Time synchronization method and device

Abstract

The invention provides a time synchronization method and device, a first device sends a second multi-carrier signal to a second device and sends first information to the second device to indicate a phase determined by local analysis of the first device, and the second device receives the second multi-carrier signal and determines the phase by local analysis of the second device. The second device can determine the phase difference and the frequency difference of the two places corresponding to the second multi-carrier signal according to the second multi-carrier signal and the first information, thereby adjusting the local clock to enable the time of the first device and the second device to be synchronized, and improving the precision of time synchronization between the devices with low cost.

Description

Time synchronization method and device Technical Field

[0001] The present application relates to the field of communications, and in particular, to a method and device for time synchronization in the field of communications. Background Art

[0002] High-precision time synchronization technology is a key foundational technology for numerous application scenarios. For example, in the communications field, in multi-station collaboration, time asynchrony between stations introduces position uncertainty. Furthermore, in current perception scenarios, time asynchrony between transmitters and receivers can introduce significant random phase noise into the collected data, impacting perception. In short, low time synchronization accuracy severely hinders improvements in perception performance and limits the scope of application scenarios for device collaboration.

[0003] Currently, the mainstream time synchronization methods for civilian communication base stations are based on the Global Navigation Satellite System (GNSS) and the Institute of Electrical and Electronics Engineers (IEEE) 1588v2 protocol. These two mainstream time synchronization methods lack sufficient accuracy in some applications. Clock discipline technology based on local, highly stable atomic clocks can achieve very high accuracy, but these clocks are expensive. Furthermore, other existing time synchronization methods struggle to achieve both high accuracy and low cost.

[0004] Summary of the Invention

[0005] In view of the above problems, the present application provides a time synchronization method based on interferometric measurement, which can achieve high-precision and low-cost time synchronization.

[0006] In a first aspect, a time synchronization method is provided, which is used in a second device to achieve time synchronization with the second device. The method includes the following steps: the second device detects a first multi-carrier signal, wherein the first multi-carrier signal includes at least two sub-carriers f1 and f2, wherein the two sub-carriers correspond to separate frequency points on the spectrum; the second device determines a first phase Φ'1 corresponding to sub-carrier f1 and a second phase Φ'2 corresponding to sub-carrier f2 included in the first multi-carrier signal; wherein the first multi-carrier signal is a second multi-carrier signal transmitted by the first device and propagated through an inter-channel; the second device receives first information, wherein the first information is used to indicate a third phase and a fourth phase corresponding to the second multi-carrier signal; wherein the third phase Φ1 corresponds to sub-carrier signal f1, and the fourth phase Φ2 corresponds to sub-carrier f2; and the second device performs time synchronization with the first device based on a first phase difference, a second phase difference, and a first frequency difference; wherein the first phase difference is the phase difference between the first phase and the third phase, i.e., ΔΦ1 = Φ'1 - Φ1. The second phase difference is the phase difference between the second phase and the fourth phase, i.e., ΔΦ2 = Φ'2 - Φ2. The first frequency difference is the frequency difference corresponding to the first multi-carrier signal, and the frequency difference corresponding to sub-carriers f1 and f2 included in the first multi-carrier signal is Δf=f2-f1.

[0007] The second device adjusts the clock of the second device according to the phases corresponding to the first multi-carrier signal and the second multi-carrier signal obtained locally and the frequency difference of the first multi-carrier signal, so that the second device and the first device are time synchronized. This can achieve high-precision time synchronization between devices while avoiding the use of expensive high-stability atomic clocks, thereby reducing costs.

[0008] In some possible implementations, the second device can use empirical formulas, neural network models, transfer functions, convolution formulas, etc. to take the first phase difference ΔΦ1, the second phase difference ΔΦ2 and the first frequency difference Δf as input quantities to output adjustment quantities or clock differences to adjust the local clock of the second device, thereby making the first device and the second device time synchronized.

[0009] In some possible implementations, the second device determines a first adjustment amount based on the first phase difference ΔΦ1, the second phase difference ΔΦ2, and the first frequency difference Δf. The first adjustment amount is used for time synchronization between the first device and the second device, and the first adjustment amount Δτ satisfies the following conditions: Where ΔΦ1 represents the first phase difference, ΔΦ2 represents the second phase difference, and Δf represents the first frequency difference. By using interferometry to calculate the first adjustment amount, high-precision, low-cost, and low-complexity time synchronization between the first and second devices can be further achieved.

[0010] In some possible implementations, the second device performs time synchronization with the first device based on the first phase difference ΔΦ1, the second phase difference ΔΦ2, and the first frequency difference Δf, and needs to consider the first delay at the same time. The first delay is associated with the geometric distance between the first device and the second device, where the geometric distance may refer to the distance that the signal propagates between the first device and the second device. The first delay may be the geometric delay Δτ g_12 By further using the geometric distance between the first device and the second device, and using empirical formulas, neural network models, transfer functions, convolution formulas, etc. to calculate the output or clock difference for the second device, the operation speed is improved.

[0011] In some possible implementations, the second device determines a first adjustment amount based on the first phase difference ΔΦ1, the second phase difference ΔΦ2, and the first frequency difference Δf, where the first adjustment amount is used for time synchronization between the first device and the second device, and the first adjustment amount Δτ satisfies the following conditions: Where ΔΦ1 represents the first phase difference, ΔΦ2 represents the second phase difference, Δf represents the first frequency difference, Δτ g_12 By using the interferometry method to calculate the first adjustment amount and directly deducting the known geometric delay amount, high-precision, low-cost, and low-complexity time synchronization between the first device and the second device can be further achieved.

[0012] In conjunction with an implementation of the first aspect, when the geometric distance between the first device and the second device is unknown, the present application provides a two-way measurement method that can further eliminate the first time delay Δτ associated with the geometric distance. g_12 The method requires the first device side and the second device side to adjust the clock, and the method includes: the second device sends a third multi-carrier signal, wherein the third multi-carrier signal includes at least two subcarriers f 21 , f 22 , wherein the two subcarriers correspond to separate frequency points on the spectrum; the second device determines the subcarrier f included in the third multicarrier signal 21 The corresponding fifth phase Φ' 21 , the sixth phase Φ' corresponding to subcarrier f2 22 The second device sends a second information, wherein the second information is used to indicate the fifth phase corresponding to the third multi-carrier signal Φ ' 21 and the sixth phase Φ' 22 The third multi-carrier signal and the second information are used by the first device to adjust the local clock; the second device detects a fourth multi-carrier signal, wherein the fourth multi-carrier signal includes at least two subcarriers f 31 , f 32, wherein the two subcarriers correspond to separate frequency points on the spectrum; the second device determines the subcarrier f included in the fourth multicarrier signal 31 The corresponding seventh phase Φ' 31 , subcarrier f 32 The corresponding eighth phase Φ' 32 The fourth multi-carrier signal is a fifth multi-carrier signal transmitted by the first device and propagated through the channels; the second device receives third information, wherein the third information is used to indicate the ninth phase and the tenth phase corresponding to the fifth multi-carrier signal. 31 Corresponding subcarrier signal f 31 , the tenth phase Φ 32 Corresponding subcarrier f 32 The second device adjusts the local clock according to the third phase difference, the fourth phase difference and the second frequency difference; wherein the third phase difference is the phase difference between the seventh phase and the ninth phase, ie ΔΦ 31 =Φ' 31 -Φ 31 The fourth phase difference is the phase difference between the eighth phase and the tenth phase, ie ΔΦ 32 =Φ' 32 -Φ 31 The second frequency difference is the frequency difference corresponding to the fourth multi-carrier signal, and the subcarrier f included in the fourth multi-carrier signal 32 , f 31 The corresponding frequency difference is Δ″f=f 32 -f 31 ; The method for adjusting the local clock of the second device can be: the second device adjusts the local clock according to the third phase difference ΔΦ 31 , the fourth phase difference ΔΦ 32 and the second frequency difference Δ″f to obtain the third adjustment value Δτ′ 12 , thereby adjusting the local clock, such as

[0013] In this way, the geometric delay Δτ corresponding to the distance between the first device and the second device can be made g_12 is eliminated, thereby achieving the purpose of high-precision, low-cost, and low-complexity time synchronization between the first device and the second device.

[0014] In conjunction with an implementation of the first aspect, when the geometric distance between the first device and the second device is unknown, the present application provides a two-way measurement method that can further eliminate the first time delay Δτ associated with the geometric distance. g_12 The method requires the second device to adjust the clock, and the method includes: the second device sends a third multi-carrier signal, wherein the third multi-carrier signal includes at least two sub-carriers f 21 , f 22, wherein the two subcarriers correspond to separate frequency points on the spectrum. The second device determines the subcarrier f included in the third multicarrier signal 21 The corresponding fifth phase Φ' 21 , subcarrier f 22 The corresponding sixth phase Φ' 22 The second device sends second information, wherein the second information is used to indicate the fifth phase Φ' corresponding to the third multi-carrier signal 21 and the sixth phase Φ' 22 The third multi-carrier signal and the second information are used by the first device to adjust the local clock. The second device detects a fourth multi-carrier signal, wherein the fourth multi-carrier signal includes at least two subcarriers f 31 , f 32 , wherein the two subcarriers correspond to separate frequency points on the spectrum. The second device determines the subcarrier f included in the fourth multicarrier signal 31 The corresponding seventh phase Φ' 31 , subcarrier f 32 The corresponding eighth phase Φ' 32 The fourth multi-carrier signal is a fifth multi-carrier signal transmitted by the first device and propagated through the channels. The second device receives third information, wherein the third information is used to indicate the ninth phase and the tenth phase corresponding to the fifth multi-carrier signal. The ninth phase Φ 31 Corresponding subcarrier signal f 31 , the tenth phase Φ 32 Corresponding subcarrier f 32 The second device determines the third adjustment amount Δτ' according to the third phase difference, the fourth phase difference and the second frequency difference. 12 The third phase difference is the phase difference between the seventh phase and the ninth phase, that is, ΔΦ 31 =Φ' 31 -Φ 31 The fourth phase difference is the phase difference between the eighth phase and the tenth phase, that is, ΔΦ 32 =Φ' 32 -Φ 31 The second frequency difference is the frequency difference corresponding to the fourth multi-carrier signal, and the subcarrier f included in the fourth multi-carrier signal 32 , f 31 The corresponding frequency difference is Δ″f=f 32 -f 31 The second device receives fourth information, wherein the fourth information is used to indicate the second adjustment amount Δτ 21 The second device adjusts the value of the second adjustment amount and the third adjustment amount Δτ' 12 Adjust the local clock, if it can be adjusted to In this way, the geometric delay Δτ corresponding to the distance between the first device and the second device can be madeg_12 is eliminated, thereby achieving the purpose of high-precision, low-cost, and low-complexity time synchronization between the first device and the second device.

