Satellite antenna having adjacent satellite interference exclusion function, and operating method thereof

Abstract

A satellite antenna having an adjacent satellite interference exclusion function is disclosed. The satellite antenna having the adjacent satellite antenna interference exclusion function according to one aspect of the present invention comprises: a signal reception unit for receiving a signal from a satellite; a signal-to-noise ratio (SNR) calculation unit for calculating an SNR of a satellite signal received by the signal reception unit; and a signal selection unit, which compares, to each other, respective SNRs calculated by the SNR calculation unit with respect to satellite signals from a plurality of satellites, so as to select any one satellite signal.

Description

Satellite antenna with adjacent satellite interference exclusion function and its operation method

[0001] The present invention relates to a satellite antenna having a function of eliminating interference from adjacent satellites and a method of operating the same.

[0002] Near-satellite interference (ASI) occurs when adjacent satellites use similar frequency bands, causing their communication signals to interact with each other and potentially disrupt communications. Small antennas, particularly those equipped with reflectors smaller than 40 cm, are particularly susceptible to this problem due to their wide beam patterns and low directivity when receiving satellite signals. In the case of Korea's Mugunghwa-5A and Mugunghwa-6 satellites, the two satellites are located close to each other in longitude and operate in the same frequency band. Mugunghwa-6's signal is 6-7 dB higher than Mugunghwa-5A's, creating an environment where interference is particularly likely to occur in tracking the 5A satellite.

[0003] Conventionally, a tracking method is used to search for the satellite with the strongest signal strength, centered on the operating frequency. However, for example, even if it operates on the same frequency and aims for 5A, there is a problem of misrecognizing 6, which has a stronger signal.

[0004] This situation occurs more frequently in small antennas with wide beam patterns, and is therefore an important consideration in the design and operation of satellite communication systems using small antennas.

[0005] (Patent Document 1) Republic of Korea Patent No. 10-2325227: Device and method for preventing interference between adjacent signals of a small communication antenna

[0006] Accordingly, the present invention has been devised to solve the above-described problem, and provides a satellite antenna having an adjacent satellite interference exclusion function and an operating method thereof so as to more accurately track a desired satellite signal.

[0007] Other objects of the present invention will become more apparent through the preferred embodiments described below.

[0008] According to one aspect of the present invention, a satellite antenna having an adjacent satellite interference rejection function is provided, the satellite antenna including an antenna unit for receiving a signal from a satellite; an SNR calculation unit for calculating a signal-to-noise ratio (SNR) for a satellite signal received by the antenna unit; and a signal selection unit for comparing the signal-to-noise ratios calculated by the SNR calculation unit for satellite signals from a plurality of satellites with each other and selecting one of the satellite signals.

[0009] Here, the signal selection unit can select a satellite signal with the highest signal-to-noise ratio.

[0010] In addition, the antenna unit further includes a rotation control unit that controls the direction of the antenna unit, and the signal selection unit can control the rotation control unit to rotate the antenna when the signal-to-noise ratio comparison result differs by less than a threshold value.

[0011] In addition, the signal selection unit can finally select a satellite signal having the highest signal-to-noise ratio with a difference greater than the threshold value by rotating the antenna unit within a predetermined angle in a predetermined direction order.

[0012] Additionally, the signal selection unit can determine the order of the directions based on the satellite to be searched and the predicted surrounding satellites.

[0013] Additionally, the signal selection unit can control the rotation control unit to rotate the antenna unit again in the direction in which the signal strength of the selected satellite signal was the strongest.

[0014] Additionally, the threshold value can be set according to the value of the highest signal-to-noise ratio.

[0015] According to another aspect of the present invention, the antenna unit may further include a directional antenna unit for receiving a satellite signal having the highest signal-to-noise ratio; and an omnidirectional antenna unit for receiving a signal including a plurality of satellite signals.

[0016] Here, the antenna unit may further include a noise generating unit that generates an ambient noise signal by differentiating a satellite signal received by the directional antenna unit from an ambient signal including a satellite signal received by the omnidirectional antenna unit; and a noise removing unit that generates a satellite signal from which noise has been removed by differentiating the ambient noise signal from the satellite signal received by the directional antenna unit.

