Inter-satellite communication ranging method and device, and first inter-satellite communication terminal

Abstract

This application discloses an inter-satellite communication ranging method, apparatus, and a first inter-satellite communication terminal. The method includes: upon receiving a ranging command, generating a first ranging optical signal and sending it to a second inter-satellite communication terminal, wherein the first ranging optical signal carries a first time identifier indicating that the second inter-satellite communication terminal sent the first ranging optical signal; receiving a second ranging optical signal returned by the second inter-satellite communication terminal in response to the first ranging optical signal, the second ranging optical signal containing a second time identifier indicating that the second inter-satellite communication terminal received the first ranging optical signal and a third time identifier indicating that the second inter-satellite communication terminal sent the second ranging optical signal; and determining the distance between the first and second inter-satellite communication terminals based on the first and second ranging optical signals. This method allows for real-time and rapid calculation of the distance between the first and second inter-satellite communication terminals, and enables inter-satellite distance measurement by generating separate ranging optical signals.

Description

Technical Field

[0001] This application relates to the field of satellite communication technology, and in particular to an inter-satellite communication ranging method, device and first inter-satellite communication terminal. Background Technology

[0002] Inter-satellite laser ranging can be used in scenarios such as navigation enhancement for low-Earth orbit satellite internet constellations. It typically achieves integrated communication and ranging through space laser links between inter-satellite communication terminals. This integrated laser communication and ranging system uses a laser beam as a carrier, sharing ranging and communication information with the same laser beam and hardware platform, enabling a single set of equipment to perform both ranging and communication functions.

[0003] Currently, bidirectional one-way communication ranging integration is generally achieved using a ranging frame timing method based on the communication data frame header and overhead. The principle is that the high-speed communication data frame header acts as the ranging synchronization code. The inter-satellite transmitter inserts a small amount of overhead information into the communication data frame to carry the ranging timestamp information; the inter-satellite receiver obtains the synchronization code and timestamp information by searching frames and de-overheading, and transmits the relevant information to the ground terminal, thereby realizing the functions of measuring inter-satellite data transmission clock difference and inter-satellite distance measurement.

[0004] However, current inter-satellite communication ranging methods cannot achieve high-precision inter-satellite ranging quickly and in real time. Summary of the Invention

[0005] The purpose of this application is to provide an inter-satellite communication ranging method, device, and first inter-satellite communication terminal, which can quickly and in real-time achieve high-precision inter-satellite ranging.

[0006] The first aspect of this specification provides an inter-satellite communication ranging method, including:

[0007] Upon receiving a ranging command, a first ranging optical signal is generated and sent to the second inter-satellite communication terminal, wherein the first ranging optical signal carries a first time identifier of the second inter-satellite communication terminal sending the first ranging optical signal;

[0008] The second inter-satellite communication terminal receives a second ranging optical signal returned in response to the first ranging optical signal. The second ranging optical signal carries a second time identifier for the second inter-satellite communication terminal receiving the first ranging optical signal and a third time identifier for sending the second ranging optical signal.

[0009] Based on the first ranging optical signal and the second ranging optical signal, the distance between the first inter-satellite communication terminal and the second inter-satellite communication terminal is determined.

[0010] In some embodiments of this specification, generating a first ranging optical signal includes:

[0011] Obtain the device information of the satellite corresponding to the first inter-satellite communication terminal and the time information of the first inter-satellite communication terminal;

[0012] A first ranging signal is generated based on the device information and the time information;

[0013] The first ranging signal is modulated into a first ranging optical signal.

[0014] In some embodiments of this specification, generating a first ranging signal based on the device information and the time information includes:

[0015] The current counting state and current time state of the first inter-satellite communication terminal are determined based on the time information.

[0016] A first time identifier is generated as a ranging frame based on the current counting state and the current time state.

[0017] Generate a ranging frame header based on the device information;

[0018] A frame synchronization header and a check bit are generated, and the frame synchronization header, the ranging frame header, the ranging frame, and the check bit are concatenated to obtain the first ranging signal.

[0019] In some embodiments of this specification, determining the distance between the first inter-satellite communication terminal and the second inter-satellite communication terminal based on the first ranging optical signal and the second ranging optical signal includes:

[0020] Determine the fourth time marker for receiving the second ranging optical signal;

[0021] Based on the first time identifier and the second time identifier, the first propagation delay of the first ranging optical signal is determined;

[0022] Based on the third time identifier and the fourth time identifier, the second propagation delay of the second ranging optical signal is determined;

[0023] Based on the first propagation delay and the second propagation delay, the distance between the first inter-satellite communication terminal and the second inter-satellite communication terminal is calculated.

[0024] In some embodiments of this specification, the second ranging optical signal also carries a fifth time identifier for the second inter-satellite communication terminal receiving the first ranging optical signal and a sixth time identifier for transmitting the second ranging optical signal;

[0025] After calculating the distance between the first inter-satellite communication terminal and the second inter-satellite communication terminal, the method further includes:

[0026] Determine the seventh time marker for sending the first ranging optical signal and the eighth time marker for receiving the second ranging optical signal;

[0027] Based on the first time identifier and the seventh time identifier, the first transmission processing delay of the first ranging optical signal is determined;

[0028] Based on the second time identifier and the fifth time identifier, the first reception and processing delay of the first ranging optical signal is determined;

[0029] Based on the third time identifier and the sixth time identifier, the second transmission processing delay of the second ranging optical signal is determined;

[0030] Based on the fourth time identifier and the eighth time identifier, the second reception and processing delay of the second ranging optical signal is determined;

[0031] Based on the first transmission processing delay, the first reception processing delay, the second transmission processing delay, the second reception processing delay, the first propagation delay, the second propagation delay, and the distance, the clock difference information between the first inter-satellite communication terminal and the second inter-satellite communication terminal is calculated.

[0032] In some embodiments of this specification, the above also includes:

[0033] Obtain the business data to be transmitted;

[0034] Based on the service data to be transmitted, a communication optical signal is generated and sent to the second inter-satellite communication terminal.

[0035] In some embodiments of this specification, the first ranging optical signal is obtained by modulating a first ranging signal onto a first signal, and the communication optical signal is obtained by modulating a target communication signal onto a second signal; wherein the first signal and the second signal are different signals at different wavelengths.

[0036] In some embodiments of this specification, the first ranging optical signal and the communication optical signal use different clock systems.

[0037] In some embodiments of this specification, after generating the communication optical signal, the method further includes:

[0038] The communication optical signal and the first ranging optical signal are mixed into a target optical signal and sent to the second inter-satellite communication terminal.

[0039] In some embodiments of this specification, generating a communication optical signal based on the service data to be transmitted includes:

[0040] The data to be transmitted is mapped to the payload area of ​​a preset communication signal template;

[0041] In the multiple sub-regions of the overhead area of ​​the preset communication signal template, mapping overhead, optical channel data overhead, and optical forwarding overhead are added respectively.

[0042] The data frames of the overhead area and the payload area are combined to obtain the initial communication signal;

[0043] The initial communication signal is encoded to obtain the target communication signal;

[0044] The target communication signal is modulated into a communication optical signal.

[0045] The second aspect of this specification provides an inter-satellite communication ranging method, applied to a second inter-satellite communication terminal, including:

[0046] The first ranging optical signal is received from the first inter-satellite communication terminal, wherein the first ranging optical signal is generated by the first inter-satellite communication terminal when it receives the ranging command, and the first ranging optical signal carries a first time identifier of the second inter-satellite communication terminal sending the first ranging optical signal.

[0047] In response to the first ranging optical signal returning a second ranging optical signal to the first inter-satellite communication terminal, the first inter-satellite communication terminal determines the distance between the first inter-satellite communication terminal and the second inter-satellite communication terminal based on the first ranging optical signal and the second ranging optical signal; wherein, the second ranging optical signal carries a second time identifier for the second inter-satellite communication terminal receiving the first ranging optical signal and a third time identifier for sending the second ranging optical signal.

[0048] A third aspect of this specification provides an inter-satellite communication ranging device, applied to a first inter-satellite communication terminal, comprising:

[0049] The signal transmission module is used to generate a first ranging optical signal and send it to the second inter-satellite communication terminal when a ranging command is received. The first ranging optical signal carries a first time identifier of the second inter-satellite communication terminal sending the first ranging optical signal.

