A system for reducing radio frequency interference in satellite and ground control system interface testing

Abstract

The application discloses a system for reducing radio frequency interference in satellite and ground TT&C system docking test, which uses a fixed attenuator to reduce the multipath interference of satellite telemetry signals on telemetry signals through a telemetry and remote control common branch, uses a first isolator to reduce the multipath interference of satellite telemetry signals on telemetry signals through a telemetry branch, and uses a second isolator to reduce the multipath interference of satellite telemetry signals on telemetry signals through a telemetry branch, so as to achieve the purpose of suppressing radio frequency multipath interference, thereby ensuring the accuracy of ranging and speed random error index testing in satellite and ground TT&C system docking test.

Description

Technical Field

[0001] This invention relates to the field of aerospace technology, and in particular to a system for reducing radio frequency interference during satellite-to-ground telemetry and control system docking tests. Background Technology

[0002] Before a satellite is launched into orbit, it must first complete the docking test and verification with the ground telemetry and control system. Only after meeting the requirements for the satellite-ground interface can the satellite meet the factory conditions to ensure stable and reliable control of the satellite in orbit.

[0003] The satellite-to-ground telemetry and control system docking test generally includes radio frequency (RF) index docking, telemetry docking, and remote control docking. Among them, the RF index docking test includes ranging and velocity measurement random error testing. This ranging and velocity measurement random error index is quite sensitive to the RF environment, especially to the influence of RF link multipath interference, which can lead to the test index being too high and thus failing to meet the index requirements. RF link multipath interference has a significant impact on the efficiency of satellite-to-ground telemetry and control system docking tests.

[0004] Existing satellite-to-ground telemetry and control system docking test systems have very low suppression of radio frequency multipath interference, resulting in large random error indicators in ranging and velocity measurement, which may even exceed the requirements. To solve this problem, this invention proposes a system to reduce radio frequency interference in satellite-to-ground telemetry and control system docking tests. Summary of the Invention

[0005] The purpose of this invention is to suppress radio frequency multipath interference in the satellite-to-ground telemetry and control system docking test system, thereby improving the accuracy of the random error index test for ranging and velocity measurement.

[0006] To achieve the above objectives, this invention proposes a system for reducing radio frequency interference during satellite-to-ground telemetry and control system docking tests, comprising:

[0007] The satellite spread spectrum transponder is used to receive uplink signals from the ground telemetry and control system and to send downlink signals to the ground telemetry and control system.

[0008] A ground-based telemetry, tracking, and command (TT&C) system is used to send the uplink signal to the satellite spread spectrum transponder and receive the downlink signal; and a system is configured between the satellite spread spectrum transponder and the ground-based TT&C system.

[0009] A fixed attenuator is used to attenuate both the uplink and downlink signals before they are transmitted.

[0010] A first circulator is used for radio frequency separation of uplink and downlink signals, which are transmitted between the first circulator and the fixed attenuator.

[0011] A first adjustable attenuator and a first isolator for transmitting uplink signals;

[0012] A second adjustable attenuator and a second isolator are used to transmit downlink signals;

[0013] The second circulator is used for radio frequency separation of uplink and downlink signals. Both uplink and downlink signals are transmitted through the second circulator and then communicate with the ground telemetry and control system.

[0014] The uplink signal passes sequentially through the ground telemetry and control system, the second circulator, the first isolator, the first adjustable attenuator, the first circulator, and the fixed attenuator before reaching the satellite spread spectrum transponder; the downlink signal passes sequentially through the satellite spread spectrum transponder, the fixed attenuator, the first circulator, the second adjustable attenuator, the second isolator, and the second circulator before reaching the ground telemetry and control system.

[0015] Preferably, the first adjustable attenuator and the second adjustable attenuator are used to control the attenuation of the uplink signal and the downlink signal, respectively, so that the uplink signal and the downlink signal meet the input level requirements of the corresponding signal receiving end.

