Control station, communication system, interference wave generation source identification method, and program

Abstract

To provide a technique that contributes to maintaining communication quality without increasing a processing load on a device side mounted with a DBF antenna.SOLUTION: The control station 200 includes a synthesis unit 270 that synthesizes reception signal information of each antenna element, which is a reception signal received by each antenna element constituting an array antenna having a DigitalBeamForming (DBF) function and is a reception signal before the DBF, and generates pre-processing signal information, a frequency identification unit 210 that identifies an interference wave frequency, which is a frequency of an interference wave, from the pre-processing signal information, and a beam identification unit 220 that identifies a beam including a generation source of the interference wave as a generation source beam among a plurality of beams formed from the reception signal in the array antenna based on the interference wave frequency.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a control station, a communication system, an interference wave source identification method, and a program Regarding. [Background technology]

[0002] In satellite communications using communications satellites, the quality of communications deteriorates when interference waves occur in the frequency band used for communications. For example, there is a technology to reduce the effects of interference waves in satellites equipped with antennas (DBF antennas) that have a Digital Beam Forming (DBF) function that can control the beam area, which is the area in which communications are possible (see, for example, Patent Document 1).

[0003] According to the technology disclosed in Patent Document 1, for each receiving beam formed by a DBF antenna mounted on a satellite, an interference candidate beam area, which is a beam area that interferes with the receiving beam estimated based on predetermined initial receiving beam characteristics, is stored, a receiving spectrum is obtained for each receiving beam based on the frequency-branched receiving beam signal, and an interference source area, which is a beam area that will be the source of interference for each combination of receiving beam and frequency, is obtained based on the receiving spectrum for each receiving beam and the receiving spectrum of the receiving beam directed toward the interference candidate beam area, and a null is formed in the direction of the interference source area. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2010 / 050269 Summary of the Invention [Problem to be solved by the invention]

[0005] The following analysis was performed by the inventors of the present disclosure.

[0006] According to the technology disclosed in Patent Document 1, a communication device mounted on a satellite detects an interference source and generates a receiving beam signal to form a null in that direction. In other words, complex and high-load processing is performed by the device on the satellite. This places a heavy processing burden on the device mounted with the DBF antenna, such as the satellite.

[0007] The present disclosure has been made in consideration of the above circumstances, and one of its objectives is to provide a technology that contributes to maintaining communication quality without increasing the processing burden on the device equipped with a DBF antenna. [Means for solving the problem]

[0008] According to a first aspect of the present disclosure, a combining unit that combines received signal information, which is a received signal received by each antenna element constituting an array antenna having a DBF (Digital Beam Forming) function and is a received signal before the DBF, to generate unprocessed signal information; a frequency identification unit that identifies an interference wave frequency, which is a frequency of an interference wave, from the unprocessed signal information; A control station is provided that includes a beam identification unit that identifies a beam that includes the source of the interference wave as a source beam based on the interference wave frequency, from among multiple beams formed by applying the DBF processing to the received signal in the array antenna.

[0009] According to a second aspect of the present disclosure, The control station; an antenna-equipped device that is equipped with the array antenna and transmits the received signal information to the control station; and an earth station that performs communication via the antenna-equipped equipment under the control of the control station.

[0010] According to a third aspect of the present disclosure, The computer in the control station generating unprocessed signal information by synthesizing received signal information, which is a received signal received by each antenna element constituting an array antenna having a DBF (Digital Beam Forming) function and is a received signal before the DBF; Identifying an interference wave frequency, which is a frequency of an interference wave, from the unprocessed signal information; There is provided an interference wave source identification method, which identifies a beam including the source of the interference wave as a source beam based on the interference wave frequency among a plurality of beams formed by performing the DBF processing on the received signal in the array antenna.

[0011] According to a fourth aspect of the present disclosure, On the computer, generating unprocessed signal information by synthesizing received signal information, which is a received signal received by each antenna element constituting an array antenna having a DBF (Digital Beam Forming) function and is a received signal before the DBF; a step of identifying an interference wave frequency, which is a frequency of an interference wave, from the unprocessed signal information; A program for executing a procedure for identifying a beam including the source of the interference wave as a source beam based on the interference wave frequency among a plurality of beams formed by performing the DBF processing on the received signal in the array antenna is provided.

[0012] These programs can be recorded on a computer-readable storage medium. The storage medium can be a non-transitory medium such as a semiconductor memory, a hard disk, a magnetic recording medium, or an optical recording medium. The present disclosure can also be embodied as a computer program product. [Effects of the Invention]

[0013] According to the present disclosure, communication quality can be maintained without increasing the processing load on the device equipped with a DBF antenna. [Brief explanation of the drawings]