[0015] In a second aspect, a time synchronization method is provided, which requires a first device so that the first device and the second device are time synchronized. The method includes the following steps: the first device sends a second multi-carrier signal, wherein the second multi-carrier signal includes at least two sub-carriers f1 and f2, and the two sub-carriers correspond to separate frequency points on the spectrum; the first device determines a third phase Φ1 corresponding to sub-carrier f1 and a fourth phase Φ2 corresponding to sub-carrier f2 included in the second multi-carrier signal; the first device sends first information, wherein the first information is used to indicate the third phase Φ1 and the fourth phase Φ2 corresponding to the second multi-carrier signal, and the second multi-carrier signal and the first information are used by the second device to adjust the local clock.

[0016] The second device adjusts the clock of the second device according to the phases corresponding to the first multi-carrier signal and the second multi-carrier signal obtained locally and the frequency difference of the first multi-carrier signal, so that the second device and the first device are time synchronized. This can achieve high-precision time synchronization between devices while avoiding the use of expensive high-stability atomic clocks, thereby reducing costs.

[0017] In conjunction with an implementation of the second aspect, when the geometric distance between the first device and the second device is unknown, the present application provides a two-way measurement method that can further eliminate the first time delay Δτ associated with the geometric distance. g_12 The method requires the first device side and the second device side to adjust the clock, and the method includes: the first device detects the sixth multi-carrier signal, wherein the sixth multi-carrier signal includes at least two subcarriers f 21 , f 22 , wherein the two subcarriers correspond to separate frequency points on the spectrum; the first device determines the subcarrier f included in the sixth multicarrier signal 21 The corresponding eleventh phase Φ' 31 , subcarrier f 32 The corresponding twelfth phase Φ' 32 wherein the sixth multi-carrier signal is a third multi-carrier signal transmitted by the second device through the inter-channel propagation; the first device receives the second information, wherein the second information is used to indicate the fifth phase and the sixth phase corresponding to the third multi-carrier signal; wherein the fifth phase Φ ' 21 Corresponding subcarrier signal f 21 , the sixth phase Φ' 22 Corresponding subcarrier f 22The first device adjusts the local clock according to the fifth phase difference, the sixth phase difference and the fifth frequency difference; wherein the fifth phase difference is the phase difference between the eleventh phase and the fifth phase, that is, ΔΦ 21 =Φ' 21 -Φ 21 The sixth phase difference is the phase difference between the twelfth phase and the sixth phase, that is, ΔΦ 22 =Φ' 22 -Φ 22 The fifth frequency difference is the frequency difference corresponding to the sixth multi-carrier signal, and the subcarrier f included in the fifth multi-carrier signal 22 , f 21 The corresponding frequency difference is Δ′f=f 22 -f 21 ; Wherein the first device can adjust the local clock to The first device sends a fifth multi-carrier signal, wherein the fifth multi-carrier signal includes at least two subcarriers f 31 , f 32 , wherein the two subcarriers correspond to separate frequency points on the spectrum; the first device determines the subcarrier f included in the fifth multicarrier signal 31 The corresponding ninth phase Φ 21 , subcarrier f 32 The corresponding tenth phase Φ 22 The first device sends a third information, wherein the third information is used to indicate the ninth phase Φ corresponding to the fifth multi-carrier signal 21 and the tenth phase Φ 22 , the fifth multi-carrier signal and the third information are used by the second device to adjust a local clock.

[0018] In this way, the geometric delay Δτ corresponding to the distance between the first device and the second device can be made g_12 is eliminated, thereby achieving the purpose of high-precision, low-cost, and low-complexity time synchronization between the first device and the second device.

[0019] In conjunction with an implementation of the second aspect, when the geometric distance between the first device and the second device is unknown, the present application provides a two-way measurement method that can further eliminate the first time delay Δτ associated with the geometric distance. g_12 The method requires the second device to adjust the clock, and the method includes: the first device detects a sixth multi-carrier signal, wherein the sixth multi-carrier signal includes at least two subcarriers f 21 , f 22 , wherein the two subcarriers correspond to separate frequency points on the spectrum. The first device determines the subcarrier f included in the sixth multicarrier signal 21 The corresponding eleventh phase Φ' 31 , subcarrier f 32The corresponding twelfth phase Φ' 32 The sixth multi-carrier signal is a third multi-carrier signal transmitted by the second device through inter-channel propagation. The first device receives second information, wherein the second information is used to indicate the fifth phase and the sixth phase corresponding to the third multi-carrier signal. The fifth phase Φ' 21 Corresponding subcarrier signal f 21 , the sixth phase Φ' 22 Corresponding subcarrier f 22 The first device determines the second adjustment amount Δτ according to the fifth phase difference, the sixth phase difference and the fifth frequency difference. 21 The fifth phase difference is the phase difference between the eleventh phase and the fifth phase, that is, ΔΦ 21 =Φ' 21 -Φ 21 The sixth phase difference is the phase difference between the twelfth phase and the sixth phase, that is, ΔΦ 22 =Φ' 22 -Φ 22 The fifth frequency difference is the frequency difference corresponding to the sixth multi-carrier signal, and the subcarrier f included in the sixth multi-carrier signal 22 , f 21 The corresponding frequency difference is Δ′f=f 22 -f 21 The first device sends fourth information, wherein the fourth information is used to indicate the second adjustment amount Δτ 21 The second adjustment amount is used by the second device to adjust the local clock. The first device sends a fifth multi-carrier signal, wherein the fifth multi-carrier signal includes at least two subcarriers f 31 , f 32 , wherein the two subcarriers correspond to separate frequency points on the spectrum. The first device determines the subcarrier f included in the fifth multicarrier signal 31 The corresponding ninth phase Φ 21 , subcarrier f 32 The corresponding tenth phase Φ 22 The first device sends third information, wherein the third information is used to indicate the ninth phase Φ corresponding to the fifth multi-carrier signal. 21 and the tenth phase Φ 22 , the fifth multi-carrier signal and the third information are used by the second device to adjust a local clock.

[0020] In this way, the geometric delay Δτ corresponding to the distance between the first device and the second device can be made g_12 is eliminated, thereby achieving the purpose of high-precision, low-cost, and low-complexity time synchronization between the first device and the second device.

[0021] In conjunction with the first or second aspect, in some possible implementations, the second device transmits the third multi-carrier signal and the first device transmits the fifth multi-carrier signal in parallel. That is, the first device transmits the third multi-carrier signal and the second device transmits the fifth multi-carrier signal at the agreed time, respectively. This can offset the response time of the first and second devices, further improving the accuracy of time synchronization.

[0022] Furthermore, the second device transmits the third multi-carrier signal and the second information, and the first device transmits the fifth multi-carrier signal and the third information in parallel. Parallel transmission means that the second device and the first device each transmit signals at the same agreed time. Furthermore, the first and second devices can operate in full-duplex mode. This further offsets the response time of the first and second devices, further improving the accuracy of time synchronization.

[0023] In combination with the first aspect or the second aspect, in some possible implementations, the first device locally analyzes the phase, third phase, and fourth phase of the second multi-carrier signal and obtains time information corresponding to the second multi-carrier signal; the first device sends first information to indicate the third phase and fourth phase corresponding to the second multi-carrier signal, and the time information corresponding to the second multi-carrier signal. As an implementation, a timestamp can be used to indicate the corresponding time information of the second multi-carrier signal. The timestamp can refer to the number of seconds since January 1, 1970 (00:00:00 GMT), and the first device can send the timestamp using a character sequence.

[0024] Thus, the second device can analyze and obtain the phases Φ′1 to Φ′2 corresponding to each subcarrier f1 and f2 included in the first multicarrier signal using the time information corresponding to the second multicarrier signal. Furthermore, due to slight variations in the subcarrier frequencies f1 and f2 included in the first multicarrier signal due to transmission through the channel, the second device can analyze and obtain the subcarriers f'1 and f'2 included in the first multicarrier signal using the corresponding moments marked by the timestamp. By transmitting and obtaining the time information corresponding to the multicarrier signal, the accuracy of time synchronization can be further improved.

[0025] In combination with the first aspect and the second aspect, in some possible implementations, the first multi-carrier signal includes a first subcarrier f1, a second subcarrier f2 and a third subcarrier f3, and the first subcarrier, the second subcarrier and the third subcarrier correspond to different frequencies respectively. The frequency difference between the first subcarrier and the second subcarrier corresponds to the third frequency difference, that is, Δf=f1-f2. The frequency difference between the second subcarrier and the third subcarrier corresponds to the fourth frequency difference, that is, Δ"'f=f2-f3. The third frequency difference Δf is greater than the fourth frequency difference Δ"'f. Since the measurement range is inversely proportional to the frequency difference, and the measurement error in calculating the signal delay difference will increase when the frequency difference is equally spaced, by setting the signal in this way, when calculating the signal delay difference based on the interference measurement technology, it is possible to expand the measurement range (that is, the distance range between the first device and the second device) and reduce the measurement error in calculating the signal delay difference.

[0026] Furthermore, the third frequency difference Δf is K times the fourth frequency difference Δ"'f, where K is a positive integer. That is, the frequency difference between the frequency points corresponding to each subcarrier on the spectrum is increased in geometric proportion, thereby further improving the operation speed, quickly calculating the ambiguity, and saving frequency resources.

[0027] Furthermore, K is 2. In the technical solution for calculating the signal delay difference based on the interferometric measurement technology in the present application, when the second device performs differential analysis based on the phase obtained by the local analysis of the first device and the second device, a series of binary index sequences are generated, such as {2 i-1}, where i is a natural number greater than or equal to 1, thereby assisting in the rapid calculation of ambiguity and improving the operation speed.

[0028] In a third aspect, a communications device is provided. In one possible implementation, the communications device may include modules or units corresponding to the methods, operations, steps, and actions described in the first aspect. The modules or units may be implemented as hardware circuits, software, or a combination of hardware circuits and software. In one possible implementation, the device may include a transceiver module and a signal processing module.

[0029] The transceiver module is configured to receive a first multi-carrier signal and first information. The processing module is configured to detect the first multi-carrier signal, thereby determining a first phase Φ'1 and a second phase Φ'2 corresponding to the first multi-carrier signal; determine a third phase Φ1 and a fourth phase Φ2 corresponding to the second multi-carrier signal based on the first information; determine a first phase difference ΔΦ1 = Φ'1 - Φ1 and a second phase difference ΔΦ2 = Φ'2 - Φ2; determine a first frequency difference Δf corresponding to the first multi-carrier signal; and perform time synchronization with the first device based on the first phase difference, the second phase difference, and the first frequency difference.

