Satellite data transmission system and method

Abstract

The invention relates to a satellite data transmission system and method, and relates to the technical field of satellite communication, the system comprises an integrated terminal 1, an integrated terminal 2, a switch matrix, a phased array antenna 1 and a phased array antenna 2; the switch matrix receives two paths of radio-frequency signals of the integrated terminal I and the integrated terminal II, respectively filters the radio-frequency signals, and transmits the radio-frequency signals to the phased-array antenna I or the phased-array antenna II through switching of the coaxial switch; the first phased-array antenna receives and amplifies a radio frequency signal sent by the switch matrix, and radiates the signal in a dual-polarization mode. The first phased-array antenna and the second phased-array antenna are installed on the two sides of the satellite relative to the ground in an axial symmetry mode with the flight direction of the satellite as the axis, and the problem of lens barrel shielding is solved. The system realizes cross backup of two sets of integrated terminals and two sets of phased-array antennas, and improves reliability and availability; the system adopts a dual-frequency-point dual-polarization mode, dual-channel data transmission is realized, and the signal transmission problem caused by poor polarization isolation of the phased array is effectively avoided.

Description

Technical Field

[0001] The present invention relates to the field of satellite communication technology, and in particular to a satellite data transmission system and method. Background Art

[0002] The optical satellite's camera system has a huge lens barrel, which seriously blocks the field of view of the data transmission antenna. Usually, the data transmission system uses a mechanically rotating parabolic antenna, which is installed at the farthest end from the lens barrel. When the antenna is working, the mechanical rotation mechanism further unfolds the parabolic antenna away from the lens barrel to solve the problem of lens barrel obstruction. However, the mechanical rotating structure is heavy and large in size, which places strict requirements on the weight, volume and installation layout of the small satellite. Summary of the invention

[0003] In order to solve the technical problems existing in the above-mentioned prior art, the purpose of the present invention is to provide a satellite data transmission system and method that realizes dual-channel data transmission, reduces product weight and volume, reduces the requirements for the installation layout of the entire satellite, improves system reliability and availability, solves the problem of obstruction of the lens barrel, and can effectively avoid signal transmission problems caused by poor polarization isolation of the phased array.

[0004] To achieve the above-mentioned object of the invention, the present invention provides a satellite data transmission system and method, comprising:

[0005] Integrated terminal 1, integrated terminal 2, switch matrix, phased array antenna 1 and phased array antenna 2;

[0006] The integrated terminal 1 and the integrated terminal 2 have the same device status and serve as cold backup for each other;

[0007] The phased array antenna 1 and the phased array antenna 2 are in the same device state and serve as hot backup for each other;

[0008] The phased array antenna 1 and the phased array antenna 2 are installed on both sides of the satellite facing the ground in an axisymmetric manner with the satellite flight direction as the axis;

[0009] The integrated terminal receives, processes, compresses and stores multiple satellite payload raw image data, performs signal conditioning and modulation on the stored data, and generates radio frequency signals to send to the switch matrix;

[0010] The integrated terminal 1 receives satellite remote control commands through the data bus to implement the analysis and execution of remote control commands, and the integrated terminal 1 collects equipment telemetry and sends it to the satellite service subsystem through the data bus;

[0011] The satellite service subsystem is a satellite center computer responsible for the management and control of the satellite;

[0012] The switch matrix receives two RF signals from the integrated terminal 1 and the integrated terminal 2 and performs filtering processing respectively, and the switch matrix transmits the signals to the phased array antenna 1 or the phased array antenna 2 through the switching of the coaxial switch;

[0013] The switch matrix receives satellite remote control instructions to implement switching of the coaxial switch;

[0014] The phased array antenna 1 receives and amplifies the radio frequency signal sent by the switch matrix, and radiates the signal in a dual-polarization manner;

[0015] The phased array antenna 1 communicates with the satellite service subsystem through the data bus and receives the remote control instructions sent by the satellite service subsystem, and the phased array antenna 1 receives the satellite broadcast data required for calculating the beam pointing and collects its own telemetry data and sends it to the satellite service subsystem.

[0016] Furthermore, the two-dimensional pointing angles of the phased array antenna 1 and the phased array antenna 2 are calculated based on the satellite data broadcast by the satellite service subsystem and combined with the data of the digital transmission receiving station to control the beam pointing of the phased array antenna 1 and the phased array antenna 2 and realize the pointing tracking and communication of the antenna beam to the ground receiving station;

[0017] The longitude, latitude and altitude data of the digital transmission receiving station on the ground are received through the data bus and stored for use in calculating the antenna beam pointing.

