A sub-nanosecond wireless time synchronization method

Abstract

The application discloses a sub-nanosecond wireless time synchronization method, and belongs to the technical field of time synchronization processing of time division multiplexing networking. The phase difference between a clock of a time synchronization terminal and a clock of a time reference terminal is measured through a double-frequency pulse reference signal, so that the influence of phase offset introduced by a link in a signal transmission process on phase measurement is eliminated. Meanwhile, the phase difference is measured by using the double-frequency pulse reference signal in the time synchronization terminal and the time reference terminal respectively, sub-nanosecond time synchronization is completed on the basis of not changing the existing wireless communication terminal hardware, and the sub-nanosecond time synchronization can be conveniently combined with the existing wireless communication networking algorithm. The time synchronization precision of the application can reach the sub-nanosecond level, and can meet the networking requirements of various high-capacity and low-delay wireless communication networks.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of time synchronization processing in time division multiplexing networking in wireless communication, and particularly relates to a wireless time synchronization method at sub-nanosecond level. BACKGROUND

[0002] In a wireless communication system, time division multiplexing (TDMA) technology is widely used in multi-terminal networking scenarios to achieve efficient resource sharing and coordination. However, the core prerequisite for time division multiplexing networking is that each communication terminal must maintain a high degree of precise time synchronization. Traditional time synchronization methods mainly rely on the Global Positioning System (GPS) or other external time reference sources, but in some special environments (such as indoors, underground, or areas with severe electromagnetic interference), these external signals may not be stably acquired, resulting in a decrease in synchronization accuracy or even failure.

[0003] Existing wireless time synchronization technologies usually adopt one-way or two-way timestamp exchange methods to achieve time synchronization by measuring signal transmission delay. However, the synchronization accuracy of such methods is limited by factors such as multipath effects in the signal transmission path, clock frequency drift, and phase offset introduced by the link, making it difficult to achieve sub-nanosecond synchronization requirements. Especially in high-capacity, low-latency wireless communication networks, the synchronization error of traditional methods can significantly affect the overall performance of the system, and even cause communication time slot conflicts or data loss.

[0004] In addition, the compensation methods for phase offset in existing technologies often require complex hardware support or additional calibration processes, increasing the cost of system deployment and maintenance. Therefore, how to achieve sub-nanosecond high-precision time synchronization between wireless communication terminals without relying on external time references through improved algorithms and signal processing techniques has become a key problem in the current technical field that needs to be solved. SUMMARY

[0005] To solve the above technical problems, the present application provides a wireless time synchronization method at sub-nanosecond level, which can solve the problem of high-precision time synchronization between communication terminals in a wireless communication system based on time division multiplexing networking without relying on external time references. The time synchronization accuracy can reach sub-nanosecond level, meeting the networking requirements of various high-capacity, low-latency wireless communication networks.

[0006] To achieve the above purpose, the present application adopts the following technical solutions:

[0007] A wireless time synchronization method at sub-nanosecond level, the method comprising:

[0008] a time reference terminal sends a start signal containing a frequency tracking sequence to a time synchronization terminal;

[0009] The time synchronization terminal adjusts the local clock frequency according to the frequency tracking sequence;

[0010] The time synchronization terminal sends a time synchronization request containing a double-frequency pulse reference signal;

[0011] The time reference terminal measures the pulse reference phase and returns a response signal containing the current time and the pulse reference phase;

[0012] The time synchronization terminal records the time from sending the time synchronization request signal to receiving the response signal, and calculates the time compensation value;

[0013] The phase error of the time synchronization terminal clock and the time reference terminal clock is calculated by double clock sampling, and the phase of the time synchronization terminal clock is adjusted according to the phase error, so as to realize sub-nanosecond synchronization.

[0014] Further, the start signal includes a frequency tracking sequence, a time synchronization terminal address, and a start time synchronization instruction.