[0030] In some implementations, the processing unit uses empirical formulas, neural network models, transfer functions, convolution formulas, etc. to take the first phase difference ΔΦ1, the second phase difference ΔΦ2 and the first frequency difference Δf as input quantities to output adjustment quantities or clock differences to adjust the local clock of the second device, thereby synchronizing the time of the first device and the second device.

[0031] In some implementations, the processing unit determines a first adjustment amount based on the first phase difference ΔΦ1, the second phase difference ΔΦ2, and the first frequency difference Δf, where the first adjustment amount is used for time synchronization between the first device and the second device, and the first adjustment amount Δτ satisfies the following conditions:

[0032] In some implementations, the processing unit performs time synchronization with the first device based on the first phase difference ΔΦ1, the second phase difference ΔΦ2, and the first frequency difference Δf, while taking into account the first time delay.

[0033] In some implementations, the processing unit determines a first adjustment amount based on the first phase difference ΔΦ1, the second phase difference ΔΦ2, and the first frequency difference Δf, where the first adjustment amount is used for time synchronization between the first device and the second device, and the first adjustment amount Δτ satisfies the following conditions:

[0034] In addition, the transceiver unit can also be used to send a third multi-carrier signal, send the second information, receive a fourth multi-carrier signal, and receive the third information. The processing unit obtains a third adjustment amount based on the third multi-carrier signal and the second information, and adjusts the local clock based on the third adjustment amount.

[0035] In addition, the transceiver unit can also be configured to receive a fourth multi-carrier signal, receive third information, receive a fourth multi-carrier signal, receive third information, and receive fourth information. The processing unit obtains a third adjustment amount based on the third multi-carrier signal and the second information; obtains a second adjustment amount based on the fourth information; and adjusts the local clock based on the second adjustment amount and the third adjustment amount.

[0036] In some implementations, the processing unit is further configured to determine time information corresponding to the second multi-carrier signal, where the time information can be determined according to a timestamp included in the first information.

[0037] In some implementations, the first multi-carrier signal received by the transceiver module includes a first subcarrier f1, a second subcarrier f2, and a third subcarrier f3, and the first subcarrier, the second subcarrier, and the third subcarrier correspond to different frequencies, respectively. The difference between the frequencies of the first subcarrier and the second subcarrier corresponds to a third frequency difference, that is, Δf=f1-f2. The difference between the frequencies of the second subcarrier and the third subcarrier corresponds to a fourth frequency difference, that is, Δ"'f=f2-f3. The third frequency difference Δf is greater than the fourth frequency difference Δ"'f. Further, the third frequency difference Δf is K times the fourth frequency difference Δ"'f, and K is a positive integer. Further, K is 2.

[0038] In a fourth aspect, a communication device is provided. In one possible implementation, the communication device may include modules or units corresponding to the methods, operations, steps, and actions described in the second aspect. The modules or units may be implemented as hardware circuits, software, or a combination of hardware circuits and software. In one possible implementation, the device may include a transceiver module and a signal processing module.

[0039] The transceiver module is used to receive the sixth multi-carrier signal and the second information; the processing module is used to detect the second multi-carrier signal, thereby determining the third phase Φ1 and the fourth phase Φ2 corresponding to the first multi-carrier signal.

[0040] In addition, the transceiver unit may also receive a sixth multi-carrier signal, receive second information, send a fifth multi-carrier signal, and send third information. The processing unit adjusts the local clock according to the sixth multi-carrier signal and the second information.

[0041] In addition, the transceiver unit can also be used to receive the sixth multi-carrier signal, receive the second information, send the fifth multi-carrier signal, send the third information, and send the fourth information. The processing unit obtains the second adjustment amount according to the sixth multi-carrier signal and the second information.

[0042] In some implementations, the processing unit is further configured to determine time information corresponding to the second multi-carrier signal, where the time information can be determined based on a timestamp and sent through the first information.

[0043] In some implementations, the second multi-carrier signal sent by the transceiver module includes a first subcarrier f1, a second subcarrier f2, and a third subcarrier f3, and the first subcarrier, the second subcarrier, and the third subcarrier correspond to different frequencies, respectively. The difference in frequency between the first subcarrier and the second subcarrier corresponds to a third frequency difference, that is, Δf = f1-f2. The difference in frequency between the second subcarrier and the third subcarrier corresponds to a fourth frequency difference, that is, Δ"'f = f2-f3. The third frequency difference Δf is greater than the fourth frequency difference Δ"'f. Further, the third frequency difference Δf is K times the fourth frequency difference Δ"'f, where K is a positive integer. Further, K is 2. In a fifth aspect, a chip is provided, comprising a processor, the processor being coupled to a memory, the memory being used to store a computer program, the processor being used to execute the computer program stored in the memory, so that some or all of the steps of the method described in the first aspect and any possible implementation thereof, the second aspect and any possible implementation thereof are executed.

[0044] In a sixth aspect, a computer-readable storage medium is provided, in which a computer program or instruction is stored. When the computer program or instruction is executed by a processor, part or all of the steps of the method described in the first aspect and any possible implementation thereof, and the second aspect and any possible implementation thereof are executed.

[0045] In a seventh aspect, a computer product is provided. When the computer program product is run, part or all of the steps of the method described in the first aspect and any possible implementation thereof, and the second aspect and any possible implementation thereof are executed.

[0046] In an eighth aspect, a communication system is provided, comprising a first communication device provided by the third aspect and various possible implementations of the aforementioned aspects, and a second communication device provided by the fourth aspect and various possible implementations of the aforementioned aspects. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] FIG1 is a schematic diagram of an application scenario of the present application for achieving time synchronization between a first device and a second device based on interferometric measurement technology.

[0048] FIG2 is a schematic diagram of implementing time synchronization between a first device and a second device based on interference measurement technology of the present application.

[0049] FIG3 is a schematic diagram of a method for calculating signal delay difference according to the present application.

[0050] FIG4 is a schematic diagram of time synchronization between a first device and a second device based on interference measurement technology of the present application.

[0051] FIG5 is a schematic diagram of a method for eliminating geometric delay difference through a two-way measurement method of the present application.

[0052] FIG6 is a schematic diagram of another method of offsetting geometric delay difference through a two-way measurement method according to the present application.

[0053] FIG7 is a flow chart of a method for achieving time synchronization based on interferometric measurement technology according to the present application.

[0054] FIG8 is a simulation result of the time synchronization solution of the present application.

[0055] FIG9 is a schematic diagram of feature settings of a multi-carrier signal sent by a first device and a second device of the present application.

[0056] FIG10 is another schematic diagram of feature settings of multi-carrier signals sent by a first device and a second device of the present application.

[0057] FIG11 is a schematic diagram of an apparatus for locally analyzing multi-carrier signals according to an implementation device of the present application.

[0058] FIG12 is a schematic diagram of a device for implementing a time synchronization method based on interferometry according to the present application.

[0059] FIG13 is a schematic structural diagram of a first device and a second device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0060] The present application provides a time synchronization method that can improve the accuracy of time synchronization between devices and reduce costs.

[0061] The technical solution in this application will be described below with reference to the accompanying drawings.

[0062] The technical solutions of the embodiments of the present application can be applied to various communication systems, such as: long term evolution (LTE) system, LTE frequency division duplex (FDD) system, LTE time division duplex (TDD) system, fifth generation (5G) system, th generation (5G) systems such as new radio (NR) systems, 5.5G systems or sixth generation (6 th Systems that evolve after 5G, such as generation, 6G) systems.

[0063] The applicable scenarios of this application include but are not limited to terrestrial cellular communications, non-terrestrial networks (NTN), vehicle-to-everything (V2X), integrated access and backhaul (IAB), and reconfigurable intelligent surface (RIS) communications. Among them, the NTN system includes non-terrestrial equipment, which can be used as base stations, terminal devices, or relay devices. Non-terrestrial equipment can be drones, hot air balloons, low-orbit satellites, medium-orbit satellites, high-orbit satellites, or high altitude platform station (HAPS) equipment.

[0064] The technical solutions of the embodiments of the present application are applicable to both homogeneous and heterogeneous network scenarios, and there is no restriction on the transmission points. It can be multi-point coordinated transmission between macro base stations, micro base stations, and macro base stations, and is applicable to FDD / TDD systems. The technical solutions of the embodiments of the present application are not only applicable to low-frequency scenarios (sub 6G), but also to high-frequency scenarios (above 6GHz), terahertz, optical communications, etc. The technical solutions of the embodiments of the present application can be applied not only to communications between network devices and terminals, but also to communications between network devices and network devices, between terminals, Internet of Vehicles, Internet of Things, Industrial Internet, etc.

[0065] The technical solutions of the embodiments of the present application can be applied to scenarios where a terminal is connected to a single base station, wherein the base station to which the terminal is connected and the core network (CN) to which the base station is connected are of the same standard or different standards. For example, the CN is a 5G CN, the base station is a 5G base station, and the 5G base station is directly connected to the 5G CN; or the CN is a 5G CN, the base station is a 4G base station, and the 4G base station is directly connected to the 5G Core. The technical solutions of the embodiments of the present application can also be applied to dual connectivity (DC) scenarios where a terminal is connected to at least two base stations.

[0066] The terminal device in the embodiment of the present application can be a device with wireless transceiver functions, which can refer to user equipment (UE), access terminal, subscriber unit, user station, mobile station, remote station, remote terminal, mobile device, user terminal, wireless communication equipment, user agent or user device. The terminal device may also be a satellite phone, a cellular phone, a smart phone, a wireless data card, a wireless modem, a machine type communication device, a cordless phone, a session initiation protocol (SIP) phone, a wireless local loop (WLL) station, a personal digital assistant (PDA), a customer premises equipment (CPE), a smart point of sale (POS) machine, a handheld device with wireless communication capabilities, a computing device or other processing device connected to a wireless modem, an in-vehicle device, a communication device carried on a high-altitude aircraft, a wearable device, a drone, a robot, a terminal in device-to-device (D2D) communication, a terminal in V2X, a virtual reality (VR) terminal device, an augmented reality (AR) terminal device, a wireless terminal in industrial control, a wireless terminal in self-driving, a wireless terminal in telemedicine, a wireless terminal in a smart grid, a wireless terminal in transportation security, a wireless terminal in medical equipment ... Safety), wireless terminals in smart cities, wireless terminals in smart homes, or terminal devices in communication networks evolved after 5G, etc., are not limited in the embodiments of the present application.

