the average misalignment value.

[0018] In one embodiment of the present application, determining an asynchronous two-way code pseudorange observation value 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, wherein the asynchronous two-way code pseudorange observation value includes the first code pseudorange observation value and the second code pseudorange observation value; and both the first device receiving the signal from the second device and the second device receiving the signal from the first device 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 that can be executed by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to execute the time synchronization method provided in any embodiment of the other aspect of the present application.

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

[0022] On another aspect, the present application provides a computer program product storing a computer program. When the computer program is executed by a processor, it implements the time synchronization method provided in any embodiment 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 pre-set 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. 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 from 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 embodiment of the present application;

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

[0028] Figure 3B This is a schematic diagram of a process for achieving system time synchronization between a first device and a second device according to one embodiment of the present application;

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

[0030] Figure 5 This is a structural diagram of a time-division multiplexing transceiver integrated antenna structure according to one 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 This 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] Figure 9 This is a schematic diagram of an experimental scenario of a time synchronization system according to an embodiment of the present application;

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

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

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

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

[0039] Figure 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] For a better understanding of the present application, various aspects of the present application will be described in more detail with reference to the accompanying drawings. It should be understood that these detailed descriptions are merely 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 terms first, second, third, etc. are used only to distinguish one feature from another feature area, and do not represent any limitation on the features, and in particular do not represent any order of precedence. Therefore, without departing from the teachings 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 accompanying drawings, the thickness, size, and shape of components have been slightly adjusted for ease of illustration. The accompanying drawings are for illustration only and are not drawn strictly to scale. As used herein, the terms "substantially," "approximately," and similar terms are used to indicate approximations, not degrees, and are intended to account for the inherent variations 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 "comprises," "including," "having," "includes," and / or "comprising" are open rather than closed expressions in this specification, indicating 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 defined, all words used herein (including engineering terms and scientific and technological terms) have the same meaning as commonly understood by those skilled in the art to which this application belongs. It should also be understood that, unless otherwise specified in this application, words defined in commonly used dictionaries should be interpreted as having the same meaning as they do 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, unless otherwise specified or inconsistent with the context, the embodiments and features of the embodiments in this application may be combined with each other. Furthermore, unless expressly limited or inconsistent with the context, the specific steps included in the methods described in this application are not necessarily limited to the order in which they are described, but may 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 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 coarse 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 coarse 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 predetermined 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 term "asynchronous two-way code pseudorange observation" refers to the two-way code pseudorange observation determined when the observation times of the first and second devices are asynchronous before the two devices are time synchronized. The term "synchronous two-way code pseudorange observation" refers to the two-way code pseudorange observation determined when the observation times of the first and second devices are synchronized after the first and second devices have undergone coarse time synchronization and their system times are synchronized. This 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 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 pre-set 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 time of different devices in a dynamic scene. 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 embodiment of the present application. Figure 3A 1 is a schematic diagram of signals sent and received by a first device 101 and a second device 102 , a third device 103 , a fourth device 105 , etc., respectively, according to one embodiment of the present application. Figure 3B1 is a schematic diagram of a process for achieving system time synchronization between a first device 101 and a second device 102 according to an embodiment of the present application.

[0051] Specifically, if 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 diagram shows a scenario where the first device 101 transmits and receives signals from the second device 102, the third device 103, the fourth device, and the fifth device 105. Multiple devices are constantly in motion, and the geometric distances between them are constantly changing. In complex scenarios, obtaining the accurate coordinates and velocities of each device in real time is difficult. Furthermore, when multiple devices are located far apart, the atmospheric delay between their transmit and receive antennas is difficult to accurately estimate using models. In dynamic applications, multiple devices can be connected using wireless signals. Compared to wired connections, wireless connections are free from the constraints of cables and are more flexible and convenient. However, in wireless applications, the channel environment between multiple devices is complex, and multipath error is a significant factor affecting the accuracy of time synchronization between multiple devices. In dynamic applications, multipath error is a constantly changing quantity, making it difficult to model. Furthermore, when multiple devices are in motion, the angles of signals entering and exiting the antennas constantly change, causing variations in antenna group delay. Although antenna group delay varies on the order of decimeters, it is orders of magnitude smaller than multipath error. However, in sub-nanosecond high-precision time synchronization, antenna group delay variation error is also one of the important factors affecting the time synchronization accuracy of multiple devices.

