KR102728983B1 - Communication satellites system to be communicated among standard terrestrial mobile phone - Google Patents

Abstract

The communication satellite system capable of communicating with a terrestrial mobile phone of the present invention is characterized by including a signal processing module for processing a communication signal transmitted and received with a terrestrial mobile phone so as to perform satellite communication with the terrestrial mobile phone; a reflector for increasing gain by reflecting a communication signal transmitted and received between the terrestrial mobile phone and the signal processing module; and a mobile phone antenna for receiving a communication signal reflected by the reflector and inputting the communication signal transmitted from the signal processing module through the reflector and transmitting the communication signal to the terrestrial mobile phone. Through this, the communication satellite system capable of communicating with a terrestrial mobile phone of the present invention enables satellite communication with a terrestrial mobile phone in a low or medium orbit by using the reflector.

Description

{COMMUNICATION SATELLITES SYSTEM TO BE COMMUNICATED AMONG STANDARD TERRESTRIAL MOBILE PHONE}

The present invention relates to a communication satellite system capable of communicating with a terrestrial mobile phone, and more specifically, to a communication satellite system capable of communicating with a terrestrial mobile phone, which uses a reflector to enable satellite communication with a terrestrial mobile phone from a communication satellite in a low or medium orbit.

In order for a terrestrial mobile phone to communicate using a geostationary satellite network, a minimum reception sensitivity of -129.81 dBm and a transmission power of 27.9 dBm are required. However, since a terrestrial mobile phone has a transmission power of 23 dBm and an antenna gain of 0 dBi, it cannot directly use the communication satellite network. Therefore, in order for a terrestrial mobile phone to directly communicate with a low-orbit communication satellite network or a geostationary communication satellite network, it must be equipped with a large, high-performance transmit/receive antenna.

In the case of using a low-orbit communication satellite network, a phased array antenna can be used because the satellite is located in a low Earth orbit and propagation loss is small. However, due to the limitations of the size and weight of the phased array antenna, satellite communication can only be performed using a satellite mobile phone equipped with a high-performance transmitting and receiving antenna.

Moreover, geostationary satellites are approximately 36,000 km away from the ground, and because of this long distance, satellite communications can only be made using satellite mobile phones equipped with high-performance transmitting and receiving antennas.

The background technology of the present invention is disclosed in Korean Patent Publication No. 10-2015-0080929 (July 13, 2015), ‘Terrestrial communication method, device and system.’

The present invention has been created to improve the above-mentioned problems, and an object of one aspect of the present invention is to provide a communication satellite system capable of communicating with a ground-based mobile phone, which enables satellite communication between a communication satellite and a ground-based mobile phone in a low or medium orbit using a reflector.

A communication satellite system capable of communicating with a terrestrial mobile phone according to one aspect of the present invention is characterized by including a signal processing module for processing a communication signal transmitted and received with a terrestrial mobile phone so as to perform satellite communication with the terrestrial mobile phone; and a reflector system for increasing the gain of a communication signal between the terrestrial mobile phone and the signal processing module and transmitting and receiving the signal.

The signal processing module of the present invention is characterized by including a second receiving unit that processes a communication signal transmitted from the ground mobile phone and received through the reflector system and inputs the signal to a digital signal processing unit; and a second transmitting unit that processes a communication signal input from the digital signal processing unit and inputs the signal to the reflector system.

The reflector system of the present invention is characterized by including a reflector that reflects a communication signal transmitted and received between the ground mobile phone and the signal processing module to increase gain; and a mobile phone antenna that receives a communication signal reflected by the reflector and inputs the communication signal to the signal processing module, and reflects a communication signal transmitted from the signal processing module through the reflector and transmits the same to the ground mobile phone.

The reflector of the present invention is characterized in that its diameter is different depending on the orbit of the communication satellite.

The reflector of the present invention is characterized in that its diameter is equal to or greater than the first set diameter when the orbit of the communication satellite is a low orbit in which the distance from the Earth's surface to the satellite is 600 km to 1,000 km.

The reflector of the present invention is characterized in that its diameter is equal to or greater than the second set diameter when the orbit of the communication satellite is a medium orbit in which the distance from the Earth's surface to the satellite is 8,000 km to 12,000 km.

