Patent Application
20160242189
This application claims the benefit of Korean Patent Application No. 10-2015-0022160, filed on Feb. 13, 2015, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference.
1. Field of the Invention
The following embodiments relate to a communication apparatus of an earth station, and more particularly, to a structure for determining a dynamic satellite link channel of a communication apparatus of an earth station to avoid frequency interference with a terrestrial communication system, and a structure for allocating a transmission frequency band.
2. Description of the Related Art
In a satellite communication network, a Demand Assigned Multiple Access (DAMA) scheme to allocate frequency resources is used. In the DAMA scheme, an appropriate frequency slot is allocated to an earth station for the satellite communication network for a communication with a space station for the satellite communication network, and the earth station communicates with the space station and returns the frequency slot. Different bandwidths of allocated frequency slots may be determined based on an amount of information (for example, sound, facsimile data, video, data, or communication data) transmitted by the earth station. However, because a limited frequency band is shared between the satellite communication network and a terrestrial communication network, frequency interference between the satellite communication network and the terrestrial communication network would occur. According to a related art, an interference avoiding method using a physical environment, for example, geographical isolation or securing a proper separation distance between a satellite communication network and a terrestrial communication network, has been introduced. However, it is difficult to apply the interference avoiding method to all general frequency sharing environments between a satellite communication network and a terrestrial communication network. In addition, a method of using a satellite communication network and a terrestrial communication network by dividing a frequency band has been provided, however, a spectral efficiency is relatively low.
According to an aspect, there is provided a communication apparatus of an earth station. The communication apparatus may include at least one processor and may be at least temporarily implemented by the at least one processor. The least one processor may include a signal extractor configured to acquire a signal of a terrestrial radio station by cancelling a signal transmitted by the earth station from received signals, a detector configured to detect an interference state between a satellite communication network and a terrestrial communication network by comparing a signal strength of the terrestrial radio station to a predetermined interference signal threshold, and a frequency allocator configured to allocate a new frequency slot to be used by the earth station to transmit a signal, when the detector detects the interference state. The communication apparatus may further include a communicator configured to monitor signals transmitted and received in a whole frequency band used by the earth station.
The detector may be configured to compare a signal strength of each of signals of the terrestrial radio station corresponding to each frequency slot to the interference signal threshold, and the frequency allocator may be configured to allocate a frequency slot from which the interference state is not detected to the earth station so that the earth station transmits a signal. The frequency allocator may be configured to allocate a frequency slot corresponding to a minimum signal strength of the terrestrial radio station to the earth station so that the earth station transmits a signal.
The detector may be configured to set the interference signal threshold based on surrounding information. The surrounding information may include geographic information, neighboring building information, location information of a terrestrial radio station, atmospheric environment information and a performance of the communication apparatus.
The communicator may include an antenna device directed towards a space station at an elevation angle in a horizontal direction, and configured to transmit and receive a communication signal for the satellite communication network, and an interference signal receiving device directed in the horizontal direction, and configured to receive a signal component of the terrestrial radio station in the same frequency band as a frequency band of the communication signal. The interference signal receiving device may be configured to receive a leak component of a signal from the earth station. The signal extractor may be configured to acquire the signal of the terrestrial radio station by cancelling a signal transmitted by the space station from the communication signal.
According to another aspect, there is provided a method of avoiding interference between a satellite communication network and a terrestrial communication network. The method may include receiving all signals in a frequency band used by the satellite communication network, extracting a signal associated with the terrestrial communication network by cancelling a signal associated with the satellite communication network from the signals, and detecting an interference state between the satellite communication network and the terrestrial communication network by comparing a signal strength of the extracted signal to an interference signal threshold. The extracting may include cancelling both a signal transmitted by an earth station and a signal transmitted by a space station as signals associated with the terrestrial communication network.
The detecting may include, when the signal strength of the extracted signal is greater than the interference signal threshold, detecting the interference state. The detecting may include comparing a signal strength associated with the terrestrial communication network for each of frequency slots included in the frequency band to the interference signal threshold. The detecting may include determining the interference signal threshold based on geographic information, neighboring building information, location information of a terrestrial radio station, atmospheric environment information and a performance of a communication apparatus.
The method may further include calculating a frequency slot corresponding to a minimum signal strength associated with the terrestrial communication network, and newly allocating the frequency slot to the satellite communication network so that the frequency slot is preferentially used by the satellite communication network, when the interference state is detected.
The receiving may include newly receiving the signals in real time or based on a predetermined period. The detecting may include, when the signals are newly received, newly detecting the interference state.
According to another aspect, there is provided an interference signal receiving device. The interference signal receiving device may include at least one processor configured to separate a signal of a terrestrial radio station from received signals, to analyze information about usage of each of frequency slots in which the signal of the terrestrial radio station is being transmitted and received, and to allocate a frequency slot for minimum frequency interference among the frequency slots to a satellite communication network signal. The at least one processor may be configured to analyze information about usage of the frequency slots by comparing a signal strength of the terrestrial radio station corresponding to the frequency slot to a predetermined threshold. The at least one processor may be configured to allocate the frequency slots to the satellite communication network signal in an ascending order of signal strengths of the terrestrial radio station.