[0052] refer to Figures 1-3BTaking the example of first device 101 transmitting and receiving signals with second device 102, third device 103, fourth device 105, etc., the second device 102, third device 103, fourth device 105, and fifth device 105 can all perform bidirectional observation with first device 101. For example, in the signal transmitted by first device 101, the intervals between signal pulses can be pseudo-random. First device 101 can receive signals from itself and other devices, and the signals transmitted by multiple devices are distinguished by color blocks of different grayscales. It should be noted that any of first device 101 to fifth device 105 can be any of multiple devices connected via wireless signals in a dynamic application scenario, and this application is not limited to this. Optionally, multiple devices connected via wireless signals in a dynamic application scenario can all include observation unit 1100, clock difference unit 1200, and adjustment unit 1300, or some of the multiple devices connected via wireless signals in a dynamic application scenario can include observation unit 1100, clock difference unit 1200, and adjustment unit 1300, but this application is not limited to this. For example, when first device 101 and second device 102 are first started, their clocks run independently, and their time systems are not synchronized. Without an external reference, the observed measurements between the two devices may differ by seconds. In this case, asynchronous two-way code pseudorange observations can be obtained between first device 101 and second device 102.

[0053] To achieve simultaneous extraction of observations across devices, the system time of each device must first be synchronized, or in other words, a coarse synchronization of the times of different devices must be performed. This coarse synchronization can then be used to achieve fine synchronization of the times of different devices. Figure 3B The process of achieving 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 time τ; the second device 102 receives a signal sent by the first device 101 at time T1 at time T2′, and the signal propagation time τ′, where the coarse 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 observations are extracted at different times, the two-way propagation delays are 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 coarse clock error δt, τ≈τ′ can be set. According to formula (1), the coarse 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 Second code pseudorange observation is proportional to the difference between them.

[0061] Optionally, 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] Combine Figure 1 、 Figure 2 and Figure 3B b. Adjustment unit 1300 can adjust the system time of the first device or the second device based on the coarse clock difference to synchronize the system times of the first and second devices, or to achieve coarse synchronization between the two devices. For example, the system time of the second device 102 can be gradually adjusted to approach the system time of the first device 101. System time synchronization of the two devices can be achieved through a single iteration. Optionally, system time can be understood as receiving unit time or 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 the synchronized two-way code pseudoranges are substantially the same, and thus can be offset in the process of determining the precise clock error.

[0064] Combine Figure 1 、 Figure 2 、 Figure 3B .b and Figure 3B .c. Based on coarse synchronization, fine synchronization of 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 can be an integer time point displayed by the device after achieving system time synchronization of different devices, for example, an integer 100 milliseconds, an integer second, or an integer minute. In addition, the clock source can include a crystal oscillator or an atomic clock.

[0067] Furthermore, to avoid the near-far effect, during the synchronization of two-way code pseudorange observations, both the signal received by first device 101 from second device 102 and the signal received by second device 102 from first device 101 may include a time-hopping direct sequence spread spectrum signal. Furthermore, the precise clock error may be proportional to the difference between the two-way code pseudorange observations.

[0068] Optionally, to account for the potential for some signal collisions due to geometric distance delay differences, a guard sequence may be set at the end of signals transmitted by multiple devices. For example, a guard sequence may be set at the end of a signal transmitted by the second device 102 and received by the first device 101, as well as at the end of a signal transmitted by the first device 102 and received by the second device 102. Optionally, the guard sequence may be equal to the time it takes for each device to transmit a signal, or may be a fraction of that time. For example, the guard sequence may be 0.2 milliseconds (ms).

