Frequency synchronization method and device of satellite multi-mode communication system and electronic equipment

Abstract

The invention relates to the technical field of communication, and discloses a frequency synchronization method and device of a satellite multi-mode communication system and electronic equipment, and the method comprises the steps: determining a reference network and a non-reference network from a plurality of communication networks; receiving real-time frequency offset of the target communication network; updating based on the real-time frequency offset by adopting an updating mode of the target communication network to obtain the crystal oscillator frequency offset of the reference network updated this time and the crystal oscillator offset between each non-reference network and the reference network updated this time; correcting the terminal frequency based on the updated crystal oscillator frequency deviation of the reference network; and when the terminal communicates with the non-reference network, performing frequency compensation based on the updated crystal oscillator deviation between the non-reference network and the reference network. According to the invention, the frequency of the terminal is consistent with the stable frequency of the reference network by offsetting the crystal oscillator deviation of the terminal, the additional frequency deviation of the crystal oscillator deviation can be accurately eliminated, the frequency synchronization of the terminal and the non-reference network is realized, and the stable frequency synchronization of the terminal and each communication network is realized.

Description

Technical Field

[0001] This invention relates to the field of communication technology, and specifically to a frequency synchronization method, apparatus, and electronic equipment for a satellite multimode communication system. Background Technology

[0002] In communication scenarios, frequency synchronization between the terminal and the base station is a prerequisite for ensuring communication quality. However, the crystal oscillators in both the terminal and the base station, which provide the fundamental frequency, can experience frequency deviations due to factors such as temperature. This frequency deviation accumulates gradually during signal transmission, eventually causing the signals between the terminal and the base station to become misaligned, resulting in issues such as call stuttering, data packet loss, or even communication interruption. Therefore, it is necessary to adjust the terminal's own frequency to offset the effects of the crystal oscillator frequency deviation, ensuring that the terminal and the base station always maintain frequency synchronization.

[0003] In multi-mode communication systems composed of satellites and communication networks such as 4G and 5G, existing technologies mainly employ the following two types of automatic frequency control schemes based on the main network to achieve frequency synchronization: (1) First scheme: The terminal selects one of the communication networks as the main network, obtains the frequency offset estimate of the main network and inputs it into AFC (Automatic Frequency Control). AFC drives the terminal to adjust its own system frequency so that the terminal frequency is aligned with the stable frequency of the main network. However, it only uses the frequency offset data of the main network and ignores the frequency offset estimate information of non-main networks, resulting in AFC adjusting the terminal frequency based on a single basis; (2) The second approach: The terminal selects different communication networks as the main network according to different communication scenarios. After each switch, the frequency offset estimate of the new main network drives the AFC to adjust the terminal frequency. However, due to the difference in crystal oscillator accuracy between different communication networks, additional deviation will be introduced during the switch.

[0004] In summary, existing frequency synchronization methods for satellite multi-mode communication systems waste information from non-main networks when the main network is fixed, and introduce additional frequency offsets when the main network is dynamically switched. Both of these issues can lead to the terminal being unable to achieve accurate and stable frequency synchronization with various communication networks. Summary of the Invention

[0005] This invention provides a frequency synchronization method, apparatus, and electronic device for a satellite multi-mode communication system, which solves the problem that existing frequency synchronization methods for satellite multi-mode communication systems waste non-main network information when the main network is fixed, and introduce additional frequency offset when the main network is dynamically switched, both of which lead to the terminal being unable to achieve accurate and stable frequency synchronization with each communication network.

[0006] In a first aspect, the present invention provides a frequency synchronization method for a satellite multi-mode communication system, the satellite multi-mode communication system comprising multiple communication networks; The method includes: Determine the reference network and multiple non-reference networks from multiple communication networks; Receive the real-time frequency offset of the target communication network; The update method corresponding to the target communication network is adopted, and the update is performed based on the real-time frequency offset to obtain the crystal frequency deviation of the reference network in this update and the crystal frequency deviation between each non-reference network and the reference network in this update. Crystal frequency deviation correction terminal frequency based on the updated reference network; When the terminal communicates with any non-reference network, frequency compensation is performed based on the crystal oscillator deviation between the updated non-reference network and the reference network.

[0007] This invention identifies reference and non-reference networks from multiple communication networks, making the reference network a global benchmark for system-wide frequency synchronization. When a terminal receives the real-time frequency offset of a target communication network, it updates using the corresponding update method for that network. This yields the crystal oscillator frequency offset of the updated reference network and the crystal oscillator offset between each non-reference network and the reference network. The terminal frequency is then corrected based on the updated crystal oscillator frequency offset of the reference network, fundamentally offsetting the terminal's own crystal oscillator deviation and ensuring the terminal's global frequency remains consistent with the stable frequency of the reference network. Furthermore, when the terminal communicates with non-reference networks, frequency compensation can be performed based on the updated crystal oscillator offset between the non-reference network and the reference network. This precisely eliminates the additional frequency offset caused by the crystal oscillator offset, achieving frequency synchronization between the terminal and non-reference networks. Ultimately, this achieves stable frequency synchronization between the terminal and all communication networks, ensuring stable communication.