[0016] Preferably, the first isolator and the second isolator are used to isolate and control interference signals in the uplink and downlink signals, respectively, thereby meeting the requirements for suppressing multipath signals.

[0017] Preferably, the satellite spread spectrum transponder operates in the S-band and adopts a non-coherent spread spectrum telemetry and control system. Telemetry and remote control share a single radio frequency channel, and there is only one radio frequency interface to the outside world. This radio frequency interface receives uplink signals sent by a fixed attenuator and sends downlink signals to the fixed attenuator.

[0018] Preferably, the uplink and downlink signals attenuated by the fixed attenuator meet the reception level requirements of the corresponding signal receivers: the uplink signal attenuated by the fixed attenuator meets the reception level requirements of the satellite spread spectrum transponder, and the downlink signal attenuated by the fixed attenuator meets the reception level requirements of the first circulator.

[0019] Preferably, both the first circulator and the second circulator have three ports: the communication interface between the first circulator and the fixed attenuator is the same port, and the communication interfaces between the first circulator and the first adjustable attenuator and the second adjustable attenuator are different ports; the communication interface between the second circulator and the ground telemetry and control system is the same port, and the communication interfaces between the second circulator and the first isolator and the second isolator are different ports.

[0020] Preferably, after the uplink signal passes through the second circulator, it is then isolated and controlled by the first isolator to isolate interference signals, and then attenuated and controlled by the first adjustable attenuator to ensure that the uplink signal meets the input level requirements of the first circulator receiver. After the downlink signal passes through the fixed attenuator and the first circulator, it is attenuated and controlled by the second adjustable attenuator to ensure that the downlink signal meets the input level requirements of the second isolator receiver, and then isolated and controlled by the second isolator to isolate interference signals before being input to the second circulator.

[0021] Preferably, the fixed attenuator, the first circulator, the second circulator, the first adjustable attenuator, the second adjustable attenuator, the first isolator, and the second isolator all operate in the S-band.

[0022] Preferably, the forward attenuation value of the first circulator and the second circulator is less than 0.5dB, and the reverse isolation is greater than 25dB; the attenuation value of the first adjustable attenuator and the second adjustable attenuator can reach a maximum of 100dB and can be adjusted in 1dB steps; the isolation of the first isolator and the second isolator is greater than 25dB.

[0023] Preferably, by adjusting the attenuation values ​​of the first and second adjustable attenuators, the uplink and downlink signals can respectively meet the input level requirements of the corresponding receivers.

[0024] Compared with the prior art, the present invention has at least the following advantages and beneficial effects:

[0025] This scheme achieves the purpose of suppressing radio frequency multipath interference by adding a fixed attenuator on the telemetry and remote control common branch and a reverse isolator on the independent telemetry and remote control branches, thereby ensuring the accuracy of the random error index test of ranging and velocity measurement in the satellite and ground telemetry and control system docking test.

[0026] This invention has a wider range of applications and has been used in docking tests between multiple satellite models and ground telemetry and control systems, all of which have achieved good results. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the system for reducing radio frequency interference during the docking test between the satellite and the ground telemetry and control system according to the present invention. Detailed Implementation

[0028] The technical solutions, structural features, achieved objectives, and effects of the present invention will be described in detail below with reference to the accompanying drawings in the embodiments of the present invention.

[0029] It should be noted that the accompanying drawings are in a very simplified form and use non-precise proportions. They are only used to facilitate and clarify the purpose of illustrating the embodiments of the present invention, and are not intended to limit the implementation conditions of the present invention. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportional relationship, or adjustments to the size should still fall within the scope of the technical content disclosed in the present invention, provided that they do not affect the effects and objectives that the present invention can produce.

[0030] It should be noted that, in this invention, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only the expressly listed elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus.