[0017] According to another aspect of the present invention, a method for operating an adjacent satellite interference rejection function performed in a satellite antenna is provided, comprising: receiving satellite signals from a plurality of satellites; calculating a signal-to-noise ratio (SNR) for each of the received satellite signals; and selecting one of the satellite signals by comparing the calculated SNRs with each other.

[0018] Here, if the signal-to-noise ratio comparison result differs by less than a threshold value, the antenna can be rotated.

[0019]

[0020] Other aspects, features and advantages other than those described above will become apparent from the following drawings, claims and detailed description of the invention.

[0021] According to the present invention, a desired satellite signal can be detected and tracked more accurately by using an adjacent satellite interference exclusion function using a signal-to-noise ratio.

[0022] FIG. 1 is a functional block diagram illustrating the configuration of a satellite antenna having an adjacent satellite interference exclusion function according to one embodiment of the present invention.

[0023] Figure 2 is an example comparing the directivity of each antenna.

[0024] Figure 3 is an example diagram showing the overlapping of satellite signals.

[0025] Figure 4 is a flowchart schematically illustrating the operation process of the adjacent satellite interference exclusion function according to one embodiment of the present invention.

[0026] FIG. 5 is a flowchart illustrating a process for eliminating adjacent satellite interference using antenna rotation according to one embodiment of the present invention.

[0027] FIG. 6 is a flowchart illustrating a tracking process after satellite signal selection by antenna rotation according to one embodiment of the present invention.

[0028] The present invention is susceptible to various modifications and embodiments. Specific embodiments are illustrated in the drawings and described in detail in the detailed description. However, this is not intended to limit the present invention to specific embodiments, but rather to encompass all modifications, equivalents, and alternatives falling within the spirit and technical scope of the present invention.

[0029] When a component is referred to as being "connected" or "connected" to another component, it should be understood that it may be directly connected or connected to that other component, but that there may be other components intervening. Conversely, when a component is referred to as being "directly connected" or "connected" to another component, it should be understood that there are no other components intervening.

[0030] Terms such as "first" and "second" may be used to describe various components, but these components should not be limited by these terms. These terms are used solely to distinguish one component from another. For example, terms such as "first threshold" and "second threshold" described below may be predefined as thresholds that are substantially different or partially identical in value. However, since there is room for confusion when expressed using the same word "threshold," terms such as "first" and "second" will be used together for convenience of distinction.

[0031] The terminology used herein is for the purpose of describing specific embodiments only and is not intended to limit the present invention. The singular expression includes the plural expression unless the context clearly indicates otherwise. In this specification, it should be understood that the terms "comprises" or "has" indicate the presence of a feature, number, step, operation, component, part, or combination thereof described in the specification, but do not exclude in advance the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0032] In addition, it is to be understood that the components of the embodiments described with reference to each drawing are not limited to the specific embodiments, but may be implemented to be included in other embodiments within the scope in which the technical idea of ​​the present invention is maintained, and that multiple embodiments may be re-implemented as a single integrated embodiment even if a separate description is omitted.

[0033] In addition, when describing with reference to the attached drawings, identical components will be assigned identical or related reference numerals regardless of the drawing reference numbers, and redundant descriptions thereof will be omitted. When describing the present invention, if a detailed description of a related known technology is judged to unnecessarily obscure the gist of the present invention, the detailed description thereof will be omitted.

[0034]

[0035] FIG. 1 is a functional block diagram showing the configuration of a satellite antenna having an adjacent satellite interference exclusion function according to one embodiment of the present invention, FIG. 2 is an example diagram comparing the degree of orientation of each antenna, and FIG. 3 is an example diagram showing the overlapping of satellite signals.

[0036] Referring to FIG. 1, a satellite antenna according to the present embodiment includes an antenna unit (10) and a control unit (20), and the control unit (20) may include an SNR calculation unit (21), a signal selection unit (22), and a rotation control unit (23).