[0008] In one optional implementation, the update method corresponding to the target communication network is adopted, and the update is performed based on the real-time frequency offset to obtain the crystal oscillator frequency offset of the reference network in this update and the crystal oscillator offset between each non-reference network and the reference network in this update, including: When the target communication network is the reference network, the first ratio of the real-time frequency offset to the carrier frequency of the target communication network is calculated and used as the filter input of the target communication network. For each non-reference network, calculate the difference between the first ratio and the crystal oscillator deviation between the previously updated non-reference network and the target communication network, and use it as the filter input for the non-reference network; For each communication network, the crystal frequency deviation of the communication network in this update is determined based on the filter input of the communication network and the historically updated crystal frequency deviation. For each non-reference network, the difference between the updated crystal frequency deviation of the reference network and the non-reference network is calculated as the crystal frequency deviation between the updated non-reference network and the reference network.

[0009] This embodiment achieves the use of the real-time frequency offset data of the reference network for the synchronous update of all non-reference networks by deriving the input of all non-reference network filters based on the real-time frequency offset of the reference network when the target communication network is the reference network.

[0010] In one optional implementation, the update method corresponding to the target communication network is adopted, and the update is performed based on the real-time frequency offset to obtain the crystal oscillator frequency offset of the reference network in this update and the crystal oscillator offset between each non-reference network and the reference network in this update, including: When the target communication network is a non-reference network, the second ratio of the real-time frequency offset to the carrier frequency of the target communication network is calculated and used as the filter input of the target communication network. The sum of the second ratio and the crystal oscillator deviation between the target communication network and the reference network updated in the last update is calculated and used as the filter input of the reference network; For each non-reference network other than the target communication network, the filter input of the non-reference network is determined based on the second ratio, the crystal oscillator deviation between the target communication network and the reference network in the last update, and the crystal oscillator deviation between the non-reference network and the reference network in the last update. For each communication network, the crystal frequency deviation of the communication network in this update is determined based on the filter input of the communication network and the historically updated crystal frequency deviation. For each non-reference network, the difference between the updated crystal frequency deviation of the reference network and the non-reference network is calculated as the crystal frequency deviation between the updated non-reference network and the reference network.

[0011] This embodiment indirectly obtains the relative offset ratio between the terminal and the reference network by converting the real-time frequency offset of the non-reference network into an effective input for full network synchronization. This ensures that even if the real-time frequency offset comes from the non-reference network, the synchronization data of the reference network can still be accurately updated, avoiding the reference network synchronization from relying on a single frequency offset source and providing an accurate reference benchmark for subsequently eliminating the terminal's own crystal oscillator deviation.

[0012] In one alternative implementation, the filter input of the non-reference network is determined by the following formula:

[0013] In the formula, Indicates non-reference network c The filter input; Indicates real-time frequency offset; Indicates the target communication network b The carrier frequency; Indicates the target communication network of the last update. b Crystal oscillator deviation from the reference network; Indicates the non-reference network of the last updatec Crystal oscillator deviation from the reference network.

[0014] In this embodiment, the offset between the terminal and the reference network is derived by the frequency offset of the target non-reference network. Then, by subtracting the crystal oscillator deviation between the other non-reference networks and the reference network, the relative offset ratio between the terminal and the other non-reference networks can be indirectly obtained.

[0015] In one optional implementation, when the terminal communicates with any non-reference network, frequency compensation is performed based on the crystal oscillator deviation between the updated non-reference network and the reference network, including: When the terminal communicates with any non-reference network, the received and transmitted signals are compensated based on the crystal oscillator deviation between the non-reference network and the reference network and the carrier frequency of the non-reference network, resulting in compensated received and transmitted signals.

[0016] In one optional implementation, the compensated received signal and transmitted signal are represented by the following formula:

[0017] In the formula, This indicates the received signal after compensation. R ( t This indicates that the terminal receives the raw received signal from a non-reference network. This indicates the non-reference network in this update. a Crystal oscillator deviation from the reference network; Indicates non-reference network a The carrier frequency.

[0018] This embodiment can accurately cancel the additional frequency offset by combining the crystal oscillator deviation and the non-reference network carrier frequency correction signal, ensuring that the terminal is frequency synchronized with the non-reference network.

[0019] In one alternative implementation, determining a reference network and multiple non-reference networks from a plurality of communication networks includes: Obtain the crystal oscillator accuracy of each communication network in a satellite multimode communication system; The communication network with the highest crystal oscillator accuracy among multiple communication networks is designated as the reference network, while the remaining communication networks are designated as non-reference networks.

[0020] This embodiment uses the communication network with the highest crystal oscillator accuracy as the reference network to serve as a global benchmark for frequency synchronization of the entire system. This provides a stable and reliable benchmark for frequency synchronization between the terminal and all communication networks, avoiding a decrease in the synchronization accuracy of the entire system due to frequency fluctuations of the benchmark network itself.

[0021] Secondly, the present invention provides a frequency synchronization device for a satellite multi-mode communication system, the satellite multi-mode communication system including multiple communication networks; The device includes: The determination module is used to determine a reference network and multiple non-reference networks from multiple communication networks; The receiving module is used to receive the real-time frequency offset of the target communication network; The update module is used to update based on the real-time frequency offset using the update method corresponding to the target communication network, and to obtain the crystal frequency offset of the reference network in this update and the crystal frequency offset between each non-reference network and the reference network in this update. The correction module is used to correct the terminal frequency based on the crystal oscillator frequency deviation of the updated reference network. The compensation module is used to perform frequency compensation based on the crystal oscillator deviation between the updated non-reference network and the reference network when the terminal communicates with any non-reference network.

[0022] Thirdly, the present invention provides an electronic device comprising: a memory and a processor, the memory and the processor being communicatively connected to each other, the memory storing computer instructions, and the processor executing the computer instructions to perform the frequency synchronization method of the satellite multimode communication system described in the first aspect or any corresponding embodiment thereof.