[0050] The signal receiving module is used to receive a second ranging optical signal returned by the second inter-satellite communication terminal in response to the first ranging optical signal. The second ranging optical signal carries a second time identifier for the second inter-satellite communication terminal receiving the first ranging optical signal and a third time identifier for sending the second ranging optical signal.

[0051] The data processing module is used to determine the distance between the first inter-satellite communication terminal and the second inter-satellite communication terminal based on the first ranging optical signal and the second ranging optical signal.

[0052] The fourth aspect of this specification provides an inter-satellite communication ranging device for use in a second inter-satellite communication terminal, comprising:

[0053] The signal receiving module is used to receive a first ranging optical signal sent by a first inter-satellite communication terminal, wherein the first ranging optical signal is generated by the first inter-satellite communication terminal when it receives a ranging command, and the first ranging optical signal carries a first time identifier of the second inter-satellite communication terminal sending the first ranging optical signal.

[0054] The signal transmission module is configured to return a second ranging optical signal to the first inter-satellite communication terminal in response to the first ranging optical signal, so that the first inter-satellite communication terminal determines the distance between the first inter-satellite communication terminal and the second inter-satellite communication terminal based on the first ranging optical signal and the second ranging optical signal; wherein the second ranging optical signal carries a second time identifier for the second inter-satellite communication terminal receiving the first ranging optical signal and a third time identifier for transmitting the second ranging optical signal.

[0055] This specification provides a first inter-satellite communication terminal in a fifth aspect, comprising: a signal transmitting unit, a signal receiving unit, and a data processing unit, wherein the signal transmitting unit and the signal receiving unit are respectively connected to the data processing unit;

[0056] The signal transmitting unit is used to generate a first ranging optical signal and send it to the second inter-satellite communication terminal when it receives a ranging command. The first ranging optical signal carries a first time identifier of the second inter-satellite communication terminal sending the first ranging optical signal.

[0057] The signal receiving unit is used to receive a second ranging optical signal returned by the second inter-satellite communication terminal in response to the first ranging optical signal. The second ranging optical signal carries a second time identifier for the second inter-satellite communication terminal receiving the first ranging optical signal and a third time identifier for sending the second ranging optical signal.

[0058] The data processing unit is used to determine the distance between the first inter-satellite communication terminal and the second inter-satellite communication terminal based on the first ranging optical signal and the second ranging optical signal.

[0059] In some embodiments of this specification, the signal transmitting unit includes a ranging signal processor and an optical antenna; the ranging signal processing subunit is connected to the optical antenna and the data processing unit;

[0060] The ranging signal processor is used to: acquire the device information of the satellite corresponding to the first inter-satellite communication terminal and the time information of the first inter-satellite communication terminal; generate a first ranging signal based on the device information and the time information; and modulate the first ranging signal into a first ranging optical signal and send it to the optical antenna.

[0061] The optical antenna is used to receive the first ranging optical signal output by the ranging signal processor and send the first ranging optical signal to the second inter-satellite communication terminal.

[0062] In some embodiments of this specification, the first inter-satellite communication terminal further includes a communication signal processing unit connected to the optical antenna;

[0063] The communication signal processing unit is used to acquire service data to be transmitted; generate a communication optical signal based on the service data to be transmitted; and send the communication optical signal to the optical antenna.

[0064] The optical antenna is also used to: receive the communication optical signal output by the communication signal processing unit, and send the communication optical signal to the second inter-satellite communication terminal.

[0065] In some embodiments of this specification, the signal transmitting unit further includes a wavelength division multiplexer, which is connected to the ranging signal processor and the communication signal processing unit;

[0066] The wavelength division multiplexer is used to mix the communication optical signal and the first ranging optical signal into a target optical signal and send it to the optical antenna;

[0067] The optical antenna is also used to: receive the target optical signal output by the wavelength division multiplexer, and send the target optical signal to the second inter-satellite communication terminal.

[0068] A sixth aspect of this specification provides a computer storage medium storing computer program instructions that, when executed, implement the steps of the method described in the first aspect.

[0069] A seventh aspect of this specification provides a computer program product comprising a computer program that, when executed by a processor, implements the steps of the method described in the first aspect.

[0070] The inter-satellite communication ranging method, apparatus, and first inter-satellite communication terminal in the embodiments of this specification generate a first ranging optical signal and send it to a second inter-satellite communication terminal upon receiving a ranging command. The first ranging optical signal carries a first time identifier indicating that the second inter-satellite communication terminal sent the first ranging optical signal. The method then receives a second ranging optical signal returned by the second inter-satellite communication terminal in response to the first ranging optical signal. This second ranging optical signal contains a second time identifier indicating that the second inter-satellite communication terminal received the first ranging optical signal and a third time identifier indicating that it sent the second ranging optical signal. Based on the first and second ranging optical signals, the distance between the first and second inter-satellite communication terminals is determined. By adding a time identifier for ranging functionality to the ranging optical signal, the first inter-satellite communication terminal can calculate the distance between itself and the second inter-satellite communication terminal in real time and quickly upon receiving the second ranging optical signal sent by the second inter-satellite communication terminal. Furthermore, the inter-satellite distance can be measured by generating a separate ranging optical signal. Attached Figure Description

[0071] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0072] Figure 1 The diagram shown is a schematic representation of an inter-satellite communication scenario provided in an embodiment of this specification.

[0073] Figure 2 The diagram shown is a schematic representation of a ranging signal frame format provided in an embodiment of this specification.

[0074] Figure 3 The diagram shown is a schematic representation of an inter-satellite communication ranging method provided in an embodiment of this specification.

[0075] Figure 4 The diagram shown is a schematic representation of a ranging signal generation method provided in an embodiment of this specification.

[0076] Figure 5 The diagram shown is a schematic representation of a ranging signal frame format provided in an embodiment of this specification.

[0077] Figure 6 The diagram shown is a schematic representation of an inter-satellite ranging method provided in an embodiment of this specification.

[0078] Figure 7 The diagram shown is a schematic representation of a communication signal generation method provided in an embodiment of this specification.

[0079] Figure 8 The diagram shown is a schematic representation of an inter-satellite communication ranging method provided in an embodiment of this specification.

[0080] Figure 9 The diagram shown is a schematic diagram of a first inter-satellite communication terminal provided in an embodiment of this specification;

[0081] Figure 10 The diagram shown is a schematic representation of an inter-satellite transmission system provided in an embodiment of this specification.

[0082] Figure 11 The diagram shown is a schematic representation of an inter-satellite receiving system provided in an embodiment of this specification.

[0083] Figure 12 The diagram shown is a schematic diagram of an electronic device provided in an embodiment of this specification. Detailed Implementation

[0084] To enable those skilled in the art to better understand the technical solutions in this application, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this application.

[0085] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, apparatus, product, or device that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or devices.

[0086] This specification provides the operational steps of the methods described in the embodiments or flowcharts, but based on conventional or non-inventive labor, more or fewer operational steps may be included. The order of steps listed in the embodiments is merely one possible execution order among many and does not represent the only possible execution order. In actual system or device products, the methods shown in the embodiments or drawings can be executed sequentially or in parallel.

[0087] It should be noted that the information involved in this application (including but not limited to user terminal device information, user personal information, etc.) is all information and data authorized by the user or fully authorized by all parties, and the acquisition, transmission, storage, use and processing of the relevant data comply with the relevant laws, regulations and standards of the relevant countries and regions.

[0088] It should be noted that in the embodiments of this specification, certain software, components, models and other existing solutions in the industry may be mentioned. These should be regarded as exemplary and are only intended to illustrate the feasibility of implementing the technical solution of the present invention. However, they do not mean that the applicant has used or necessarily used such solutions.

[0089] The satellite communication terminal described in the embodiments of this specification is a terminal device with satellite communication capabilities. This application does not specifically limit its manufacturer, model, etc.

[0090] refer to Figure 1 As shown, in a satellite communication scenario, an inter-satellite laser network can include multiple satellites, such as Satellite 1, Satellite 2, Satellite 3, etc., which can communicate with each other via inter-satellite laser links. Each satellite can include onboard access payloads, onboard routers, inter-satellite communication terminals, and satellite service systems. For example... Figure 1 The satellite 1 includes an inter-satellite communication terminal 1, a satellite-borne router 1, and a satellite-borne access payload 1.

[0091] Among them, the spaceborne access payload is used to support the access of ground terminals; the spaceborne router is used to support the signal forwarding between satellite communication payloads; and the inter-satellite communication terminal is used to transmit signals between satellites through inter-satellite links.