[0018] Furthermore, the dual frequency points of the phased array antenna 1 and the phased array antenna 2 are N Hz apart, where N=150 MHz.

[0019] Furthermore, the angle between the phased array antenna 1, the phased array antenna 2 and the sub-satellite point direction is

[0020] Furthermore, the data storage capacity of the integrated terminal 1 and the integrated terminal 2 are both greater than 4 Tbits.

[0021] Furthermore, the interfaces between the integrated terminal 1, the integrated terminal 2 and the load subsystem all adopt CXP interface and LVDS interface.

[0022] A transmission method based on a satellite data transmission system comprises the following steps:

[0023] Step 1: Integrated terminal 1 and integrated terminal 2 receive the payload data, cache it, add synchronization words to the payload data, perform CRC check, LDPC encoding, scramble it, and transmit it to the ground equipment via the ground-to-space channel after modulation;

[0024] Step 2: After demodulation, the ground equipment undergoes demodulation, frame synchronization, descrambling, and decoding, and transmits the data frame by frame to the back-end equipment;

[0025] Step 3: The integrated terminal 1 and the integrated terminal 2 complete modulation of the baseband signal;

[0026] Step 4: Phased array antenna 1 and phased array antenna 2 complete the injection of the digital transmission receiving station address through ground injection;

[0027] Step 5: The phased array antenna 1 and the phased array antenna 2 implement the RF signal input of the integrated terminal 1 or the integrated terminal 2 through the switching of the switch matrix;

[0028] Step 6: Turn on the phased array antenna 1 and the phased array antenna 2 at the same time, receive the satellite time and position information broadcast by the whole satellite bus, and calculate the antenna pointing of the phased array antenna 1 and the phased array antenna 2 in real time in combination with the preset digital ground receiving station address information to complete the beam control and meet the real-time data transmission requirements of the whole satellite during attitude maneuvers.

[0029] Furthermore, the switch matrix is ​​switched through the whole-satellite command to realize that only one of the phased array antennas 1 or 2 has a radio frequency signal input, and the antenna is visible to the ground data transmission receiving station.

[0030] Furthermore, the modulation system used by the integrated terminal one and the integrated terminal two is QPSK, and the transmission rate is 2×450Mbps or 2×300Mbps or 2×150Mbps.

[0031] Furthermore, the phased array antenna 1 and the phased array antenna 2 support multiple groups of digital transmission ground station sites, and the number of digital transmission ground station sites is within 30.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] 1. The present invention uses a switch matrix to switch two phased array antennas, realizes cross-backup of two sets of integrated terminals and two sets of phased array antennas, and improves system reliability and availability;

[0034] 2. The present invention adopts the method of tilting the two phased array antennas, that is, the two phased array antennas are installed on both sides of the satellite facing the ground in an axisymmetric manner with the satellite flight direction as the axis, so as to solve the problem of the obstruction of the lens barrel;

[0035] 3. The present invention adopts a dual-frequency dual-polarization method to achieve dual-channel data transmission, which can effectively avoid signal transmission problems caused by poor polarization isolation of the phased array. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0037] Figure 1 A block diagram of a satellite data transmission system provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0038] In order to solve the technical problems existing in the above-mentioned prior art, the present invention provides a satellite data transmission system, which realizes dual-channel data transmission, reduces product weight and volume, reduces the requirements for the installation layout of the entire satellite, improves system reliability and availability, solves the obstruction problem of the lens barrel, and can effectively avoid signal transmission problems caused by poor polarization isolation of the phased array.

[0039] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0040] See also Figure 1 :

[0041] A satellite data transmission system comprises an integrated terminal 1, an integrated terminal 2, a switch matrix, a phased array antenna 1 and a phased array antenna 2;

[0042] The device status of integrated terminal 1 and integrated terminal 2 are consistent and serve as cold backup for each other;

[0043] The phased array antenna 1 and the phased array antenna 2 are in the same state and serve as hot backup for each other;

[0044] Phased array antenna 1 and phased array antenna 2 are installed on both sides of the satellite facing the ground in an axisymmetric manner with the satellite flight direction as the axis;

[0045] The integrated terminal receives, processes, compresses and stores the original image data of multiple satellite payloads, performs signal conditioning and modulation on the stored data, and generates radio frequency signals to send to the switch matrix;

[0046] The integrated terminal receives satellite remote control commands through the data bus to implement the analysis and execution of remote control commands, and the integrated terminal collects equipment telemetry and sends it to the satellite service subsystem through the data bus;