[0067] In the embodiments of the present application, the device for implementing the functions of the terminal device can be the terminal device; it can also be a device that can support the terminal device to implement the functions, such as a chip system. The device can be installed in the terminal device or used in conjunction with the terminal device. In the embodiments of the present application, the chip system can be composed of a chip or include a chip and other discrete devices.

[0068] The network device in the embodiment of the present application is a device with wireless transceiver functions, and is an access network device for communicating with a terminal device. The access network device may be a node in a radio access network (RAN), which may also be referred to as a base station, or a RAN node. The access network device may also be a device with some or all base station functions. For example, when the base station adopts a centralized unit (CU) and a distributed unit (DU) architecture, the access network device may include a CU and / or a DU. The access network device may be an evolved Node B (eNB or eNodeB) in LTE; or a base station in a 5G network such as a next-generation base station (gNodeB, gNB) or a base station in a public land mobile network (PLMN) evolved after 5G, a broadband network service gateway (BNG), an aggregation switch or a third generation partnership project (3GPP) rd generation partnership project, 3GPP) access equipment, etc.

[0069] The network devices in the embodiments of the present application may also include various forms of base stations, such as: macro base stations, micro base stations (also called small stations), relay stations, transmission points (transmitting and receiving points, TRP), transmitting points (transmitting points, TP), mobile switching centers, and drone communications, device-to-device (D2D), vehicle-to-everything (V2X), machine-to-machine (M2M) communications, etc., and network devices in NTN communication systems, which are not specifically limited in the embodiments of the present application.

[0070] In the embodiments of the present application, the device for implementing the functions of the network device can be a network device, or a device that can support the network device to implement the functions, such as a chip system. The device can be installed in the network device or used in conjunction with the network device. The chip system in the embodiments of the present application can be composed of a chip, or can include a chip and other discrete devices.

[0071] In the present application, a time synchronization method is provided, which can calculate the signal delay difference based on the interference measurement technology, thereby obtaining the clock difference for time synchronization of the first device and the second device.

[0072] First, the application scenario of the time synchronization method provided by the present application is explained. Figure 1 is a schematic diagram of the application scenario of the present application for realizing time synchronization between the first device and the second device based on the interference measurement technology. As shown in Figure 1 (a), the time synchronization solution of the present application can be applied to the scenario where the terminal is connected to multiple network devices. For example, in the process where network device 101 and network device 102 locate the terminal device 103 based on the time difference of arrival (TDOA) positioning method, the time synchronization error will directly cause the network device 101 and network device 102 to locate the terminal device 103 inaccurately, and the technical solution of the present application can achieve higher time synchronization accuracy at a lower cost, thereby improving the accuracy of positioning. As shown in Figure 1 (b), the time synchronization solution of the present application can be applied to the scenario where the terminal is connected to the network device. For example, in the process of network device 112 positioning terminal device 111 based on the time difference of arrival (TOA) positioning method, the time synchronization error will directly lead to inaccurate positioning of terminal device 111 by network device 112. The technical solution of the present application can achieve higher time synchronization accuracy at a lower cost, thereby improving positioning accuracy. In addition, the time synchronization solution of the present application can be applied to multi-station collaboration. The technical solution of the present application can achieve higher time synchronization accuracy at a lower cost, thereby improving perception performance.

[0073] FIG2 is a schematic diagram of the time synchronization between the first device and the second device based on the interferometric measurement technology of the present application. In the collaboration between the first device and the second device, the first device is now set to have an independent clock t clk1 Independent clock t local to the second device clk2 Asynchronous, there is a clock difference t clk1 -t clk2 =Δτ clk .

[0074] Due to the distance and clock difference between the first device and the second device, the signal from the same signal source has a signal delay difference between the first device and the second device. It can be understood that when the first device sends a signal to the second device, there is a signal delay difference Δτ 12 =Δτ g_12 +Δτ clk +n1τ r . Among them, Δτ g_12 Δτ is the geometric delay, which is the delay difference caused by the geometric distance between the first device and the second device. The geometric distance can refer to the route taken by the signal during propagation and is only related to the distance between the first device and the second device. clk is the clock difference, i.e. the local independent clock t of the first device clk1 Independent clock t local to the second deviceclk2 Delay caused by asynchrony. n1τ r is the integer ambiguity, that is, the number of unknown integer wavelengths contained in the estimated value of the delay, where n1 is a natural number greater than or equal to 1, τ r is an integer ambiguity, the integer ambiguity n1τ r The signal delay difference Δτ can be calculated by constraining the calculated value. 12 process of elimination.

[0075] Similarly, when the second device sends a signal to the first device, since the directions of the two signal transmissions are opposite, there is a signal delay difference of Δτ 21 =Δτ g_12 -Δτ clk +n2τ r . Among them, Δτ g_12 is the geometric delay, that is, the delay difference caused by the geometric distance between the first device and the second device. clk is the clock difference. n2τ r is the integer ambiguity, where n2 is a natural number greater than or equal to 1, τ r is an integer ambiguity, the integer ambiguity n2τ r The signal delay difference Δτ can be calculated by constraining the calculated value. 21 process of elimination.

[0076] When the geometric distance between the first device and the second device is known, that is, the geometric delay Δτ f_ If known, in this application, the interference measurement technology shown in process 2 in Figure 2 can be used to send a signal from the first device to the second device, and the second device calculates the signal delay difference Δτ 12 =Δτ g_12 +Δτ clk +n1τ r , eliminating the integer ambiguity n1τ r , and deducting the known geometric delay Δτ g_12 Then, calculate the clock difference Δτ clk The second device uses the clock difference Δτ clk Adjust the local clock t′ clk2 =t clk2 -Δτ clk , so that the time of the first device and the second device are synchronized, thereby achieving high precision of time synchronization between devices and reducing costs.

[0077] When the geometric distance between the first device and the second device is unknown, that is, the geometric delay Δτ g_12 In the unknown case, as shown in process 1 and process 2 in FIG2 , in this application, a two-way measurement method can be used to eliminate the geometric delay and achieve time synchronization.

[0078] Process 1:

[0079] The first device sends a signal to the second device, and the second device calculates the signal delay difference Δ′τ based on the signal sent by the first device. 12 =Δτ g_12 +Δτ clk +n1τ r ;

[0080] The second device sends a signal to the first device. The first device calculates the delay difference based on the signal sent by the second device. Since the directions of the two signal transmissions are opposite, the signal delay difference calculated by the first device is Δτ 21 =Δτ g_12 -Δτ clk +n2τ r ;

[0081] Process 2:

[0082] The first device sends a signal to the second device, and the second device calculates the signal delay difference Δτ based on the signal sent by the first device. 12 =Δτ g_12 +Δτ clk +n1τ r .

[0083] As a way to achieve time synchronization based on process 1 and process 2, the first device is based on Δτ 21 =Δτ g_12 -Δτ clk +n2τ r Adjust the local clock t clk1 , the second device is based on Δ′τ 12 =Δτ g_12 +Δτ clk +n1τ r and Δτ 12 =Δτ g_12 +Δτ clk +n1 adjust the local clock t clk2 The local clock of the first device is adjusted to The local clock of the second device is adjusted to At this time, the difference between the local clocks of the first device and the second device is Eliminating the integer ambiguity n1τ by constraining the calculated value r and n2τ r After that, the difference between the local clocks of the first device and the second device is t′ clk1 -t′ clk2 =(t clk1 -t clk2 )-Δτ clk=0, the first device is time synchronized with the second device.

[0084] As another way to achieve time synchronization based on process 1 and process 2, the first device calculates the signal delay difference as Δτ 21 =Δτ g_12 -Δτ clk +n2τ r Sent to the second device, the second device based on Δτ 12 =Δτ g_12 +Δτ clk +n1τ r , Δ′τ 12 =Δτ g_12 +Δτ clk +n1τ r and Δτ 21 =Δτ g_12 -Δτ clk +n2τ r Adjust the local clock t clk2 The local clock of the second device is adjusted to At this time, the difference between the local clocks of the first device and the second device is Eliminating the integer ambiguity n1τ by constraining the calculated value r and n2τ r After that, the difference between the local clocks of the first device and the second device is t′ clk1 -t′ clk2 =(t clk1 -t clk2 )-Δτ clk =0, the first device is time synchronized with the second device.

[0085] In the above-mentioned time synchronization process, the whole cycle ambiguity can be eliminated, for example, by constraining eliminate.

[0086] Based on process 1 and process 2 in Figure 2, the time synchronization between the first device and the second device is achieved, further realizing the effect of high-precision, low-cost, and low-process-complexity time synchronization between the first device and the second device when the geometric distance between the first device and the second device is unknown.

[0087] The signal delay difference calculated based on the interference measurement technology referred to in this application can be based on the first device sending a multi-carrier signal to the second device. The multi-carrier signal includes at least two sub-carriers, wherein each sub-carrier corresponds to a different discrete frequency point on the spectrum, and the frequency point f corresponding to each sub-carrier on the spectrum can be i (i is a natural number greater than or equal to 1) is set to f1~f iFor the convenience of description, the multi-carrier signal sent by the first device and not transmitted through the channel is referred to as the second multi-carrier signal; the multi-carrier signal received by the second device and propagated through the channels is referred to as the first multi-carrier signal.

[0088] As an implementation method, the first device can locally analyze and obtain the subcarriers f1 to f2 included in the second multicarrier signal. i Corresponding phase Φ1~Φ i The first information is used to instruct the first device to analyze and obtain the subcarriers f1 to f2 included in the second multicarrier signal locally. i Corresponding phase Φ1~Φ i After the second device receives the first multi-carrier signal transmitted between channels, the second device locally analyzes and obtains the sub-carriers f1 to f i Corresponding phase Φ′1~Φ′ i and by performing the multi-carrier signal on each subcarrier f1 to f i Corresponding phase Φ′1~Φ′ i and the subcarriers f1 to f2 included in the second multicarrier signal. i Corresponding phase Φ1~Φ i Perform the difference and convert Φ′ i -Φ i Obtain ΔΦ i , according to each subcarrier f1~f i The frequency difference between ΔΦ1 and ΔΦ i , calculate the signal delay difference.