[0092] Among them, the satellite user terminal is the ground user access terminal. The ground gateway station is connected to the ground network and can receive user data transmitted through the satellite network and access the user data to other ground networks.

[0093] Service data from satellite user terminals can be accessed via the onboard access payload to satellite 1. The onboard access payload 1 then sends the received service data to the onboard router 1. The onboard router 1, based on the destination address, forwards the service data to the corresponding inter-satellite communication terminal 1 via the service interface. If the next-hop destination address for satellite 1 is satellite 2, inter-satellite communication terminal 1 transmits the signal to inter-satellite communication terminal 2 on satellite 2 via inter-satellite link 1. In this case, inter-satellite communication terminal 1 can act as an inter-satellite transmitter, and inter-satellite communication terminal 2 can act as an inter-satellite receiver. Of course, in other scenarios, inter-satellite communication terminal 1 can act as an inter-satellite receiver, and inter-satellite communication terminal 2 can act as an inter-satellite transmitter.

[0094] In some embodiments, the transmission signal sent from inter-satellite communication terminal 1 to inter-satellite communication terminal 2 may include communication data frames corresponding to service data, and ranging frames for inter-satellite ranging. To achieve inter-satellite ranging, inter-satellite communication terminal 2 may also send ranging frames to inter-satellite communication terminal 1 via inter-satellite link 1. Inter-satellite communication terminal 1 and inter-satellite communication terminal 2 can send ranging signals to ground terminals (e.g., satellite user terminals) based on the received ranging frames and signal reception status, enabling the ground terminals to calculate the distance and clock difference between satellite 1 and satellite 2 based on the received ranging signals.

[0095] The aforementioned calculations of inter-satellite distance and clock bias require the transmission of ranging frames between inter-satellite communication terminals before calculation using ground terminals. This method cannot provide real-time inter-satellite ranging results and involves inserting ranging frames into communication data frames for distance measurement, resulting in low calculation accuracy. Therefore, a method is needed that allows for real-time, high-precision calculation of inter-satellite distance and clock bias directly from the inter-satellite communication terminals, without the involvement of ground terminals.

[0096] Specifically, when generating the ranging signal, information related to calculating inter-satellite distances can be used to generate corresponding ranging parameters, and these parameters can be added to the ranging signal. For example... Figure 2 The image illustrates the frame format of a ranging signal according to one embodiment of this specification. The ranging signal may include a frame synchronization header 201, a ranging frame header 202, a ranging parameter frame 203, and a check bit 204. The frame synchronization header 201 indicates the start of the frame; the ranging frame header 202 may include information related to the satellite to which the satellite communication terminal is located; the ranging parameter frame 203 may include ranging-related parameters such as week count, week seconds, local time identifier, initiation / end of ranging, and local measurement value; and the check bit 204 is used for information verification to improve the reliability of the ranging signal transmission. Furthermore, at inter-satellite communication terminal 1 or inter-satellite communication terminal 2, relevant ranging parameters can be extracted from the received ranging signal, and combined with the relevant ranging parameters of the current device, the inter-satellite distance and clock difference can be calculated accurately and in real time.

[0097] It is understood that the frame format of the ranging signal described above is only one example of this specification, and other embodiments may include more or less content than the frame format described above, which is not limited by this specification.

[0098] Based on this, the embodiments of this specification provide an inter-satellite communication ranging method, which is applied to a first inter-satellite communication terminal. Figure 3The diagram illustrates an inter-satellite communication ranging method provided in an embodiment of this specification. While this specification provides method operation steps or system structures as shown in the following embodiments or figures, the method or system may include more or fewer operation steps or module units, either combined or without inventive effort, based on conventional methods or without requiring creative labor. In steps or structures where there is no logically necessary causal relationship, the execution order of these steps or the module structure of the system is not limited to the execution order or module structure shown in the embodiments or figures of this specification. When the method or module structure is applied in actual systems, servers, or terminal products, it can be executed sequentially or in parallel according to the method or module structure shown in the embodiments or figures (e.g., in a parallel processor or multi-threaded processing environment, or even in a distributed processing or server cluster implementation environment). It should also be noted that the first inter-satellite communication terminal and the second inter-satellite communication terminal in the following embodiments can be an inter-satellite transmitting terminal and an inter-satellite receiving terminal, respectively. The first and second inter-satellite communication terminals are merely distinguished as two inter-satellite communication terminals used for ranging. In some real-time scenarios, the first inter-satellite communication terminal can be an inter-satellite receiving terminal, and the second inter-satellite communication terminal can be an inter-satellite transmitting terminal. Furthermore, the inter-satellite communication ranging method in the following embodiments can be applied to different inter-satellite laser communication systems, such as OTN (Optical Transport Network) communication system, CCSDS (Consultative Committee for Space Data Systems) communication system, and other custom communication systems. This application does not impose any limitations on this. Figure 3 As shown, this inter-satellite communication ranging method may include:

[0099] S301: Upon receiving a ranging command, a first ranging optical signal is generated and sent to a second inter-satellite communication terminal, wherein the first ranging optical signal carries a first time identifier of the second inter-satellite communication terminal sending the first ranging optical signal.

[0100] The ranging command can be used to trigger the generation of a ranging optical signal. That is, when the first inter-satellite communication terminal receives the ranging command, it can respond by generating a first ranging optical signal for inter-satellite ranging and sending it to the second inter-satellite communication terminal. The first time identifier can be the identifier information for the time when the first inter-satellite communication terminal sends the first frame of the first ranging optical signal.

[0101] In some embodiments of this specification, the ranging command may be sent from ground equipment to the first inter-satellite communication terminal, or it may be generated and sent to the first inter-satellite communication terminal in advance in the satellite's satellite service system according to a preset time interval. This specification does not limit this.

[0102] S302: Receive a second ranging optical signal returned by the second inter-satellite communication terminal in response to the first ranging optical signal, wherein the second ranging optical signal carries a second time identifier for the second inter-satellite communication terminal receiving the first ranging optical signal and a third time identifier for sending the second ranging optical signal.

[0103] The second ranging optical signal can be generated by the inter-satellite receiving terminal by adding the reception time of the first ranging optical signal and the transmission time of the second ranging optical signal to the ranging signal based on the reception status of the first ranging optical signal. Furthermore, the second ranging optical signal can be generated in the same way as the first ranging optical signal. The second time identifier can be the time identifier information of the first frame in the first ranging optical signal received by the second inter-satellite communication terminal, and the third time identifier can be the time identifier information of the first frame in the second ranging optical signal transmitted by the second inter-satellite communication terminal.

[0104] In some embodiments of this specification, the second ranging optical signal may be generated immediately in response to the first ranging optical signal when the second inter-satellite communication terminal receives the first ranging optical signal, or it may be generated by a ranging command after receiving the first ranging optical signal.

[0105] S303: Based on the first ranging optical signal and the second ranging optical signal, determine the distance between the first inter-satellite communication terminal and the second inter-satellite communication terminal.

[0106] In the embodiments of this specification, by adding a first time identifier, a second time identifier, and a third time identifier for ranging function to the ranging optical signal, that is, by the first inter-satellite communication terminal and the second inter-satellite communication terminal exchanging a first ranging optical signal and a second ranging optical signal containing overhead information of both parties, the first inter-satellite communication terminal can calculate the distance between the first inter-satellite communication terminal and the second inter-satellite communication terminal in real time and quickly when it receives the second ranging optical signal sent by the second inter-satellite communication terminal, and can realize the measurement of inter-satellite distance by generating a separate ranging optical signal.

[0107] In some embodiments of this specification, step S301, when generating the first ranging optical signal, may include: acquiring the device information of the satellite corresponding to the first inter-satellite communication terminal and the time information of the first inter-satellite communication terminal; generating the first ranging signal based on the device information and the time information; and modulating the first ranging signal into a first ranging optical signal.

[0108] The device information may include information related to the satellite on which the first inter-satellite communication terminal is located. Device information may include, but is not limited to, version number, spacecraft identifier, and logical channel identifier. Time information may include information related to the local time of the first inter-satellite communication terminal. Since different inter-satellite communication terminals may use different clock systems, or different programs and modules within the terminal may use different clock systems, the time information of the first inter-satellite communication terminal can be added to the ranging optical signal when generating the ranging optical signal to achieve high-precision measurement of inter-satellite distance. Specifically, time information may include, but is not limited to, week count, seconds within the week, and local time identifier.