[0023] Fourthly, the present invention provides a computer-readable storage medium storing computer instructions for causing a computer to execute the frequency synchronization method of the satellite multimode communication system described in the first aspect or any corresponding embodiment thereof. Attached Figure Description

[0024] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0025] Figure 1 This is a flowchart of a frequency synchronization method for a satellite multi-mode communication system according to an embodiment of the present invention; Figure 2 This is a flowchart illustrating the operation of a loop filter according to an embodiment of the present invention; Figure 3 This is a flowchart of a frequency synchronization method for another satellite multi-mode communication system according to an embodiment of the present invention; Figure 4 This is a structural block diagram of a frequency synchronization device for a satellite multimode communication system according to an embodiment of the present invention; Figure 5 This is a schematic diagram of the hardware structure of an electronic device according to an embodiment of the present invention. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] It is understood that before using the technical solutions disclosed in the various embodiments of the present invention, users should be informed of the types, scope of use, and usage scenarios of the personal information involved in the present invention and their authorization should be obtained in accordance with relevant laws and regulations through appropriate means.

[0028] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0029] Existing frequency synchronization methods in satellite multi-mode communication systems waste information from non-master networks when the master network is fixed, and introduce additional frequency offsets when the master network is dynamically switched. Both of these issues prevent the terminal from achieving accurate and stable frequency synchronization with various communication networks. This invention addresses this by compensating for the deviation of the terminal's own crystal oscillator, ensuring that the terminal's global frequency remains consistent with the stable frequency of the reference network. Furthermore, it precisely eliminates the additional frequency offset caused by crystal oscillator deviation, achieving frequency synchronization between the terminal and non-reference networks, and ultimately achieving stable frequency synchronization between the terminal and all communication networks, thus ensuring stable communication.

[0030] According to an embodiment of the present invention, a frequency synchronization method for a satellite multimode communication system is provided. It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. Furthermore, although a logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in a different order than that shown here.

[0031] This embodiment provides a frequency synchronization method for a satellite multi-mode communication system, which includes multiple communication networks and can be used by terminals. Figure 1 This is a flowchart of a frequency synchronization method for a satellite multi-mode communication system according to an embodiment of the present invention, such as... Figure 1As shown, the process includes the following steps: Step S101: Determine the reference network and multiple non-reference networks from multiple communication networks.

[0032] Specifically, assuming a satellite multi-mode communication system includes multiple communication networks such as satellite, 4G, and 5G, for a terminal to achieve stable communication with these networks, it needs to ensure frequency synchronization with all networks. Since the crystal oscillator accuracy varies among the base stations of different communication networks, it is necessary to determine one reference network and multiple non-reference networks based on the crystal oscillator accuracy of each network, making the reference network a global benchmark for frequency synchronization across the entire system.

[0033] Step S102: Receive the real-time frequency offset of the target communication network.

[0034] Specifically, to maintain frequency synchronization between the terminal and various communication networks and to prevent synchronization failure of the terminal's own crystal oscillator due to factors such as temperature, the terminal receives signals from the reference network and various non-reference networks at different times without conflict, based on preset parameters (such as reception period and signal priority) of different communication networks, and extracts the real-time frequency offset from the received signals. When the terminal receives the real-time frequency offset of a target communication network, this frequency offset value will be used as the basis for subsequent frequency synchronization updates.

[0035] Step S103: Using the update method corresponding to the target communication network, update based on real-time frequency offset to obtain the crystal oscillator frequency deviation of the reference network in this update and the crystal oscillator deviation between each non-reference network and the reference network in this update.

[0036] Specifically, there is a difference in crystal oscillator accuracy between the reference network and each non-reference network. Without addressing this, even after the terminal aligns with the reference network, direct communication with non-reference networks will still result in frequency offset due to this difference, leading to synchronization failure. Since the target communication network could be either the reference network or any non-reference network, a differentiated update method is needed for both types of networks. This involves calculating the crystal oscillator frequency offset of the updated reference network and simultaneously updating the crystal oscillator offset between each non-reference network and the reference network. Only by accurately correcting the signal frequency offset based on the crystal oscillator offset can the terminal, already aligned with the reference network, further synchronize with non-reference networks, ultimately achieving system-wide frequency synchronization.

[0037] Step S104: Correct the terminal frequency based on the crystal oscillator frequency deviation of the updated reference network.

[0038] Specifically, the crystal oscillator frequency deviation of the updated reference network reflects the frequency offset between the terminal's current frequency and the stable frequency of the reference network. Therefore, the terminal uses the AFC module to adjust its voltage-controlled oscillator (VCO) based on the updated reference network's crystal oscillator frequency deviation. If the updated reference network's crystal oscillator frequency deviation is positive, it indicates that the terminal's own crystal oscillator generates a frequency that is too fast. The AFC will control the VCO to reduce its output frequency until the terminal's generated frequency matches the stable frequency of the reference network. If the updated reference network's crystal oscillator frequency deviation is negative, it indicates that the terminal's own crystal oscillator generates a frequency that is too slow. The AFC will control the VCO to increase its output frequency to align the terminal's frequency with the reference network. By correcting based on the updated reference network's crystal oscillator frequency deviation, the deviation of the terminal's own crystal oscillator can be offset at its source, ensuring that the terminal's global frequency is consistent with the stable frequency of the reference network, thus establishing a unified benchmark for subsequent synchronization with non-reference networks.