[0015] Further, the time synchronization terminal adjusts the local clock frequency according to the frequency tracking sequence includes:

[0016] The time synchronization terminal calculates the frequency difference between the intermediate frequency carrier frequency generated by the local clock and the frequency received by the time reference terminal using the frequency tracking sequence, adjusts the local clock generation circuit according to the frequency difference, and completely synchronizes the clock frequencies of the time synchronization terminal and the time reference terminal.

[0017] Further, the time synchronization terminal sends a time synchronization request containing a double-frequency pulse reference signal includes:

[0018] After completing frequency synchronization, the time synchronization terminal starts time synchronization at a specific time slot, and sends a time synchronization request signal to the time reference terminal, which includes the time reference terminal address, the time synchronization request instruction, and the pulse reference signal.

[0019] Further, the pulse reference signal is a 4MHz and 8MHz sine wave.

[0020] Further, the time reference terminal measures the pulse reference phase and returns a response signal containing the current time and the pulse reference phase includes:

[0021] After receiving the time synchronization request signal, the time reference terminal samples the pulse reference signal using a 64MHz frequency, and calculates the pulse reference signal phase p1 of the sampling point.

[0022] The current time T1, the pulse reference signal phase p1, the address information of the time synchronization terminal to be synchronized, and the pulse reference signal generated according to the time reference terminal clock phase are combined into a time synchronization response signal, which is sent to the time synchronization terminal to be synchronized.

[0023] Further, the time synchronization terminal to be synchronized records the time from sending the time synchronization request signal to receiving the response signal, and calculates a time compensation value, including:

[0024] After the time synchronization terminal to be synchronized receives the time synchronization response signal matching the local address, the timing is stopped, and the time Δt from sending the time synchronization request signal to receiving the time synchronization response signal is recorded.

[0025] Further, the phase error between the time synchronization terminal to be synchronized clock and the time reference terminal clock is calculated by double clock sampling, and the time synchronization terminal to be synchronized clock phase is adjusted according to the phase error, to achieve sub-nanosecond synchronization, including:

[0026] Setting the time of the time synchronization terminal to be synchronized , wherein tn is the processing time of the time synchronization terminal to be synchronized and the time reference terminal for receiving and sending signals;

[0027] The received pulse reference signal is sampled by a 64MHz and 32MHz clock respectively, and the pulse reference signal phases p2 and p3 of the new sampling points are calculated respectively, wherein p2 is the data sampled by the high-speed clock, and p3 is the data calculated by the low-speed clock sampling;

[0028] When p2 = p3, if p2 > p1, the phase difference between the time synchronization terminal to be synchronized clock and the time reference terminal clock is , the time synchronization terminal to be synchronized clock phase lags behind the time reference terminal clock phase, and the time synchronization terminal to be synchronized clock phase is advanced by ; if p2 < p1, the time synchronization terminal to be synchronized clock phase leads the time reference terminal clock phase, and the time synchronization terminal to be synchronized clock phase lags behind by ;

[0029] When p2 > p3, if p2 > p1, the phase difference between the time synchronization terminal to be synchronized clock and the time reference terminal clock is , the time synchronization terminal to be synchronized clock phase leads the time reference terminal clock phase, and the time synchronization terminal to be synchronized clock phase lags behind by ; if p2 < p1, the time synchronization terminal to be synchronized clock phase lags behind the time reference terminal clock phase, and the time synchronization terminal to be synchronized clock phase is advanced by .

[0030] In a second aspect, the present application provides an electronic device, comprising: one or more processors; a memory for storing one or more programs; wherein when the one or more programs are executed by the one or more processors, the one or more processors implement the aforementioned sub-nanosecond wireless time synchronization method.

[0031] In a third aspect, the present application provides a computer-readable storage medium having stored thereon executable instructions that, when executed by a processor, enable the processor to implement the aforementioned sub-nanosecond wireless time synchronization method.