[0089] As another implementation method, the first device can locally analyze and obtain the subcarriers f1 to f2 included in the second multicarrier signal. i Corresponding phase Φ1~Φ i , and the time information corresponding to the second multi-carrier signal in the first device. The first device sends the second multi-carrier signal and the first information to the second device. The first information is used to instruct the first device to analyze the subcarriers f1 to f1 included in the second multi-carrier signal locally. i Corresponding phase Φ1~Φ i After the second device receives the first multi-carrier signal transmitted between channels, the second device analyzes the time information corresponding to the second multi-carrier signal locally to obtain the sub-carriers f1 to f2 included in the first multi-carrier signal. i Corresponding phase Φ′1~Φ′ i and by performing the multi-carrier signal on each subcarrier f1 to f i Corresponding phase Φ′1~Φ′ iand the subcarriers f1 to f2 included in the second multicarrier signal. i Corresponding phase Φ1~Φ i Perform the difference, such as Φ′ i -Φ i Obtain ΔΦ i , according to each subcarrier f1~f i The frequency difference between ΔΦ1 and ΔΦ i , calculate the signal delay difference. Furthermore, since the first multi-carrier signal is transmitted between channels, the frequencies of the sub-carriers included in the first multi-carrier signal may change slightly. The second device can also locally analyze the time information corresponding to the second multi-carrier signal to obtain the sub-carriers f′1 to f′ included in the first multi-carrier signal. i , so as to further accurately calculate the signal delay difference.

[0090] As another implementation, the first device sends the second multi-carrier signal and the time information corresponding to the second multi-carrier signal on the first device to the second device. After the second device receives the first multi-carrier signal transmitted through the inter-channel, the second device analyzes and obtains the subcarriers f1 to f2 included in the first multi-carrier signal locally. i Corresponding phase Φ′1~Φ′ i , and using the time information corresponding to the second multi-carrier signal, the first device reversely analyzes the sub-carriers f1 to f included in the first multi-carrier signal i Corresponding phase Φ1~Φ i The second device performs the following operations on the subcarriers f1 to f2 of the first multicarrier signal: i Corresponding phase Φ′1~Φ′ i and the subcarriers f1 to τ included in the second multicarrier signal i Corresponding phase Φ1~Φ i Perform the difference, such as Φ′ i -Φ i Get ΔΦ1~ΔΦ i , according to each subcarrier f1~f i The frequency difference between i , calculating the signal delay difference. By inferring the phase of the first multi-carrier signal locally on the first device using the time information corresponding to the second multi-carrier signal on the second device, the complexity of the signal form sent by the first device to the second device can be reduced, thereby reducing the complexity of the process.

[0091] It should be understood that in the above calculation, each subcarrier f1~f i The frequency difference between ΔΦ1 and ΔΦ iThe calculation method of uniformly utilizing the corresponding difference between the first multi-carrier signal and the second multi-carrier signal is for illustrative purposes only. The specific calculation method and the positive or negative nature of the calculation are determined according to actual conditions. For example, the phase difference may also be the phase of the second multi-carrier signal minus the phase of the first multi-carrier signal.

[0092] It should be understood that the present application does not limit the specific form of the time information or how the first device transmits the time information. As an implementation, a timestamp can be used to indicate the corresponding time information of the second multi-carrier signal. The timestamp can refer to the number of seconds since January 1, 1970 (00:00:00 GMT), and the first device can use a character sequence to transmit the timestamp.

[0093] In the above three methods, the signal delay difference is calculated by adopting the interference measurement method based on local correlation, that is, the second device locally analyzes and obtains the phases corresponding to the first multi-carrier signal and the second multi-carrier signal, and then obtains the delay difference based on the measured phases. This method is used to obtain a round-trip time measurement method with a simple form and small system error when measuring round-trip time (RTT). In addition, directly sending the signal phase can reduce the amount of information in the interaction process and avoid the transmission of the sampled original data. Finally, this method avoids the use of cross-correlation to calculate the phase difference, which not only reduces the amount of calculation but also avoids the signal-to-noise ratio deterioration problem that may be caused by the cross-correlation method, thereby improving the synchronization accuracy.

[0094] It should be understood that this application does not explain how the second device performs the operations according to the subcarriers f1 to f2. i The frequency difference between i , the method for calculating the signal delay difference is limited. For example, the calculation method can be a mapping relationship obtained by fitting a large amount of experimental data, or a dedicated neural network model trained based on a large amount of experimental data.

[0095] As an implementation method, FIG3 is a schematic diagram of a method for calculating a signal delay difference of the present application. In the case where the first multi-carrier signal includes two subcarriers, the signal delay difference Δτ 12 The formula can be Obtained. Wherein, f1 is the frequency of the first subcarrier included in the first multicarrier signal, and f2 is the frequency of the second subcarrier included in the first multicarrier signal. Wherein, ΔΦ1 is the difference in the phase of the first subcarrier obtained by the local analysis of the first device and the second device, and ΔΦ2 is the difference in the phase of the second subcarrier obtained by the local analysis of the first device and the second device. In the case where the first multicarrier signal includes more than two subcarriers, as an example and not a limitation, the slope of the straight line can be obtained by straight line fitting, which is the signal delay difference Δτ 12By using the interferometry method to calculate the first adjustment amount, the time synchronization effect between the first device and the second device can be further achieved with high precision, low cost and low process complexity.

[0096] In addition, in some solutions of the present application, the second device can also directly input the values ​​f1 to f i The frequency difference between i Directly output the adjustment amount or clock difference Δτ through transfer functions, convolution formulas, etc. clk In some embodiments of the present invention, the second device adjusts the local clock of the second device by inputting the quantities f1 to f i The frequency difference between i The first delay is directly output as an adjustment or clock difference Δτ through transfer functions, convolution formulas, etc. clk Thus, the local clock of the second device is adjusted, wherein the first delay is associated with the geometric distance between the first device and the second device, and the geometric distance may refer to the distance that the signal propagates between the first device and the second device. The first delay may be the geometric delay Δτ g_12 By taking the first delay amount into consideration, the operation speed can be increased.

[0097] Below, the time synchronization method of the present application will be described in conjunction with a specific interaction process between the first device and the second device.

[0098] FIG4 is a schematic diagram of a method for implementing time synchronization between a first device and a second device based on interferometry technology in the present application. The method is applicable when the geometric distance between the first device and the second device is known, and includes the following steps:

[0099] S210, the first device sends a second multi-carrier signal to the second device, wherein the second multi-carrier signal includes at least two sub-carriers, for example, the second multi-carrier signal includes: sub-carriers f1 to f2 i , where i is a positive integer greater than or equal to 2.

[0100] Optionally, before step S210, the first device sends indication information to the second device, where the indication information is used to instruct the first device to perform time synchronization with the second device.

[0101] As another implementation method, the first device may send an indication information packet for time synchronization and interference measurement to the second device. The indication information packet may include indication information and parameters for interference measurement, wherein the indication information is used to instruct the first device to perform time synchronization with the second device, and the parameters for interference measurement may include a time synchronization period, signal parameters, etc. The time synchronization period is used to specify the period for performing a time synchronization operation. Signal parameters include the center frequency, frequency difference, number of frequencies, etc., which are used to specify the characteristics of the multi-carrier signal sent by the first device to the second device and received by the second device. In the present application, the first device and the second device may also obtain the above parameters by methods such as local pre-setting, and the present application is not limited to this. By sending the indication information packet, the time synchronization process can be standardized and resource allocation can be optimized.

[0102] S220, the first device sends first information to the second device, where the first information is used to indicate the subcarriers f1 to f2 included in the second multicarrier signal obtained by the first device through local analysis. i Corresponding phase Φ1~Φ i .

[0103] As an implementation method, the first information directly indicates the subcarriers f1 to f2 included in the second multicarrier signal obtained by the first device through local analysis. i Corresponding phase Φ1~Φ i .

[0104] As another implementation, the first information directly indicates the subcarriers f1 to f2 included in the second multicarrier signal obtained by the first device through local analysis. i Corresponding phase Φ1~Φ i , and time information corresponding to the second multi-carrier signal locally in the first device.

[0105] As another implementation method, the first information is used to indicate the time information corresponding to the second multi-carrier signal in the first device. The second device uses the time information corresponding to the second multi-carrier signal to reversely analyze the subcarriers f1 to f included in the second multi-carrier signal obtained by the first device locally. i Corresponding phase Φ1~Φ i .

[0106] S230, the second device receives the first multi-carrier signal, and locally analyzes the phases Φ'1 to Φ' corresponding to the sub-carriers included in the first multi-carrier signal. i And the frequencies f1 to f2 corresponding to each subcarrier i The first multi-carrier signal is a signal obtained by propagating the second multi-carrier signal sent by the first device through channels.

[0107] S240, the second device performs differential analysis based on the phases obtained by the local analysis of the first device and the second device, such as i -Φ i Obtain ΔΦ i , each subcarrier f1~f included in the second multi-carrier signal i The frequency difference between them is used to synchronize the time with the first device.

[0108] The second device may synchronize time with the first device in the following manner:

[0109] Method a: The second device inputs subcarriers f1 to f i The frequency difference between i , directly output the adjustment amount or clock difference Δτ through transfer function, convolution formula, etc. clk , adjust the local clock of the second device so that the time of the first device is synchronized with the second device.

[0110] Mode b: The second device inputs subcarriers f1 to f i The frequency difference between i , and according to the first time delay associated with the geometric distance between the first device and the second device, the clock difference Δτ is obtained by, for example, a transfer function, a convolution formula, etc. clk , adjust the local clock of the second device so that the time of the first device and the second device are synchronized. The first delay can be a geometric delay Δτ g_12 .

[0111] Method c: The first delay corresponding to the geometric distance between the first device and the second device is the geometric delay Δτ g_12 , when the geometric delay is known, the second device uses the formula Get the first adjustment value Δτ 12 =Δτ g_12 +Δτ clk +n1τ r , the second device can deduct the known geometric delay Δτ from the first adjustment amount g_12 After eliminating the integer ambiguity, calculate the clock difference Δτ clk =Δτ 12 -Δτ g_12 , and according to the clock difference Δτ clk Adjust the local clock of the second device, for example, it can be adjusted to t clk2 -Δτ clk , so that the time of the first device is synchronized with the time of the second device.

[0112] It should be understood that in the above calculation, each subcarrier f1~f i The frequency difference between ΔΦ1 and ΔΦ iThe calculation method of uniformly utilizing the difference between the first multi-carrier signal and the corresponding multi-carrier signal is for illustrative purposes only, and its specific calculation method and positive and negative values ​​are determined according to actual conditions. clk1 -t clk2 =Δτ clk , or t clk2 -t clk1 =Δτ clk .

[0113] It should be understood that this application does not impose any specific restrictions on the information conveyed by the first multi-carrier signal. Furthermore, this application does not impose any specific restrictions on the signal format in which the first information is carried. As one possible implementation, the first information is carried on the second multi-carrier signal.