[0039] Step S105: When the terminal communicates with any non-reference network, frequency compensation is performed based on the crystal oscillator deviation between the updated non-reference network and the reference network.

[0040] Specifically, although the terminal has achieved frequency synchronization with the reference network through the VCO, there is a crystal oscillator deviation between the non-reference network and the reference network, introduced by the difference in crystal oscillator offset between the base station and the reference network. If the terminal communicates directly with the non-reference network, this accuracy difference will cause additional frequency offset between the terminal and the non-reference network, affecting communication quality. Therefore, when the terminal needs to communicate with any non-reference network, the terminal's digitally controlled oscillator (NCO) will perform targeted frequency compensation based on the updated crystal oscillator deviation between the non-reference network and the reference network. Through the compensation operation, the additional frequency offset caused by the crystal oscillator deviation can be accurately eliminated, ultimately achieving frequency synchronization between the terminal and the non-reference network and ensuring stable communication.

[0041] This invention identifies reference and non-reference networks from multiple communication networks, making the reference network a global benchmark for system-wide frequency synchronization. When a terminal receives the real-time frequency offset of a target communication network, it updates using the corresponding update method for that network. This yields the crystal oscillator frequency offset of the updated reference network and the crystal oscillator offset between each non-reference network and the reference network. The terminal frequency is then corrected based on the updated crystal oscillator frequency offset of the reference network, fundamentally offsetting the terminal's own crystal oscillator deviation and ensuring the terminal's global frequency remains consistent with the stable frequency of the reference network. Furthermore, when the terminal communicates with non-reference networks, frequency compensation can be performed based on the updated crystal oscillator offset between the non-reference network and the reference network. This precisely eliminates the additional frequency offset caused by the crystal oscillator offset, achieving frequency synchronization between the terminal and non-reference networks. Ultimately, this achieves stable frequency synchronization between the terminal and all communication networks, ensuring stable communication.

[0042] This embodiment provides a frequency synchronization method for a satellite multi-mode communication system, which can be used in the aforementioned terminal. The method specifically includes the following steps: Step S201: Determine the reference network and multiple non-reference networks from multiple communication networks.

[0043] Specifically, step S201 includes: Step S2011: Obtain the crystal oscillator accuracy of each communication network in the satellite multimode communication system.

[0044] Specifically, the crystal oscillator accuracy of each communication network refers to the frequency stability of the crystal oscillator built into each communication network base station. For example, the crystal oscillator accuracy of a satellite base station is about 0.01ppm, and the crystal oscillator accuracy of a 4G / 5G terrestrial base station is about 0.1ppm. The smaller the value, the less the base station crystal oscillator output frequency is affected by factors such as temperature and aging, and the stronger the frequency stability.

[0045] In step S2012, the communication network with the highest crystal oscillator accuracy among multiple communication networks is determined as the reference network, and the remaining communication networks are determined as non-reference networks.

[0046] Specifically, the communication network with the highest crystal oscillator accuracy, i.e., the smallest value, is designated as the reference network, while the remaining communication networks are designated as non-reference networks. The base station output frequency of the reference network has the strongest stability and can serve as a global benchmark for frequency synchronization of the entire system. It can provide a stable and reliable benchmark for frequency synchronization between subsequent terminals and all communication networks, avoiding a decrease in the synchronization accuracy of the entire system due to frequency fluctuations of the reference network itself.

[0047] Step S202: Receive the real-time frequency offset of the target communication network. For details, please refer to [link to relevant documentation]. Figure 1 Step S102 of the illustrated embodiment will not be described again here.

[0048] Step S203: Using the update method corresponding to the target communication network, update based on real-time frequency offset to obtain the crystal oscillator frequency deviation of the reference network in this update and the crystal oscillator deviation between each non-reference network and the reference network in this update.

[0049] Specifically, when the target communication network is a reference network, step S203 includes: Step S2031: When the target communication network is the reference network, calculate the first ratio of the real-time frequency offset to the carrier frequency of the target communication network, and use it as the filter input of the target communication network.

[0050] Specifically, when the real-time frequency offset received by the terminal comes from the reference network, the input of the AFC loop filter of the reference network is calculated using the following formula (1). This value can quantify the degree of deviation between the terminal's own crystal oscillator and the reference network, serving as the basis for the terminal to correct its own crystal oscillator deviation in the future.

[0051] (1) In the formula, Reference network r The filter input; Indicates real-time frequency offset; Reference network r The carrier frequency.

[0052] Step S2032: For each non-reference network, calculate the difference between the first ratio and the crystal oscillator deviation between the previously updated non-reference network and the target communication network, and use it as the filter input of the non-reference network.

[0053] Specifically, for each non-reference network, the difference between the filter input (i.e., the first ratio) of the reference network and the crystal oscillator deviation between the non-reference network and the reference network in the last update is calculated as shown in the following formula (2), and the difference is used as the AFC loop filter input of the non-reference network.

[0054] (2) In the formula, Indicates non-reference network a The filter input; Indicates the non-reference network of the last update a Crystal oscillator deviation from the reference network.

[0055] Even when the non-reference network does not provide frequency offset, it can still update based on the data of the reference network. Since the crystal oscillator deviation between the non-reference network and the reference network is relatively stable, the current frequency offset quantization value of the non-reference network can be indirectly derived through the above formula (2), ensuring that the filter input of the non-reference network can be linked with the synchronization state of the reference network.

[0056] Step S2033: For each communication network, determine the crystal oscillator frequency deviation of the communication network in this update based on the filter input of the communication network and the historically updated crystal oscillator frequency deviation.