The reflector of the present invention comprises a sub-reflector formed to have a curvature and arranged to face the mobile phone antenna; and a main reflector formed to have a curvature and arranged to face the sub-reflector, wherein the sub-reflector reflects a communication signal transmitted from the mobile phone antenna and transmits it to the main reflector, and reflects a communication signal transmitted from the ground mobile phone and reflected by the main reflector and transmits it to the mobile phone antenna, and the main reflector reflects a communication signal transmitted from the mobile phone antenna and reflected by the sub-reflector and transmits it to the ground mobile phone, and reflects a communication signal transmitted from the ground mobile phone and transmits it to the sub-reflector.

The mobile phone antenna of the present invention is characterized by being a phased array antenna.

A communication satellite system capable of communicating with a terrestrial mobile phone according to one aspect of the present invention uses a reflector to enable satellite communication with a terrestrial mobile phone in a low or medium orbit.

According to another aspect of the present invention, a communication satellite system capable of communicating with a ground mobile phone is capable of transmitting and receiving communication signals with a ground mobile phone by using a reflector system having a reflector having a diameter of 1.6 m or more (low-orbit) or a diameter of 10 m or more (medium-orbit), thereby enabling satellite communication with a ground mobile phone without the need to install a large, high-performance antenna on the ground mobile phone.

FIG. 1 is a block diagram of a communication satellite system capable of communicating with a terrestrial mobile phone according to one embodiment of the present invention.
Figure 2 is a configuration diagram of a reflector system according to one embodiment of the present invention.
FIG. 3 is a conceptual diagram of a service area for a terrestrial mobile phone provided from one medium-orbit communication satellite according to one embodiment of the present invention.
FIG. 4 is a conceptual diagram of a service area for ground mobile phones provided from a plurality of low-orbit communication satellites according to one embodiment of the present invention.

Hereinafter, a communication satellite system capable of communicating with a terrestrial mobile phone according to one embodiment of the present invention will be described in detail with reference to the attached drawings. In this process, the thickness of lines and the size of components illustrated in the drawings may be exaggerated for the sake of clarity and convenience of explanation. In addition, the terms described below are terms defined in consideration of functions in the present invention, and may vary depending on the intention or custom of the user or operator. Therefore, the definitions of these terms should be made based on the contents throughout this specification.

FIG. 1 is a block diagram of a communications satellite system capable of communicating with a ground mobile phone according to one embodiment of the present invention, FIG. 2 is a diagram of a configuration of a reflector system according to one embodiment of the present invention, FIG. 3 is a conceptual diagram of a service area for a ground mobile phone provided from one medium-orbit communications satellite according to one embodiment of the present invention, and FIG. 4 is a conceptual diagram of a service area for a ground mobile phone provided from a plurality of low-orbit communications satellites according to one embodiment of the present invention.

Referring to FIG. 1, a communication satellite system capable of communicating with a terrestrial mobile phone according to one embodiment of the present invention includes a signal processing module (100) and a reflector system (200).

The signal processing module (100) processes signals transmitted and received through a ground mobile phone (10) and a reflector system (200), or processes signals transmitted and received with a ground satellite gateway (20).

The signal processing module (100) includes a gateway antenna (Antenna for Gateway Link) (110), a first receiver (120), a first transmitter (130), a digital signal processing unit (160), a second transmitter (140), and a second receiver (150).

The gateway antenna (110) receives a communication signal from a satellite gateway (20) on the ground and inputs it into the first receiving unit (120).

The gateway antenna (110) transmits a communication signal input from the first transmitter (130) to the satellite gateway (20) on the ground.

As the gateway antenna (110), a satellite gateway (20) and a reflector antenna having an air interface can be employed.

The first receiver (120) amplifies and frequency converts a weak communication signal input through the gateway antenna (110) and inputs it to the digital signal processing unit (160).

The first transmitter (130) converts and amplifies the communication signal input from the digital signal processing unit (160) and inputs it to the gateway antenna (110). At this time, the gateway antenna (110) transmits the communication signal input from the first transmitter (130) to the satellite gateway (20) on the ground.