[0037] First, let's talk about satellite antennas. Satellite antennas track satellites through signal confirmation and stabilization functions, and the antenna control unit transmits navigation and satellite inertial data installed onboard the ship to the satellite antenna. Users can use the modem to receive emergency and rescue requests and broadcasts, as well as for communication such as phone calls and the Internet.

[0038] A satellite antenna includes an upper radome, a lower radome, an antenna, a pedestal control unit (PCU), an inertial measurement unit (IMU), a multi-RF unit (MRU), and a pedestal. The upper radome protects the equipment from the elements of the marine environment, and the lower radome protects the equipment from the elements of the marine environment and is fixed to the pedestal and the hull. The antenna, which is usually a parabolic dish, is a structure that collects or transmits satellite signals. The PCU (Pedestal Control Unit) is a device that searches and tracks the antenna, the IMU (Inertial Measurement Unit) determines inertial information, and the MRU (Multi-RF Unit) processes analog and digital satellite reception signals. The pedestal is a mechanical structure that supports the antenna and can move in any desired direction on each axis.

[0039] The antenna unit (10) receives signals from satellites, including the above-described antenna. The antenna unit (10) equipped with a reflector, etc., will be readily apparent to those skilled in the art, and thus a detailed description thereof will be omitted. However, referring to FIGS. 2 and 3 together, a large antenna has a narrow beam pattern and thus high directivity, whereas a small antenna has a wide beam pattern, which may result in interference due to overlapping satellite signals, as shown in FIG. 3.

[0040] For this purpose, the signal-to-noise ratio (SNR) of each satellite signal is used in this embodiment.

[0041] The SNR calculation unit (21) of the control unit (20) calculates the signal-to-noise ratio (SNR) for the satellite signal received by the antenna unit (10). The signal-to-noise ratio is defined as in the following <Mathematical Formula 1>.

[0042] <Mathematical Formula 1>

[0043] SNR = Ps / Pn

[0044] Here, Ps and Pn represent the signal power (signal strength) and noise power, respectively. This is to indicate the relative signal power by looking at the signal power compared to the noise power. This is because the performance of a communication system is determined by the signal power compared to the noise power, not the absolute signal power. The performance of a communication system includes factors such as channel capacity, which represents the maximum achievable capacity; error rate, which represents reliability; and delay rate, which represents how smoothly the transmission occurs.

[0045] That is, errors in precise tracking may occur due to interference between signals received in the same band from an operational satellite (target satellite) and a geographically close neighboring satellite. In this case, when multiple satellite signals are received, the SNR of each is calculated.

[0046] The signal selection unit (22) of the control unit (20) compares the signal-to-noise ratios (SNRs) calculated by the SNR calculation unit (21) for each satellite signal from a plurality of satellites and selects one satellite signal. For example, the signal selection unit (22) selects the satellite signal with the highest SNR. That is, in the past, the signal with the strongest signal strength was selected, but according to the present embodiment, the satellite signal with a high SNR is selected. For example, in the past, when using the signal strength, even if it operates at the same frequency and aims for 5A, there was a problem of misrecognizing the stronger signal 6, whereas since it aims for 5A, the SNR is calculated to be higher, so that the targeted satellite signal can be accurately searched for and tracked.

[0047] And, according to an example, the control unit (20) further includes a rotation control unit (23) that controls the direction (angle, azimuth, left and right inclination angle, etc.) of the antenna unit (10), and the signal selection unit (22) controls the rotation control unit (23) to rotate the antenna unit (10) when the signal-to-noise ratio comparison result is less than a threshold value.

[0048] For example, when two satellite signals are searched, there is a possibility of false detection if the SNR of the two differs by less than a threshold value. In this case, the antenna's directional direction is adjusted to ultimately select the satellite signal whose SNR differs by more than the threshold value.

[0049] Accordingly, the signal selection unit (22) rotates the antenna unit (10) within a predetermined angle in a predetermined direction sequence to finally select the satellite signal having the highest signal-to-noise ratio with a difference greater than a threshold value. Here, the order of directions can be determined based on the target satellite to be searched and the predicted surrounding satellites. For example, the priority rotation direction is determined using the movement path of the target satellite, the surrounding satellite corresponding to the current time, and its movement path, etc. For the convenience of understanding, if the target satellite moves from left to right in the viewing direction and the identified surrounding satellite moves from top to bottom, the rotation direction can be determined as [left-right direction] first, and then determined in the order of left-right inclination angle - up-down direction.