[0057] Specifically, Figure 2 This is a flowchart of the loop filter according to an embodiment of the present invention, as follows: Figure 2 As shown, both the reference network and the non-reference network adopt a loop filter with a second-order filter structure. Based on their respective filter inputs, and combined with the crystal frequency deviation obtained from the last and previous updates of the filter on each communication network, the updated crystal frequency deviation is calculated by the following formula (3).

[0058] (3) In the formula, This indicates the reference network for this update. r The crystal oscillator frequency deviation; This refers to the reference network from the last update. r The crystal oscillator frequency deviation; This refers to the reference network from the previous update. r The crystal oscillator frequency deviation; and Reference network r The loop filter coefficients can be adjusted to control the filter convergence speed; This indicates the non-reference network in this update. a The crystal oscillator frequency deviation; Indicates the non-reference network of the last update a The crystal oscillator frequency deviation; This refers to the non-reference network updated two weeks ago. a The crystal oscillator frequency deviation; and Indicates non-reference network a The loop filter coefficients.

[0059] By incorporating historical crystal oscillator frequency deviations, noise interference in real-time frequency deviations can be smoothed out, ensuring that the updated crystal oscillator frequency deviations are more accurate.

[0060] Step S2034: For each non-reference network, calculate the difference between the updated crystal frequency deviation of the reference network and the non-reference network, and use it as the crystal frequency deviation between the updated non-reference network and the reference network.

[0061] Specifically, for each non-reference network, the difference between the crystal frequency deviation of the updated reference network and the crystal frequency deviation of the updated non-reference network is calculated, and this difference is used as the crystal frequency deviation between the updated non-reference network and the reference network, thereby realizing the real-time update of the crystal frequency deviation.

[0062] Specifically, when the target communication network is a non-reference network, step S203 includes: Step S2035: When the target communication network is a non-reference network, calculate the second ratio of the real-time frequency offset to the carrier frequency of the target communication network, and use it as the filter input of the target communication network.

[0063] Specifically, when the real-time frequency offset received by the terminal comes from a non-reference network, the real-time frequency offset and the carrier frequency of the target communication network are substituted into the above equation (1) to obtain the filter input of the target communication network.

[0064] Step S2036: Calculate the sum of the second ratio and the crystal oscillator deviation between the target communication network and the reference network in the last update, and use it as the filter input of the reference network.

[0065] Specifically, the filter input of the reference network is calculated using the following equation (4).

[0066] (4) In the formula, Indicates the target communication network b The carrier frequency; Indicates the target communication network of the last update. b Crystal oscillator deviation from the reference network.

[0067] Since the target communication network is a non-reference network, the real-time frequency offset includes the terminal's own crystal oscillator offset and the crystal oscillator offset between the non-reference network and the reference network. By superimposing the previous crystal oscillator offset, the latter's influence can be offset, indirectly obtaining the relative offset ratio between the terminal and the reference network. This ensures that even if the real-time frequency offset comes from the non-reference network, the synchronization data of the reference network can still be accurately updated, avoiding the reference network's reliance on a single frequency offset source for synchronization, and providing an accurate reference benchmark for subsequently eliminating the terminal's own crystal oscillator offset.

[0068] Step S2037: For each non-reference network other than the target communication network, determine the filter input of the non-reference network based on the second ratio, the crystal oscillator deviation between the target communication network and the reference network in the last update, and the crystal oscillator deviation between the non-reference network and the reference network in the last update.

[0069] Specifically, the target communication network is a non-reference network, which calculates the filter input through step S2035. For each of the other non-reference networks, the filter input can be calculated by the following formula (5).

[0070] (5) In the formula, Indicates non-reference network c The filter input; Indicates real-time frequency offset; Indicates the target communication network b The carrier frequency; Indicates the target communication network of the last update. b Crystal oscillator deviation from the reference network; Indicates the non-reference network of the last update c Crystal oscillator deviation from the reference network.

[0071] By deriving the offset between the terminal and the reference network from the frequency offset of the target non-reference network, and then subtracting the crystal oscillator deviation between the other non-reference networks and the reference network, the relative offset ratio between the terminal and the other non-reference networks can be indirectly obtained.

[0072] Step S2038: For each communication network, determine the crystal oscillator frequency deviation of the communication network in this update based on the filter input of the communication network and the historically updated crystal oscillator frequency deviation. See step S2033 for details, which will not be repeated here.

[0073] Step S2039: For each non-reference network, calculate the difference between the updated crystal oscillator frequency deviation of the reference network and the non-reference network, and use this difference as the crystal oscillator deviation between the updated non-reference network and the reference network. See step S2034 for details, which will not be repeated here.

[0074] Step S204: Correct the terminal frequency based on the crystal oscillator frequency deviation of the updated reference network. For details, please refer to [link to relevant documentation]. Figure 1 Step S104 of the illustrated embodiment will not be described again here.

[0075] Step S205: When the terminal communicates with any non-reference network, frequency compensation is performed based on the crystal oscillator deviation between the updated non-reference network and the reference network.

[0076] Specifically, step S205 includes: Step S2051: When the terminal communicates with any non-reference network, the received signal and the transmitted signal are compensated based on the crystal oscillator deviation between the non-reference network and the reference network and the carrier frequency of the non-reference network, so as to obtain the compensated received signal and transmitted signal.

