System and method for predicting and avoiding wireless communication interference between ground station and communication satellite

Abstract

Disclosed is a method for predicting and avoiding wireless communication interference between a ground station and a communication satellite. The method for predicting and avoiding wireless communication interference comprises: calculating a three-dimensional Voronoi diagram for a communication satellite, which has entered a communicable area of a ground station, and neighboring satellites; and extracting a satellite of interest on the basis of the distance between a Voronoi diagram cell including the communication satellite and the neighboring satellites.

Description

System and method for predicting and avoiding wireless communication interference between a ground station and a communication satellite

[0001] The present invention relates to a system and method for predicting and avoiding wireless communication interference between a ground station and a communication satellite, and more particularly, to a system and method for predicting and avoiding wireless communication interference that can predict communication interference caused by surrounding satellites during wireless communication between a communication satellite and a ground station and control wireless communication of the communication satellite so that communication interference does not occur.

[0002] Since Sputnik in 1957, thousands of satellites have been deployed, and it is predicted that over 100,000 new satellites will be deployed over the next decade. The primary missions of these satellites are remote sensing to observe and measure the Earth and space, and communications between ground stations and satellites. Recent research on Space-based Space-Situational Awareness (SSA) adds another important method to this measurement. Both missions generate and transmit data, ultimately requiring uplinks and downlinks between satellites and ground stations. Other types of satellites, such as security and defense satellites, typically have similar capabilities. The emerging blue ocean of In-Orbit Service, Assembly, and Manufacturing (ISAM) should also incorporate these capabilities.

[0003] Satellite communications typically use two media: radio frequency (RF) and optical. RF has long played a key role in space communications, offering the advantages of ease, convenience, and low cost. However, it also has its drawbacks. RF is vulnerable to hacking and jamming due to the ease of designing and implementing RF interference (RFI). As more satellites are deployed in space, and the spectrum becomes increasingly congested due to RF communications with ground stations and other satellites, RFI can cause significant communication disruptions. Satellite operators may experience image download failures due to RFI, a phenomenon that will become more pronounced as more satellites, such as Stralink, Oneweb, and Planet, are deployed in orbit. Furthermore, while RF itself is a limited resource that can be shared by everyone, new satellites require ITU licenses.

[0004] On the other hand, optical communications using lasers are gaining popularity due to their numerous advantages. They offer significantly higher data bandwidth than RF. They are also more resistant to hacking, jamming, and interference than RF, and do not require ITU authorization. For these reasons, laser communications between satellites and ground stations, and between satellites via inter-satellite links (ISLs), are emerging as a promising future.

[0005] However, despite the advantages of optical communications, RF is expected to remain a primary medium due to its aforementioned advantages. Especially in heterogeneous space environments, where multiple operators operate multiple satellites in multiple orbits, RFI-related issues are critical to the safety and sustainability of space operations and are expected to remain so in the future. Therefore, designing an interference-free satellite operation environment utilizing RF communications is essential. However, there are no good computational methods for designing satellite communication systems that are free of RFI or less susceptible to RFI, and for predicting RFI and avoiding predicted interference. Therefore, research is needed.

[0006] The present invention provides a wireless communication interference prediction and avoidance system and method capable of predicting communication interference caused by surrounding satellites during wireless communication between a communication satellite and a ground station and controlling wireless communication of the communication satellite so as to prevent communication interference from occurring.

[0007] In addition, the present invention provides a wireless communication interference prediction and avoidance system and method capable of efficiently, accurately, and in real time predicting the occurrence of wireless communication interference.

[0008] The wireless communication interference prediction and avoidance method according to the present invention calculates a three-dimensional Voronoi diagram for a communication satellite and surrounding satellites that have entered a communication area of ​​a ground station, and extracts a satellite of interest based on the distance between a Voronoi diagram cell including the communication satellite and the surrounding satellites.

[0009] Additionally, the communication satellite and the surrounding satellites can move along their own orbits.

[0010] Additionally, the satellite of interest can be extracted based on the boundary of the Voronoi diagram cell and the shortest distance between the surrounding satellites.