[0069] Furthermore, multiple devices may have a silent state and a signal transmission state, where the silent state can be understood as a non-transmitting state. The signal transmission state is only part of the time, with the device remaining in the non-transmitting state for the majority of the time. While a device remains in the silent state, its receiving unit, or the integrated receiving unit described below, may continuously generate baseband signals to ensure signal coherence.

[0070] For example, using UWB (Ultra-Wideband) signals for two-way ranging to achieve sub-nanosecond time synchronization, the transmission range of UWB signals is only on the order of hundreds of meters, making it usable only within a small area. Furthermore, when using UWB signals for two-way ranging to achieve time synchronization, some devices must first send a request, and the corresponding device then responds. Therefore, the received and sent signals are asynchronous, requiring UWB nodes 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 integrated receiving unit of the device can continuously generate baseband signals to ensure signal coherence. Leveraging the signal's coherence, the receiving unit or integrated receiving unit can extract observations at any time.

[0072] Figure 4 It is a structural diagram of a receiving integrated unit 2400 according to one 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 results and further solve the above technical problems, the time synchronization method system 1000 may also include a receiving integrated unit 2400. The receiving integrated 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 an example, the integrated receiving unit 2400 can be respectively set in the first device 101 and the second device 102. The integrated receiving unit 2400 can output pulse-per-second (PPS) to the system internally and externally 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 normal working state, the system time of the device can no longer be adjusted or modified. Instead, the crystal oscillator frequency is adjusted to achieve precise synchronization and maintain time synchronization of each device.

[0074] Specifically, the integrated receiving unit 2400 may include a timing unit 2401, a transmitting unit 2402, and a receiving unit 2403. The timing unit 2401 may output a PPS every second, which is also transmitted to the receiving unit 2403 to trigger observation extraction. The receiving unit 2403 may adjust the frequency of the clock source of the local device (e.g., the second device 102) based on the precise clock difference between the local device (e.g., the second device 102) and the reference device (e.g., the first device 101), thereby achieving time synchronization between the local device and the reference device.

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

[0076] In dynamic applications, the geometric distances measured in two one-way trips are likely inconsistent, necessitating distance delay correction based on the antenna geometry. Furthermore, due to antenna manufacturing variations, the group delays of the receiving and transmitting antennas may vary, and the angle at which the signal enters the receiving antenna differs from the angle at which the signal leaves the transmitting antenna. This results in inconsistent group delays between the receiving and transmitting antennas, making it impossible to eliminate these differences through bidirectional differencing. Furthermore, the inconsistent propagation paths of the signals in the two one-way trip measurements can lead to inconsistent multipath errors, making them impossible to eliminate through bidirectional differencing.

[0077] Figure 5 It is a structural diagram of a time-division multiplexing transceiver integrated antenna structure 2404 according to one 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 in 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 transmitted. 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, while 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 transmitted.

[0080] In the transmitting state, upon detecting a signal, power amplifier 201 is enabled to amplify the signal and transmit it through antenna 202. After transmission is complete, the power amplifier is disabled, and the device enters a silent state. Antenna 202 then switches to a receiving state. Since low-noise amplifier 203 remains operational, the signal received by antenna 202 is amplified by low-noise amplifier 203 and then processed.

[0081] refer to Figure 3A and Figure 5 From the signal format, we can see that the time slice for transmission and reception is only 0.2 milliseconds. Precisely because of this short switching time, on a larger time scale, the signal transmission and reception occur simultaneously. This allows the simultaneously extracted observations to be considered approximately symmetrical, further eliminating the delays and errors mentioned above.