[0032] The present application has the following beneficial effects:

[0033] The sub-nanosecond wireless time synchronization method of the present application can significantly improve the synchronization accuracy and reliability of wireless communication networks. By measuring the phase difference using a dual-frequency pulse reference signal and combining frequency synchronization compensation technology, this method can control the time error between the time synchronization terminal and the reference terminal to the sub-nanosecond level, thereby meeting the stringent synchronization requirements in high-capacity, low-latency communication scenarios. Compared with traditional solutions that rely on external time references, the present application completely implements synchronization based on the interaction between terminals within the network, effectively avoiding the synchronization failure problem caused by the unavailability of GPS signals or environmental interference. At the same time, by measuring and calculating the phase difference of dual-frequency, this method can automatically offset the phase shift introduced by the link during signal transmission, significantly improving the synchronization accuracy and anti-interference ability. In addition, the present application makes full use of the hardware resources of existing wireless terminals, and can achieve high-precision synchronization without adding additional equipment, greatly reducing the system deployment and operation and maintenance costs. This innovative synchronization mechanism is not only suitable for conventional wireless communication networks, but also provides reliable technical support for 5G / 6G, industrial Internet of Things and other application scenarios with extremely high time synchronization requirements. BRIEF DESCRIPTION OF DRAWINGS

[0034] Figure 1 Flowchart of the sub-nanosecond wireless time synchronization method of the present application;

[0035] Figure 2 Specific step diagram of the sub-nanosecond wireless time synchronization method executed by the embodiment of the present application. DETAILED DESCRIPTION

[0036] The present application will be further described below in conjunction with the drawings and embodiments.

[0037] As shown in Figure 1 The present application provides a sub-nanosecond wireless time synchronization method, which divides each terminal in the network into a time reference terminal and a time synchronization terminal, and synchronizes the time synchronization terminal to the time reference terminal, specifically including the following steps:

[0038] The time reference terminal sends a start signal containing a frequency tracking sequence to the time synchronization terminal;

[0039] The time synchronization terminal adjusts the local clock frequency according to the frequency tracking sequence;

[0040] The time synchronization terminal sends a time synchronization request signal containing a double-frequency pulse reference signal;

[0041] The time reference terminal measures the pulse reference phase and returns a response signal containing the current time and the pulse reference phase;

[0042] The time synchronization terminal records the time from sending the time synchronization request signal to receiving the response signal, and calculates the time compensation value;

[0043] The phase error between the time synchronization terminal clock and the time reference terminal clock is calculated by double clock sampling, and the time synchronization terminal clock phase is adjusted according to the phase error, achieving sub-nanosecond synchronization.

[0044] Embodiment:

[0045] As shown in Figure 2 , the time synchronization terminal is synchronized to the time reference terminal based on the foregoing method, and the wireless communication parameters involved are: high-speed sampling rate 64MHz, low-speed sampling rate 32MHz, communication carrier frequency 120MHz, pulse reference signal frequency 8MHz and 4MHz.

[0046] The time reference terminal sends a time synchronization start reference signal to the time synchronization terminal at a specific address in a time division multiplexing network, the reference signal includes a frequency tracking sequence, the time synchronization terminal address and the time synchronization start instruction;

[0047] After receiving the sent time synchronization start reference signal, the time synchronization terminal uses the frequency tracking sequence to calculate the intermediate frequency carrier frequency generated by the local clock The difference between the received time reference terminal frequency 120MHz , adjusts the local clock generation circuit according to the difference At this time, the clock frequencies of the time synchronization terminal and the time reference terminal are completely synchronized.

[0048] After completing frequency synchronization, the time synchronization terminal starts time synchronization at a specific time slot, and sends a time synchronization request signal to the time reference terminal, the time synchronization request signal includes the time reference terminal address, the time synchronization request instruction and the pulse reference signal. The pulse reference signal is a 4MHz and 8MHz sine wave. After sending the time synchronization request signal, start receiving the synchronization response signal, and start timing;

[0049] After the time reference terminal receives the time synchronization request signal, the pulse reference signal is sampled with a 64MHz frequency, and the pulse reference signal phase pi of the sampling point is calculated;

[0050] The current time Tl, the measured pulse reference signal phase pi, the address information of the time synchronization terminal, and the pulse reference signal generated according to the time reference terminal clock phase are combined to form a time synchronization response signal, which is sent to the time synchronization terminal;