[0011] Additionally, the shape of the Bonoroi diagram cell may change depending on the movement of the communication satellite and the surrounding satellites.

[0012] In addition, the angular distance between the first baseline connecting the communication satellite and the ground station and the second baseline connecting the satellite of interest and the ground station is calculated, and the angular distance and the angular tolerance are compared to predict communication interference between the communication satellite and the ground station due to a signal generated from the satellite of interest.

[0013] Additionally, if the above communication interference is predicted, wireless communication between the communication satellite and the ground station may be temporarily suspended.

[0014] In addition, when the above communication interference is predicted, a relay satellite can be selected from the surrounding satellites, and wireless communication can be performed between the communication satellite and the ground station via the relay satellite.

[0015] Additionally, if the above communication interference is predicted, the communication satellite can communicate wirelessly with another ground station adjacent to the ground station.

[0016] A wireless communication interference prediction and avoidance system according to an embodiment of the present invention comprises: a frequency interference prediction unit that calculates a three-dimensional Voronoi diagram for a communication satellite that has entered a communication range of a ground station and surrounding satellites, extracts a satellite of interest based on a distance between a Voronoi diagram cell including the communication satellite and the surrounding satellites, and predicts communication interference between the communication satellite and the ground station due to a signal generated from the satellite of interest; and a communication control unit that, when the communication interference is predicted, controls wireless communication of the communication satellite to avoid the communication interference and enable wireless communication between the communication satellite and the ground station.

[0017] According to the present invention, a system and method for predicting and avoiding wireless communication interference extracts a satellite of interest by calculating a three-dimensional Voronoi diagram for a communication satellite and surrounding satellites that have entered a communication area of ​​a ground station, predicts communication interference caused by the satellite of interest in wireless communication between the communication satellite and the ground station, and, when the communication interference is predicted, controls wireless communication of the communication satellite so that wireless communication between the communication satellite and the ground station is performed by avoiding the communication interference.

[0018] In addition, according to the present invention, a three-dimensional Voronoi diagram is calculated for communication satellites that have entered the communication range of a ground station and surrounding satellites to extract satellites of interest and predict communication interference for these satellites, so that occurrence of wireless communication interference can be predicted efficiently, accurately, and in real time.

[0019] FIG. 1 is a drawing showing a detailed configuration of a wireless communication interference prediction and avoidance system according to an embodiment of the present invention.

[0020] FIG. 2 is a diagram showing a communication area of ​​a ground station and artificial satellites moving along a set orbit in space according to an embodiment of the present invention.

[0021] FIG. 3 is a diagram illustrating a process of extracting a satellite of interest according to an embodiment of the present invention.

[0022] FIG. 4 is a diagram illustrating a process of extracting a satellite capable of communication interference according to an embodiment of the present invention.

[0023] FIGS. 5 to 7 are drawings for explaining a communication control method for avoiding communication interference according to various embodiments of the present invention.

[0024] FIG. 8 is a flowchart illustrating a method for predicting and avoiding wireless communication interference between a ground station and a communication satellite according to an embodiment of the present invention.

[0025] The wireless communication interference prediction and avoidance method according to the present invention calculates a three-dimensional Voronoi diagram for a communication satellite and surrounding satellites that have entered a communication area of ​​a ground station, and extracts a satellite of interest based on the distance between a Voronoi diagram cell including the communication satellite and the surrounding satellites.

[0026] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. However, the technical concept of the present invention is not limited to the embodiments described herein and may be embodied in other forms. Rather, the embodiments introduced herein are provided to ensure that the disclosed content is thorough and complete and to sufficiently convey the spirit of the present invention to those skilled in the art.

[0027] In this specification, when a component is referred to as being on another component, it means that it can be formed directly on the other component, or a third component may be interposed between them. In addition, in the drawings, the thicknesses of films and regions are exaggerated for the purpose of effectively explaining the technical contents.

[0028] Also, although terms such as first, second, and third have been used to describe various components in various embodiments of this specification, these components should not be limited by these terms. These terms are only used to distinguish one component from another. Thus, what is referred to as a first component in one embodiment may be referred to as a second component in another embodiment. Each embodiment described and illustrated herein also includes its complementary embodiments. Also, the term "and / or" has been used herein to mean including at least one of the components listed before and after.