That is, the gateway antenna (110) receives a communication signal from the ground satellite gateway (20) and inputs it into the first receiver (120), and the first receiver (120) amplifies and frequency-converts the communication signal received from the gateway antenna (110) and transmits it to the digital signal processing unit (160). In addition, the first transmitter (130) frequency-converts and amplifies the communication signal received from the digital signal processing unit (160) and inputs it into the gateway antenna (110), and the gateway antenna (110) transmits the communication signal input from the first transmitter (130) to the ground satellite gateway (20). Through this, the signal processing module (100) performs satellite communication with the ground satellite gateway (20).

The second receiver (150) amplifies and frequency converts the signal transmitted from the ground mobile phone (10) and received by the reflector system (200) and inputs it to the digital signal processing unit (160).

The second transmitter (140) converts and amplifies the communication signal input from the digital signal processing unit (160) and inputs it to the reflector system (200). At this time, the reflector system (200) transmits the communication signal input from the second transmitter (140) to a ground mobile phone (10).

The digital signal processing unit (160) analyzes the communication signals transmitted from the satellite gateway (20) and the ground mobile phone (10) and performs packet switching.

That is, the digital signal processing unit (160) inputs a communication signal transmitted from the satellite gateway (20) and input through the gateway antenna (110) and the first receiving unit (120) into the first transmitting unit (130).

In addition, the digital signal processing unit (160) inputs a communication signal transmitted from a ground mobile phone (10) and input through the reflector system (200) and the second receiver (150) into the second transmitter (140).

The reflector system (200) increases the gain of the communication signal between the ground mobile phone (10) and the signal processing module (100) and transmits and receives it.

In this case, the reflector system (200) inputs a communication signal received from a ground mobile phone (10) into the second receiving unit (150) of the signal processing module (100), and transmits a communication signal input from the second transmitting unit (140) of the signal processing module (100) to the ground mobile phone (10).

The reflector system (200) includes a mobile phone antenna (210) and a reflector (220) as shown in FIG. 2.

The mobile phone antenna (210) transmits and receives communication signals with a ground mobile phone (10). Here, the communication signals transmitted and received through the mobile phone antenna (210) are reflected by the reflector (220).

That is, the mobile phone antenna (210) receives a communication signal transmitted from a ground mobile phone (10) and reflected by a reflector (220).

In addition, the mobile phone antenna (210) transmits a communication signal input from the signal processing module (100) to the reflector (220). At this time, the communication signal input from the mobile phone antenna (210) is reflected from the reflector (220) and transmitted to the ground mobile phone (10).

The mobile phone antenna (210) may be installed on the main body of the communication satellite, but may also be installed on the reflector (220).

The mobile phone antenna (210) may employ a phased array antenna in which a number of radiating elements are arranged, but the type of the mobile phone antenna (210) is not particularly limited.

The reflector (220) reflects the communication signal transmitted and received between the mobile phone antenna (210) and the mobile phone antenna (210) to increase the gain of the communication signal.

The reflector (220) includes a main reflector and a sub reflector.

The sub-reflector is formed to have a curvature and is positioned to face the mobile phone antenna (210).

The shape and arrangement structure of the sub-reflector are not particularly limited, and can be adopted in various ways as long as it can effectively reflect and transmit communication signals.

The sub-reflector reflects a communication signal transmitted from a mobile phone antenna (210) and transmits it to the main reflector. In addition, the sub-reflector reflects a communication signal transmitted from a ground mobile phone (10) and reflected by the main reflector and transmits it to the mobile phone antenna (210).

The main reflector is formed to have a curvature and is positioned to face the sub reflector. A mobile phone antenna (210) may be installed on the central axis of the main reflector.

There are no particular limitations on the shape and arrangement structure of the main reflector, and it can be adopted in various ways as long as it can effectively reflect and transmit communication signals.

The main reflector has a relatively large area compared to the sub reflector.

The main reflector reflects a communication signal transmitted from a mobile phone antenna (210) and reflected by a sub reflector and transmits it to a ground mobile phone (10). In addition, the main reflector reflects a communication signal transmitted from a ground mobile phone (10) and transmits it to a sub reflector.

Meanwhile, the reflector (220) can be formed with various diameters depending on the orbit of the communication satellite.

The orbit of a communication satellite is divided into a low orbit, where the distance from the Earth's surface to the satellite is 600 to 1,000 km, and a medium orbit, where the distance from the Earth's surface to the satellite is 8,000 to 12,000 km. The service range also becomes relatively narrower than that of a satellite (geostationary satellite) depending on the orbit of the communication satellite. Accordingly, the performance of the signal processing module (100) mounted on the communication satellite may be relatively lower than that of a geostationary satellite.