[0109] In some embodiments of this specification, a first ranging signal can also be generated by combining ephemeris information, signal power information, bit error rate information, etc. of the satellite where the first inter-satellite communication terminal is located, which is required for transmitting inter-satellite laser link establishment and link stabilization, so that the first ranging optical signal can be reliably transmitted between the first inter-satellite communication terminal and the second inter-satellite communication terminal.

[0110] refer to Figure 4 As shown, in some embodiments of this specification, generating a first ranging signal based on the device information and the time information may include:

[0111] S401: Determine the current counting state and current time state of the first inter-satellite communication terminal based on the time information.

[0112] S402: Generate a first time identifier as a ranging frame based on the current counting state and the current time state.

[0113] S403: Generate a ranging frame header based on the device information.

[0114] S404: Generate a frame synchronization header and a check bit, and concatenate the frame synchronization header, the ranging frame header, the ranging frame, and the check bit to obtain the first ranging signal.

[0115] It is understood that the first ranging signal contains time information related to the current counting state and current time state of the first inter-satellite communication terminal. This time information can be used as a ranging parameter to generate a ranging frame in the first ranging signal. Based on the time information, the first transmission time of the first ranging optical signal can be determined, and a corresponding first time identifier can be generated, providing a data basis for subsequent inter-satellite distance calculations. The first ranging signal may also carry equipment information of the satellite where the first inter-satellite communication terminal is located, used to identify the source of the first ranging signal, serving as the ranging frame header in the first ranging signal. Furthermore, the first ranging signal may also carry a frame synchronization header indicating the start of the frame and check bits for information verification. These check bits may include, but are not limited to, CRC (Cyclic Redundancy Check) check bits and RS (ReedSolomon) encoded check bits, used for information verification of the first ranging signal, ensuring reliable transmission of the first ranging optical signal between satellites. In other embodiments, the ranging frame and ranging frame header may also carry other information, which can be set based on the application scenario; this application does not impose any limitations on this.

[0116] In some embodiments of this specification, the ranging frame of the first ranging signal may carry not only the current counting state and the current time state, but also the local measurement value of the first inter-satellite communication terminal. The local measurement value can be used to characterize the reception time of the ranging signal received by the first inter-satellite communication terminal. This reception time can be used to characterize the reception time of the first frame of the ranging signal sent by the second inter-satellite communication terminal during this inter-satellite ranging process. In this case, the second inter-satellite communication terminal can first send a ranging optical signal to the first inter-satellite communication terminal. Alternatively, the reception time can be the reception time of the ranging signal received from the second inter-satellite communication terminal during the previous inter-satellite ranging process. This reception time can then be used to calculate the inter-satellite distance during this inter-satellite ranging process, or to calculate the inter-satellite distance during the previous inter-satellite ranging process.

[0117] Of course, it is understandable that when the second inter-satellite communication terminal generates the second ranging signal corresponding to the second ranging optical signal, it can add local measurement values ​​of the second inter-satellite communication terminal to the ranging frame. These local measurement values ​​can carry the reception time of the first ranging optical signal received by the second inter-satellite communication terminal. Furthermore, the method by which the second inter-satellite communication terminal generates the second ranging signal can be the same as the method by which the first inter-satellite communication terminal generates the first ranging optical signal.

[0118] Specifically, the frame format of the ranging signal provided in some embodiments of this specification can be referred to Figure 5 As shown. This is understandable. Figure 5 The frame format can be the frame format of the first ranging signal and / or the frame format of the second ranging signal, and Figure 5The frame format described herein is an example, and you can define the data frames and the number of bytes in each frame according to your needs.

[0119] refer to Figure 5 As shown, the ranging signal may specifically include a frame synchronization header, a ranging frame header, ranging parameters, inter-satellite information transmission overhead, a CRC check bit, and an RS encoding check bit.

[0120] Taking a ranging signal frame length of 1000 bytes as an example, the frame synchronization header can include 4 bytes to indicate the start of the frame. The ranging frame header can include 6 bytes to identify the satellite version number, spacecraft identifier, and logical channel identifier, etc. The ranging parameters can be used as a ranging frame and can include 16 bytes to identify ranging initiation / termination, ranging timestamp validity / invalidity, week count, week seconds, local time identifier, and local measurement values, etc., which can be used for dedicated ranging functions. The inter-satellite information transmission overhead can include 844 bytes to transmit ephemeris information, signal power information, bit error rate information, local time identifier information, local measurement values, and solar avoidance angle, etc., which are required for inter-satellite laser link establishment and link stabilization between the two terminals. The CRC check bit can include 2 bytes for information verification. The RS encoding check bit can include 128 bytes to ensure reliable transmission of the ranging optical signal between satellites.

[0121] In some embodiments of this specification, determining the distance between the first inter-satellite communication terminal and the second inter-satellite communication terminal based on the first ranging optical signal and the second ranging optical signal in step S303 may include: determining a fourth time identifier for receiving the second ranging optical signal; determining a first propagation delay of the first ranging optical signal based on the first time identifier and the second time identifier; determining a second propagation delay of the second ranging optical signal based on the third time identifier and the fourth time identifier; and calculating the distance between the first inter-satellite communication terminal and the second inter-satellite communication terminal based on the first propagation delay and the second propagation delay.

[0122] The fourth time identifier can be the identifier information of the time when the first inter-satellite communication terminal receives the first frame of the second ranging optical signal, the first propagation delay can be used to characterize the propagation delay of the first ranging optical signal from the first inter-satellite communication terminal to the second inter-satellite communication terminal, and the second propagation delay can be used to characterize the propagation delay of the second ranging optical signal from the second inter-satellite communication terminal to the first inter-satellite communication terminal.

[0123] Specifically, the second time identifier included in the second ranging optical signal can be a time count under the clock system of the second inter-satellite communication terminal, and the fourth time identifier of the second ranging optical signal can be a time count under the clock system of the first inter-satellite communication terminal. During distance calculation, since the physical environment for the transmission of the first and second ranging optical signals is basically the same, and their transmission directions are opposite, and the clock differences between the two terminals can cancel each other out, the influence of the clock differences between the terminals on the propagation delay of the two ranging optical signals can be ignored. Based on the first and second propagation delays, the transmission delay between the first and second inter-satellite communication terminals can be obtained, and then the distance between the first and second inter-satellite communication terminals can be calculated based on this transmission delay.

[0124] In some embodiments of this specification, the second ranging optical signal also carries a fifth time identifier for the second inter-satellite communication terminal receiving the first ranging optical signal and a sixth time identifier for transmitting the second ranging optical signal.

[0125] Furthermore, after calculating the distance between the first inter-satellite communication terminal and the second inter-satellite communication terminal, the method further includes: determining a seventh time marker for transmitting the first ranging optical signal and an eighth time marker for receiving the second ranging optical signal; determining a first transmission processing delay of the first ranging optical signal based on the first time marker and the seventh time marker; determining a first reception processing delay of the first ranging optical signal based on the second time marker and the fifth time marker; determining a second transmission processing delay of the second ranging optical signal based on the third time marker and the sixth time marker; determining a second reception processing delay of the second ranging optical signal based on the fourth time marker and the eighth time marker; and calculating clock difference information between the first inter-satellite communication terminal and the second inter-satellite communication terminal based on the first transmission processing delay, the first reception processing delay, the second transmission processing delay, the second reception processing delay, the first propagation delay, the second propagation delay, and the distance.

[0126] It can be understood that the fifth time identifier can be used to identify the time when the second inter-satellite communication terminal receives the last frame of the first ranging optical signal; the sixth time identifier can be used to identify the time when the second inter-satellite communication terminal sends the last frame of the second ranging optical signal; the seventh time identifier can be used to identify the time when the first inter-satellite communication terminal sends the last frame of the first ranging optical signal; and the eighth time identifier can be used to identify the time when the first inter-satellite communication terminal receives the last frame of the second ranging optical signal. The receive processing delay can be used to characterize the time required for the inter-satellite communication terminal to receive the ranging optical signal from the first frame to the last frame, that is, the time required for the inter-satellite communication terminal to receive the ranging optical signal. The transmit processing delay can characterize the time required for the inter-satellite communication terminal to transmit the ranging optical signal from the first frame to the last frame, that is, the time required for the inter-satellite communication terminal to transmit the ranging optical signal.