[0114] When the geometric distance between the first device and the second device is unknown, the present application provides a two-way measurement method, which can further eliminate the geometric delay Δτ g_12 , thereby calculating the clock difference through the signal delay difference.

[0115] The second device adjusts the clock of the second device according to the phases corresponding to the first multi-carrier signal and the second multi-carrier signal obtained locally and the frequency difference of the first multi-carrier signal, so that the second device and the first device are time synchronized. This can achieve high-precision time synchronization between devices while avoiding the use of expensive high-stability atomic clocks, thereby reducing costs.

[0116] FIG5 is a schematic diagram of a method for eliminating geometric delay difference by a two-way measurement method of the present application. The method includes the following steps:

[0117] S311, the second device sends a third multi-carrier signal to the first device, where the third multi-carrier signal includes each subcarrier f 21 ~f 2i , where i is a positive integer greater than or equal to 2.

[0118] S312, the second device sends second information to the first device, where the second information is used to indicate the subcarriers f included in the second multicarrier signal obtained by local analysis by the second device. 21 ~f 2i Corresponding phase Φ 21 ~Φ 2i .

[0119] As an implementation method, the second information directly indicates the subcarriers f included in the third multi-carrier signal obtained by the first device through local analysis. 21 ~f 2i Corresponding phase Φ 21 ~Φ 2i .

[0120] As another implementation, the first information directly indicates the subcarriers f included in the third multi-carrier signal obtained by the first device through local analysis. 21 ~f 2i Corresponding phase Φ 21 ~Φ 2i , and time information corresponding to the third multi-carrier signal locally in the first device.

[0121] As another implementation method, the first information is used to indicate the time information corresponding to the third multi-carrier signal in the first device, and the second device uses the time information corresponding to the third multi-carrier signal to reversely analyze the subcarriers f included in the third multi-carrier signal obtained by the first device locally. 21 ~f 2i Corresponding phase Φ 21 ~Φ 2i .

[0122] S320, the first device obtains a second adjustment amount based on the received third multi-carrier signal and the second information after inter-channel propagation. The second adjustment amount can be based on the interferometric measurement technology, and the phase difference obtained by the local analysis of the first device and the second device is performed, such as Φ' 21 -Φ' 2i Obtain ΔΦ 2i , according to each subcarrier f 21 ~f 2i The frequency difference between 21 ~ΔΦ 2i , calculate the signal delay difference Δτ 21 =Δτ g_12 -Δτ clk +n2τ r .

[0123] S331, the first device sends a fourth multi-carrier signal to the second device, where the fourth multi-carrier signal includes each subcarrier f 31 ~f 3i , where i is a positive integer greater than or equal to 2.

[0124] S332: The first device sends third information to the second device, where the third information is used to indicate the subcarriers f included in the fourth multicarrier signal obtained by local analysis by the first device. 31 ~f 3i Corresponding phase Φ 31 ~Φ 3i .

[0125] As an implementation method, the second information directly indicates the subcarriers f included in the fourth multi-carrier signal obtained by the first device through local analysis. 31 ~f 3i Corresponding phase Φ 31 ~Φ3i .

[0126] As another implementation, the first information directly indicates the subcarriers f included in the fourth multi-carrier signal obtained by the first device through local analysis. 31 ~f 3i Corresponding phase Φ 31 ~Φ 3i , and time information corresponding to the fourth multi-carrier signal locally in the first device.

[0127] As another implementation method, the first information is used to indicate the time information corresponding to the fourth multi-carrier signal in the first device, and the second device uses the time information corresponding to the fourth multi-carrier signal to reversely analyze the subcarriers f included in the fourth multi-carrier signal obtained by the first device locally. 21 ~f 2i Corresponding phase Φ 21 ~Φ 2i .

[0128] S340, the second device obtains a third adjustment amount based on the received fourth multi-carrier signal and the third information after inter-channel propagation. The third adjustment amount can be based on the interferometric measurement technology, by performing a phase difference between the first device and the second device and the phase difference between the first device and the second device, and converting Φ' 31 -Φ' 3i Obtain ΔΦ 3i , according to each subcarrier f 31 ~f 3i The frequency difference between 31 ~ΔΦ 3i , calculate the signal delay difference Δτ' 12 =Δτ g_12 +Δτ clk +n1τ r .

[0129] As a way to eliminate the geometric delay, through step S350, the first device adjusts the second amount Δτ 21 =Δτ g_12 -Δτ clk +n2τ r Adjust the local clock t clk1 ; and performing the steps shown in FIG3, the second device performs the steps shown in FIG3 according to the interferometry method to obtain the signal delay Δτ 12 =Δτ g_12 +Δτ clk +n1τ r , and the third adjustment amount Δτ' 12 =Δτ g_12 +Δτ clk +n1τ r Adjust the local clock tclk2 As an example and not a limitation, the local clock of the first device is adjusted to The local clock of the second device is adjusted to At this time, the difference between the local clocks of the first device and the second device is Eliminating the integer ambiguity n1τ by constraining the calculated value r and n2τ r After that, the difference between the local clocks of the first device and the second device is t′ clk1 -t′ clk2 =(t clk1 -t clk2 )-Δτ clk =0, the first device is time synchronized with the second device.

[0130] In this way, the geometric delay Δτ corresponding to the distance between the first device and the second device can be made g_12 is eliminated, thereby achieving the purpose of high-precision, low-cost, and low-complexity time synchronization between the first device and the second device.

[0131] By using local correlation-based interferometry to calculate the signal delay difference, the first and second devices each analyze the phase of the first multi-carrier signal locally, and then calculate the delay difference. In two-way measurements, this method eliminates systematic errors caused by the device response times of the first and second devices, improving the measurement accuracy of geometric delay.

[0132] Furthermore, step S311 and step S331 may occur in parallel, that is, the first device and the second device send the third multi-carrier signal and the fourth multi-carrier signal to each other at the agreed time; further, step S311, the second device sends the second information, and step S331, the first device sends the third information, which occur in parallel; further, the working mode of the first device and the second device is full-duplex mode, so as to further offset the response time of the first device and the second device, and further improve the accuracy of time synchronization.

[0133] It should be understood that this application does not impose specific limitations on the information conveyed by the third and fourth multi-carrier signals. Furthermore, this application does not impose specific limitations on the signal formats in which the second and third information are carried. As one possible implementation, the second information is carried on the third multi-carrier signal. As one possible implementation, the third information is carried on the fourth multi-carrier signal.

[0134] It should be understood that this application does not limit the order of steps, and the specific order should be determined according to the specific application environment and design.

[0135] FIG6 is a schematic diagram of another method for offsetting geometric delay difference by a two-way measurement method of the present application. The method includes the following steps:

[0136] S411, S412, S420, S431, S432, and S440 correspond to steps S311, S312, S320, S331, S332, and S340 in Figure 5, respectively, and are not repeated here.

[0137] As a way to eliminate geometric delay:

[0138] Through step S450, the first device sends fourth information to the second device, where the fourth information indicates the second adjustment amount.

[0139] And execute the steps shown in FIG3 , the second device obtains the signal delay Δτ according to the interference measurement method according to the steps shown in FIG3 12 =Δτ g_12 +Δτ clk +n1τ r , the second adjustment amount Δτ 21 =Δτ g_12 -Δτ clk +n2τ r , the third adjustment amount Δτ' 12 =Δτ g_12 +Δτ clk +n1τ r Adjust the local clock t clk2 As an example and not a limitation, the local clock of the second device may be adjusted to At this time, the difference between the local clocks of the first device and the second device is Eliminating the integer ambiguity n1τ by constraining the calculated value r and n2τ r After that, the difference between the local clocks of the first device and the second device is t′ clk1 -t ′ clk2 =(t clk1 -t clk2 )-Δτ clk =0, the first device is time synchronized with the second device.

[0140] In this way, the geometric delay Δτ corresponding to the distance between the first device and the second device can be made g_12 is eliminated, thereby achieving the purpose of high-precision, low-cost, and low-complexity time synchronization between the first device and the second device.

[0141] By using local correlation-based interferometry to calculate the signal delay difference, the first and second devices each analyze the phase of the first multi-carrier signal locally, and then calculate the delay difference. In two-way measurements, this method eliminates systematic errors caused by the device response times of the first and second devices, improving the measurement accuracy of geometric delay.

[0142] In practical applications, when the distance between the first device or the second device is unknown, the present application can eliminate the geometric delay Δτ corresponding to the distance between the first device and the second device by implementing the steps shown in Figure 5 and / or Figure 6. g_12 4, and calculate the clock difference Δτ between the first device and the second device by repeatedly implementing the steps shown in FIG4. clk , thereby achieving time synchronization between the first device and the second device. It should be understood that in specific implementations, there is no limitation on the number of times Figures 5 and / or 6 and Figure 4 are implemented, nor on the order in which they are implemented. Therefore, in this application, the geometric delay and clock difference between the first and second devices can be eliminated in real time through a closed-loop approach, thereby achieving high-precision time synchronization.

[0143] It should be understood that the algorithms for phase difference, frequency difference, clock difference, delay amount, and adjustment amount in the above description are schematic illustrations for easy understanding, and their specific calculation methods and positive and negative values ​​are determined according to actual conditions.

[0144] FIG7 is a flow chart of a method for achieving time synchronization based on interferometric measurement technology according to the present application.

[0145] The method comprises the steps of:

[0146] The first device sends an indication information packet to the second device, which includes indication information and parameters for interference measurement, wherein the indication information is used to instruct the first device to perform time synchronization with the second device; the parameters for interference measurement may include a time synchronization period, signal parameters, etc.

[0147] Two-way measurement eliminates geometric delay and multiple implementation steps:

[0148] S511, S512, S520, S531, S532, and S540 correspond to steps S411, S412, S420, S431, S432, and S440 in Figure 5, respectively, and are not repeated here.

[0149] And / or as shown in the steps of FIG6, eliminating the geometric delay Δτ corresponding to the distance between the first device and the second device. g_12 .

[0150] Calculate the signal delay difference based on interferometry technology, and implement it multiple times:

[0151] S531 and S532 correspond to steps S210 and S220 shown in FIG4 , respectively, and are not described again here.

[0152] The second device obtains the clock difference Δτ according to the adjustment amount obtained in the above steps clk , and adjust the local clock of the second device, so that the first device and the second device are synchronized.

[0153] The second device analyzes that the two stations have achieved synchronization, and transmits a second indication message to the first device. The second indication message is used to instruct the first device to adjust the signal structure so that the multi-carrier signal transmitted by the first device includes only two subcarriers, where the two subcarriers correspond to separate frequency points on the spectrum, thereby saving transmission resources. As another implementation, the second indication message is used to instruct the first device to adjust the signal structure so that the multi-carrier signal transmitted by the first device includes three subcarriers, where the three subcarriers correspond to separate frequency points on the spectrum, thereby saving transmission resources while making time synchronization more stable.

