A high-precision clock synchronization method and system between two wireless devices

Abstract

This invention discloses a high-precision clock synchronization method between two wireless devices, comprising: Initially, a first wireless device sends a first message containing a transmission timestamp to a second wireless device. Upon receiving the message, the second wireless device overwrites its local reception timestamp with this first message, completing initial clock alignment. Subsequently, after a turnaround time, the second wireless device returns a second message to the first wireless device and calculates the one-way time of flight based on the time interval and turnaround time. At the next predefined superframe moment, the first wireless device sends a third message. The second wireless device calculates and corrects its local clock frequency offset based on this message and the timestamp of the previous message, while simultaneously correcting the local reception timestamp of the third message using the one-way time of flight. Thereafter, the above message exchange and calculation process is repeated at each superframe moment to continuously maintain high-precision synchronization. This invention fundamentally improves the clock synchronization accuracy between wireless devices.

Description

Technical Field

[0001] This invention belongs to the field of wireless communication clock synchronization, specifically relating to a high-precision clock synchronization method and system between two wireless devices. Background Technology

[0002] In applications such as ultra-wideband (UWB) high-precision positioning, achieving nanosecond-level clock synchronization between devices is a core requirement. However, conventional clock synchronization technologies often fall short of meeting this stringent requirement.

[0003] Currently, the mainstream synchronization methods used in UWB systems are mainly based on the two-way ranging (TWR) principle, such as single-sided TWR (SS-TWR) and double-sided TWR (DS-TWR). These technologies have the following specific drawbacks in their implementation: 1. Highly sensitive to clock frequency offset (CFO): Especially for SS-TWR, its time of flight (TOF) estimation and synchronization accuracy are extremely susceptible to the impact of carrier frequency offset.

[0004] 2. Insufficient accuracy: Due to CFO limitations, existing solutions are usually unable to achieve nanosecond-level synchronization (corresponding to centimeter-level positioning), making it difficult to fully realize the potential of UWB technology.

[0005] 3. Low compensation efficiency: Although more complex solutions (such as DS-TWR) can mitigate the impact of CFO to some extent, they also bring additional expenses, and the CFO's estimates and compensation are often not accurate or timely enough.

[0006] 4. Lack of continuous tracking mechanism: Existing methods lack an efficient mechanism to continuously track and compensate for CFO drift during equipment operation, making it difficult to maintain high-precision synchronization over a long period of time.

[0007] Therefore, developing a new method that can effectively overcome the influence of CFO and achieve and maintain stable nanosecond-level clock synchronization has become a key requirement for improving the performance of UWB systems (such as achieving high-precision positioning). Summary of the Invention

[0008] The purpose of this invention is to provide a high-precision clock synchronization method and system between two wireless devices, aiming to solve the problems of existing wireless communication clock synchronization methods being highly sensitive to clock frequency offset, having insufficient accuracy, low compensation efficiency, and lacking a continuous tracking mechanism.

[0009] In view of the above problems, this application provides a high-precision clock synchronization method and system between two wireless devices.

[0010] The first aspect disclosed in this application provides a high-precision clock synchronization method between two wireless devices, the method comprising the following steps: S1: The first wireless device sends a first message to the second wireless device at an initial time. The first message contains the sending timestamp of the first device. After receiving the first message, the second wireless device replaces its local receiving timestamp with the sending timestamp to complete the initial clock alignment. S2: After the turnaround time following receiving the first message, the second wireless device returns a second message to the first wireless device, the second message containing the turnaround time; the first wireless device calculates the one-way flight time based on the time interval between sending the first message and receiving the second message and the turnaround time; S3: At the next predefined superframe moment, the first wireless device sends a third message, which includes the transmission timestamp of the superframe moment and the one-way time of flight in step S2; after receiving the third message, the second wireless device combines the transmission timestamps of the first message and the third message with the local reception timestamp to calculate and correct the local clock frequency offset, and uses the one-way time of flight to adjust the local reception timestamp of the third message. S4: After the local clock frequency offset is corrected, the second wireless device executes step S2 again. The first wireless device recalculates the one-way flight time and repeats steps S3 and S4 at each subsequent superframe time to maintain nanosecond-level clock synchronization.

[0011] Preferably, step S1 specifically includes the following steps: S1-1: At time t0, the first wireless device sends a first message to the second wireless device, wherein the first message contains the first device's sending timestamp T1(t0); S1-2: The second wireless device at time t0+TOF 12 Upon receiving the first message, record the local reception timestamp T2(t0+TOF). 12 ), where TOF 12 For flight time; S1-3: The second wireless device changes the local received timestamp from T2(t0+TOF) 12 Replace ) with T1(t0) to complete the initial clock alignment.