[0127] For any inter-satellite communication terminal, its local ranging value can include the transmission and processing delay of the ranging signal, the reception and processing delay, the propagation delay, and the clock difference between the terminals due to differences in clock systems. Therefore, the clock difference between the terminals can be calculated based on the correlation delay information of the ranging optical signals emitted by the two terminals.

[0128] Specifically, since the physical environment and transmission links of the ranging optical signals transmitted in both directions are the same, the local ranging values ​​of the two terminals are the same. Based on this, and combined with the transmission delay between the two terminals calculated from the first and second propagation delays, as well as the transmission processing delay and reception processing delay of the ranging signal, the local ranging values ​​of the first inter-satellite communication terminal and the second inter-satellite communication terminal can be calculated. Then, based on the local ranging value and the delay in the transmission process of the corresponding ranging optical signal, the clock difference between the first inter-satellite communication terminal and the second inter-satellite communication terminal can be obtained.

[0129] The following is combined Figure 6 The transmission principle of the ranging optical signal in the diagram further explains the calculation process of the distance and time difference between the first and second inter-satellite communication terminals. In the diagram, uppercase letters represent time periods, and lowercase letters represent times.

[0130] Reference Figure 6 As shown, terminal A (corresponding to satellite A) and terminal B (corresponding to satellite B) complete the inter-satellite ranging process by sending ranging optical signals to each other. Specifically, the process of transmitting signals from terminal A to terminal B and from terminal B to terminal A needs to be considered. Since the inter-satellite laser link is symmetrical, the physical environment (such as space medium properties) along the signal paths in both directions is almost identical. Assume the signal transmission delay from terminal A to terminal B is T. L1 The signal transmission delay from terminal B to terminal A is T. L2When performing ranging, signal transmission in both directions is considered, and the total measurement includes two processes: from terminal A to terminal B and from terminal B to terminal A. Because the link is symmetrical and the physical conditions are the same, T L1 =T L2 Meanwhile, during the calculation process, the delays in the two directions can cancel each other out under certain measurement and calculation methods.

[0131] The local ranging value T1 obtained by terminal A can be expressed as: T1 = t RB -t SA =T L1 +T SA +T RB +ΔT. Where t RB t can represent the time when terminal B receives the ranging optical signal. SA T can represent the time when terminal A sends the ranging optical signal. L1 T can represent the propagation delay of the ranging optical signal from terminal A in the air. SA The transmission processing delay T of terminal A can be represented. RB ΔT can represent the reception and processing delay of terminal B, and ΔT can represent the clock difference between terminal A and terminal B.

[0132] The local ranging value T2 obtained by terminal B can be expressed as: T2 = t RA -t SB =T L2 +T SB +T RA +ΔT. Where t RB t can represent the time when terminal A receives the ranging optical signal. SA T can represent the time when terminal B sends the ranging optical signal. L1 T can represent the propagation delay of the ranging optical signal from terminal B in the air. SA This can represent the transmission processing delay T of terminal B. RB This can represent the reception and processing delay of terminal A.

[0133] Since the transmission paths from terminal A to terminal B and from terminal B to terminal A are symmetrical in a vacuum, the inter-satellite (between terminal A and terminal B) transmission delay T can be derived from the above two formulas. L It can be represented as:

[0134] Based on the transmission and reception times of the two ranging optical signals, the propagation delay of the two ranging optical signals can be determined, i.e., the aforementioned T. L1 and T L2 Furthermore, based on the time information contained in the ranging optical signal and the actual reception of the signal by the terminal, T can be determined. SA TRB T SA and T RB Based on the calculated delays and the inter-satellite transmission delay formulas mentioned above, the local ranging values ​​T1 and / or T2 can be calculated. Then, based on the corresponding local ranging formulas, the inter-satellite clock difference ΔT can be calculated.

[0135] In some embodiments of this specification, the above method may further include: acquiring service data to be transmitted; generating a communication optical signal based on the service data to be transmitted and sending it to a second inter-satellite communication terminal.

[0136] It is understood that the first inter-satellite communication terminal can send the aforementioned first ranging optical signal, and can also process the service data to be transmitted, and send the processed communication optical signal to the inter-satellite communication terminal. Furthermore, the first ranging optical signal and the communication optical signal can be sent separately.

[0137] In some embodiments of this specification, the first ranging optical signal is obtained by modulating a first ranging signal onto a first signal, and the communication optical signal is obtained by modulating a target communication signal onto a second signal; wherein the first signal and the second signal are different signals at different wavelengths.

[0138] It can be understood that by modulating the first ranging signal and the target communication signal onto signals of different wavelengths, the resulting communication optical signal and the first ranging optical signal are also optical signals of different wavelengths, thus achieving integrated communication and ranging based on different wavelengths. The wavelength difference between the first signal and the second signal can satisfy a preset threshold. For example, the wavelength difference can be greater than 0.8 nm.

[0139] In other embodiments, the first ranging signal and the target communication signal can be modulated onto the same signal at the same wavelength, or onto different signals at the same wavelength, to achieve integrated inter-satellite communication ranging.

[0140] Furthermore, generating a communication optical signal based on the service data to be transmitted may include: mapping the service data to be transmitted to the payload area of ​​a preset communication signal template; adding mapping overhead, optical channel data overhead, and optical forwarding overhead to multiple sub-regions of the overhead area of ​​the preset communication signal template respectively; combining the data frames of the overhead area and the payload area to obtain an initial communication signal; encoding the initial communication signal to obtain a target communication signal; and modulating the target communication signal into a communication optical signal.

[0141] Specifically, refer to Figure 7As shown, the service data to be transmitted can be mapped to the payload area of ​​the ISL-OPU frame, and OPU overhead can be added to the mapping overhead sub-area to form an ISL-OPU frame; ODU overhead can be added to the optical channel data overhead area to form an ISL-ODU frame to provide functions such as path monitoring (PM); OTU overhead can be added to the optical forwarding overhead sub-area to form an ISL-OUT frame, which can provide SM (Section Monitoring) detection function; furthermore, an FEC area (including PHY overhead and FEC overhead) can be added to the ISL-OTU frame to form an inter-satellite transmission physical frame, i.e., an ISL-OTN interface signal, and the formed ISL-OTN interface signal is converted into an optical signal for transmission.

[0142] In some embodiments of this specification, the first ranging optical signal and the communication optical signal can be transmitted simultaneously. Furthermore, after generating the communication optical signal, the method may further include: mixing the communication optical signal and the first ranging optical signal into a target optical signal and transmitting it to the second inter-satellite communication terminal.

[0143] It is understandable that the first inter-satellite communication terminal can send the first ranging optical signal and the communication optical signal separately, or it can mix the first ranging optical signal and the communication optical signal into a single optical signal, namely the target optical signal, through wavelength division multiplexing, and then send the target optical signal to the second inter-satellite communication terminal.

[0144] Furthermore, for the first ranging optical signal, communication optical signal, or target optical signal generated above for separate transmission, or for transmission after mixing, the optical signal can be amplified before transmission, and the amplified optical signal can be emitted through an optical antenna.

[0145] In some embodiments of this specification, the aforementioned communication optical signal and the first ranging optical signal can be generated separately and can employ different clock systems. Since inter-satellite laser ranging requires an extremely precise and stable clock system for high-precision ranging, compared to the prior art where inter-satellite laser ranging and communication use the same clock system, the embodiments of this specification employ independent clock systems for communication and ranging. This minimizes the system's dependence on the clock, thereby supporting communication over a wider range of clock accuracies, enabling inter-satellite ranging to achieve higher accuracy while satisfying a higher Doppler effect.

[0146] Based on the above-described communication ranging method, this specification also provides an inter-satellite communication ranging device applied to a first inter-satellite communication terminal, comprising:

[0147] The signal transmission module is used to generate a first ranging optical signal and send it to the second inter-satellite communication terminal when a ranging command is received. The first ranging optical signal carries a first time identifier of the second inter-satellite communication terminal sending the first ranging optical signal.

[0148] The signal receiving module is used to receive a second ranging optical signal returned by the second inter-satellite communication terminal in response to the first ranging optical signal. The second ranging optical signal carries a second time identifier for the second inter-satellite communication terminal receiving the first ranging optical signal and a third time identifier for sending the second ranging optical signal.