[0154] Figure 8 shows the simulation results of the time synchronization scheme of the present application. Based on the interferometry-based time synchronization process shown in Figure 7, when the multi-carrier signal bandwidth is set to 10 Hz, the present application can achieve high-precision estimation of the clock difference between the first and second devices within a millisecond integration time. This allows the generation of high-precision dual-device time synchronization corrections within a millisecond integration time, thereby correcting rapidly changing dual-device clock differences.

[0155] In interferometry, if the measurement signal used includes multiple subcarriers, each of which corresponds to a discrete frequency point on the spectrum, and the frequency points of the measurement signal are selected with equal frequency differences, excessive frequency resources will be consumed and the computational effort will be increased.

[0156] In the present application, the characteristics of the multi-carrier signal sent by the first device to the second device can be set to further optimize the technical solution of calculating the signal delay difference based on the interference measurement technology of the present application. In the present application, a multi-carrier signal can be sent by the first device to the second device, wherein the signal includes at least three subcarriers, and the three subcarriers correspond to separate frequency points on the spectrum. The first subcarrier and the second subcarrier have a first frequency difference, and the second subcarrier and the third subcarrier have a second frequency difference. The first frequency difference is greater than the second frequency difference.

[0157] Since the measurement range is inversely proportional to the frequency difference, and when the frequency difference is equally spaced, the measurement error when calculating the signal delay difference will increase, by setting the signal in this way, when calculating the signal delay difference based on interference measurement technology, it is possible to expand the measurement range (i.e., the distance range between the first device and the second device) and reduce the measurement error when calculating the signal delay difference.

[0158] Furthermore, the first frequency difference can be set to an integer multiple of the second frequency difference. For example, when the signal sent by the first device to the second device includes multiple subcarriers, the frequency difference between the frequency points corresponding to each subcarrier on the spectrum can be increased in geometric proportion, thereby further improving the calculation speed, quickly calculating the ambiguity, and saving frequency resources.

[0159] Figure 9 is a schematic diagram of the characteristic setting of a multi-carrier signal transmitted by a first device and a second device of the present invention. As shown in the figure, taking the first frequency difference as an integer multiple of the second frequency difference as 2 as an example, the frequency point f corresponding to each subcarrier on the spectrum can be set to i (i is a positive integer greater than or equal to 1) set to Where f0 is the center frequency. Similarly, the values ​​of the frequencies symmetrical about the center frequency are Also meets the application requirements.

[0160] FIG10 is another schematic diagram of the characteristic setting of the multi-carrier signal sent by the first device and the second device of the present invention. As shown in the figure, taking the first frequency difference as an integer multiple of the second frequency difference as 2 as an example, the frequency point f corresponding to each subcarrier on the spectrum can be set to i (i is a positive integer greater than or equal to 1) set to f i =f0+2 i-1 Δf. Similarly, a set of frequency points designed to be symmetrical about the center frequency f0 also meet the application requirements, expressed as f i =f0-2 i-1 Taking the example of setting the first frequency difference as an integer multiple of the second frequency difference to 2, in the technical solution of calculating the signal delay difference based on the interferometric measurement technology in this application, when the second device performs differential analysis based on the phase obtained by the local analysis of the first device and the second device, a series of binary exponential sequences are generated, such as {2 i-1}, where i is a natural number greater than or equal to 1, thereby assisting in the rapid calculation of ambiguity and improving the operation speed.

[0161] As a way to implement the characteristic setting of the multi-carrier signal sent by the first device and the second device, the characteristics of the multi-carrier signal can be set to the pilot signal of the orthogonal frequency division multiplexing technology (Orthogonal Frequency Division Multiplexing, referred to as OFDM), and multiple subcarriers are used to generate a signal corresponding to the frequency point characteristics on the spectrum.

[0162] By applying the characteristic setting of the multi-carrier signal sent by the first device and the second device to the process of achieving time synchronization based on the interferometric measurement technology as shown in Figure 7 of this application, since the use of the interferometric measurement method can achieve high-precision estimation of the clock difference between the two stations at an integration time of ms, the clock correction amount can be generated to synchronize the clocks of the two stations at an integration time of ms. Furthermore, phase noise changes rapidly, and the time synchronization correction operation with a short integration time can track the clock difference caused by phase noise and eliminate it. The time synchronization method proposed in this application has the potential to achieve wireless time synchronization at the level of 100ps to 10ps when using a general crystal oscillator. Therefore, this application can achieve high-precision time synchronization between two stations at a low cost.

[0163] In addition, an embodiment of the present application also provides a device that can implement the above method. Figure 11 is a schematic diagram of a device for locally analyzing multi-carrier signals in an implementation device of the present application. Taking the example of a first device sending a multi-carrier signal to a second device, in the first device: first generate data; and perform steps such as encoding, modulation, and mapping on the data to obtain a digital signal; then perform digital-to-analog conversion (DAC) on the generated digital signal to obtain an analog signal; convert the medium and low frequency analog signal into a high frequency signal through an up-converter, and amplify the high frequency signal through a power amplifier to obtain a valid signal to be sent; the first device obtains the transmitted multi-carrier signal through a local antenna, and converts the high frequency signal into a medium and low frequency signal through a receiving down-converter; then perform analog-to-digital conversion (ADC) on the medium and low frequency signal to obtain a digital signal; perform steps such as demodulation and decoding on the digital signal to obtain data; and use signal processing methods to measure the phase of the signal.

[0164] Similarly, the first device can obtain the multi-carrier signal sent by the second device through the local antenna and transmitted between channels, and convert the high-frequency signal into a medium- and low-frequency signal through a receiving down-converter; then perform ADC on the medium- and low-frequency signals to obtain digital signals; perform demodulation, decoding and other steps on the digital signals to obtain data; and use signal processing methods to measure the phase of the signal.

[0165] Figure 12 is a schematic diagram of a communication device for implementing the interferometry-based time synchronization method of the present application. The device 600 includes: a transceiver module 601 for communicating with the outside world, which may also be called a communication interface or communication unit; and a processing module 602 for processing data.

[0166] Device 600 can be used to execute the actions performed by the first device side in the above method embodiment as shown in Figures 4 to 7. Transceiver module 601 is used to execute the operations related to sending and receiving as shown in Figures 4 to 7 on the first device side in the above method embodiment. Processing module 602 is used to execute the operations related to processing as shown in Figures 4 to 7 on the first device side in the above method embodiment.

[0167] Device 600 can be used to execute the actions performed by the second device in the above method embodiment as shown in Figures 4 to 7. Transceiver module 601 is used to execute the sending and receiving operations related to Figures 4 to 7 on the second device side in the above method embodiment. Processing module 602 is used to execute the processing operations related to Figures 4 to 7 on the second device side in the above method embodiment.

[0168] FIG13 is a schematic structural diagram of a first device and a second device provided in an embodiment of the present application.

[0169] The first device includes at least one processor 701 and at least one transceiver 703. Optionally, the first device may further include at least one memory 702, at least one output device 704, or at least one input device 705.

[0170] The processor 701, the memory 702, and the transceiver 703 are connected via a communication line. The communication line may include a path for transmitting information between the above components.

[0171] The processor 701 may be a general-purpose central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field programmable gate arrays (FPGA), or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. A general-purpose processor may be a microprocessor or any conventional processor. In a specific implementation, as an embodiment, the processor 701 may also include multiple CPUs, and the processor 701 may be a single-core processor or a multi-core processor. The processor here may refer to one or more devices, circuits, or processing cores for processing data.

[0172] The memory 702 may be a device having a storage function. For example, it may be a read-only memory (ROM) or other types of static storage devices that can store static information and instructions, a random access memory (RAM) or other types of dynamic storage devices that can store information and instructions, or a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), a compact disc read-only memory (CD-ROM) or other optical disc storage, an optical disc storage (including a compact disc, laser disc, optical disc, digital versatile disc, Blu-ray disc, etc.), a magnetic disk storage medium or other magnetic storage device, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and can be accessed by a computer, but is not limited thereto. The memory 702 may exist independently and be connected to the processor 701 via a communication line. The memory 502 may also be integrated with the processor 701.

[0173] The memory 702 is used to store computer-executable instructions for executing the solution of the present application, and the execution is controlled by the processor 701. Specifically, the processor 701 is used to execute the computer-executable instructions stored in the memory 702, thereby implementing the random access method described in the embodiment of the present application.

[0174] Alternatively, optionally, in an embodiment of the present application, the processor 701 may also perform processing-related functions in the random access method provided in the following embodiments of the present application, and the transceiver 703 is responsible for communicating with other devices or communication networks. The embodiments of the present application do not specifically limit this.

[0175] Optionally, the computer-executable instructions in the embodiments of the present application may also be referred to as application code or computer program code, which is not specifically limited in the embodiments of the present application.

[0176] The transceiver 703 can be any transceiver-like device for communicating with other devices or communication networks, such as Ethernet, RAN, or wireless local area networks (WLAN). The transceiver 703 includes a transmitter (Tx) and a receiver (Rx).

[0177] Output device 704 communicates with processor 701 and can display information in a variety of ways. For example, output device 704 can be a liquid crystal display (LCD), a light emitting diode (LED) display device, a cathode ray tube (CRT) display device, or a projector.

[0178] The input device 705 communicates with the processor 701 and can accept user input in various ways. For example, the input device 505 can be a mouse, keyboard, touch screen device, or sensor device.

[0179] The second device includes at least one processor 801, at least one transceiver 803 and at least one network interface 804. Optionally, the second device may further include at least one memory 802. The processor 801, the memory 802, the transceiver 803 and the network interface 804 are connected via a communication line. The network interface 804 is used to connect to the core network device through a link (for example, an S1 interface), or to connect to the network interface of other second devices through a wired or wireless link (for example, an X2 interface) (not shown in Figure 13), and this embodiment of the application does not specifically limit this. In addition, the relevant description of the processor 801, the memory 802 and the transceiver 803 can refer to the description of the processor 801, the memory 802 and the transceiver 803 in the first device, and will not be repeated here.

[0180] In addition, an embodiment of the present application also provides a chip that obtains instructions and executes the instructions to implement the above method.

[0181] Optionally, as an implementation, the chip includes a processor and a communication interface, and the processor reads instructions stored in the memory through the communication interface to execute the above method.

[0182] Optionally, as an implementation manner, the chip may further include a memory, in which instructions are stored, and the processor is used to execute the instructions stored in the memory. When the instructions are executed, the processor is used to execute the above method.