[0031] like Figure 1As shown, a system for reducing radio frequency interference during satellite-to-ground telemetry and control system (TT&C) docking tests according to the present invention includes: a satellite spread spectrum transponder 101 for communication with the ground, the satellite spread spectrum transponder 101 being installed on the satellite end, for receiving uplink telemetry and ranging signals (hereinafter referred to as uplink signals) sent by the ground TT&C system 109, and sending downlink telemetry and ranging signals (hereinafter referred to as downlink signals) to the ground TT&C system 109; a fixed attenuator 102, through which the uplink signals are attenuated before being sent to the satellite spread spectrum transponder 101, and the downlink signals are attenuated before being transmitted to the ground TT&C system 109; and a first circulator 103 for radio frequency separation of the uplink and downlink signals, wherein both the uplink and downlink signals are transmitted between the first circulator 103 and the fixed attenuator 102, the first circulator 103 transmitting the uplink signals to the fixed attenuator 102, and the fixed attenuator 102 transmitting the downlink signals to the first circulator 103. The system includes a first adjustable attenuator 105 and a first isolator 107 for transmitting uplink signals, and a second adjustable attenuator 104 and a second isolator 106 for transmitting downlink signals. The first adjustable attenuator 105 and the second adjustable attenuator 104 are used to control the attenuation of the uplink and downlink signals, respectively, so that the uplink and downlink signals meet the input level requirements of the corresponding signal receivers. The first isolator 107 and the second isolator 106 are used to control the isolation of interference signals in the uplink and downlink signals, respectively, so as to meet the requirements for suppressing multipath signals. A second circulator 108 is also used for radio frequency separation of the uplink and downlink signals. The uplink and downlink signals are transmitted through the second circulator 108 and then communicate with the ground telemetry and control system 109. The ground telemetry and control system 109 is used to communicate with the satellite. The ground telemetry and control system 109 sends the uplink signal to the satellite spread spectrum transponder 101 and receives and analyzes the downlink signal sent by the satellite spread spectrum transponder 101.

[0032] The ground control system 109 sends uplink remote control and ranging signals to the satellite spread spectrum transponder 101, and the satellite spread spectrum transponder 101 sends downlink telemetry and ranging signals to the ground control system 109. Telemetry refers to sending data from the satellite to the ground, remote control refers to sending data from the ground to the satellite, and ranging is the distance between the satellite and the ground station measured by the round-trip signal. The uplink signal passes through the ground control system 109, the second circulator 108, the first isolator 107, the first adjustable attenuator 105, the first circulator 103, and the fixed attenuator 102 in sequence before reaching the satellite spread spectrum transponder 101. The downlink signal passes through the satellite spread spectrum transponder 101, the fixed attenuator 102, the first circulator 103, the second adjustable attenuator 104, the second isolator 106, and the second circulator 108 in sequence before reaching the ground control system 109.

[0033] The satellite spread spectrum transponder 101 operates in the S-band and adopts a non-coherent spread spectrum telemetry and control system. Telemetry and remote control share a single radio frequency channel, meaning it has only one external radio frequency interface. This interface receives uplink signals from the fixed attenuator 102 and sends downlink signals to the fixed attenuator 102.

[0034] The uplink and downlink signals attenuated by the fixed attenuator 102 meet the reception level requirements of the corresponding signal receivers. Specifically, the uplink signal attenuated by the fixed attenuator 102 meets the reception level requirements of the satellite spread spectrum transponder 101, and the downlink signal attenuated by the fixed attenuator 102 meets the reception level requirements of the first circulator 103. By setting the fixed attenuator 102, the multipath interference generated by the satellite telemetry signal on the remote control signal when passing through the telemetry and remote control common branch is reduced. The fixed attenuator 102 operates in the S-band.