[0082] Figure 6 1 is a schematic 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. Calibration unit 1400 may determine an average misalignment value of the PPS within a predetermined time period after adjusting at least one of the frequency and phase of the clock source. Adjustment unit 1300 may adjust the system time based on the hardware delay, where the hardware delay is the average misalignment value.

[0084] Specifically, due to manufacturing imperfections, each device's hardware has certain differences, resulting in inconsistent hardware delays. To achieve synchronized PPS output from multiple devices, hardware delay differences can be corrected.

[0085] Hardware delays can include delays in the transmitting and receiving units, such as antennas, cables, and electronics. These delays can be measured and deducted in advance. Alternatively, rather than precisely measuring the delay of each hardware component, the hardware delays can be measured as a whole. Furthermore, ignoring the effects of temperature and aging, hardware delays do not change with system restarts, making them generally stable. Therefore, they can be calibrated in advance and stored in the device parameters for the next time synchronization.

[0086] In other words, system time synchronization (coarse time synchronization) can be performed first, followed by fine time synchronization. Afterwards, PPS misalignment is statistically recorded over a predetermined period of time, and the average PPS misalignment value over the predetermined period is determined. By writing the average PPS misalignment value over the predetermined period of time into, for example, a configuration file, errors caused by inconsistent hardware delays can be eliminated, achieving PPS alignment.

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

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

[0089]

[0090] Wherein, the subscript i represents the receiving device and the superscript j represents the transmitting device; and Represent the code pseudorange and carrier phase observation respectively, 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 multiple devices in a 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] Alternatively, hardware delay calibration can be performed 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 connecting the PPS of the two devices to the same frequency meter, the two-way code pseudorange difference 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 devices remain 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. Furthermore, as described above, hardware delay does not change across system reboots, so it is generally stable. The difference in hardware delay is constant, and the pulse misalignment observed from the frequency counter is caused by inconsistent hardware delay. In other words, hardware delay is the average PPS misalignment over a predetermined period of time.

[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 misalignment 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, 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 predetermined 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 time of different devices in a dynamic scene. This eliminates various delays and errors between the time of different devices in a dynamic scene 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 (CMC) is the differential observation obtained by subtracting the carrier phase observation from the code pseudorange observation. CMC can be expressed using 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] Furthermore, antenna group delay varies with the signal's entry and exit angles, affecting the code pseudorange. The CMC fluctuation can be used to reflect changes in antenna group delay. Antenna group delay can be modeled as a function of azimuth and zenith angle. During motion, the angles at which signals enter and exit the antennas change with the carrier's attitude, causing changes in group delay. Antenna group delay can vary by decimeters or even meters, equivalent to several nanoseconds in time. Therefore, antenna group delay variation is a significant error source affecting high-precision time synchronization.

[0111] Figure 7 1 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 from the experimental scenarios. Figure 9 1 is a schematic diagram of an experimental scenario of a time synchronization system 1000 according to an embodiment of the present application. Figure 10 yes Figure 9 Comparison chart of results from the experimental scenarios. Figure 11 1 is a schematic diagram of an experimental scenario of a time synchronization system 1000 according to an embodiment of the present application. Figure 12 yes Figure 11 Comparison chart of results from 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) remained stationary throughout the experiment. Multipath was artificially introduced by walking around the antennas with a reflector between seconds 86 and 176. The antennas remained stationary at all 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 in the scenario where 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 Figure 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 robotic arm (e.g. Figure 9 (As shown in the left figure of the figure). During the 160th to 250th second period, the robotic arm rotates the antenna of second device 2 clockwise one revolution in place, ensuring that its position remains almost stationary. This indicates that the multipath error remains almost constant. During the 310th to 400th second period, the robotic arm rotates the antenna of second device 2 counterclockwise one revolution in place, restoring the antenna to its original state. The antenna remains stationary during the rest of the time. Figure 10 are the corresponding CMC observations and two-way code pseudorange differential observations. Figure 10 As shown in Figure .a, when the antenna is stationary, the CMC (1—>2) has no obvious fluctuation except for the observation noise. When the antenna rotates clockwise and counterclockwise, a fluctuation of about 0.5m occurs. This is mainly because when the antenna rotates, the incident angle of the signal changes, resulting in a change in the antenna group delay, which affects the code pseudorange observation. Figure 10 As shown in .b, “CMC(2—>1)” and “CMC(1—>2)” have similar performances. Figure 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 antenna group delay variation.

