Space-based adaptive node terminal based on optical frequency comb and communication method

Abstract

The invention provides a space-based adaptive node terminal based on an optical frequency comb and a communication method, and aims to solve the problem that frequencies, modulation formats, transmission rates and coding modes among different constellations are not matched in the prior art. And interconnection and intercommunication among different constellation systems are realized. Therefore, the whole space-based communication system can efficiently and cooperatively operate under various constellation systems, an innovative solution is provided for a constellation network node interconnection architecture, and the method has a wide application prospect.

Description

Technical Field

[0001] The present invention relates to the field of space laser communication systems, and in particular to a space-based adaptive node terminal and a communication method based on an optical frequency comb. Background Art

[0002] Space laser communication has become a universal means of building high-speed data transmission links for space satellite communications due to its higher transmission rate, lower latency and higher security. In the above-mentioned various satellite constellation systems, there is no unified standard for the main indicators such as the center frequency, modulation format, working mode, and coding method used in space laser communication links, and they cannot be interconnected. For example, the system of the laser link of Constellation 1 adopts BPSK modulation, LDPC coding, and a communication rate of 2Gbps@1550nm, and the system of the laser link of Constellation 2 adopts QPSK modulation, Polar coding, and a communication rate of 5Gbps@1530nm. Therefore, information can only be transmitted between the payload nodes of Constellation 1 or Constellation 2, and cross-constellation communication cannot be achieved, resulting in "information islands". Summary of the invention

[0003] The space-based adaptive node terminal is designed to solve this problem. It is a reconfigurable space optical communication payload that can adapt to most optical intersatellite link standards and can achieve interconnection between different constellations and different systems within a constellation.

[0004] Optical frequency comb (OFC) naturally has the characteristics of multi-carrier comb teeth and large coverage bandwidth, which provides conditions for corresponding to multiple different constellations through multiple comb teeth. In addition, the optical frequency comb has the characteristics of high frequency stability, strong spectral line phase coherence, and integration, making it potential as a key payload in space laser communication systems to achieve data transmission between different constellations.

[0005] The present invention proposes a space-based adaptive node terminal and communication method based on an optical frequency comb, which utilizes the characteristics of the optical frequency comb with multiple carrier teeth and wide coverage frequency band to make different carrier wavelengths correspond to different constellations and communication systems, thus playing a "bridge" role. Specifically, each wavelength carrier signal generated by the optical frequency comb is connected to nodes corresponding to different communication systems, thereby achieving collaborative work between multiple constellations and multiple systems, and can adaptively switch between various systems to complete the "bridge" function between different constellations and between nodes of different systems in the same constellation.

[0006] In order to achieve the above technical tasks, the present invention adopts the following technical solutions:

[0007] A space-based adaptive node terminal based on an optical frequency comb, the adaptive node terminal comprising at least an optical head, a wide-spectrum optical amplifier, an optical frequency comb and an adaptive optical processor;

[0008] The optical head is used to realize the spatial optical information transmission when the adaptive node terminal transmits and receives. The wide-spectrum optical amplifier is used to complete the power amplification and equalization of the multi-carrier comb teeth of the optical frequency comb, ensuring that the comb tooth power after amplification meets the power requirements of optical signal reception and transmission. The optical frequency comb provides the carrier basis for the interconnection between the adaptive node and multiple different constellations through its own multiple carrier comb teeth with different wavelengths. The adaptive optical processor is compatible with the communication systems of all target constellations and completes the modulation, demodulation, encoding, decoding and switching of multiple communication systems.

[0009] The adaptive node terminal uses the nodes of different communication systems corresponding to each wavelength carrier signal generated by the optical frequency comb to achieve adaptive switching and interconnection between multiple constellations and multiple systems.

[0010] In particular, the adaptive node terminal communication system, including communication wavelength, modulation mode, communication rate, coding mode, and link budget, is respectively consistent with the communication system of each target connection constellation; the optical frequency comb is adjusted so that the wavelength of the comb teeth can cover the communication wavelengths of all target connection constellations, and the comb tooth power is amplified by a wide-spectrum optical amplifier to meet the link budget required for communication with the constellation corresponding to the comb tooth; the adaptive optical processor is compatible with the systems of all target connection constellations communicating with the node, and completes the modulation, demodulation, coding and decoding of the corresponding communication system.