[0051] After the time synchronization terminal receives the time synchronization response signal matching the local address, the timing is stopped, and the time △t from sending the time synchronization request signal to receiving the time synchronization response signal is recorded;

[0052] Setting the time of the time synchronization terminal Wherein tn is the processing time of the time synchronization terminal and the time reference terminal for receiving and sending signals;

[0053] The received pulse reference signal generated by the time reference terminal clock phase is sampled with a 64MHz and 32MHz clock, respectively, to calculate the pulse reference signal phase p2 and p3 of the new sampling point. The phase error p2 and p3 of the time synchronization terminal clock and the time reference terminal clock calculated by the two sampling clocks are in the relationship of n times of the high-speed clock and the low-speed clock, and n is an integer. Wherein p2 is the data sampled by the high-speed clock, and p3 is the data calculated by the low-speed clock sampling. When p2 = p3, if p2 > pi, the phase difference between the time synchronization terminal clock and the time reference terminal clock is The time synchronization terminal clock phase lags behind the time reference terminal clock phase, and the time synchronization terminal clock phase is ahead of If p2 < pi, the time synchronization terminal clock phase leads the time reference terminal clock phase, and the time synchronization terminal clock phase lags behind When p2 > p3, if p2 > pi, the phase difference between the time synchronization terminal clock and the time reference terminal clock is The time synchronization terminal clock phase lags behind the time reference terminal clock phase, and the time synchronization terminal clock phase is ahead of If p2 < pi, the time synchronization terminal clock phase lags behind the time reference terminal clock phase, and the time synchronization terminal clock phase is ahead of The true determination of sub-nanosecond level accuracy is the measurement resolution of the phase difference between the two sampling clocks, and the frequency ratio of the two sampling clocks must be highly stable and known.

[0054] Here only the different data obtained by sampling the clock with the frequency of 64MHz and 32MHz is described, that is, when p1=5 degrees: when the sampled data p2=p3, and when p2>p1, for example, p2=10 degrees, according to , it is obtained . According to the clock with the frequency of 64MHz, since a complete cycle time T=(1s) / (64MHZ)=15.624ns, and the time T(△p=2.5) represented by△p=2.5 is Therefore, sub-nanosecond synchronization can be achieved, and the same is true for other cases.

[0055] The present application provides an electronic device, comprising: one or more processors; a memory for storing one or more programs; wherein when the one or more programs are executed by the one or more processors, the one or more processors implement the foregoing sub-nanosecond wireless time synchronization method.

[0056] The present application provides a computer readable storage medium, which stores executable instructions, and the instructions can make the processor implement the foregoing sub-nanosecond wireless time synchronization method when executed by the processor.

[0057] The above-described specific embodiments further detail the purpose, technical solutions and beneficial effects of the present application. It should be understood that the above-described specific embodiments are only specific embodiments of the present application and are not intended to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application should be included in the protection scope of the present application.​