[0114] exist Figure 11 In the experimental scenario shown, device 1 and device 4 act as the initiating and terminating devices, respectively outputting PPS signals to a frequency counter to verify time synchronization accuracy. Devices 2 and 3 act as relays, transmitting time information. In other words, time information is transmitted from device 1 through devices 2 and 3 to device 4. Figure 12 The PPS deviation between the first device 1 and the fourth device 4 is shown, with an accuracy of 0.157ns. This demonstrates that the system's time synchronization accuracy has reached the sub-nanosecond level, enabling high-precision time synchronization in dynamic scenarios.

[0115] Figure 13 1 is a schematic diagram of the steps of a time synchronization method according to an embodiment of the present application.

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

[0117] S1. Determine an asynchronous two-way code pseudorange observation value between a first device and a second device.

[0118] S2. Determine 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 and the second device.

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

[0121] S5. Determine 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 the clock source of the first device or the second device based on the precise clock difference.

[0123] The following describes in detail the various specific steps of the above-mentioned time synchronization method 2000.

[0124] refer to Figure 4 and Figure 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 Figure 13 As shown, time-division multiplexing (TDDM) transceiver technology can be used to transmit and receive signals on the same frequency carrier using different time slots. For example, TDDM transceiver antenna structure 2404 can be used to transmit and receive signals, where TDDM transceiver antenna structure 2404 can perform different functions in different time intervals.

[0126] In addition, reference Figure 3A and Figure 13 Multiple devices can have both silent and signal-transmitting states. The silent state can be understood as a non-transmitting state. The signal-transmitting state is only part of the time, with the device remaining non-transmitting for the majority of the time. While a device remains in the silent state, its receiving unit or integrated receiving unit can continuously generate baseband signals to ensure signal coherence. Leveraging this signal coherence, the receiving unit or integrated receiving unit can extract observations 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 manufacturing imperfections, each device's hardware may vary, leading to inconsistent hardware latency. To achieve synchronized PPS output from multiple devices, hardware latency differences can be corrected.

[0129] After completing fine time synchronization, PPS misalignment can be statistically recorded within a predetermined time period, and an average value of the PPS misalignment within the predetermined time period can be determined. This average value of the PPS misalignment within the predetermined time period can then be written, for example, to a configuration file. During time synchronization, after determining a portion of the time difference using asynchronous two-way code pseudorange observations and synchronous two-way code pseudorange observations, the aforementioned steps are then used to determine the remaining hardware delay difference to achieve PPS alignment.

[0130] In addition, 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 both the signal received by the first device from the second device and the signal received by the second device from the first device may include a time-hopping-direct sequence spread spectrum signal.

[0131] In addition, in step S4, after system time synchronization, at a predetermined 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 from the second device and the second device receiving the signal from the first device may also include time hopping-direct sequence spread spectrum signals.

[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 embodiments 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] Figure 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 Figure 14 , which shows a schematic structural diagram of an electronic device 600 suitable for implementing the embodiments of the present application. The terminal devices in the embodiments of the present application may include, but are 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. Figure 14 The electronic device shown is only an example and should not limit the functions and scope of use of the embodiments of the present application.

[0138] like Figure 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. Various programs and data required for the operation of the electronic device 600 are also stored in the RAM 603. 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 touchpad, 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 Figure 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 of the devices shown. More or fewer devices may be implemented or possessed instead. Figure 14 Each block shown in the figure may represent one device, or may represent multiple devices as needed.