[0012] Preferably, step S2 specifically includes the following steps: S2-1: After receiving the first message, the second wireless device returns a second message to the first wireless device after a turnaround time Δ(f2), and the second message contains the turnaround time Δ(f2); S2-2: The first wireless device records the round-trip time Δr(f1) between sending the first message and receiving the second message; S2-3: The first wireless device calculates the one-way time of flight (TOF) based on the round-trip time Δr(f1) and the turnaround time Δ(f2). O =[Δr(f1) Δ(f2)] / 2.

[0013] Preferably, step S3 specifically includes the following steps: S3-1: At time t0+SF, the first wireless device sends a third message to the second wireless device. The third message includes the sending timestamp T1(t0+SF) and the calculated one-way flight time in step S2. SF is the system-predefined duration. S3-2: The second wireless device at time t0+SF+TOF 12 The third message is received, and the local receive timestamp T2(t0+SF+TOF) is recorded. 12 ); S3-3: The second wireless device uses the sending timestamps T1(t0) and T1(t0+SF) of the first and third messages, and the local receiving timestamp T2(t0+TOF) 12 ) and T2(t0+SF+TOF 12 Perform local clock frequency offset correction to ensure that the absolute value of the difference between the local clock frequency of the second wireless device and the local clock frequency of the first wireless device is less than or equal to 0.01ppm. S3-4: The second wireless device changes the local received timestamp from T2(t0+SF+TOF) 12 Replace ) with T1(t0+SF)+TOF O Among them, TOF O This refers to the one-way flight time.

[0014] Preferably, step 4 specifically includes the following steps: S4-1: After the second wireless device receives the third message based on the local clock frequency offset correction, and after a turnaround time Δ(f2)... ’ The system sends a fourth message to the first wireless device, the fourth message containing the turnaround time Δ(f2). ’ ); S4-2: After receiving the fourth message, the first wireless device recalculates the one-way flight time using the same method as in step 2; S4-3: At each subsequent superframe moment, repeat steps S3 and S4 to continuously maintain nanosecond-level clock synchronization between the first wireless device and the second wireless device.

[0015] A second aspect of this application discloses an electronic device including a wireless communication module, a memory, and a processor coupled to the memory, multiple application programs, and one or more programs; when the processor executes the one or more programs, the electronic device enables the aforementioned high-precision clock synchronization method between two wireless devices.

[0016] A third aspect of this application discloses a chip system applied to an electronic device, the chip including one or more processors, the processors being configured to invoke computer instructions to cause the electronic device to execute the aforementioned high-precision clock synchronization method between two wireless devices.

[0017] The fourth aspect disclosed in this application provides a communication device, including a memory, a processor, and a program stored in the memory and executable on the processor, wherein the processor executes the program to implement the aforementioned high-precision clock synchronization method between two wireless devices.

[0018] The beneficial effects of this invention are as follows: 1. Suppress CFO sensitivity: By using high-precision CFO estimation and correction, the system's sensitivity to carrier frequency offset is fundamentally reduced; 2. Improve synchronization accuracy: Based on CFO correction, perform precise clock synchronization to meet nanosecond-level accuracy requirements; 3. Achieve continuous tracking: Perform CFO correction and TOF estimation in each superframe loop to dynamically maintain long-term synchronization at the nanosecond level (a few nanoseconds or less). Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is an overall flowchart of a high-precision clock synchronization method between two wireless devices. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] Example 1: like Figure 1 As shown in the figure, this application provides a high-precision clock synchronization method between two wireless devices, the method comprising: S1: The first wireless device sends a first message to the second wireless device at an initial time. The first message contains the sending timestamp of the first device. After receiving the first message, the second wireless device replaces its local receiving timestamp with the sending timestamp to complete the initial clock alignment.

[0023] Step S1 specifically includes the following steps: S1-1: At time t0, the first wireless device sends a first message to the second wireless device, wherein the first message contains the first device's sending timestamp T1(t0); S1-2: The second wireless device at time t0+TOF 12 Upon receiving the first message, record the local reception timestamp T2(t0+TOF). 12 ), where TOF 12 For flight time; S1-3: The second wireless device changes the local received timestamp from T2(t0+TOF) 12 Replace ) with T1(t0) to complete the initial clock alignment.

[0024] S2: After receiving the turnaround time of the first message, the second wireless device returns a second message to the first wireless device, the second message containing the turnaround time; the first wireless device calculates the one-way flight time based on the time interval between sending the first message and receiving the second message and the turnaround time.