[0077] Specifically, when a terminal needs to communicate with any non-reference network, although the terminal has achieved global frequency synchronization with the reference network through the VCO, the actual operating frequency of the non-reference network has a stable deviation from the reference network due to the lower crystal oscillator accuracy. If no compensation is made for the transmit and receive signals, the terminal and the non-reference network will experience communication frequency offset due to this deviation. By combining the crystal oscillator deviation and the carrier frequency correction signal of the non-reference network, this additional frequency offset can be accurately canceled, ensuring frequency synchronization between the terminal and the non-reference network.

[0078] In some alternative implementations, the compensated received signal and transmitted signal are represented by the following formula (6): (6) In the formula, This indicates the received signal after compensation. R ( t This indicates that the terminal receives the raw received signal from a non-reference network. This indicates the non-reference network in this update. a Crystal oscillator deviation from the reference network; Indicates non-reference network a The carrier frequency.

[0079] In some alternative implementations, Figure 3 This is a flowchart of a frequency synchronization method for another satellite multi-mode communication system according to an embodiment of the present invention, such as... Figure 3 As shown, a reference network and multiple non-reference networks are determined from multiple communication networks in a satellite multi-mode communication system. The real-time frequency offset of the target communication network is received. When the target communication network is a reference network, the filter inputs for both the reference and non-reference networks are calculated. When the target communication network is a non-reference network, the filter inputs for the target communication network, the reference network, and the remaining non-reference networks are calculated for this update. Based on the filter structure and the filter inputs, the crystal oscillator frequency offset of each communication network in this update is obtained, thus enabling the determination of the crystal oscillator offset between each non-reference network and the reference network. Finally, the terminal frequency is corrected based on the crystal oscillator frequency offset of the updated reference network, and the received and transmitted signals are compensated based on the crystal oscillator offset between the updated non-reference networks and the reference network, and the carrier frequency of the non-reference networks.

[0080] This invention identifies reference and non-reference networks from multiple communication networks, making the reference network a global benchmark for system-wide frequency synchronization. When a terminal receives the real-time frequency offset of a target communication network, it updates using the corresponding update method for that network. This yields the crystal oscillator frequency offset of the updated reference network and the crystal oscillator offset between each non-reference network and the reference network. The terminal frequency is then corrected based on the updated crystal oscillator frequency offset of the reference network, fundamentally offsetting the terminal's own crystal oscillator deviation and ensuring the terminal's global frequency remains consistent with the stable frequency of the reference network. Furthermore, when the terminal communicates with non-reference networks, frequency compensation can be performed based on the updated crystal oscillator offset between the non-reference network and the reference network. This precisely eliminates the additional frequency offset caused by the crystal oscillator offset, achieving frequency synchronization between the terminal and non-reference networks. Ultimately, this achieves stable frequency synchronization between the terminal and all communication networks, ensuring stable communication.

[0081] This embodiment also provides a frequency synchronization device for a satellite multi-mode communication system. This device is used to implement the above embodiments and preferred embodiments, and details already described will not be repeated. As used below, the term "module" can refer to a combination of software and / or hardware that performs a predetermined function. Although the device described in the following embodiments is preferably implemented in software, hardware implementation, or a combination of software and hardware, is also possible and contemplated.

[0082] This embodiment provides a frequency synchronization device for a satellite multi-mode communication system, such as... Figure 4 As shown, it includes: The determination module 401 is used to determine a reference network and multiple non-reference networks from multiple communication networks.

[0083] The receiving module 402 is used to receive the real-time frequency offset of the target communication network.

[0084] The update module 403 is used to update based on real-time frequency offset using the update method corresponding to the target communication network, so as to obtain the crystal frequency deviation of the reference network in this update and the crystal frequency deviation between each non-reference network and the reference network in this update.

[0085] Correction module 404 is used to correct the terminal frequency of the crystal oscillator frequency deviation based on the updated reference network.

[0086] The compensation module 405 is used to perform frequency compensation based on the crystal oscillator deviation between the updated non-reference network and the reference network when the terminal communicates with any non-reference network.

[0087] In some alternative implementations, the update module 403 includes: The first calculation unit is used to calculate the first ratio of the real-time frequency offset to the carrier frequency of the target communication network when the target communication network is the reference network, and use it as the filter input of the target communication network.

[0088] The second calculation unit is used to calculate, for each non-reference network, the difference between the first ratio and the crystal oscillator deviation between the previously updated non-reference network and the target communication network, and use it as the filter input of the non-reference network.

[0089] The first determining unit is used to determine the crystal frequency deviation of the communication network being updated in this update, based on the filter input of the communication network and the historically updated crystal frequency deviation, for each communication network.

[0090] The third calculation unit is used to calculate, for each non-reference network, the difference between the updated crystal oscillator frequency deviation of the reference network and the non-reference network in this update, as the crystal oscillator deviation between the non-reference network and the reference network in this update.

[0091] In some alternative implementations, the update module 403 includes: The fourth calculation unit is used to calculate the second ratio of the real-time frequency offset to the carrier frequency of the target communication network when the target communication network is a non-reference network, and use it as the filter input of the target communication network.

[0092] The fifth calculation unit is used to calculate the sum of the second ratio and the crystal oscillator deviation between the target communication network and the reference network in the last update, which is used as the filter input of the reference network.

[0093] The second determining unit is used to determine the filter input of each non-reference network other than the target communication network based on the second ratio, the crystal oscillator deviation between the target communication network and the reference network in the last update, and the crystal oscillator deviation between the non-reference network and the reference network in the last update.