[0011] The present invention also provides a communication method using the space-based adaptive node terminal, which specifically includes the following steps:

[0012] Step S1: Complete the design of space-based adaptive node terminal based on optical frequency comb;

[0013] Step S2: When the Nth node of any target connection constellation M initiates a communication request, the information to be transmitted is modulated and encoded according to the wavelength, modulation format, transmission rate and coding method of the laser communication system adopted by the target connection constellation M, and then transmitted to the space-based adaptive node terminal based on the optical frequency comb;

[0014] Step S3: the space-based adaptive node terminal receives the signal, and the space-based adaptive node terminal selects a carrier comb tooth in the optical frequency comb that matches the wavelength of the Nth node, and receives the laser signal from the Nth node;

[0015] Step S4: the space-based adaptive node terminal completes the wavelength and communication system switching; the space-based adaptive node terminal selects the wavelength matching the target communication constellation P in the optical frequency comb according to the communication requirements of the target communication constellation P of the constellation M, completes the reception of the signal of the Nth node of the constellation M by the space-based adaptive node terminal, and determines the modulation format, transmission rate, and coding method adopted by the constellation P;

[0016] Step S5: the space-based adaptive node terminal sends a signal; after the space-based adaptive node terminal completes the conversion of wavelength, modulation format, communication rate and coding mode matching the target communication constellation P with the help of the optical frequency comb, the signal is sent to the Qth target node in the target communication constellation P;

[0017] Step S6: The target node Q in the target communication constellation P receives the laser signal; the node Q receives the signal from the space-based adaptive node terminal and prepares to demodulate;

[0018] Step S7: Node Q in the target communication constellation P completes reception and information extraction; Node Q receives and extracts information from the received signal, obtains all information sent from constellation M, and thus completes information transmission and connectivity from constellation M to constellation P;

[0019] Step S8: Repeat steps S2 to S7 until any two constellations in the space network achieve information transmission and connectivity through the space-based adaptive node terminal.

[0020] Furthermore, the step S1: completing the design and construction of a space-based adaptive node terminal based on an optical frequency comb specifically includes the following steps:

[0021] Step S1-1: clarify the communication system adopted by each constellation to which the adaptive node terminal needs to be connected in the space network, including communication wavelength, modulation mode, communication rate, coding mode, and link budget;

[0022] Step S1-2: adjusting the optical frequency comb so that the wavelength of its comb teeth covers the communication wavelength of the target connection;

[0023] Step S1-3: adjusting the wide-spectrum optical amplifier so that it covers all wavelengths of the optical frequency comb, and the amplified comb tooth power satisfies the link budget required for communication with the constellation corresponding to the comb tooth;

[0024] Step S1-4: configure the adaptive optical processor to be compatible with the system of the target connection constellation that communicates with the space-based adaptive node terminal, and complete the modulation, demodulation, encoding and decoding of the corresponding communication system.

[0025] The space-based adaptive node terminal and communication method based on optical frequency comb proposed in the present invention aims to solve the problem of mismatch in frequency, modulation format, transmission rate and coding mode between different constellations in the prior art, and realize interconnection and intercommunication between different constellation systems through adaptive switching between different systems by space-based adaptive nodes. Thus, the entire space-based communication system can be efficiently coordinated under multiple constellation systems, providing an innovative solution for the interconnection and intercommunication architecture of constellation network nodes, and has broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a schematic diagram of the composition of a space-based adaptive node terminal based on an optical frequency comb according to the present invention;

[0027] Figure 2 It is a schematic diagram of the overall scheme principle of the present invention;

[0028] Figure 3 This is a flow chart of one embodiment of the method of utilizing a space-based adaptive node terminal based on an optical frequency comb according to the present invention. DETAILED DESCRIPTION

[0029] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0030] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present application.

[0031] See, Figure 1 A schematic diagram of the structure of the space-based adaptive node terminal based on the optical frequency comb of the present invention is given. The space-based adaptive node mainly includes four parts: an optical head, a wide-spectrum optical amplifier, an optical frequency comb and an adaptive optical processor. Among them, the main function of the optical head is to realize the transmission of spatial optical information when the adaptive node terminal transmits and receives. The main function of the wide-spectrum optical amplifier is to complete the power amplification and equalization of the multi-carrier comb teeth of the optical frequency comb, ensuring that the amplified comb tooth power meets the power requirements of the optical signal reception and transmission. The optical frequency comb provides a carrier basis for the interconnection between the adaptive node and multiple different constellations through its own multiple carrier comb teeth of different wavelengths. The adaptive optical processor is compatible with the communication systems of all target constellations, and completes the modulation, demodulation, encoding, decoding and switching functions of multiple communication systems.

[0032] The present invention provides a space-based adaptive node terminal based on an optical frequency comb, and its overall technical solution includes the following core parts:

[0033] 1. Design of space-based adaptive node terminal based on optical frequency comb: Space-based adaptive node mainly includes four parts: optical head, wide-spectrum optical amplifier, optical frequency comb and adaptive optical processor. In particular, it is necessary to clarify the communication system adopted by each constellation that the adaptive node needs to connect, including communication wavelength, modulation mode, communication rate, coding mode, link budget, etc. And design and adjust the optical frequency comb so that the wavelength of its comb teeth can cover the communication wavelength of all constellations. Then design a wide-spectrum optical amplifier so that it can cover all wavelengths of the optical frequency comb, and the amplified comb tooth power can meet the link budget required for communication with the constellation corresponding to the comb tooth. The adaptive optical processor in the node needs to be compatible with all systems adopted by the constellation communicating with the node, and can complete the modulation, demodulation, encoding and decoding functions of the corresponding communication system.