Meanwhile, in the case of a low-orbit communication satellite, the reflector (220) is formed with a diameter equal to or greater than the first set diameter, for example, 1.6 m.

Additionally, in the case of a medium-orbit communication satellite, the reflector (220) may be formed with a diameter equal to a second set diameter, for example, 10 m or more.

Mathematical expression 1 below is an equation that expresses free space propagation loss in dB scale.

Here, FSPL (Free Space Propagation Loss in dB scale) is the free propagation loss, d is the distance, f is the frequency, and c is the speed of light.

Therefore, referring to the mathematical expression 2 below, when a communication satellite descends from a geostationary orbit of 36,000 km to a low orbit of 600 km, an improvement of 36 dB can be achieved as in the mathematical expression 2 below, and when it descends from a geostationary orbit of 36,000 km to a medium orbit of 12,000 km, an improvement of 9.5 dB can be achieved as in the mathematical expression 3.

Mathematical expression 2 is the free propagation loss based on 600 km in low orbit.

Mathematical expression 3 is the free propagation loss based on 12,000 km of medium orbit.

That is, for low orbit, the free propagation loss is improved by 36 dB, and for medium orbit, the free propagation loss is improved by 9.5 dB.

Accordingly, the ground mobile phone (10) can receive a signal transmitted from a communication satellite without changing the size and performance of the mobile phone antenna (210), and the communication satellite can also receive a signal transmitted from the ground mobile phone (10).

Table 1 below shows the antenna gain and transmission power of a land mobile phone (10).

Land mobile phone low-orbit communications satellite
(Reflector system: 1.6m) Medium orbit communications satellite
(Reflector system: 10m) data rate modulation BW SNR antenna
Gain Power EIRP Frequency altitude EIRP Frequency altitude 9.8Kbps BPSK 31.25 -0.1dB 0dB 23dBm 56.5dBW 2.0GHz 600Km 72.4dBW 2.0GHz 12,000Km

Referring to Table 1, when using a ground mobile phone (10) (EIRP = 23 dBm) that requires an antenna gain of 0 dBi and a transmission power of 23 dBm, the link margin is reduced by 4.9 dB (4.9 dB = 27.9 dBm - 23 dBm) with a geostationary communication satellite network equipped with a reflector (220) having a diameter of 13 m, making it impossible to communicate with the satellite using the ground mobile phone (10).

When a communications satellite equipped with a reflector (220) with a diameter of 13 m from a geostationary orbit of 36,000 km descends to a low Earth orbit of 600 km, there is an improvement in transmission output link margin of 31.1 dB (31.1 dB = 36 dB-4.9 dB), and even if the transmission output is reduced by 17.5 dB when the size of the reflector (220) is reduced from 13 m to 1.6 m, there is still a gain of 13.6 dB (13.6 dB = 31.1-17.5).

In addition, when a communication satellite equipped with a reflector (220) with a diameter of 13 m from a geostationary orbit of 36,000 km descends to a medium Earth orbit of 12,000 km, there is an improvement in transmission output link margin of 4.6 dB (4.6 dB = 9.5 dB - 4.9 dB), and even if the transmission output decreases by 1.6 dB when the size of the reflector (220) is reduced from 13 m to 10 m, there is still a gain of 3 dB (3 dB = 4.6 - 1.6).

This means that compared to existing satellite communication systems, the reception sensitivity and transmission output have an increase effect of about 22.9 times (13.6 dB) in low-orbit and about 2 times (3 dB) in medium-orbit, meaning that all mobile phones within the cell range of the signal can use satellite communication without a separate satellite communication antenna.

In this way, when the diameter of the reflector (220) is 1.6 m or more in the case of low Earth orbit and about 10 m or more in the case of medium Earth orbit, communication with the satellite is possible using a ground mobile phone (10).

Meanwhile, low-orbit communication satellites orbit the Earth in a period of about 1 hour and 30 minutes, and medium-orbit communication satellites orbit the Earth in a period of about 6 hours and 50 minutes. Therefore, at least 11 communication satellites should be deployed in low-orbit, and at least 7 communication satellites should be deployed in medium-orbit.

Figure 3 illustrates a service area (300) for a ground mobile phone (10) when seven or more communication satellites form a group in a medium orbit.