[0149] The data processing module is used to determine the distance between the first inter-satellite communication terminal and the second inter-satellite communication terminal based on the first ranging optical signal and the second ranging optical signal.

[0150] For descriptions and functions of the above modules, please refer to [link / reference]. Figure 3 The content regarding the inter-satellite communication ranging method is not elaborated here.

[0151] This specification also provides an inter-satellite communication ranging method in the embodiments, applied to a second inter-satellite communication terminal, which may specifically include the following steps:

[0152] S1. Receive a first ranging optical signal sent by a first inter-satellite communication terminal, wherein the first ranging optical signal is generated by the first inter-satellite communication terminal when it receives a ranging command, and the first ranging optical signal carries a first time identifier of the second inter-satellite communication terminal sending the first ranging optical signal.

[0153] S2. In response to the first ranging optical signal, a second ranging optical signal is returned to the first inter-satellite communication terminal, so that the first inter-satellite communication terminal determines the distance between the first inter-satellite communication terminal and the second inter-satellite communication terminal based on the first ranging optical signal and the second ranging optical signal; wherein, the second ranging optical signal carries a second time identifier for the second inter-satellite communication terminal receiving the first ranging optical signal and a third time identifier for sending the second ranging optical signal.

[0154] It is understood that the descriptions of each step in the communication ranging method applied to the second inter-satellite communication terminal described above can be found in [reference needed]. Figure 3 The content regarding the inter-satellite communication ranging method is not elaborated here.

[0155] Based on the above-described communication ranging method, this specification also provides an inter-satellite communication ranging device applied to a second inter-satellite communication terminal, comprising:

[0156] The signal receiving module is used to receive a first ranging optical signal sent by a first inter-satellite communication terminal, wherein the first ranging optical signal is generated by the first inter-satellite communication terminal when it receives a ranging command, and the first ranging optical signal carries a first time identifier of the second inter-satellite communication terminal sending the first ranging optical signal.

[0157] The signal transmission module is configured to return a second ranging optical signal to the first inter-satellite communication terminal in response to the first ranging optical signal, so that the first inter-satellite communication terminal determines the distance between the first inter-satellite communication terminal and the second inter-satellite communication terminal based on the first ranging optical signal and the second ranging optical signal; wherein the second ranging optical signal carries a second time identifier for the second inter-satellite communication terminal receiving the first ranging optical signal and a third time identifier for transmitting the second ranging optical signal.

[0158] For descriptions and functions of the above modules, please refer to [link / reference]. Figure 3 The content on inter-satellite communication ranging methods is not elaborated here.

[0159] Reference Figure 8 As shown in the embodiments of this specification, an inter-satellite communication ranging method is also provided, applied to an inter-satellite communication ranging system. The inter-satellite communication ranging system may include inter-satellite communication terminal A and inter-satellite communication terminal B. The above method may include:

[0160] S801: When inter-satellite communication terminal A receives a ranging command, it generates the first ranging optical signal.

[0161] The first ranging optical signal carries a first time identifier for the first ranging optical signal sent by inter-satellite communication terminal A.

[0162] S802: Inter-satellite communication terminal A sends the first ranging optical signal to inter-satellite communication terminal B.

[0163] S803: Inter-satellite communication terminal B generates a second ranging optical signal in response to the first ranging optical signal.

[0164] The second ranging optical signal carries a second time identifier for the inter-satellite communication terminal B receiving the first ranging optical signal and a third time identifier for sending the second ranging optical signal.

[0165] S804: Inter-satellite communication terminal B sends a second ranging optical signal to inter-satellite communication terminal A.

[0166] S805: Inter-satellite communication terminal A determines the distance between inter-satellite communication terminal A and inter-satellite communication terminal B based on the first ranging optical signal and the second ranging optical signal.

[0167] It is understood that the descriptions and specific implementation methods of the above steps can be found in [reference needed]. Figure 3 The content regarding the inter-satellite communication ranging method is not elaborated here.

[0168] Based on the inter-satellite communication ranging method described above, this specification also provides a first inter-satellite communication terminal in its embodiments. The second inter-satellite communication terminal can be an inter-satellite communication terminal with the same structure as the first inter-satellite communication terminal. Although the system described in the following embodiments is preferably implemented in hardware, software implementation, or a combination of software and hardware, is also possible and contemplated. Reference Figure 9 As shown, the first inter-satellite communication terminal may include: a signal transmitting unit 901, a signal receiving unit 902, and a data processing unit 903, wherein the signal transmitting unit 901 and the signal receiving unit 902 are respectively connected to the data processing unit 903;

[0169] The signal transmitting unit 901 can be used to generate a first ranging optical signal and send it to a second inter-satellite communication terminal when a ranging command is received, wherein the first ranging optical signal carries a first time identifier of the second inter-satellite communication terminal sending the first ranging optical signal.

[0170] The signal receiving unit 902 can be used to receive a second ranging optical signal returned by the second inter-satellite communication terminal in response to the first ranging optical signal. The second ranging optical signal carries a second time identifier for the second inter-satellite communication terminal receiving the first ranging optical signal and a third time identifier for sending the second ranging optical signal.

[0171] The data processing unit 903 can be used to determine the distance between the first inter-satellite communication terminal and the second inter-satellite communication terminal based on the first ranging optical signal and the second ranging optical signal.

[0172] It is understood that the modules included in the aforementioned first inter-satellite communication terminal can be a single integrated unit or multiple distributed units. They can be integrated into one electronic device terminal or distributed across different electronic device terminals. For example, the signal transmitting module 901, the signal receiving module 902, and the data processing module 903 can be integrated into one unit; as another example, the signal transmitting module 901 and the signal receiving module 902 can be integrated into one unit, and the data processing module 903 can be integrated into one unit.

[0173] In some embodiments of this specification, the signal transmitting unit includes a ranging signal processor and an optical antenna; the ranging signal processing subunit is connected to the optical antenna and the data processing unit. The ranging signal processor is used to: acquire equipment information of the satellite corresponding to the first inter-satellite communication terminal and time information of the first inter-satellite communication terminal; generate a first ranging signal based on the equipment information and the time information; and modulate the first ranging signal into a first ranging optical signal and transmit it to the optical antenna. The optical antenna is used to receive the first ranging optical signal output by the ranging signal processor and transmit the first ranging optical signal to the second inter-satellite communication terminal.

[0174] In some embodiments of this specification, the first inter-satellite communication terminal further includes a communication signal processing unit connected to the optical antenna. The communication signal processing unit is used to acquire service data to be transmitted; generate a communication optical signal based on the service data to be transmitted; and transmit the communication optical signal to the optical antenna. The optical antenna is further used to: receive the communication optical signal output by the communication signal processing unit; and transmit the communication optical signal to the second inter-satellite communication terminal.

[0175] In some embodiments of this specification, the signal transmitting unit further includes a wavelength division multiplexer (WDM), which connects the ranging signal processor and the communication signal processing unit. The WDM is used to mix the communication optical signal and the first ranging optical signal into a target optical signal and transmit it to the optical antenna. The optical antenna is further used to receive the target optical signal output by the WDM and transmit the target optical signal to a second inter-satellite communication terminal.

[0176] The descriptions and functions of the above modules can be understood by referring to the section on inter-satellite communication ranging methods, and will not be repeated here.

[0177] The first and second inter-satellite communication terminals are further described below with reference to the accompanying drawings. This embodiment provides an inter-satellite communication system based on a custom ranging protocol and a 100G ISL-OTN transmission protocol using dual-wavelength transmission technology, which may include reference... Figure 10 Inter-satellite transmission system and Figure 11 Inter-satellite receiving system.

[0178] Specifically, the inter-satellite transmission system may include: a communication signal processing module 1001, a ranging signal processing module 1002, a wavelength division multiplexer 1003, an optical amplifier 1004, a rear optical path 1005, an optical antenna 1006, a servo turntable 1007, and a control system 1008.

[0179] The communication signal processing module 1001, ranging signal processing module 1002, wavelength division multiplexer 1003, and optical amplifier 1004 all possess signal transmission and reception functions. The communication signal processing module 1001 has a 100Gbps ISL-OTN baseband signal processing capability, including channel coding, scrambling, interleaving, and framing. During baseband signal processing of the router-side service data by the communication signal processing module 1001, the ranging signal processing module 1002 and the communication signal processing module 1001 synchronize their time and synchronously generate ranging signals. The communication signal and the ranging signal are modulated onto different optical wavelengths (the wavelength difference between the two is greater than 0.8nm), resulting in a ranging optical signal and a communication optical signal. The two optical signals are mixed into a single beam after passing through the wavelength division multiplexer 1003 and amplified by the optical amplifier 1004. The amplified optical signal is then transmitted to the inter-satellite receiving system via the rear optical path 1005 and the optical antenna 1006.