The interference signal receiving device may further include a communicator configured to transmit and receive the satellite communication network signal and to receive a terrestrial communication network signal. The communicator may be configured to receive a leak component of a transmitted signal, and the at least one processor may be configured to cancel the leak component and to separate the signal of the terrestrial radio station.
These and/or other aspects, features, and advantages of the invention will become apparent and more readily appreciated from the following description of exemplary embodiments, taken in conjunction with the accompanying drawings of which:
Hereinafter, some embodiments will be described in detail with reference to the accompanying drawings. The present disclosure, however, should not be construed as limited to the embodiments set forth herein. Regarding the reference numerals assigned to the elements in the drawings, it should be noted that the same elements will be designated by the same reference numerals.
Also, terms used herein are selected from general terms being used in the related arts. Yet, the meanings of the terms used herein may be changed depending on a change and/or development of technologies, a custom, or preference of an operator in the art. Accordingly, the terms are merely examples to describe the embodiments, and should not be construed as limited to the technical idea of the present disclosure.
In addition, in a specific case, most appropriate terms are arbitrarily selected by the applicant for ease of description and/or for ease of understanding. In this instance, the meanings of the arbitrarily used terms will be clearly explained in the corresponding description. Hence, the terms should be understood not by the simple names of the terms but by the meanings of the terms and the following overall description of this specification.
The communication apparatus 100 may include a communicator 110, a signal extractor 120, a detector 130 and a frequency allocator 140. The communicator 110 may receive and monitor signals of a predetermined frequency band. The predetermined frequency band may be, for example, a whole frequency band used by the satellite communication network. The communicator 110, the signal extractor 120, the detector 130 and the frequency allocator 140 may be included in at least one processor and may be at least temporarily implemented by the at least one processor.
The communicator 110 may include at least one receiving device. The at least one receiving device may comprise a receiving device having an elevation angle from a horizontal plane. The receiving device may be installed in a direction perpendicular to the horizontal plane. For example, a receiving device having an elevation angle from a horizontal plane may receive a signal from a space station for the satellite communication network (hereinafter, referred to as a “space station”). The receiving device may be installed at an elevation angle with a highest rate of transmission from the space station based on geographic information, a communication state, and the like.
The at least one receiving device may be directed in a horizontal direction. For example, a receiving device directed in the horizontal direction may receive a terrestrial communication network signal. The receiving device directed in the horizontal direction may receive a terrestrial communication network signal with a high reception efficiency in comparison to a receiving device having an elevation angle from a horizontal plane. The communicator 110 may receive a leak component of a signal transmitted by the earth station to a space station.
The signal extractor 120 may acquire a signal of a radio station for a terrestrial communication network by cancelling a signal transmitted by the earth station from received signals. Hereinafter, the radio station for the terrestrial communication network may be referred to as a “terrestrial radio station.” Because the communication apparatus 100 is connected to the earth station, the communication apparatus 100 may acquire information about a signal transmitted by the earth station. The signal extractor 120 may cancel a component of the signal transmitted by the earth station from signals received by the communicator 110, and may acquire a component of the signal of the terrestrial radio station.
The signal extractor 120 may cancel, from the received signals, a signal component that is transmitted by the space station and that is received by the earth station, and may acquire a signal of the terrestrial radio station. As described above, a specific receiving device installed at an elevation angle may have a higher reception efficiency in a direction of the space station. The signal extractor 120 may extract information that is transmitted by the space station and that is received by the earth station, based on information of a signal received by the specific receiving device. The signal extractor 120 may cancel, from the received signals, a signal that is transmitted by the space station and that is received by the earth station, and may acquire a signal component of the terrestrial radio station. In addition, the earth station may receive a leak signal in information that is transmitted from the earth station to the space station, and the signal extractor 120 may cancel the received leak signal and may acquire the signal component of the terrestrial radio station.
The detector 130 may compare a signal strength of the terrestrial radio station to a predetermined interference signal threshold, and may detect an interference state between the satellite communication network and the terrestrial communication network. For example, the detector 130 may compare a signal strength of each of signals of the terrestrial radio station corresponding to each of frequency slots to the interference signal threshold. The frequency slots may be included in a frequency band used by the satellite communication network. The detector 130 may detect an interference state for each of signals of the terrestrial radio station corresponding to each of frequency slots with respect to the satellite communication network.
The detector 130 may set the interference signal threshold based on surrounding information. The interference signal threshold may be a reference value used to determine an interference state when the same frequency band is used by a satellite communication network signal and a terrestrial communication network signal. In an example, when a signal strength of a received signal of the terrestrial radio station is less than the interference signal threshold, the terrestrial radio station may be interpreted to operate in a great distance from a transmitting device of the earth station. Thus, it may be determined that there is no interference effect or that an interference effect is negligible.