Figure 4 illustrates a service area (300) for a ground mobile phone (10) when forming multiple groups, each of which is composed of 11 or more communication satellites in low orbit.

Here, the number of low-orbit and medium-orbit communication satellites is not particularly limited.

In this way, a communication satellite system capable of communicating with a ground mobile phone according to one embodiment of the present invention uses a reflector to enable satellite communication with a ground mobile phone in a low or medium orbit.

In addition, a communication satellite system capable of communicating with a ground mobile phone according to one embodiment of the present invention can transmit and receive radio waves with a ground mobile phone using a reflector system having a reflector with a diameter of 1.6 m or more (low orbit) or a diameter of 10 m or more (medium orbit), thereby enabling satellite communication with a ground mobile phone without the need to install a large, high-performance antenna on the ground mobile phone.

The implementations described herein may be implemented as, for example, a method or process, an apparatus, a software program, a data stream or a signal. Even if discussed in the context of only a single form of implementation (e.g., discussed only as a method), the implementation of the features discussed may also be implemented in other forms (e.g., as an apparatus or a program). The apparatus may be implemented as suitable hardware, software, firmware, and the like. The method may be implemented in a device such as a signal processing module, which generally refers to a processing device including, for example, a computer, a microsignal processing module, an integrated circuit, or a programmable logic device. A signal processing module also includes a communication device such as a computer, a cell phone, a personal digital assistant ("PDA"), and other devices that facilitate communication of information between end-users.

Although the present invention has been described with reference to the embodiments shown in the drawings, these are merely exemplary, and those skilled in the art will understand that various modifications and equivalent other embodiments are possible from this. Accordingly, the true technical protection scope of the present invention should be determined by the following patent claims.

10: Terrestrial mobile phone 20: Satellite gateway
100: Signal processing module 110: Gateway antenna
120: 1st receiver 130: 1st transmitter
140: Second transmitter 150: Second receiver
160: Digital signal processing unit 200: Reflector system
210: Mobile phone antenna 220: Reflector

Claims (8)

A signal processing module for processing communication signals transmitted and received with a ground mobile phone so that ground mobile phone and satellite communication can be performed; and
Including a reflector system for transmitting and receiving communication signals between the above-mentioned ground mobile phone and the above-mentioned signal processing module,
The above reflector system includes a reflector that reflects a communication signal transmitted and received between the ground mobile phone and the signal processing module.
If the orbit of the communication satellite is a low orbit where the distance from the Earth's surface to the satellite is 600 km to 1,000 km, the reflector has a diameter of 1.6 m or more,
A communications satellite system capable of communicating with a terrestrial mobile phone, characterized in that the orbit of the communications satellite is a medium orbit in which the distance from the Earth's surface to the satellite is 8,000 km to 12,000 km, and the reflector has a diameter of 10 m or more. In the first paragraph, the signal processing module
A second receiving unit that processes a communication signal transmitted from the above-mentioned ground mobile phone and received through the above-mentioned reflector system and inputs the signal to a digital signal processing unit; and
A communication satellite system capable of communicating with a terrestrial mobile phone, characterized by including a second transmitter that processes a communication signal input from the digital signal processing unit and inputs the signal to the reflector system. In the first paragraph, the reflector system
A communication satellite system capable of communicating with a ground mobile phone, characterized in that it further includes a mobile phone antenna that receives a communication signal reflected from the reflector and inputs it into the signal processing module, and reflects a communication signal transmitted from the signal processing module through the reflector and transmits it to the ground mobile phone. delete delete delete In the third paragraph, the reflector
A sub-reflector formed to have a curvature and positioned facing the mobile phone antenna; and
It comprises a main reflector formed to have a curvature and positioned facing the sub reflector,
The sub-reflector reflects a communication signal transmitted from the mobile phone antenna and transmits it to the main reflector, and reflects a communication signal transmitted from the ground mobile phone and reflected by the main reflector and transmits it to the mobile phone antenna.
A communication satellite system capable of communicating with a ground mobile phone, characterized in that the main reflector reflects a communication signal transmitted from the mobile phone antenna and reflected by the sub reflector and transmits it to the ground mobile phone, and reflects a communication signal transmitted from the ground mobile phone and transmits it to the sub reflector.
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