[0029] In the specification, singular expressions include plural expressions unless the context clearly dictates otherwise. In addition, terms such as "comprise" or "have" are intended to specify the presence of a feature, number, step, component, or combination thereof described in the specification, and should not be construed as excluding the presence or addition of one or more other features, numbers, steps, components, or combinations thereof. In addition, the term "connection" is used in the present specification to mean both indirectly connecting multiple components and directly connecting them.

[0030] In addition, when describing the present invention below, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the gist of the present invention, the detailed description will be omitted.

[0031]

[0032] FIG. 1 is a drawing showing a detailed configuration of a wireless communication interference prediction and avoidance system according to an embodiment of the present invention, and FIG. 2 is a drawing showing a communication area of ​​a ground station and artificial satellites moving along a set orbit in space according to an embodiment of the present invention.

[0033] Referring to FIGS. 1 and 2, a wireless communication interference prediction and avoidance system (100) between a ground station and a communication satellite according to an embodiment of the present invention predicts communication interference caused by a surrounding satellite (30) during wireless communication between a communication satellite (20) and a ground station (10), and controls wireless communication of the communication satellite (20) so that communication interference does not occur.

[0034] A ground station (10) is installed on the ground and has an antenna capable of communicating with artificial satellites (20, 30) moving along a set orbit in space. The antenna has a spatial range capable of receiving signals from the artificial satellites (20, 30), which is referred to as a communicable area (50). The communicable area (50) appears in a cone shape toward space centered on the ground station (10), and its direction can change depending on the movement of the antenna. The antenna can receive radio frequencies from the artificial satellites (20, 30).

[0035] A communication satellite (20) refers to a satellite that moves along a set orbit in space and periodically communicates with a ground station (10), and a peripheral satellite (30) refers to a satellite that moves along a set orbit in space and enters the communication area (50) of a ground station (10).

[0036] A wireless communication interference prediction and avoidance system (100) includes a signal receiving unit (110), a communication satellite position tracking unit (120), a frequency interference prediction unit (130), and a communication control unit (140).

[0037] The signal receiving unit (110) receives real-time 3D spatial information of artificial satellites (20, 30) moving in space, location information of the ground station (10), and 3D spatial information of the communicable area (50).

[0038] The communication satellite position tracking unit (120) tracks the position of the communication satellite (20) when the communication satellite (20) enters the communication area (50). In addition, it tracks the positions of surrounding satellites (30) located within the communication area (50).

[0039] The frequency interference prediction unit (130) predicts whether there is frequency interference (Radio Frequency Interference, RFI) by surrounding satellites (30) during wireless communication between a communication satellite (20) and a ground station (10) according to the movement of the communication satellite (20).

[0040] Specifically, when a communication satellite (20) enters a communicable area (50), the frequency interference prediction unit (130) calculates a three-dimensional Voronoi diagram targeting the communication satellite (20) and surrounding satellites (30) located within the communicable area (50) at the same time. By calculating the three-dimensional Voronoi diagram, Voronoi diagram cells centered on each of the communication satellite (20) and surrounding satellites (30) are formed. The boundaries of the Voronoi diagram cells contact adjacent cells to form boundary surfaces. The calculation of the three-dimensional Voronoi diagram continues until the communication satellite (20) exits the communicable area (50), and the shapes of the Voronoi diagram cells change in real time due to the movement of the communication satellite (20) and surrounding satellites (30).

[0041] The frequency interference prediction unit (140) extracts satellites of interest using Voronoi diagram cells.

[0042] FIG. 3 is a diagram showing a process for extracting a satellite of interest according to an embodiment of the present invention, and FIG. 4 is a diagram showing a process for extracting a satellite capable of communication interference according to an embodiment of the present invention.

[0043] Referring to FIGS. 3 and 4, the frequency interference prediction unit (140) extracts surrounding satellites (31 to 37) included in Voronoi diagram cells (220 to 280) that share a boundary (211 to 217) with a Voronoi diagram cell (210) including a communication satellite (20), as satellites of interest. The satellites of interest (31 to 37) refer to satellites among the surrounding satellites (30) that are highly likely to cause communication interference during communication between the communication satellite (20) and the ground station (10).