[0050] Below, we will explain in more detail the processing process of the adjacent satellite interference exclusion function.

[0051]

[0052] FIG. 4 is a flowchart illustrating a schematic operation process of an adjacent satellite interference exclusion function according to one embodiment of the present invention, and FIG. 5 is a flowchart illustrating a process of an adjacent satellite interference exclusion function using antenna rotation according to one embodiment of the present invention.

[0053] First, referring to FIG. 4, when searching for a satellite signal for a target satellite, if satellite signals from multiple satellites are received (S410), the signal-to-noise ratio (SNR) for each of the received satellite signals is calculated (S420).

[0054] By comparing the generated signal-to-noise ratios (SNRs), a satellite signal is selected and tracked (S430). For example, the satellite signal with the highest signal-to-noise ratio (SNR) is selected and tracked.

[0055] Referring further to FIG. 5 for an example, at S430, the calculated SNRs are compared (S510) and it is determined whether the difference between the two compared signals is below a threshold value (S520). For example, this determines whether two interfered satellite signals have nearly similar or identical signal-to-noise ratios, which is intended to reduce false positives.

[0056] If there is a difference greater than the threshold value, the probability of accurate search is high, so in this case, the satellite signal with the strongest SNR is selected and tracked (S530).

[0057] Conversely, if the value is below the threshold, the antenna is sequentially rotated in each direction within a predetermined angle for more accurate search (S540), and it is checked whether the difference in each newly calculated SNR exceeds the threshold (S540). As described above, the order of directions can be determined based on the target satellite to be searched and the predicted surrounding satellites.

[0058] According to another embodiment of the present invention, the antenna unit may further include a directional antenna unit for receiving a satellite signal; and an omnidirectional antenna unit for receiving an ambient signal including a satellite signal.

[0059] The directional antenna unit for receiving satellite signals may be provided to primarily receive signals from a specific satellite. The directional antenna unit may further include, for example, a Cassegrain antenna or a parabolic antenna to concentrate and receive satellite signals transmitted from a specific direction.

[0060] The above omnidirectional antenna unit is non-directional and can receive signals evenly in all directions. The omnidirectional antenna unit may include, for example, a coil antenna, a helical antenna, or a dipole antenna. The radio waves received by the omnidirectional antenna unit may include signals transmitted by various satellites as well as specific satellites, as well as surrounding electromagnetic noise.

[0061]

[0062] *In addition, the antenna unit may further include a noise generating unit that generates an ambient noise signal by differentiating a satellite signal received by the directional antenna unit from an ambient signal including a satellite signal received by the omni-directional antenna unit, and a noise removing unit that generates a satellite signal from which noise has been removed by differentiating the ambient noise signal from the satellite signal received by the directional antenna unit.

[0063] Satellite signals received by the directional antenna may contain ambient noise. Therefore, modulating the satellite signals received by the directional antenna may result in noise being modulated as well, potentially reducing the signal-to-noise ratio or amplifying the noise. To prevent this, the radio waves received by the omnidirectional antenna are differentiated to leave satellite signals specific to the desired satellite, thereby removing noise and improving satellite signal modulation performance.

[0064] FIG. 6 is a flowchart illustrating a tracking process after satellite signal selection by antenna rotation according to one embodiment of the present invention.

[0065] Referring to FIG. 6, when the selection of the final target satellite is completed by comparing the SNR while rotating the antenna according to the embodiment according to FIG. 5 (S610), the antenna unit (10) is rotated again in the direction in which the signal strength of the selected satellite signal was the strongest (S620). That is, the direction in which the signal strength of the target satellite measured while rotating was the strongest is confirmed and the antenna is positioned in that direction. At this time, the direction in which not only the signal strength but also the SNR was the highest may be selected. For example, the antenna unit (10) is positioned in the direction in which the [signal strength*signal-to-noise ratio] was measured to be the highest.