[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 the communication device 609, or installed from the storage device 608, or installed from the ROM 602. When the computer program is executed by the processing device 601, the above-mentioned 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, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, device or device, or any combination of the above. More specific examples of computer-readable storage media may include, but are not limited to, an electrical connection having one or more conductors, a portable computer disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination thereof. In embodiments of the present application, a computer-readable storage medium may be any tangible medium that contains or stores a program that can be used by or in conjunction with an instruction execution system, apparatus, or device. In embodiments of the present application, a computer-readable signal medium may include a data signal propagated in baseband or as part of a carrier wave, which carries computer-readable program code. Such a propagated data signal may take a variety of forms, including, but not limited to, an electromagnetic signal, an optical signal, or any suitable combination thereof. A computer-readable signal medium may also be any computer-readable medium other than a computer-readable storage medium that can transmit, propagate, or transfer a program for use by or in conjunction with an instruction execution system, apparatus, or device. Program code embodied on a 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 thereof.

[0141] The computer-readable medium may be included in the electronic device, or may exist independently and not incorporated into the electronic device. The computer-readable medium carries one or more programs. When executed by the electronic device, the electronic device: determines an asynchronous two-way code pseudorange observation between the first device and the second device; determines a coarse 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 coarse clock difference to synchronize the system times of the first device and the second device; determines a synchronous two-way code pseudorange observation between the first device and the second device at a predetermined time point after the system times are synchronized; determines a precise clock difference between the first device and the second device based on the synchronous two-way code pseudorange observation; and adjusts 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.

[0142] The computer program code for performing the operations of the embodiments of the present application can be written in one or more programming languages ​​or a combination thereof, including object-oriented programming languages ​​such as Java, Smalltalk, C++, and also conventional procedural programming languages ​​such as "C" language or similar programming languages. 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 a remote computer, or entirely on a 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 via the Internet).

[0143] The flow charts and block diagrams in the accompanying drawings illustrate the possible architecture, functions and operations of the systems, methods and computer program products according to various embodiments of the present application. In this regard, each box in the flow chart or block diagram can represent a module, program segment or a part of code, and the module, program segment or a part of 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 box can also occur in a different order than that marked in the accompanying drawings. For example, two 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 box in the block diagram and / or flow chart, and the combination of the boxes in the block diagram and / or flow chart can be implemented by a dedicated hardware-based system that performs the specified function or operation, or can be implemented by a combination of dedicated hardware and computer instructions.

[0144] The units involved in the embodiments described in this application may be implemented in software or hardware. The units described may also be provided in a processor. For example, they may be described as comprising an observation unit, an estimation unit, and a time synchronization unit. The names of these units do not, in some cases, limit the units themselves. For example, the time synchronization unit may also be described as a "time-synchronized 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 the specific combination of the above-mentioned technical features, but should also cover other technical solutions formed by any combination of the above-mentioned technical features or their equivalent features without departing from the above-mentioned inventive concept. For example, the above-mentioned features can be 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, configured to determine an asynchronous two-way code pseudorange observation amount between the first device and the second device; a clock difference unit, configured to determine 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, configured to adjust the system time of the first device or the second device based on the rough clock difference so that the system times of the first device and 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 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; 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, provided 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 receiving integrated unit includes a time division multiplexing transmitting and receiving integrated 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 no signal is transmitted.

6. The system according to claim 2, wherein: The system further comprises a calibration unit for determining hardware delay, 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 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: Determining an asynchronous two-way code pseudorange observation between the first device and the second device; determining a coarse clock difference between the first device and the second device based on the asynchronous two-way code pseudorange observation; Adjusting the system time of the first device or the second device based on the rough clock difference so that the system times of the first device and the second device are synchronized; After the system time is synchronized, at a preset time point, determining a synchronized two-way code pseudorange observation 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 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 are 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 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 between the first device and the 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 as to enable the at least one processor to execute the time synchronization method according to 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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