[0035] The first circulator 103 and the second circulator 108 each have three ports: a first port 1, a second port 2, and a third port 3. If a signal is input from the first port 1, it is output from the third port 3; if it is input from the third port 3, it is output from the second port 2; and if it is input from the second port 2, it is output from the first port 1. The uplink and downlink signals are input to different ports in the first circulator 103 or the second circulator 108, thereby separating the radio frequency of the uplink and downlink signals and realizing independent control of the uplink and downlink signals. In this embodiment, the downlink signal is input from the first port 1 and output from the third port of the first circulator 103, and the uplink signal is input from the second port 2 and output from the first port 1 of the first circulator 103. Thus, the communication interface between the first circulator 103 and the fixed attenuator 102 is the same port, and the communication interface between the first circulator 103 and the first adjustable attenuator 105 and the second adjustable attenuator 104 is different ports. The downlink signal is input from the second port 2 and output from the first port 1 of the second circulator 108, and the uplink signal is input from the first port 1 and output from the third port 3 of the second circulator 108. Thus, the communication interface between the second circulator 108 and the ground telemetry and control system 109 is the same port, and the communication interface between the second circulator 108 and the first isolator 107 and the second isolator 106 is different ports.

[0036] The first circulator 103 and the second circulator 108 both operate in the S-band, with a forward attenuation of less than 0.5 dB and a reverse isolation of greater than 25 dB.

[0037] The first adjustable attenuator 105 and the first isolator 107 are installed on the uplink signal transmission channel. The uplink signal sent by the ground telemetry and control system 109 passes through the second circulator 108, and then through the first isolator 107 to isolate and control interference signals. It then passes through the first adjustable attenuator 105 to attenuate the uplink signal, so that the uplink signal meets the input level requirements of the receiving end of the first circulator 103, which in this embodiment is the second port. The second adjustable attenuator 104 and the second isolator 106 are installed on the downlink signal transmission channel. The downlink signal output by the satellite spread spectrum transponder 101 passes through the fixed attenuator 102 and the first circulator 103, and then through the second adjustable attenuator 104 to attenuate the downlink signal, so that the downlink signal meets the input level requirements of the receiving end of the second isolator 106. It then passes through the second isolator 106 to isolate and control interference signals, and then enters the second port of the second circulator 108.

[0038] The first adjustable attenuator 105 and the second adjustable attenuator 104 operate in the S-band, with a maximum attenuation value of 100dB, which can be adjusted in 1dB steps. By adjusting the attenuation values ​​of the first adjustable attenuator 105 and the second adjustable attenuator 104, the uplink and downlink signals can respectively meet the input level requirements of the corresponding receivers.

[0039] The first isolator 107 is used to reduce multipath interference generated by the downlink signal to the uplink signal in the uplink signal transmission channel, and the second isolator 106 is used to reduce multipath interference generated by the uplink signal to the downlink signal in the downlink signal transmission channel. The first isolator 107 and the second isolator 106 operate in the S-band and have an isolation greater than 25dB.

[0040] Although the present invention has been described in detail through the preferred embodiments above, it should be understood that the above description should not be considered as a limitation of the present invention. Various modifications and substitutions to the present invention will be apparent to those skilled in the art after reading the above description. Therefore, the scope of protection of the present invention should be defined by the appended claims.

Claims

1. A system for reducing radio frequency interference during satellite-to-ground telemetry and control system docking tests, characterized in that, include: The satellite spread spectrum transponder is used to receive uplink signals from the ground telemetry and control system and to send downlink signals to the ground telemetry and control system. A ground-based telemetry, tracking, and command (TT&C) system is used to send the uplink signal to the satellite spread spectrum transponder and receive the downlink signal; and a system is configured between the satellite spread spectrum transponder and the ground-based TT&C system. A fixed attenuator is used to attenuate both the uplink and downlink signals before they are transmitted. A first circulator is used for radio frequency separation of uplink and downlink signals, which are transmitted between the first circulator and the fixed attenuator. A first adjustable attenuator and a first isolator for transmitting uplink signals; A second adjustable attenuator and a second isolator are used to transmit downlink signals; The second circulator is used for radio frequency separation of uplink and downlink signals. Both uplink and downlink signals are transmitted through the second circulator and then communicate with the ground telemetry and control system. The uplink signal passes sequentially through the ground telemetry and control system, the second circulator, the first isolator, the first adjustable attenuator, the first circulator, and the fixed attenuator before reaching the satellite spread spectrum transponder. The downlink signal passes sequentially through the satellite spread spectrum transponder, fixed attenuator, first circulator, second adjustable attenuator, second isolator, and second circulator before reaching the ground telemetry and control system.