[0094] The third determining unit is used to determine the crystal frequency deviation of the communication network being updated this time, based on the filter input of the communication network and the historically updated crystal frequency deviation, for each communication network.

[0095] The sixth calculation unit is used to calculate, for each non-reference network, the difference between the updated crystal oscillator frequency deviation of the reference network and the non-reference network, as the crystal oscillator deviation between the updated non-reference network and the reference network.

[0096] In some alternative implementations, the filter input of the non-reference network is determined by the following formula:

[0097] In the formula, Indicates non-reference network c The filter input; Indicates real-time frequency offset; Indicates the target communication network b The carrier frequency; Indicates the target communication network of the last update. b Crystal oscillator deviation from the reference network; Indicates the non-reference network of the last update c Crystal oscillator deviation from the reference network.

[0098] In some alternative implementations, the compensation module 405 includes: The compensation unit compensates for the received and transmitted signals based on the crystal oscillator deviation between the updated non-reference network and the reference network and the carrier frequency of the non-reference network when the terminal communicates with any non-reference network, thus obtaining the compensated received and transmitted signals.

[0099] In some optional implementations, the compensated received and transmitted signals are represented by the following formulas:

[0100] In the formula, This indicates the received signal after compensation. R ( t This indicates that the terminal receives the raw received signal from a non-reference network. This indicates the non-reference network in this update. a Crystal oscillator deviation from the reference network; Indicates non-reference network a The carrier frequency.

[0101] In some alternative implementations, the determining module 401 includes: The acquisition unit is used to acquire the crystal oscillator accuracy of each communication network in the satellite multimode communication system.

[0102] The fourth determining unit is used to determine the communication network with the highest crystal oscillator accuracy among multiple communication networks as the reference network, and the remaining communication networks as non-reference networks.

[0103] The frequency synchronization device for a satellite multi-mode communication system provided in this embodiment of the invention can execute the frequency synchronization method for a satellite multi-mode communication system provided in any embodiment of the invention, and has the corresponding functional modules and beneficial effects for executing the method. Further functional descriptions of the above modules and units are the same as those in the corresponding embodiments described above, and will not be repeated here.

[0104] Figure 5 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present invention.

[0105] The following is a detailed reference. Figure 5 The diagram illustrates a structural schematic suitable for implementing an electronic device according to embodiments of the present invention. The electronic device may include a processor (e.g., a central processing unit, graphics processor, etc.) 501, which can perform various appropriate actions and processes according to a program stored in read-only memory (ROM) 502 or a program loaded from memory 508 into random access memory (RAM) 503. The RAM 503 also stores various programs and data required for the operation of the electronic device. The processor 501, ROM 502, and RAM 503 are interconnected via a bus 504. An input / output (I / O) interface 505 is also connected to the bus 504.

[0106] Typically, the following devices can be connected to I / O interface 505: input devices 506 including, for example, touchscreens, touchpads, keyboards, mice, cameras, microphones, accelerometers, gyroscopes, etc.; output devices 507 including, for example, liquid crystal displays (LCDs), speakers, vibrators, etc.; memory devices 508 including, for example, magnetic tapes, hard disks, etc.; and communication devices 509. Communication device 509 allows electronic devices to communicate wirelessly or wiredly with other devices to exchange data. Although Figure 5 Electronic devices with various devices are shown, but it should be understood that it is not required to implement or have all of the devices shown, and more or fewer devices may be implemented or have instead.

[0107] In particular, according to embodiments of the present invention, the processes described above with reference to the flowcharts can be implemented as computer software programs. For example, embodiments of the present invention include a computer program product comprising a computer program carried on a non-transitory computer-readable medium, the computer program containing program code for performing the methods shown in the flowcharts. In such embodiments, the computer program can be downloaded and installed from a network via a communication device 509, or installed from a memory 508, or installed from a ROM 502. When the computer program is executed by the processor 501, it performs the functions defined above in the frequency synchronization method of the satellite multi-mode communication system according to embodiments of the present invention.

[0108] Figure 5 The electronic device shown is merely an example and should not be construed as limiting the functionality and scope of use of the embodiments of the present invention.

[0109] This invention also provides a computer-readable storage medium. The methods described above according to embodiments of the invention can be implemented in hardware or firmware, or implemented as computer code that can be recorded on a storage medium, or implemented as computer code downloaded via a network and originally stored on a remote storage medium or a non-transitory machine-readable storage medium and then stored on a local storage medium. Thus, the methods described herein can be processed by software stored on a storage medium using a general-purpose computer, a dedicated processor, or programmable or dedicated hardware. The storage medium can be a magnetic disk, optical disk, read-only memory, random access memory, flash memory, hard disk, or solid-state drive, etc.; further, the storage medium can also include combinations of the above types of memory. It is understood that computers, processors, microprocessor controllers, or programmable hardware include storage components capable of storing or receiving software or computer code. When the software or computer code is accessed and executed by the computer, processor, or hardware, the frequency synchronization method of the satellite multi-mode communication system shown in the above embodiments is implemented.

[0110] A portion of this invention can be applied as a computer program product, such as computer program instructions, which, when executed by a computer, can invoke or provide the methods and / or technical solutions according to the invention through the operation of the computer. Those skilled in the art will understand that the forms in which computer program instructions exist in a computer-readable medium include, but are not limited to, source files, executable files, installation package files, etc. Correspondingly, the ways in which computer program instructions are executed by a computer include, but are not limited to: the computer directly executing the instructions, or the computer compiling the instructions and then executing the corresponding compiled program, or the computer reading and executing the instructions, or the computer reading and installing the instructions and then executing the corresponding installed program. Here, the computer-readable medium can be any available computer-readable storage medium or communication medium accessible to a computer.