[0025] Step S2 specifically includes the following steps: S2-1: After receiving the first message, the second wireless device returns a second message to the first wireless device after a turnaround time Δ(f2), and the second message contains the turnaround time Δ(f2); S2-2: The first wireless device records the round-trip time Δr(f1) between sending the first message and receiving the second message; S2-3: The first wireless device calculates the one-way time of flight (TOF) based on the round-trip time Δr(f1) and the turnaround time Δ(f2). O =[Δr(f1) Δ(f2)] / 2.

[0026] S3: At the next predefined superframe moment, the first wireless device sends a third message, which includes the transmission timestamp of the superframe moment and the one-way time of flight in step S2; after receiving the third message, the second wireless device calculates and corrects the local clock frequency offset by combining the transmission timestamps of the first message and the third message with the local reception timestamp, and uses the one-way time of flight to adjust the local reception timestamp of the third message.

[0027] Step S3 specifically includes the following steps: S3-1: At time t0+SF, the first wireless device sends a third message to the second wireless device. The third message includes the sending timestamp T1(t0+SF) and the calculated one-way flight time in step S2. SF is the system-predefined duration. S3-2: The second wireless device at time t0+SF+TOF 12 The third message is received, and the local receive timestamp T2(t0+SF+TOF) is recorded. 12 ); S3-3: The second wireless device uses the sending timestamps T1(t0) and T1(t0+SF) of the first and third messages, and the local receiving timestamp T2(t0+TOF) 12 ) and T2(t0+SF+TOF 12 Perform local clock frequency offset correction to ensure that the absolute value of the difference between the local clock frequency of the second wireless device and the local clock frequency of the first wireless device is less than or equal to 0.01ppm. S3-4: The second wireless device changes the local received timestamp from T2(t0+SF+TOF) 12 Replace ) with T1(t0+SF)+TOF O Among them, TOF O This refers to the one-way flight time.

[0028] S4: After the local clock frequency offset is corrected, the second wireless device executes step S2 again. The first wireless device recalculates the one-way flight time and repeats steps S3 and S4 at each subsequent superframe time to maintain nanosecond-level clock synchronization.

[0029] Step 4 specifically includes the following steps: S4-1: After the second wireless device receives the third message based on the local clock frequency offset correction, and after a turnaround time Δ(f2)... ’ The system sends a fourth message to the first wireless device, the fourth message containing the turnaround time Δ(f2). ’ ); S4-2: After receiving the fourth message, the first wireless device recalculates the one-way flight time using the same method as in step 2; S4-3: At each subsequent superframe moment, repeat steps S3 and S4 to continuously maintain nanosecond-level clock synchronization between the first wireless device and the second wireless device.

[0030] In summary, the high-precision clock synchronization method between two wireless devices provided in this application has the following technical effects: 1. Suppress CFO sensitivity: By using high-precision CFO estimation and correction, the system's sensitivity to carrier frequency offset is fundamentally reduced; 2. Improve synchronization accuracy: Based on CFO correction, perform precise clock synchronization to meet nanosecond-level accuracy requirements; 3. Achieve continuous tracking: Perform CFO correction and TOF estimation in each superframe loop to dynamically maintain long-term synchronization at the nanosecond level (a few nanoseconds or less).

[0031] Through the foregoing detailed description of a high-precision clock synchronization method between two wireless devices, those skilled in the art can clearly understand the high-precision clock synchronization system between two wireless devices in this embodiment. Since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and relevant parts can be referred to in the method section.

[0032] Example 2: In Embodiment 2, an electronic device is provided, including a wireless communication module, a memory, and a processor coupled to the memory, multiple application programs, and one or more programs; when the processor executes one or more programs, the electronic device implements the above-described high-precision clock synchronization method between two wireless devices.

[0033] Example 3: In Embodiment 3, a chip system is provided, which is applied to an electronic device. The chip includes one or more processors, which are used to invoke computer instructions to cause the electronic device to execute the high-precision clock synchronization method between two wireless devices described above.

[0034] Example 4: In Embodiment 4, a communication device is provided, including a memory, a processor, and a program stored in the memory and executable on the processor. When the processor executes the program, it implements the above-described high-precision clock synchronization method between two wireless devices.