[0180] The inter-satellite receiving system includes: a communication signal processing module 1101, a ranging signal processing module 1102, a wave demultiplexer 1103, an optical amplifier 1104, a rear optical path 1105, an optical antenna 1106, a servo turntable 1107, and a control system 1108.

[0181] The communication signal processing module 1101, ranging signal processing module 1102, wavelength division multiplexer 1103, and optical amplifier 1104 all have signal transmission and reception functions. The optical signal, after passing through the telescope's optical system, is coupled into a single-mode optical fiber, and then enters the wavelength division multiplexer 1103 for dual-wavelength demultiplexing after passing through the optical amplifier 1104. The demultiplexed dual wavelengths are then input to the ranging signal processing module 1102 and the communication signal processing module 1101, respectively. The communication signal processing module 1101 performs a series of baseband signal processing operations on the received signal, including frame deframing, channel decoding, descrambling, and deinterleaving, and then sends the service data signal to the onboard router. The ranging signal processing module 1102 timestamps and calculates the local distance of the received ranging signal to obtain the local measurement result. After generating a ranging optical signal, the ranging signal processing module 1102 transmits the signal through an optical amplifier 1104, a rear optical path 1105, and an optical antenna 1106 to the inter-satellite transmission system. The inter-satellite transmission system can calculate the inter-satellite distance using the received and transmitted ranging optical signals to obtain a high-precision inter-satellite distance and the clock difference between the two satellites.

[0182] The above-described ranging process will be further described below with reference to another embodiment. However, it is worth noting that this specific embodiment is only for better illustration of this application and does not constitute an undue limitation on this application.

[0183] In this embodiment, taking the ranging between terminal A and terminal B as an example, the ranging process of terminal A sending and terminal B receiving is the same as that of terminal B sending and terminal A receiving. Terminal A can be an inter-satellite transmission system, and terminal B can be an inter-satellite receiving system; or, terminal A can be an inter-satellite receiving system, and terminal B can be an inter-satellite transmission system. The ranging process between the two terminals includes the following steps:

[0184] S1. Ranging Frame Settings: The transmission frame rate and frame length are designed appropriately to ensure that the number of frames per second is an integer. The transmission frame format includes an insertion field with a built-in unified time system for week count, week-inclusive second count, and second-inclusive frame count. The second-inclusive frame count uses the second pulse as the starting reference. The receiving end uses frames with a second-inclusive frame count of 0 (or frames with a ranging identifier) ​​as ranging frames for identification and related measurement work.

[0185] S2. Range frame transmission: The starting bit of the range frame synchronization code of the terminal is precisely locked with the pulse timing signal to ensure that the start time of the starting bit of the range frame synchronization code is a whole second.

[0186] S3. Received Ranging Frame Identification and Arrival Time Measurement: The terminal's receiving and demodulation module identifies the ranging frame by checking if the frame count within a second is 0 (or the corresponding overhead), and accurately measures the arrival time of the starting bit of the ranging frame's synchronization code. The modulation and demodulation module obtains the departure time of the received ranging frame at the other terminal by reading the week count and second count of the arrival time in the insertion field, and can also obtain the integer number of seconds of the ranging frame's arrival time at the local terminal. The modulation and demodulation module uses appropriate methods to measure the code phase of the received and transmitted frames corresponding to the frame's departure and arrival times, and can obtain the non-integer second precise time or symbol count of the ranging frame's arrival time based on this. Through the above measurement process, accurate measurements of the transmission ranging frame's departure time and the received ranging frame's arrival time can be obtained. Using the received transmission ranging frame's departure time and the received ranging frame's arrival time measurements or the corresponding symbol count values, distance information and clock difference information are calculated.

[0187] One embodiment of the present invention also provides an electronic device, such as... Figure 12As shown, located on a satellite, electronic device 1201 may include one or more processors 1202, such as one or more central processing units (CPUs), each of which may implement one or more hardware threads. Electronic device 1201 may also include any memory 1203 for storing information of any kind, such as code, settings, data, etc. Non-limitingly, for example, memory 1203 may include any type of RAM, any type of ROM, flash memory, hard disk, optical disk, etc. More generally, any memory can use any technology to store information. Furthermore, any memory may provide volatile or non-volatile retention of information. Furthermore, any memory may represent a fixed or removable component of electronic device 1202. In one case, when processor 1202 executes associated instructions stored in any memory or combination of memories, electronic device 1201 may perform any operation of the associated instructions. Electronic device 1201 also includes one or more drive mechanisms 1204 for interacting with any memory, such as hard disk drive mechanisms, optical disk drive mechanisms, etc.

[0188] Electronic device 1201 may also include one or more network interfaces 1205 for exchanging data with other devices via one or more communication links 1206. One or more communication buses 1207 couple the components described above together.

[0189] Communication link 1206 can be implemented in any way, such as via a local area network, a wide area network (e.g., the Internet), a point-to-point connection, or any combination thereof. Communication link 1206 may include any combination of hardwired links, wireless links, routers, gateway functions, name servers, etc., governed by any protocol or combination of protocols.

[0190] This invention also provides a computer-readable storage medium storing a computer program that, when executed by a processor, performs the steps of the above-described method.

[0191] This invention also provides a computer-readable instruction, wherein when a processor executes the instruction, the program therein causes the processor to perform the method described in any of the foregoing embodiments.

[0192] It should be understood that, in various embodiments of the present invention, the order of the above-mentioned process numbers does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0193] It should also be understood that, in the embodiments of the present invention, the term "and / or" is merely a description of the relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Furthermore, in the present invention, the character " / " generally indicates that the preceding and following associated objects have an "or" relationship.

[0194] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed in this invention can be implemented in electronic hardware, computer software, or a combination of both. To clearly illustrate the interchangeability of hardware and software, the components and steps of each example have been generally described in terms of functionality in the foregoing description. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this invention.

[0195] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0196] In the embodiments provided by this invention, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative. For instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. In addition, the mutual coupling or direct coupling or communication connection shown or discussed may be indirect coupling or communication connection through some interfaces, devices, or units, or may be electrical, mechanical, or other forms of connection.

[0197] The units described as separate components may or may not be physically separate. 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 the units can be selected to achieve the purpose of the embodiments of the present invention, depending on actual needs.

[0198] Furthermore, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0199] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause an electronic device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0200] Specific embodiments have been used to illustrate the principles and implementation methods of this invention. The descriptions of the embodiments above are only for the purpose of helping to understand the method and core ideas of this invention. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this invention. Therefore, the content of this specification should not be construed as a limitation of this invention.

Claims

1. An inter-satellite communication ranging method, applied to a first inter-satellite communication terminal, characterized in that, include: Upon receiving a ranging command, a first ranging optical signal is generated and sent to the second inter-satellite communication terminal, wherein the first ranging optical signal carries a first time identifier of the second inter-satellite communication terminal sending the first ranging optical signal; The second inter-satellite communication terminal receives a second ranging optical signal returned in response to the first ranging optical signal. The second ranging optical signal carries a second time identifier for the second inter-satellite communication terminal receiving the first ranging optical signal and a third time identifier for sending the second ranging optical signal. Based on the first ranging optical signal and the second ranging optical signal, the distance between the first inter-satellite communication terminal and the second inter-satellite communication terminal is determined.

2. The inter-satellite communication ranging method according to claim 1, characterized in that, Generate the first ranging optical signal, including: Obtain the device information of the satellite corresponding to the first inter-satellite communication terminal and the time information of the first inter-satellite communication terminal; A first ranging signal is generated based on the device information and the time information; The first ranging signal is modulated into a first ranging optical signal.

3. The inter-satellite communication ranging method according to claim 2, characterized in that, Generate a first ranging signal based on the device information and the time information, including: The current counting state and current time state of the first inter-satellite communication terminal are determined based on the time information. A first time identifier is generated as a ranging frame based on the current counting state and the current time state. Generate a ranging frame header based on the device information; A frame synchronization header and a check bit are generated, and the frame synchronization header, the ranging frame header, the ranging frame, and the check bit are concatenated to obtain the first ranging signal.