[0034] 2. Adaptive adjustment function of optical frequency comb: Utilizing the multi-wavelength characteristics of optical frequency comb, it can adaptively switch according to the wavelength requirements between different constellations. Each constellation uses a different communication wavelength, and the optical frequency comb in the adaptive node payload can select the matching frequency for information transmission according to the communication requirements between constellations.

[0035] 3. Frequency conversion and communication system switching: During the transmission process, the optical frequency comb can convert the received signal in the optical frequency domain and simultaneously convert the communication system to adapt to the communication standards of different constellations.

[0036] 4. Inter-constellation bridging function: When a certain initiating constellation needs to communicate with other target constellations, the adaptive node first receives the optical signal of the initiating constellation node, and completes demodulation through the corresponding wavelength of the optical frequency comb in the adaptive node; then the demodulated information is modulated and encoded in the adaptive optical processor according to the target constellation communication system (including modulation mode, communication rate, encoding mode, etc.); finally, the modulated and encoded signal is loaded onto the comb teeth in the optical frequency comb that are consistent with the wavelength of the target constellation and transmitted to the target constellation node, completing the information transmission from the initiating constellation to the target constellation. All the above processes are completed in the space-based adaptive node terminal based on the optical frequency comb of the present invention.

[0037] See also Figure 2 The schematic diagram of the overall scheme of the space-based adaptive node terminal and communication method based on optical frequency comb adopted by the present invention is given. Among them, the adaptive node represents the adaptive node load based on optical frequency comb, and the nodes 1-N (the Nth node in constellation 1, and the subsequent naming is similar), 2-N, and 3-N represent the constellation nodes under three different laser communication parameters.

[0038] like Figure 3 Taking the communication between the initiating node 1-N in the constellation 1 and the target node 2-N in the constellation 2 as an example, the specific steps include:

[0039] Step S1: Complete the design and construction of the space-based adaptive node terminal based on the optical frequency comb. Clarify the communication system adopted by each constellation that the adaptive node needs to connect to, including communication wavelength, modulation method, communication rate, coding method, link budget, etc. Design and adjust the optical frequency comb so that the wavelength of its comb teeth can cover the communication wavelength of all constellations. Design a wide-spectrum optical amplifier so that it can cover all wavelengths of the optical frequency comb, and the amplified comb tooth power can meet the link budget required for communication with the constellation corresponding to the comb tooth. Design an adaptive optical processor that is compatible with all systems adopted by the constellation that communicates with the node, and can complete the modulation, demodulation, encoding and decoding functions of the corresponding communication system.

[0040] Step S2: Nodes 1-N in constellation 1 initiate a communication request. When nodes 1-N need to transmit data with other constellation nodes, they first modulate and encode the information to be transmitted according to the wavelength, modulation format, transmission rate and coding method of the laser communication system adopted by constellation 1, and then transmit it to the space-based adaptive node terminal based on the optical frequency comb.

[0041] Step S3: The space-based adaptive node terminal receives the signal. The space-based adaptive node terminal selects a carrier comb tooth in the optical frequency comb that matches the wavelength of nodes 1-N, receives the laser signal from nodes 1-N, and prepares to process it.

[0042] Step S4: The space-based adaptive node terminal completes the wavelength and communication system switching process. Since different constellation systems use different laser wavelengths and communication systems, it is necessary to switch the signal wavelength and communication system. The space-based adaptive node terminal selects a wavelength in the optical frequency comb that matches the communication requirements of the target communication constellation (e.g., constellation 2). The adaptive node terminal receives the signals from nodes 1-N and determines the modulation format, transmission rate, coding method, etc. adopted by constellation 2.

[0043] Step S5: The space-based adaptive node terminal sends a signal. After the space-based adaptive node completes the conversion of wavelength, modulation format, communication rate and coding method matching the target communication constellation 2 with the help of the optical frequency comb, it sends the signal to the 2-N target nodes in constellation 2.

[0044] Step S6: The target node 2-N in the constellation 2 receives the laser signal. The node 2-N receives the signal from the space-based adaptive node and prepares to demodulate.

[0045] Step S7: Node 2-N in constellation 2 completes reception and information extraction. Node 2-N receives and extracts information from the received signal, obtains all the information sent from constellation 1, and thus completes the information transmission and intercommunication from constellation 1 to constellation 2.

[0046] Step S8: Step S2-Step S7, until any two constellations in the space network realize information transmission and connectivity through the space-based adaptive node terminal.