[0111] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A method of frequency synchronization for a satellite multi-mode communication system, characterized by, The satellite multi-mode communication system comprises a plurality of communication networks; The method comprises: determining a reference network and a plurality of non-reference networks from the plurality of communication networks; receiving a real-time frequency offset of a target communication network; updating based on the real-time frequency offset using an updating mode corresponding to the target communication network to obtain a crystal oscillator frequency offset of the reference network in this updating and a crystal oscillator offset between each non-reference network and the reference network in this updating; correcting the terminal frequency based on the crystal oscillator frequency offset of the reference network in this updating; when the terminal communicates with any non-reference network, performing frequency compensation based on the crystal oscillator offset between the non-reference network and the reference network in this updating.

2. The method of claim 1, wherein, The updating based on the real-time frequency offset using the updating mode corresponding to the target communication network to obtain the crystal oscillator frequency offset of the reference network in this updating and the crystal oscillator offset between each non-reference network and the reference network in this updating comprises: when the target communication network is the reference network, calculating a first ratio of the real-time frequency offset and a carrier frequency of the target communication network as a filter input of the target communication network; for each non-reference network, calculating a difference between the first ratio and a crystal oscillator offset between the non-reference network and the target communication network in the last updating as a filter input of the non-reference network; for each communication network, determining a crystal oscillator frequency offset of the communication network in this updating based on the filter input of the communication network and a historical updating crystal oscillator frequency offset; for each non-reference network, calculating a difference between the crystal oscillator frequency offset of the reference network in this updating and the crystal oscillator frequency offset of the non-reference network in this updating as the crystal oscillator offset between the non-reference network and the reference network in this updating.

3. The method of claim 1, wherein, The updating based on the real-time frequency offset using the updating mode corresponding to the target communication network to obtain the crystal oscillator frequency offset of the reference network in this updating and the crystal oscillator offset between each non-reference network and the reference network in this updating comprises: when the target communication network is a non-reference network, calculating a second ratio of the real-time frequency offset and a carrier frequency of the target communication network as a filter input of the target communication network; calculating a sum of the second ratio and a crystal oscillator offset between the target communication network and the reference network in the last updating as a filter input of the reference network; for each non-reference network other than the target communication network, determining a filter input of the non-reference network based on the second ratio, the crystal oscillator offset between the target communication network and the reference network in the last updating, and a crystal oscillator offset between the non-reference network and the reference network in the last updating; for each communication network, determining a crystal oscillator frequency offset of the communication network in this updating based on the filter input of the communication network and a historical updating crystal oscillator frequency offset; for each non-reference network, calculating a difference between the crystal oscillator frequency offset of the reference network in this updating and the crystal oscillator frequency offset of the non-reference network in this updating as the crystal oscillator offset between the non-reference network and the reference network in this updating.

4. The method of claim 3, wherein, The filter input of the non-reference network is determined by the following formula: wherein represents a filter input of the non-reference network c ; represents a real-time frequency offset; represents a carrier frequency of the target communication network b ; represents a last updated crystal oscillator deviation between the target communication network b and the reference network; represents a last updated crystal oscillator deviation between the non-reference network c and the reference network.

5. The method of claim 1, wherein, The frequency compensation is based on the crystal oscillator deviation between the non-reference network and the reference network updated this time when the terminal communicates with any non-reference network. The compensation of the received signal and the transmitted signal is based on the crystal oscillator deviation between the non-reference network and the reference network updated this time and the carrier frequency of the non-reference network when the terminal communicates with any non-reference network, to obtain the compensated received signal and the transmitted signal.

6. The method of claim 5, wherein, The compensated received signal and the transmitted signal are represented by the following formula: In the formula, represents the compensated received signal; R ( t ) represents the original received signal of the non-reference network received by the terminal; represents the crystal oscillator deviation between the non-reference network a updated this time and the reference network; represents the carrier frequency of the non-reference network a .

7. The method of claim 1, wherein, The reference network and the multiple non-reference networks are determined from the multiple communication networks, including: Obtaining the crystal oscillator precision of each communication network in the satellite multi-mode communication system; The communication network with the highest crystal oscillator precision in the multiple communication networks is determined as the reference network, and the remaining communication networks are determined as non-reference networks.

8. A frequency synchronization apparatus for a satellite multi-mode communication system, characterized by, The satellite multi-mode communication system includes multiple communication networks; The device includes: A determination module for determining the reference network and the multiple non-reference networks from the multiple communication networks; A receiving module for receiving the real-time frequency offset of the target communication network; An update module for updating based on the real-time frequency offset by using the update mode corresponding to the target communication network, to obtain the crystal oscillator deviation of the reference network updated this time and the crystal oscillator deviation between each non-reference network and the reference network updated this time; A correction module for correcting the terminal frequency based on the crystal oscillator deviation of the reference network updated this time; A compensation module for performing frequency compensation based on the crystal oscillator deviation between the non-reference network and the reference network updated this time when the terminal communicates with any non-reference network.

9. An electronic device, comprising: including: A memory and a processor, which are communicatively connected, and the memory stores computer instructions, and the processor executes the computer instructions to perform the frequency synchronization method of the satellite multi-mode communication system according to any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that, The computer readable storage medium stores computer instructions for making a computer execute the frequency synchronization method of the satellite multi-mode communication system according to any one of claims 1 to 7.

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