[0183] An embodiment of the present application further provides a computer-readable storage medium, which stores instructions used in the method in the above method embodiment.

[0184] An embodiment of the present application also provides a computer program product comprising instructions for implementing the method in the above method embodiment.

[0185] As used in this specification, the terms "component," "module," "system," and the like are used to represent computer-related entities, hardware, firmware, a combination of hardware and software, software, or software in execution. For example, a component can be, but is not limited to, a process running on a processor, a processor, an object, an executable file, an execution thread, a program, and / or a computer. By way of illustration, both an application running on a computing device and a computing device can be a component. One or more components can reside in a process and / or an execution thread, and a component can be located on a computer and / or distributed between two or more computers. In addition, these components can be executed from various computer-readable media having various data structures stored thereon. Components can communicate, for example, via local and / or remote processes based on signals having one or more data packets (e.g., data from two components interacting with another component on a local system, a distributed system, and / or a network, such as the Internet interacting with other systems via signals).

[0186] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0187] Those skilled in the art will clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0188] In the several embodiments provided in this application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are merely schematic. For example, the division of the units is merely a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0189] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0190] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0191] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, server, or network device, etc.) to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes various media that can store program codes, such as a USB flash drive, a mobile hard disk, a ROM, a RAM, a magnetic disk, or an optical disk.

[0192] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. A method for time synchronization, characterized in that: Including steps: A second device detects a first multi-carrier signal to determine a first phase and a second phase of the first multi-carrier signal, wherein the first multi-carrier signal is a signal of the second multi-carrier signal sent by the first device after propagation between channels, and the first multi-carrier signal includes at least two subcarriers; The second device receives first information, wherein the first information is used to indicate a third phase and a fourth phase corresponding to the second multi-carrier signal; The second device performs time synchronization with the first device based on a first phase difference, a second phase difference and a first frequency difference, wherein the first phase difference is a phase difference between the first phase and the third phase, the second phase difference is a phase difference between the second phase and the fourth phase, and the first frequency difference is a frequency difference corresponding to the first multi-carrier signal.

2. The method according to claim 1, wherein The second device performs time synchronization with the first device according to the first phase difference, the second phase difference, and the first frequency difference, including: The second device performs time synchronization of the second device according to the first adjustment amount, and the first adjustment amount Δτ satisfies the following conditions: Wherein ΔΦ1 represents the first phase difference, ΔΦ2 represents the second phase difference, and Δf represents the first frequency difference.

3. The method according to claim 1, wherein The second device performs time synchronization with the first device according to the first phase difference, the second phase difference, and a first frequency difference between the first signal and the second signal, including: The second device performs time synchronization with the first device based on the first phase difference, the second phase difference, the first frequency difference and a first time delay, where the first time delay is associated with a geometric distance between the first device and the second device.

4. The method according to claim 3, wherein The second device performs time synchronization with the first device according to the first phase difference, the second phase difference, the first frequency difference, and the first time delay, including: The second device performs time synchronization of the second device according to the first adjustment amount, and the first adjustment amount satisfies the following conditions: Wherein ΔΦ1 represents the first phase difference, ΔΦ2 represents the second phase difference, Δf represents the first frequency difference, Δτ g_12 Indicates the first delay.

5. The method according to any one of claims 1 to 4, characterized in that Before the second device detects the first multi-carrier signal, the method further includes: The second device sends a third multi-carrier signal; The second device sends second information, wherein the second information is used to indicate the fifth phase and the sixth phase corresponding to the third multi-carrier signal, and the third multi-carrier signal and the second information are used by the first device to adjust the local clock; The second device detects a fourth multi-carrier signal to determine a seventh phase and an eighth phase of the fourth multi-carrier signal, wherein the fourth multi-carrier signal is a signal obtained by propagating the fifth multi-carrier signal sent by the first device through an inter-channel channel; The second device receives third information, wherein the third information is used to indicate a ninth phase and a tenth phase corresponding to the fifth multi-carrier signal; The second device adjusts the local clock according to the third phase difference, the fourth phase difference and the second frequency difference, wherein the third phase difference is the phase difference between the seventh phase and the ninth phase, the fourth phase difference is the phase difference between the eighth phase and the tenth phase, and the second frequency difference is the frequency difference corresponding to the fourth multi-carrier signal.

6. The method according to any one of claims 1 to 4, characterized in that Before the second device detects the first multi-carrier signal, the method further includes: The second device sends a third multi-carrier signal; The second device sends second information, wherein the second information is used to indicate the fifth phase and the sixth phase corresponding to the third multi-carrier signal, and the third multi-carrier signal and the second information are used by the first device to determine a second adjustment amount; The second device detects a fourth multi-carrier signal to determine a seventh phase and an eighth phase of the fourth multi-carrier signal, wherein the fourth multi-carrier signal is a signal after the fifth multi-carrier signal sent by the first device is propagated between channels; The second device receives third information, wherein the third information is used to indicate a ninth phase and a tenth phase corresponding to the fifth multi-carrier signal; The second device determines a third adjustment amount according to a third phase difference, a fourth phase difference, and a second frequency difference, wherein the third phase difference is the phase difference between the seventh phase and the ninth phase, the fourth phase difference is the phase difference between the eighth phase and the tenth phase, and the second frequency difference is the frequency difference corresponding to the fourth multi-carrier signal; The second device receives fourth information, wherein the fourth information is used to indicate a second adjustment amount; The second device adjusts the local clock according to the second adjustment value and the third adjustment value.

7. The method according to claim 5 or 6, wherein: The third multi-carrier signal and the fifth multi-carrier signal are transmitted in parallel.

8. The method according to claim 7, wherein The second information and the third information are sent in parallel.

9. The method according to any one of claims 1 to 6, wherein: The first information is specifically used to indicate a third phase and a fourth phase corresponding to the second multi-carrier signal, and time information corresponding to the third phase and the fourth phase.

10. The method according to any one of claims 1 to 9, wherein: The first multi-carrier signal includes a first subcarrier, a second subcarrier, and a third subcarrier, wherein the first subcarrier, the second subcarrier, and the third subcarrier correspond to different frequencies respectively, wherein the frequency difference between the first subcarrier and the second subcarrier corresponds to a third frequency difference, the frequency difference between the second subcarrier and the third subcarrier corresponds to a fourth frequency difference, and the third frequency difference is greater than the fourth frequency difference.

11. The method according to claim 10, wherein The first frequency difference is K times the third frequency difference, where K is a positive integer.

12. The method according to claim 11, wherein The K is 2.

13. A method for time synchronization, characterized in that: Including steps: The first device sends a second multi-carrier signal; The first device sends first information, where the first information is used to indicate a third phase and a fourth phase corresponding to the second multi-carrier signal, and the second multi-carrier signal and the first information are used by the second device to adjust a local clock.

14. The method according to claim 13, wherein Before the first device sends the second multi-carrier signal, the method further includes: The first device detects a sixth multi-carrier signal to determine an eleventh phase and a twelfth phase corresponding to the sixth multi-carrier signal, wherein the sixth multi-carrier signal is a signal after the third multi-carrier signal sent by the second device is propagated through channels; The first device receives second information, wherein the second information is used to indicate a fifth phase and a sixth phase corresponding to the third multi-carrier signal; The first device adjusts the local clock according to a fifth phase difference, a sixth phase difference, and a fifth frequency difference, wherein the fifth phase difference is a phase difference between the eleventh phase and the fifth phase, the sixth phase difference is a phase difference between the twelfth phase and the sixth phase, and the fifth frequency difference is a frequency difference corresponding to the sixth multi-carrier signal; The first device sends a fifth multi-carrier signal; The first device sends third information, where the third information is used to indicate a ninth phase and a tenth phase corresponding to a fifth multi-carrier signal. The fifth multi-carrier signal and the third information are used by the second device to adjust a local clock.

15. The method according to claim 13, wherein Before the first device sends the second multi-carrier signal, the method further includes: The first device detects a sixth multi-carrier signal to determine an eleventh phase and a twelfth phase corresponding to the sixth multi-carrier signal, wherein the sixth multi-carrier signal is a signal after the third multi-carrier signal sent by the second device is propagated through channels; The first device receives second information, wherein the second information is used to indicate a fifth phase and a sixth phase corresponding to the third multi-carrier signal; The first device obtains a second adjustment amount according to a fifth phase difference, a sixth phase difference, and a fifth frequency difference, wherein the fifth phase difference is a phase difference between the eleventh phase and the fifth phase, the sixth phase difference is a phase difference between the twelfth phase and the sixth phase, and the fifth frequency difference is a frequency difference corresponding to the sixth multi-carrier signal; The first device sends fourth information, where the fourth information is used to indicate the second adjustment amount, and the second adjustment amount is used by the second device to adjust the local clock; The first device sends a fifth multi-carrier signal; The first device sends third information, where the third information is used to indicate a ninth phase and a tenth phase corresponding to a fifth multi-carrier signal. The fifth multi-carrier signal and the third information are used by the second device to adjust a local clock.

16. The method according to any one of claims 13 to 15, wherein: The first multi-carrier signal includes a first subcarrier, a second subcarrier, and a third subcarrier, wherein the first subcarrier, the second subcarrier, and the third subcarrier correspond to different frequencies respectively, wherein the frequency difference between the first subcarrier and the second subcarrier corresponds to a third frequency difference, the frequency difference between the second subcarrier and the third subcarrier corresponds to a fourth frequency difference, and the third frequency difference is greater than the fourth frequency difference.

17. The method according to claim 16, wherein The first frequency difference is K times the third frequency difference, where K is a positive integer.

18. The method according to claim 17, wherein The K is 2.

19. A communication device, configured to execute the method according to any one of claims 1 to 12, characterized in that: include: Transceiver module, signal processing module.

20. A communication device, configured to execute the method according to any one of claims 13 to 18, characterized in that: include: Transceiver module, signal processing module.

21. A chip, characterized in that: The chip comprises a processor coupled to a memory, the memory being used to store a computer program, and the processor being used to execute the computer program stored in the memory, so that the chip executes the method according to any one of claims 1 to 18.

22. A computer-readable storage medium, characterized in that The storage medium stores a computer program or instruction. When the computer program or instruction is executed by a processor, the method according to any one of claims 1 to 18 is implemented.

23. A computer product, characterized in that When the computer is run, the method according to any one of claims 1 to 18 is executed.

24. A communication system, characterized in that: The method comprises a terminal device and a network device, wherein the terminal device is used to execute the method according to any one of claims 1 to 12, and the network device is used to execute the method according to any one of claims 13 to 18.

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