[0047] Through the technical solution of the present invention, efficient and flexible laser communication between multiple constellations can be achieved, the problem of incompatibility of frequency, modulation format and coding method in the prior art can be solved, and the ability of interconnection between global space constellation nodes can be significantly improved.

Claims

1. A space-based adaptive node terminal based on optical frequency comb, characterized by: The adaptive node terminal comprises at least an optical head, a wide spectrum optical amplifier, an optical frequency comb and an adaptive optical processor; The optical head is used to realize the spatial optical information transmission when the adaptive node terminal transmits and receives. The wide-spectrum optical amplifier is used to complete the power amplification and equalization of the multi-carrier comb teeth of the optical frequency comb, ensuring that the comb tooth power after amplification meets the power requirements of optical signal reception and transmission. The optical frequency comb provides the carrier basis for the interconnection between the adaptive node and multiple different constellations through its own multiple carrier comb teeth with different wavelengths. The adaptive optical processor is compatible with the communication system of the target constellation and completes the modulation, demodulation, encoding, decoding and switching of multiple communication systems; The adaptive node terminal uses the nodes of different communication systems corresponding to each wavelength carrier signal generated by the optical frequency comb to achieve adaptive switching and interconnection between multiple constellations and multiple systems.

2. The space-based adaptive node terminal based on optical frequency comb according to claim 1, characterized in that: The adaptive node terminal communication system includes communication wavelength, modulation mode, communication rate, coding mode, and link budget, which are respectively consistent with the communication systems of each target connection constellation; by adjusting the optical frequency comb, the wavelength of the comb teeth can cover the communication wavelengths of all target connection constellations, and the comb tooth power is amplified by a wide-spectrum optical amplifier to meet the link budget required for communication with the constellation corresponding to the comb teeth; the adaptive optical processor is compatible with the systems of all target connection constellations communicating with the node, and completes the modulation, demodulation, encoding and decoding of the corresponding communication system.

3. A communication method using the space-based adaptive node terminal based on optical frequency comb according to claim 1 or 2, characterized in that: The specific steps include: Step S1: Complete the design of space-based adaptive node terminal based on optical frequency comb; Step S2: When the Nth node of any target connection constellation M initiates a communication request, the information to be transmitted is modulated and encoded according to the wavelength, modulation format, transmission rate and coding method of the laser communication system adopted by the target connection constellation M, and then transmitted to the space-based adaptive node terminal based on the optical frequency comb; Step S3: the space-based adaptive node terminal receives the signal, and the space-based adaptive node terminal selects a carrier comb tooth in the optical frequency comb that matches the wavelength of the Nth node, and receives the laser signal from the Nth node; Step S4: the space-based adaptive node terminal completes the wavelength and communication system switching; the space-based adaptive node terminal selects the wavelength matching the target communication constellation P in the optical frequency comb according to the communication requirements of the target communication constellation P of the constellation M, completes the reception of the signal of the space-based adaptive node terminal to the Nth node of the constellation M, and determines the modulation format, transmission rate, and coding method adopted by the constellation P; Step S5: the space-based adaptive node terminal sends a signal; after the space-based adaptive node terminal completes the conversion of wavelength, modulation format, communication rate and coding mode matching the target communication constellation P with the help of the optical frequency comb, the signal is sent to the Qth target node in the target communication constellation P; Step S6: The target node Q in the target communication constellation P receives the laser signal; the node Q receives the signal from the space-based adaptive node terminal and prepares to demodulate; Step S7: Node Q in the target communication constellation P completes reception and information extraction; Node Q receives and extracts information from the received signal, obtains all information sent from constellation M, and thus completes information transmission and connectivity from constellation M to constellation P; Step S8: Repeat steps S2 to S7 until any two constellations in the space network achieve information transmission and connectivity through the space-based adaptive node terminal.

4. The communication method of the space-based adaptive node terminal based on optical frequency comb according to claim 3, characterized in that: The step S1: completing the design and construction of a space-based adaptive node terminal based on an optical frequency comb, specifically includes the following steps: Step S1-1: clarify the communication system adopted by each constellation to which the adaptive node terminal needs to be connected in the space network, including communication wavelength, modulation mode, communication rate, coding mode, and link budget; Step S1-2: adjusting the optical frequency comb so that the wavelength of its comb teeth covers the communication wavelength of the target connection; Step S1-3: adjusting the wide-spectrum optical amplifier so that it covers all wavelengths of the optical frequency comb, and the amplified comb tooth power satisfies the link budget required for communication with the constellation corresponding to the comb tooth; Step S1-4: configure the adaptive optical processor to be compatible with the system of the target connection constellation that communicates with the space-based adaptive node terminal, and complete the modulation, demodulation, encoding and decoding of the corresponding communication system.

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