[0044] The frequency interference prediction unit (130) extracts a satellite of interest that satisfies the communication distance condition with the boundary (220 to 280) among the surrounding satellites (31 to 37) included in the Voronoi diagram cells (220 to 280) that share the boundary (211 to 217) with the Voronoi diagram cell (210) that includes the communication satellite (20).

[0045] The frequency interference prediction unit (130) predicts communication interference between the communication satellite (20) and the ground station (10) by signals generated from the satellites of interest (31 to 37). Specifically, the frequency interference prediction unit (130) calculates an angular distance (θ) between a first baseline (L1) connecting the communication satellite (20) and the ground station (10) and a second baseline (L2) connecting the satellite of interest (31) and the ground station (10), and compares the angular distance (θ) with an angular tolerance (τ) to predict communication interference. According to an embodiment, the frequency interference prediction unit (130) predicts communication interference by using mathematical expression 1.

[0046] [Mathematical Formula 1]

[0047] RFI=f(G, F, P)

[0048] Here, RFI stands for frequency interference, G stands for geometry, F stands for frequency of the communication signal, and P stands for power density of the communication signal. G stands for the angular distance (θ) between the first baseline (L1) connecting the ground station (10) to the communication satellite (20) and the second baseline (L2) connecting the satellite of interest (31). Since G changes over time (t) depending on the movement of the communication satellite (20) and the satellite of interest (31), it can be expressed as a function G(t). F and P are constants.

[0049] The frequency interference prediction unit (130) predicts that a communication signal generated from the satellite of interest (31) will interfere with the communication between the communication satellite (20) and the ground station (10) if the angular distance (θ) between the communication satellite (20) and the satellite of interest (31) is within the range of the angular tolerance (τ) and the requirements for the frequency (F) and power density (P) are met, and tracks the satellite of interest (31) as a satellite capable of causing communication interference.

[0050] The communication control unit (140) controls the wireless communication of the communication satellite (20) so that wireless communication is established between the communication satellite (20) and the ground station (10) by avoiding communication interference while a communication interference condition is maintained between the communication satellite (20) and a communication interference-prone satellite (31).

[0051]

[0052] FIGS. 5 to 7 are drawings for explaining a communication control method for avoiding communication interference according to various embodiments of the present invention.

[0053] First, referring to FIG. 5, the communication control unit (140) can control the communication satellite (20) so that wireless communication between the communication satellite (20) and the ground station (10) is temporarily interrupted while a communication interference condition is maintained.

[0054] Referring to FIG. 6, the communication control unit (140) can select a satellite among surrounding satellites that does not cause communication interference in communication between the communication satellite (20) and the ground station (10) as a relay satellite (21) while the communication interference condition is maintained, and control the communication satellite so that wireless communication is performed between the communication satellite (20) and the ground station (10) via the relay satellite (21).

[0055] Referring to FIG. 7, the communication control unit (140) can control the communication satellite (20) to wirelessly communicate with the ground station (10) via another ground station (11) while the communication interference condition is maintained.

[0056]

[0057] FIG. 8 is a flowchart illustrating a method for predicting and avoiding wireless communication interference between a ground station and a communication satellite according to an embodiment of the present invention.

[0058] Referring to FIG. 8, a method for predicting and avoiding wireless communication interference between a ground station and a communication satellite includes a signal receiving step (S10), a communication satellite position tracking step (S20), a frequency interference prediction step (S30), and a communication control step (S40).

[0059] The signal receiving step (S10) receives real-time 3D spatial information of artificial satellites (20, 30) moving in space, location information of a ground station (10), and 3D spatial information of a communicable area (50).

[0060] The communication satellite position tracking step (S20) tracks the position of the communication satellite (20) when the communication satellite (20) enters the communication area (50) and tracks the positions of surrounding satellites (30) located within the communication area (50).