In another example, when the signal strength of the terrestrial radio station is greater than the interference signal threshold, the earth station and the terrestrial radio station may interfere with each other. In this example, the detector 130 may set a proper interference signal threshold to detect an interference state based on geographic information, neighboring building information, location information of the terrestrial radio station, atmospheric environment information and a performance of a communication system for the earth station.
When the detector 130 detects the interference state, the frequency allocator 140 may allocate a new frequency slot that is to be used by the earth station to transmit a signal. For example, the frequency allocator 140 may preferentially allocate a frequency slot from which the interference state is not detected to the earth station so that the earth station may transmit a signal. Also, the frequency allocator 140 may preferentially allocate a frequency slot corresponding to a minimum signal strength of the terrestrial radio station to the earth station so that the earth station may transmit a signal. The above-described frequency slots may be included in the frequency band used by the satellite communication network.
Referring to
Referring to
Among signals received by the earth station 332, the leak signal 312 and the terrestrial communication network signal 322 other than the signal 311 received from the space station 331 may correspond to interference signals. For example, for detection of interference signals, the signal extractor 120 of
Referring to
A signal strength of each of signals transmitted and received between terrestrial radio stations may be determined based on a frequency band. For example, a detector of a communication apparatus of an earth station may compare a signal strength of a terrestrial radio station to a predetermined interference signal threshold, and may detect the interference state between the satellite communication network and the terrestrial communication network. Referring to
In another example, the detector may compare a signal strength of each of signals of the terrestrial radio station corresponding to each of frequency slots included in a frequency band used by the satellite communication network to the interference signal threshold, and may detect the interference state. When a signal strength of each of the signals of the terrestrial radio station corresponding to each of the frequency slots is greater than the interference signal threshold, the detector may detect the interference state from a corresponding frequency slot. As shown in
As shown in
The frequency allocator may preferentially allocate a frequency slot corresponding to a minimum signal strength of the terrestrial radio station to the earth station so that the earth station may transmit a signal. As shown in
For example, when a detector detects an interference state, a frequency allocator may allocate a new frequency slot to be used by an earth station to transmit signal. Referring to
The frequency allocator may allocate the frequency slots 511 through 514 using the DAMA scheme. In
Referring to
In operation 620, a terrestrial communication network signal component may be extracted from all the received signals. For example, a signal transmitted by an earth station may be cancelled from all the received signals and a terrestrial communication network signal component may be extracted. In an example, in operation 620, information about a signal transmitted by the earth station in a satellite communication system may be stored, the stored information may be removed from the received signals, and the terrestrial communication network signal component may be extracted. In another example, in operation 620, a received satellite communication network signal may be removed, and a terrestrial communication network signal may be acquired. The received satellite communication network signal may include a signal component transmitted from the space station, and a leak component of a signal transmitted by the earth station.
In operation 630, use of each frequency slot may be analyzed. In operation 640, an interference state may be detected for each frequency slot. In operation 630, a signal strength of a satellite communication network signal corresponding to a frequency slot may be calculated. A frequency slot that is being used in the satellite communication system, and a frequency slot that is not used in the satellite communication system may be detected. An amount of the frequency slot that is being used may be calculated.
In operation 640, a signal strength of a terrestrial communication network signal for each frequency slot is compared to an interference signal threshold, and an interference state may be detected. A process of setting an interference signal threshold has been described above, and accordingly further description of the process is omitted. A signal strength of a terrestrial communication network signal corresponding to a frequency slot may be compared to the interference signal threshold. When the signal strength of the terrestrial communication network signal is greater than the interference signal threshold, the interference state may be detected. Based on a definition of the interference state, when the signal strength of the terrestrial communication network signal is equal to the interference signal threshold, the interference state may be detected.
Operations 651 and 652 may be performed based on whether the interference state is detected. When the interference state is detected, a new frequency slot may be allocated to the earth station in operation 651. Operation 651 may be the same as the above-described operation of the frequency allocator, and accordingly further description thereof is omitted. When the interference state is not detected, the satellite communication network may be used while maintaining a frequency slot that is being used in operation 652. The method of
While this disclosure includes specific examples, it will be apparent to one of ordinary skill in the art that various changes in form and details may be made in these examples without departing from the spirit and scope of the claims and their equivalents. The examples described herein are to be considered in a descriptive sense only, and not for purposes of limitation. Descriptions of features or aspects in each example are to be considered as being applicable to similar features or aspects in other examples. Suitable results may be achieved if the described techniques are performed in a different order, and/or if components in a described system, architecture, device, or circuit are combined in a different manner and/or replaced or supplemented by other components or their equivalents. Therefore, the scope of the disclosure is defined not by the detailed description, but by the claims and their equivalents, and all variations within the scope of the claims and their equivalents are to be construed as being included in the disclosure.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2015-0022160 | Feb 2015 | KR | national |