[0047] The satellite service subsystem is the satellite center computer responsible for the management and control of the satellite;

[0048] The switch matrix receives two RF signals from the integrated terminal 1 and the integrated terminal 2 and performs filtering processing respectively, and the switch matrix transmits the signals to the phased array antenna 1 or the phased array antenna 2 through the switching of the coaxial switch;

[0049] The switch matrix receives satellite remote control commands to implement the switching of the coaxial switches;

[0050] Phased array antenna 1 receives and amplifies the radio frequency signal sent by the switch matrix, and radiates the signal in a dual-polarized manner;

[0051] The phased array antenna communicates with the satellite service subsystem through the data bus and receives the remote control commands sent by the satellite service subsystem. The phased array antenna receives the satellite broadcast data required for calculating the beam pointing and collects its own telemetry data and sends it to the satellite service subsystem.

[0052] According to the satellite data broadcast by the satellite service subsystem and combined with the data of the digital transmission receiving station, the two-dimensional pointing angles of the phased array antenna 1 and the phased array antenna 2 are calculated to control the beam pointing of the phased array antenna 1 and the phased array antenna 2 and realize the pointing tracking and communication of the antenna beam to the ground receiving station;

[0053] The longitude, latitude and altitude data of the digital receiving station on the ground are received through the data bus and stored for use in calculating the antenna beam pointing.

[0054] The dual frequency points of the phased array antenna 1 and the phased array antenna 2 are N Hz apart, where N=150 MHz.

[0055] The angle between phased array antenna 1, phased array antenna 2 and the sub-satellite point is

[0056] The data storage capacity of the integrated terminal 1 and the integrated terminal 2 are both greater than 4Tbits.

[0057] The interfaces between the integrated terminal 1, the integrated terminal 2 and the load subsystem both adopt CXP interface and LVDS interface.

[0058] The data flow operation process of integrated terminal 1 and integrated terminal 2 is as follows: receiving payload data, caching, adding synchronization words, CRC check, LDPC coding, scrambling to the payload data, and transmitting it to the ground equipment through the ground-to-space channel after modulation; after demodulation, the ground equipment undergoes demodulation, frame synchronization, descrambling, decoding, and transmits the data to the back-end equipment frame by frame; integrated terminal 1 and integrated terminal 2 complete the modulation of the baseband signal, the modulation system is QPSK, and the transmission rate supports three gears: 2×450Mbps, 2×300Mbps, and 2×150Mbps;

[0059] Phased array antenna 1 and phased array antenna 2 can complete the injection of digital transmission receiving station sites through ground injection, and can support up to 30 digital transmission ground station sites;

[0060] Phased array antenna one and phased array antenna two realize the RF signal input of integrated terminal one or integrated terminal two through the switching of the switch matrix; in order to meet the real-time data transmission during the whole satellite attitude maneuver, phased array antenna two and phased array antenna one can be turned on at the same time to receive the satellite time and position information broadcast by the whole satellite bus, and combine with the preset digital ground receiving station address information to perform real-time calculation of the antenna pointing of phased array antenna one and phased array antenna two to complete the beam control; but only one pair of antennas of phased array antenna one and phased array antenna two can receive RF signals. Specifically, the switch matrix is ​​switched through the whole satellite command to realize that one and only one pair of antennas of phased array antenna one or phased array antenna two have RF signal input, and at the same time, it can be guaranteed that the pair of antennas can be visible to the ground digital receiving station.

[0061] It should be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or terminal device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or terminal device. In the absence of further restrictions, the elements defined by the sentence "includes..." do not exclude the existence of other identical elements in the process, method, article or terminal device including the elements.

[0062] Finally, it should be noted that the above is a preferred embodiment of the present invention. It should be pointed out that although the preferred embodiment of the present invention has been described, for those skilled in the art, once the basic creative concept of the present invention is known, several improvements and modifications can be made without departing from the principles of the present invention, and these improvements and modifications should also be regarded as the protection scope of the present invention. Therefore, the attached claims are intended to be interpreted as including the preferred embodiment and all changes and modifications that fall within the scope of the embodiments of the present invention.