[0066] Once rotation is complete, tracking of the satellite begins (S630).

[0067] According to this embodiment, by utilizing the antenna direction history rotated by the adjacent satellite interference exclusion function to search for and track the optimal direction, it is possible to receive a clearer satellite signal.

[0068] According to another embodiment of the present invention, the antenna according to the present invention can perform nutation operation. Nutation operation can mean a motion that sways or nods about a rotation axis. In other words, the antenna according to the present invention can not only search by drawing a circle in the air to search for satellite signals, but also search by performing a precession motion as if drawing a spring in the air.

[0069] The advantage of satellite signal tracking through nutation is its ability to continuously track the communications of rapidly moving low-Earth orbit satellites. Continuous nutation causes signals to weaken and strengthen, and by rotating the antenna in this direction, the strength of satellite signals can be maintained at all times.

[0070] 10: Antenna section 20: Control section 21: SNR calculation section 22: Signal selection section 23: Rotation control section

[0071] Although the present invention has been described above with reference to preferred embodiments thereof, it will be understood by those skilled in the art that various modifications and changes may be made to the present invention without departing from the spirit and scope of the present invention as set forth in the claims below.

Claims

1. Antenna section for receiving signals from satellites; An SNR calculation unit that calculates a signal-to-noise ratio (SNR) for a satellite signal received by the antenna unit; and A satellite antenna having an adjacent satellite interference exclusion function, comprising a signal selection unit for selecting one satellite signal by comparing the signal-to-noise ratios calculated by the SNR calculation unit for satellite signals from multiple satellites.

2. In claim 1, The above signal selection unit is a satellite antenna equipped with an adjacent satellite interference exclusion function that selects a satellite signal having the highest signal-to-noise ratio.

3. In claim 2, Further comprising a rotation control unit for controlling the direction of the antenna unit, A satellite antenna having an adjacent satellite interference exclusion function, wherein the signal selection unit controls the rotation control unit to rotate the antenna when the signal-to-noise ratio comparison result is less than a threshold value.

4. In claim 3, A satellite antenna having an adjacent satellite interference exclusion function, wherein the signal selection unit rotates the antenna unit within a predetermined angle in a predetermined direction order to finally select a satellite signal having the highest signal-to-noise ratio with a difference greater than the threshold value.

5. In claim 4, A satellite antenna having an adjacent satellite interference exclusion function, wherein the signal selection unit determines the order of the direction based on the satellite to be searched and the predicted surrounding satellites.

6. In claim 5, A satellite antenna having an adjacent satellite interference exclusion function, wherein the signal selection unit controls the rotation control unit to rotate the antenna unit again in the direction in which the signal strength of the selected satellite signal was the strongest.

7. In claim 4, A satellite antenna having an adjacent satellite interference rejection function, wherein the above threshold value is set according to the value of the highest signal-to-noise ratio.

8. In claim 1, The above antenna part, A directional antenna section for receiving satellite signals with the highest signal-to-noise ratio; and A satellite antenna having an adjacent satellite interference rejection function, characterized in that it further includes an omni-directional antenna section for receiving a signal including multiple satellite signals.

9. In claim 8, The above antenna part, A noise generating unit that generates an ambient noise signal by differentiating a satellite signal received by the directional antenna unit from an ambient signal including a satellite signal received by the omni-directional antenna unit; A satellite antenna having an adjacent satellite interference rejection function, characterized in that it further includes a noise removal unit that generates a satellite signal from which noise has been removed by differentiating the ambient noise signal from the satellite signal received by the directional antenna unit.

10. In the method of operating the adjacent satellite interference exclusion function performed in the satellite antenna, A step of receiving satellite signals from multiple satellites; A step of calculating the signal-to-noise ratio (SNR) for each of the received satellite signals; and A method for operating an adjacent satellite interference rejection function performed in a satellite antenna, comprising a step of selecting one satellite signal by comparing the generated signal-to-noise ratios with each other.

11. In claim 10, A method of operating an adjacent satellite interference rejection function performed in a satellite antenna, which rotates the antenna when the difference between the signal-to-noise ratio comparison results is less than a threshold value.

Images