[0035] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0036] The above description of the disclosed embodiments enables those skilled in the art to make or use this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A high-precision clock synchronization method between two wireless devices, characterized in that, The method includes the following steps: S1: The first wireless device sends a first message to the second wireless device at an initial time. The first message contains the sending timestamp of the first device. After receiving the first message, the second wireless device replaces its local receiving timestamp with the sending timestamp to complete the initial clock alignment. S2: After the turnaround time following receiving the first message, the second wireless device returns a second message to the first wireless device, the second message containing the turnaround time; the first wireless device calculates the one-way flight time based on the time interval between sending the first message and receiving the second message and the turnaround time; S3: At the next predefined superframe moment, the first wireless device sends a third message, which includes the transmission timestamp of the superframe moment and the one-way time of flight in step S2; after receiving the third message, the second wireless device combines the transmission timestamps of the first message and the third message with the local reception timestamp to calculate and correct the local clock frequency offset, and uses the one-way time of flight to adjust the local reception timestamp of the third message. S4: After the local clock frequency offset is corrected, the second wireless device executes step S2 again. The first wireless device recalculates the one-way flight time and repeats steps S3 and S4 at each subsequent superframe time to maintain nanosecond-level clock synchronization.

2. The high-precision clock synchronization method between two wireless devices as described in claim 1, characterized in that, Step S1 specifically includes the following steps: S1-1: At time t0, the first wireless device sends a first message to the second wireless device, wherein the first message contains the first device's sending timestamp T1(t0); S1-2: The second wireless device at time t0+TOF 12 Upon receiving the first message, record the local reception timestamp T2(t0+TOF). 12 ), where TOF 12 For flight time; S1-3: The second wireless device changes the local received timestamp from T2(t0+TOF) 12 Replace ) with T1(t0) to complete the initial clock alignment.

3. The high-precision clock synchronization method between two wireless devices as described in claim 1, characterized in that, Step S2 specifically includes the following steps: S2-1: After receiving the first message, the second wireless device returns a second message to the first wireless device after a turnaround time Δ(f2), and the second message contains the turnaround time Δ(f2); S2-2: The first wireless device records the round-trip time Δr(f1) between sending the first message and receiving the second message; S2-3: The first wireless device calculates the one-way time of flight (TOF) based on the round-trip time Δr(f1) and the turnaround time Δ(f2). O =[Δr(f1) Δ(f2)] / 2.

4. The high-precision clock synchronization method between two wireless devices as described in claim 1, characterized in that, Step S3 specifically includes the following steps: S3-1: At time t0+SF, the first wireless device sends a third message to the second wireless device. The third message includes the sending timestamp T1(t0+SF) and the calculated one-way flight time in step S2. SF is the system-predefined duration. S3-2: The second wireless device at time t0+SF+TOF 12 The third message is received, and the local receive timestamp T2(t0+SF+TOF) is recorded. 12 ); S3-3: The second wireless device uses the sending timestamps T1(t0) and T1(t0+SF) of the first and third messages, and the local receiving timestamp T2(t0+TOF) 12 ) and T2(t0+SF+TOF 12 Perform local clock frequency offset correction to ensure that the absolute value of the difference between the local clock frequency of the second wireless device and the local clock frequency of the first wireless device is less than or equal to 0.01ppm. S3-4: The second wireless device changes the local received timestamp from T2(t0+SF+TOF) 12 Replace ) with T1(t0+SF)+TOF O Among them, TOF O This refers to the one-way flight time.

5. The high-precision clock synchronization method between two wireless devices as described in claim 1, characterized in that, Step 4 specifically includes the following steps: S4-1: After the second wireless device receives the third message based on the local clock frequency offset correction, and after a turnaround time Δ(f2)... ’ The system sends a fourth message to the first wireless device, the fourth message containing the turnaround time Δ(f2). ’ ); S4-2: After receiving the fourth message, the first wireless device recalculates the one-way flight time using the same method as in step 2; S4-3: At each subsequent superframe moment, repeat steps S3 and S4 to continuously maintain nanosecond-level clock synchronization between the first wireless device and the second wireless device.

6. An electronic device, characterized in that, The device includes a wireless communication module, a memory, and a processor coupled to the memory, multiple application programs, and one or more programs; when the processor executes the one or more programs, it causes the electronic device to implement a high-precision clock synchronization method between two wireless devices as described in any one of claims 1 to 5.

7. A chip system applied to an electronic device, the chip including one or more processors, the processors being configured to invoke computer instructions to cause the electronic device to perform a high-precision clock synchronization method between two wireless devices as claimed in any one of claims 1 to 5.

8. A communication device, comprising a memory, a processor, and a program stored in the memory and executable on the processor, characterized in that, When the processor executes the program, it implements a high-precision clock synchronization method between two wireless devices as described in any one of claims 1 to 5.

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