4. The inter-satellite communication ranging method according to claim 1, characterized in that, Determining the distance between the first inter-satellite communication terminal and the second inter-satellite communication terminal based on the first ranging optical signal and the second ranging optical signal includes: Determine the fourth time marker for receiving the second ranging optical signal; Based on the first time identifier and the second time identifier, the first propagation delay of the first ranging optical signal is determined; Based on the third time identifier and the fourth time identifier, the second propagation delay of the second ranging optical signal is determined; Based on the first propagation delay and the second propagation delay, the distance between the first inter-satellite communication terminal and the second inter-satellite communication terminal is calculated.

5. The inter-satellite communication ranging method according to claim 4, characterized in that, The second ranging optical signal also carries a fifth time identifier for the second inter-satellite communication terminal to receive the first ranging optical signal and a sixth time identifier for the second ranging optical signal to be transmitted; After calculating the distance between the first inter-satellite communication terminal and the second inter-satellite communication terminal, the method further includes: Determine the seventh time marker for sending the first ranging optical signal and the eighth time marker for receiving the second ranging optical signal; Based on the first time identifier and the seventh time identifier, the first transmission processing delay of the first ranging optical signal is determined; Based on the second time identifier and the fifth time identifier, the first reception and processing delay of the first ranging optical signal is determined; Based on the third time identifier and the sixth time identifier, the second transmission processing delay of the second ranging optical signal is determined; Based on the fourth time identifier and the eighth time identifier, the second reception and processing delay of the second ranging optical signal is determined; Based on the first transmission processing delay, the first reception processing delay, the second transmission processing delay, the second reception processing delay, the first propagation delay, the second propagation delay, and the distance, the clock difference information between the first inter-satellite communication terminal and the second inter-satellite communication terminal is calculated.

6. The inter-satellite communication ranging method according to claim 1, characterized in that, Also includes: Obtain the business data to be transmitted; Based on the service data to be transmitted, a communication optical signal is generated and sent to the second inter-satellite communication terminal.

7. The inter-satellite communication ranging method according to claim 6, characterized in that, The first ranging optical signal is obtained by modulating a first ranging signal onto a first signal, and the communication optical signal is obtained by modulating a target communication signal onto a second signal; wherein the first signal and the second signal are different signals at different wavelengths.

8. The inter-satellite communication ranging method according to claim 6, characterized in that, The first ranging optical signal and the communication optical signal use different clock systems.

9. The inter-satellite communication ranging method according to claim 6, characterized in that, After generating the communication optical signal, the process also includes: The communication optical signal and the first ranging optical signal are mixed into a target optical signal and sent to the second inter-satellite communication terminal.

10. The inter-satellite communication ranging method according to claim 6, characterized in that, Generating a communication optical signal based on the service data to be transmitted includes: The data to be transmitted is mapped to the payload area of ​​a preset communication signal template; In the multiple sub-regions of the overhead area of ​​the preset communication signal template, mapping overhead, optical channel data overhead, and optical forwarding overhead are added respectively. The data frames of the overhead area and the payload area are combined to obtain the initial communication signal; The initial communication signal is encoded to obtain the target communication signal; The target communication signal is modulated into a communication optical signal.

11. An inter-satellite communication ranging method, applied to a second inter-satellite communication terminal, characterized in that, include: The first ranging optical signal is received from the first inter-satellite communication terminal, wherein the first ranging optical signal is generated by the first inter-satellite communication terminal when it receives the ranging command, and the first ranging optical signal carries a first time identifier of the second inter-satellite communication terminal sending the first ranging optical signal. In response to the first ranging optical signal returning a second ranging optical signal to the first inter-satellite communication terminal, the first inter-satellite communication terminal determines the distance between the first inter-satellite communication terminal and the second inter-satellite communication terminal based on the first ranging optical signal and the second ranging optical signal; wherein, the second ranging optical signal carries a second time identifier for the second inter-satellite communication terminal receiving the first ranging optical signal and a third time identifier for sending the second ranging optical signal.

12. An inter-satellite communication ranging device, applied to a first inter-satellite communication terminal, characterized in that, include: The signal transmission module is used to generate a first ranging optical signal and send it to the second inter-satellite communication terminal when a ranging command is received. The first ranging optical signal carries a first time identifier of the second inter-satellite communication terminal sending the first ranging optical signal. The signal receiving module is used to receive a second ranging optical signal returned by the second inter-satellite communication terminal in response to the first ranging optical signal. The second ranging optical signal carries a second time identifier for the second inter-satellite communication terminal receiving the first ranging optical signal and a third time identifier for sending the second ranging optical signal. The data processing module is used to determine the distance between the first inter-satellite communication terminal and the second inter-satellite communication terminal based on the first ranging optical signal and the second ranging optical signal.

13. An inter-satellite communication ranging device, applied to a second inter-satellite communication terminal, characterized in that, include: The signal receiving module is used to receive a first ranging optical signal sent by a first inter-satellite communication terminal, wherein the first ranging optical signal is generated by the first inter-satellite communication terminal when it receives a ranging command, and the first ranging optical signal carries a first time identifier of the second inter-satellite communication terminal sending the first ranging optical signal. The signal transmission module is configured to return a second ranging optical signal to the first inter-satellite communication terminal in response to the first ranging optical signal, so that the first inter-satellite communication terminal determines the distance between the first inter-satellite communication terminal and the second inter-satellite communication terminal based on the first ranging optical signal and the second ranging optical signal; wherein the second ranging optical signal carries a second time identifier for the second inter-satellite communication terminal receiving the first ranging optical signal and a third time identifier for transmitting the second ranging optical signal.

14. A first inter-satellite communication terminal, characterized in that, include: The system includes a signal transmitting unit, a signal receiving unit, and a data processing unit, wherein the signal transmitting unit and the signal receiving unit are respectively connected to the data processing unit; The signal transmitting unit is used to generate a first ranging optical signal and send it to the second inter-satellite communication terminal when it receives a ranging command. The first ranging optical signal carries a first time identifier of the second inter-satellite communication terminal sending the first ranging optical signal. The signal receiving unit is used to receive a second ranging optical signal returned by the second inter-satellite communication terminal in response to the first ranging optical signal. The second ranging optical signal carries a second time identifier for the second inter-satellite communication terminal receiving the first ranging optical signal and a third time identifier for sending the second ranging optical signal. The data processing unit is used to determine the distance between the first inter-satellite communication terminal and the second inter-satellite communication terminal based on the first ranging optical signal and the second ranging optical signal.

15. The first inter-satellite communication terminal according to claim 14, characterized in that, The signal transmitting unit includes a ranging signal processor and an optical antenna; the ranging signal processing subunit is connected to the optical antenna and the data processing unit. The ranging signal processor is used to: acquire the device information of the satellite corresponding to the first inter-satellite communication terminal and the time information of the first inter-satellite communication terminal; generate a first ranging signal based on the device information and the time information; and modulate the first ranging signal into a first ranging optical signal and send it to the optical antenna. The optical antenna is used to receive the first ranging optical signal output by the ranging signal processor and send the first ranging optical signal to the second inter-satellite communication terminal.

16. The first inter-satellite communication terminal according to claim 15, characterized in that, It also includes a communication signal processing unit, which is connected to the optical antenna; The communication signal processing unit is used to acquire service data to be transmitted; generate a communication optical signal based on the service data to be transmitted; and send the communication optical signal to the optical antenna. The optical antenna is also used to: receive the communication optical signal output by the communication signal processing unit, and send the communication optical signal to the second inter-satellite communication terminal.

17. The first inter-satellite communication terminal according to claim 16, characterized in that, The signal transmitting unit further includes a wavelength division multiplexer, which is connected to the ranging signal processor and the communication signal processing unit; The wavelength division multiplexer is used to mix the communication optical signal and the first ranging optical signal into a target optical signal and send it to the optical antenna; The optical antenna is also used to: receive the target optical signal output by the wavelength division multiplexer, and send the target optical signal to the second inter-satellite communication terminal.

18. A computer storage medium, characterized in that, The computer storage medium stores computer program instructions, which, when executed, implement the steps of the method according to any one of claims 1 to 10 or claim 11.

19. A computer program product, characterized in that, It includes a computer program that, when executed by a processor, implements the steps of the method according to any one of claims 1 to 10 or 11.

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