Claims

1. A sub-nanosecond wireless time synchronization method, characterized in that, The method includes: The time reference terminal sends a start signal containing a frequency tracking sequence to the terminal to be time-synchronized; The terminal to be time-synchronized adjusts its local clock frequency according to the frequency tracking sequence; The terminal to be time-synchronized sends a time synchronization request containing a dual-frequency pulse reference signal; The time reference terminal measures the phase of the pulse reference signal and returns a response signal containing the current time T1 and the phase p1 of the pulse reference signal; The terminal to be time-synchronized records the time from sending the time synchronization request signal to receiving the response signal, and calculates the time compensation value; Calculate the phase error between the clock of the terminal to be time-synchronized and the clock of the time reference terminal through dual-clock sampling, and adjust the clock phase of the terminal to be time-synchronized according to the phase error to achieve sub-nanosecond-level synchronization, including: Set the time T2 of the terminal to be time-synchronized as T1 + △t / 2 + tn, where tn is the processing time of the terminal to be time-synchronized and the time reference terminal for receiving and sending signals; Sample the received pulse reference signal with clocks of 64 MHz and 32 MHz respectively, and calculate the phases p2 and p3 of the pulse reference signal at the new sampling points respectively, where p2 is the data sampled at high speed and p3 is the data calculated by low-speed clock sampling; When p2 = p3, if p2 > p1, the phase difference △p between the clock of the terminal to be time-synchronized and the clock of the time reference terminal is |p2 - p1| / 2, the clock phase of the terminal to be time-synchronized lags behind the clock phase of the time reference terminal, and the clock phase of the terminal to be time-synchronized is advanced by △p; if p2 < p1, the clock phase of the terminal to be time-synchronized leads the clock phase of the time reference terminal, and the clock phase of the terminal to be time-synchronized is lagged by △p; When p2 > p3, if p2 > p1, the phase difference △p between the clock of the terminal to be time-synchronized and the clock of the time reference terminal is π / 2 - |p2 - p1| / 2, the clock phase of the terminal to be time-synchronized leads the clock phase of the time reference terminal, and the clock phase of the terminal to be time-synchronized is lagged by △p, if p2 < p1, the clock phase of the terminal to be time-synchronized lags behind the clock phase of the time reference terminal, and the clock phase of the terminal to be time-synchronized is advanced by △p; Where, △t is the time from sending the time synchronization request signal to receiving the time synchronization response signal.

2. The sub-nanosecond wireless time synchronization method according to claim 1, characterized in that, The start signal includes a frequency tracking sequence, the address of the terminal to be time-synchronized and a start time synchronization instruction.

3. The sub-nanosecond wireless time synchronization method according to claim 1, characterized in that, The terminal to be time-synchronized adjusts its local clock frequency according to the frequency tracking sequence, including: The terminal to be time-synchronized uses the frequency tracking sequence to calculate the frequency difference between the intermediate-frequency carrier frequency generated by its local clock and the frequency of the received time reference terminal, and adjusts and compensates the local clock generation circuit according to the frequency difference to completely synchronize the clock frequencies of the terminal to be time-synchronized and the time reference terminal.

4. The sub-nanosecond wireless time synchronization method according to claim 1, characterized in that, The terminal to be time-synchronized sends a time synchronization request containing a dual-frequency pulse reference signal, including: After completing frequency synchronization, the terminal to be time-synchronized starts time synchronization in a specific time slot and sends a time synchronization request signal to the time reference terminal. The time synchronization request signal includes the address of the time reference terminal, a time synchronization request instruction and a pulse reference signal.

5. The sub-nanosecond wireless time synchronization method according to claim 4, characterized in that, The pulse reference signal is a 4MHz and 8MHz sine wave.

6. The sub-nanosecond wireless time synchronization method according to claim 1, characterized in that, The time reference terminal measures the pulse reference phase and returns a response signal containing the current time and the pulse reference phase, including: After receiving the time synchronization request signal, the time reference terminal samples the pulse reference signal at a frequency of 64MHz and calculates the phase p1 of the pulse reference signal at the sampling point. The current time T1, the pulse reference signal phase p1, the address information of the terminal to be synchronized, and the pulse reference signal generated according to the clock phase of the time reference terminal are combined to form a time synchronization response signal, which is then sent to the terminal to be synchronized.

7. The sub-nanosecond wireless time synchronization method according to claim 6, characterized in that, The time synchronization terminal records the time from sending the time synchronization request signal to receiving the response signal, and calculates the time compensation value, including: Once the time synchronization terminal receives a time synchronization response signal that matches the local address, it stops timing and records the time Δt from sending the time synchronization request signal to receiving the time synchronization response signal.

8. An electronic device, characterized in that, include: One or more processors; Memory, used to store one or more programs; When one or more programs are executed by the one or more processors, the one or more processors implement a sub-nanosecond wireless time synchronization method as described in any one of claims 1-7.

9. A computer-readable storage medium, characterized in that, It stores executable instructions that, when executed by a processor, enable the processor to implement a sub-nanosecond wireless time synchronization method as described in any one of claims 1-7.

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