Claims

1. A satellite data transmission system, characterized in that: include: Integrated terminal 1, integrated terminal 2, switch matrix, phased array antenna 1 and phased array antenna 2; The integrated terminal 1 and the integrated terminal 2 have the same device status and serve as cold backup for each other; The phased array antenna 1 and the phased array antenna 2 are in the same device state and serve as hot backup for each other; The phased array antenna 1 and the phased array antenna 2 are installed on both sides of the satellite facing the ground in an axisymmetric manner with the satellite flight direction as the axis; The integrated terminal receives, processes, compresses and stores multiple satellite payload raw image data, performs signal conditioning and modulation on the stored data, and generates radio frequency signals to send to the switch matrix; The integrated terminal 1 receives satellite remote control commands through the data bus to implement the analysis and execution of remote control commands, and the integrated terminal 1 collects equipment telemetry and sends it to the satellite service subsystem through the data bus; The satellite service subsystem is a satellite center computer responsible for the management and control of the satellite; The switch matrix receives two RF signals from the integrated terminal 1 and the integrated terminal 2 and performs filtering processing respectively, and the switch matrix transmits the signals to the phased array antenna 1 or the phased array antenna 2 through the switching of the coaxial switch; The switch matrix receives satellite remote control instructions to implement switching of the coaxial switch; The phased array antenna 1 receives and amplifies the radio frequency signal sent by the switch matrix, and radiates the signal in a dual-polarization manner; The phased array antenna 1 communicates with the satellite service subsystem through the data bus and receives the remote control instructions sent by the satellite service subsystem, and the phased array antenna 1 receives the satellite broadcast data required for calculating the beam pointing and collects its own telemetry data and sends it to the satellite service subsystem.

2. A satellite data transmission system according to claim 1, characterized in that: According to the satellite data broadcast by the satellite service subsystem and in combination with the data of the digital transmission receiving station, the two-dimensional pointing angles of the phased array antenna 1 and the phased array antenna 2 are calculated to control the beam pointing of the phased array antenna 1 and the phased array antenna 2 and realize the pointing tracking and communication of the antenna beam to the ground receiving station; The longitude, latitude and altitude data of the digital transmission receiving station on the ground are received through the data bus and stored for use in calculating the antenna beam pointing.

3. A satellite data transmission system according to claim 1, characterized in that: The dual frequency points of the phased array antenna 1 and the phased array antenna 2 are N Hz apart, where N=150 MHz.

4. A satellite data transmission system according to claim 1, characterized in that: The angle between the phased array antenna 1, the phased array antenna 2 and the sub-satellite point direction is 5. A satellite data transmission system according to claim 1, characterized in that: The data storage capacity of the integrated terminal 1 and the integrated terminal 2 are both greater than 4 Tbits.

6. A satellite data transmission system according to claim 1, characterized in that: The interfaces between the integrated terminal 1, the integrated terminal 2 and the load subsystem all adopt CXP interface and LVDS interface.

7. A satellite data transmission method, implemented based on the satellite data transmission system according to any one of claims 1 to 6, characterized in that: The following steps are involved: Step 1: Integrated terminal 1 and integrated terminal 2 receive the payload data, cache it, add synchronization words to the payload data, perform CRC check, LDPC encoding, scramble it, and transmit it to the ground equipment via the ground-to-space channel after modulation; Step 2: After demodulation, the ground equipment undergoes demodulation, frame synchronization, descrambling, and decoding, and transmits the data frame by frame to the back-end equipment; Step 3: The integrated terminal 1 and the integrated terminal 2 complete modulation of the baseband signal; Step 4: Phased array antenna 1 and phased array antenna 2 complete the injection of the digital transmission receiving station address through ground injection; Step 5: The phased array antenna 1 and the phased array antenna 2 implement the RF signal input of the integrated terminal 1 or the integrated terminal 2 through the switching of the switch matrix; Step 6: Turn on the phased array antenna 1 and the phased array antenna 2 at the same time, receive the satellite time and position information broadcast by the whole satellite bus, and calculate the antenna pointing of the phased array antenna 1 and the phased array antenna 2 in real time in combination with the preset digital ground receiving station address information to complete the beam control and meet the real-time data transmission requirements of the whole satellite during attitude maneuvers.

8. A satellite data transmission method according to claim 7, characterized in that: The switch matrix is ​​switched through the whole-satellite command to realize that only one of the phased array antennas 1 and 2 has a radio frequency signal input, and the antenna is visible to the ground data transmission receiving station.

9. A satellite data transmission method according to claim 7, characterized in that: The modulation system used by the integrated terminal 1 and the integrated terminal 2 is QPSK, and the transmission rate is 2×450Mbps or 2×300Mbps or 2×150Mbps.

10. A satellite data transmission method according to claim 7, characterized in that: The phased array antenna 1 and the phased array antenna 2 support multiple groups of digital transmission ground station sites, and the number of digital transmission ground station sites is within 30.

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