[0061] The frequency interference prediction step (S30) calculates a three-dimensional Voronoi diagram for the communication satellite (20) and surrounding satellites (30) located within the communication area (50) at the same time when the communication satellite (20) enters the communication area (50). By calculating the three-dimensional Voronoi diagram, Voronoi diagram cells are formed centered on the communication satellite (20) and the surrounding satellites (30). The boundaries of the Voronoi diagram cells contact adjacent cells to form boundary surfaces. The calculation of the three-dimensional Voronoi diagram continues until the communication satellite (20) exits the communication area (50), and the shapes of the Voronoi diagram cells change in real time due to the movement of the communication satellite (20) and the surrounding satellites (30).

[0062] And the frequency interference prediction step (S30) extracts the surrounding satellites (31 to 37) included in the Voronoi diagram cells (220 to 280) that share the boundary (211 to 217) with the Voronoi diagram cell (210) that includes the communication satellite (20), as satellites of interest. According to an embodiment, among the surrounding satellites included in the Voronoi diagram cells (220 to 280) that share the boundary (211 to 217) with the Voronoi diagram cell (210) that includes the communication satellite (20), the satellites of interest (31 to 37) that satisfy the communication distance condition with the boundary (211 to 217) are extracted.

[0063] In addition, the frequency interference prediction step (S30) predicts communication interference between the communication satellite (20) and the ground station (10) by signals generated from the satellites of interest (31 to 37). Specifically, the frequency interference prediction step (S30) calculates an angular distance (θ) between a first baseline (L1) connecting the communication satellite (20) and the ground station (10) and a second baseline (L2) connecting the satellites of interest (31 to 37) and the ground station (10), and compares the angular distance (θ) with an angular tolerance (τ) to predict communication interference. If the angular distance (θ) between the communication satellite (20) and the satellite of interest (31 to 37) is within the angular tolerance (τ) range and the requirements for frequency and power density are met, it is predicted that the communication signal generated from the satellite of interest (31 to 37) will cause interference in the communication between the communication satellite (20) and the ground station (10), and the satellite of interest (31) is tracked as a satellite capable of communication interference.

[0064] The communication control step (S40) controls the wireless communication of the communication satellite so that wireless communication is established between the communication satellite (20) and the ground station (10) by avoiding communication interference while a communication interference condition is maintained between the communication satellite (20) and the communication interference-prone satellite (31).

[0065] For example, the communication control step (S40) can control the communication satellite (20) so that wireless communication between the communication satellite (20) and the ground station (10) is temporarily interrupted while the communication interference condition is maintained.

[0066] In another example, the communication control step (S40) may select a satellite (21) that does not cause communication interference between the communication satellite (20) and the ground station (10) among surrounding satellites as a relay satellite while the communication interference condition is maintained, and control the communication satellite (20) so that wireless communication is performed between the communication satellite (20) and the ground station (10) via the relay satellite (21).

[0067] In another embodiment, the communication control step (S40) may control the communication satellite (20) to wirelessly communicate with the ground station (10) through another ground station (11) while a communication interference condition is maintained.

[0068]

[0069] FIG. 9 is a diagram for explaining a process of predicting and avoiding communication interference of a communication satellite owned and operated by the Korea Aerospace Research Institute (KARI) using a wireless communication interference prediction and avoidance method according to an embodiment of the present invention.

[0070] Referring to Figure 9, ground stations located in Jeju Island, South Korea, Svalbard, Norway, and Neustrelitz, Germany were selected. The range of antennas available for communication from these ground stations was assumed to be 120 degrees. In Figure 9, the yellow area (50) indicates the range of communication of the antenna installed in Jeju Island, South Korea, the blue area (51) indicates the range of communication of the antenna installed in Svalbard, Norway, and the green area (52) indicates the range of communication of the antenna installed in Neustrelitz, Germany. These three ground stations are operated by the Korea Aerospace Research Institute, and four satellites that can communicate with them are designated as communication satellites. The communication satellites are indicated by red dots, and surrounding satellites are indicated by green dots. Below, the process of predicting and avoiding communication interference between the ground station installed in Jeju Island, South Korea and the communication satellites is described. This method of predicting and avoiding communication interference can be equally applied to the ground stations installed in Svalbard, Norway, and Neustrelitz, Germany.