2. The system for reducing radio frequency interference during satellite-to-ground telemetry and control system docking tests as described in claim 1, characterized in that, The first adjustable attenuator and the second adjustable attenuator are used to control the attenuation of the uplink signal and the downlink signal, respectively, so that the uplink signal and the downlink signal meet the input level requirements of the corresponding signal receiving end.

3. The system for reducing radio frequency interference during satellite-to-ground telemetry and control system docking tests as described in claim 1, characterized in that, The first isolator and the second isolator are used to isolate and control interference signals in the uplink and downlink signals, respectively, thereby meeting the requirements for suppressing multipath signals.

4. The system for reducing radio frequency interference during satellite-to-ground telemetry and control system docking tests as described in claim 1, characterized in that, The satellite spread spectrum transponder operates in the S-band and adopts a non-coherent spread spectrum telemetry and control system. Telemetry and remote control share a single radio frequency channel, and it has only one radio frequency interface to the outside world. This radio frequency interface receives uplink signals sent by a fixed attenuator and sends downlink signals to the fixed attenuator.

5. The system for reducing radio frequency interference during satellite-to-ground telemetry and control system docking tests as described in claim 1, characterized in that, The uplink and downlink signals attenuated by the fixed attenuator meet the reception level requirements of the corresponding signal receivers: the uplink signal attenuated by the fixed attenuator meets the reception level requirements of the satellite spread spectrum transponder, and the downlink signal attenuated by the fixed attenuator meets the reception level requirements of the first circulator.

6. The system for reducing radio frequency interference during satellite-to-ground telemetry and control system docking tests as described in claim 1, characterized in that, The first circulator and the second circulator each have three ports. The communication interface between the first circulator and the fixed attenuator is the same port, and the communication interfaces between the first circulator and the first adjustable attenuator and the second adjustable attenuator are different ports. The communication interface between the second circulator and the ground measurement and control system is the same port, and the communication interfaces between the second circulator and the first isolator and the second isolator are different ports.

7. The system for reducing radio frequency interference during satellite-to-ground telemetry and control system docking tests as described in claim 1, characterized in that, The uplink signal, after passing through the second circulator, is then isolated and controlled by the first isolator to prevent interference signals. It is then attenuated by the first adjustable attenuator to ensure the uplink signal meets the input level requirements of the first circulator receiver. Similarly, the downlink signal, after passing through a fixed attenuator and the first circulator, is attenuated by the second adjustable attenuator to ensure the downlink signal meets the input level requirements of the second isolator receiver. It is then isolated and controlled by the second isolator before being input to the second circulator.

8. The system for reducing radio frequency interference during satellite-to-ground telemetry and control system docking tests as described in claim 1, characterized in that, The fixed attenuator, the first circulator, the second circulator, the first adjustable attenuator, the second adjustable attenuator, the first isolator, and the second isolator all operate in the S-band.

9. The system for reducing radio frequency interference during satellite-to-ground telemetry and control system docking tests as described in claim 8, characterized in that, The forward attenuation of the first circulator and the second circulator is less than 0.5dB, and the reverse isolation is greater than 25dB; the attenuation of the first adjustable attenuator and the second adjustable attenuator can reach a maximum of 100dB and can be adjusted in 1dB steps; the isolation of the first isolator and the second isolator is greater than 25dB.

10. The system for reducing radio frequency interference during satellite-to-ground telemetry and control system docking tests as described in claim 9, characterized in that, By adjusting the attenuation values ​​of the first and second adjustable attenuators, the uplink and downlink signals can respectively meet the input level requirements of the corresponding receivers.

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