[0071] When a communication satellite (20) enters the yellow area (50), a three-dimensional Voronoi diagram is calculated for the communication satellite (20) and surrounding satellites (30) located within the yellow area at the same time. Then, a satellite of interest that satisfies the boundary surface of the Voronoi diagram cells centered on the communication satellite (20) and the communication distance conditions of the surrounding satellites is extracted. The extraction of the satellite of interest continues until the communication satellite (20) leaves the yellow area (50).

[0072] By following the movement of the communication satellite (20) and the satellite of interest, the angular distance between the first baseline connecting the communication satellite (20) and the ground station and the second baseline connecting the satellite of interest (31) and the ground station is calculated, and the angular distance and the angular tolerance are compared to predict communication interference.

[0073] If the angular distance is within the angular tolerance, the radio communication of the communication satellite is controlled to avoid communication interference.

[0074] In one example, while communication interference conditions persist, the communication satellite is controlled so that wireless communication between the communication satellite (20) and the ground station is temporarily interrupted.

[0075] In another example, while communication interference conditions are maintained, another communication satellite that does not cause communication interference with the ground station among the communication satellites is selected as a relay satellite, and wireless communication is controlled to be performed through the relay satellite.

[0076] In another example, while communication interference conditions persist, the communication satellite is controlled to communicate wirelessly with another ground station adjacent to the ground station.

[0077]

[0078] While the present invention has been described in detail using preferred embodiments, the scope of the present invention is not limited to the specific embodiments described above, and should be interpreted in accordance with the appended claims. Furthermore, those skilled in the art will appreciate that numerous modifications and variations are possible without departing from the scope of the present invention.

[0079]

[0080] A wireless communication interference prediction and avoidance system according to an embodiment of the present invention can be used for wireless communication between a communication satellite and a ground station.

Claims

1. A wireless communication interference prediction and avoidance method that calculates a three-dimensional Voronoi diagram for communication satellites and surrounding satellites that have entered the communication range of a ground station, and extracts satellites of interest based on the distance between the Voronoi diagram cell containing the communication satellite and the surrounding satellites.

2. In paragraph 1, A method for predicting and avoiding wireless communication interference in which the above communication satellite and the surrounding satellites move along their respective orbits.

3. In paragraph 1, A wireless communication interference prediction and avoidance method for extracting the satellite of interest that satisfies the communication distance conditions of the boundary surface of the Voronoi diagram cell and the surrounding satellites.

4. In paragraph 1, A method for predicting and avoiding wireless communication interference, wherein the shape of the Bonoroi diagram cell changes according to the movement of the communication satellite and the surrounding satellites.

5. In paragraph 1, A wireless communication interference prediction and avoidance method for calculating the angular distance between a first baseline connecting the communication satellite and the ground station and a second baseline connecting the satellite of interest and the ground station, and comparing the angular distance with an angular tolerance to predict communication interference between the communication satellite and the ground station due to a signal generated from the satellite of interest.

6. In paragraph 5, A method for predicting and avoiding wireless communication interference, which temporarily suspends wireless communication between the communication satellite and the ground station when the above communication interference is predicted.

7. In paragraph 5, A method for predicting and avoiding wireless communication interference, wherein, when the above communication interference is predicted, a relay satellite is selected from among the surrounding satellites, and wireless communication is performed between the communication satellite and the ground station via the relay satellite.

8. In paragraph 5, A method for predicting and avoiding wireless communication interference, in which the communication satellite wirelessly communicates with another ground station adjacent to the ground station when the above communication interference is predicted.

9. A frequency interference prediction unit that calculates a three-dimensional Voronoi diagram for communication satellites and surrounding satellites that have entered the communication range of a ground station, extracts a satellite of interest based on the distance between the Voronoi diagram cell containing the communication satellite and the surrounding satellites, and predicts communication interference between the communication satellite and the ground station due to a signal generated from the satellite of interest; and A wireless communication interference prediction and avoidance system including a communication control unit that controls wireless communication of the communication satellite so that wireless communication between the communication satellite and the ground station is performed by avoiding the communication interference when the communication interference is predicted.

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