[0014] [Figure 1] 1A to 1C are diagrams illustrating an overview of an example of a communication system according to the present disclosure. [Figure 2] 1A is a functional block diagram of an example of a control station according to the present disclosure, and FIG. 1B is a flowchart of an example of a source identification process according to the present disclosure. [Figure 3] 1A to 1C are functional block diagrams of examples of control units of a control station, an earth station, and an artificial satellite, respectively, according to the present disclosure. [Figure 4] 1A is a flowchart of an example of a communication plan creation process according to the present disclosure, and FIG. 1B and FIG. 1C are diagrams for explaining an example of a communication request and a communication plan according to the present disclosure, respectively. [Figure 5] 10(a) to 10(c) are diagrams for explaining examples of unprocessed signal information, a communication plan, and information obtained by converting the unprocessed signal information into data, respectively, according to the present disclosure. [Figure 6] 1A is a diagram for explaining an example of a communication plan according to the present disclosure, and FIG. 1B is a diagram for explaining an outline of a frequency identification process according to the present disclosure. [Figure 7] FIG. 10 is a diagram for explaining a beam identification process according to the present disclosure. [Figure 8] 10A and 10B are diagrams illustrating a position estimation process according to the present disclosure. [Figure 9] 10 is a flowchart of an interference wave source identification and reduction process according to the present disclosure. [Figure 10] 10(a) to 10(d) are diagrams for explaining a position estimation process according to a modified example of the present disclosure. [Figure 11] 1A is a diagram for explaining an example of the hardware configuration of a control station according to the present disclosure, and FIG. 1B is a diagram for explaining an example of the configuration of an array antenna according to the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. Note that reference numerals in the drawings are assigned to each element for convenience as an example to facilitate understanding, and are not intended to limit the present disclosure to the illustrated aspects. Furthermore, connecting lines between blocks in the drawings and the like referred to in the following description include both bidirectional and unidirectional lines. Unidirectional arrows are used to schematically indicate the flow of the main signal (data) and do not exclude bidirectionality. Furthermore, in the following description, "A and / or B" means A or B, or A and B.

[0016] <<First Embodiment>> A first embodiment to which the present disclosure is applied will be described. Fig. 1(a) is an overall configuration diagram of a communication system 100 of this embodiment. As shown in this figure, the communication system of this embodiment includes a control station 200, an earth station 300, and an antenna-mounted device equipped with an array antenna 410 (see Fig. 1(c)). In the following, this embodiment will be described taking as an example a case where the antenna-mounted device is an artificial satellite 400.

[0017] As shown in FIG. 1(b), the communication system 100 of this embodiment is a multi-beam satellite communication system that covers a communication area with multiple beams (multi-beams 500). The array antenna 410 provided in the artificial satellite 400 has a DBF (Digital Beam Forming) function and forms multiple beams (multi-beams 500). An area in which the earth station 300 and the artificial satellite 400 can communicate with each other using each beam 510 that makes up the multi-beam 500 is called a beam area 520. Each beam 510 is assigned a frequency band used for communication (communication frequency band fc). It is desirable that adjacent beam areas 520 be assigned different communication frequency bands fc.

[0018] In the communication system 100 of this embodiment, the control station 200 identifies the beam 510 that includes the source of the interference wave based on information from the artificial satellite 400. The communication system 100 that achieves this will be described below.

[0019] The satellite 400 of this embodiment is equipped with an array antenna 410 and transmits information about received signals, which are uplink signals (UL signals) transmitted from the earth station 300, to the control station 200. The transmitted information is, for example, the received signals of each antenna element before DBF processing, i.e., the input signals to each antenna element. Hereinafter, this information will be referred to as received signal information 601 of each antenna element. The control station 200 combines the received signal information 601 of each antenna element collected from the satellite 400 to generate pre-processing signal information 610. Note that the pre-processing signal information 610 is obtained, for example, as a spectral image. Furthermore, the spectral image of the beam after decomposition by the DBF function will hereinafter be referred to as beam signal information 650.

[0020] Under the control of the control station 200, the earth station 300 communicates with other earth stations 300 within the beam 510 via the artificial satellite 400. At this time, each earth station 300 uses an operating frequency fu, which is a frequency previously set for each earth station 300 by the control station 200. The number of earth stations 300 is not limited to one. Furthermore, each earth station 300 communicates with user terminals subordinate to the earth station 300. A user terminal can communicate with user terminals subordinate to another earth station 300 via the earth station 300 that it controls.

[0021] The control station 200 identifies a beam 510 that includes a source of interference waves among the multiple beams 500 formed by the array antenna 410, based on information about the received signal from the artificial satellite 400 (received signal information 601 of each antenna element and beam signal information 650). To achieve this, the control station 200 of this embodiment includes a synthesis unit 270, a frequency identification unit 210, and a beam identification unit 220, as shown in FIG. 2(a).

[0022] The combiner 270 receives received signal information 601 from the satellite 400, which is the received signal received by each antenna element constituting the array antenna 410 and is the received signal before DBF. Then, the combiner 270 combines the received signal information 601 of each antenna element to generate raw signal information 610. The combiner 270 generates the raw signal information 610 as, for example, a spectral image. Note that when generating the raw signal information 610, there may be a large amount of noise in the information for one antenna element received from the satellite 400, making it difficult to distinguish between signals. For this reason, it may be possible to implement measures such as integrating the input level for each frequency.

[0023] The frequency identifying unit 210 identifies the interference wave frequency fi, which is the frequency of the interference wave, from the pre-processing signal information 610.

[0024] Here, interference waves refer to signals other than those used within the communication system 100. In this embodiment, as described above, the operating frequency fu to be used for communication by each earth station 300 included in the communication system 100 is determined in advance, and this is stored as a communication plan. Signals of frequencies other than those determined in this communication plan are referred to as interference waves. Hereinafter, the interference wave frequency fi is referred to as the center frequency of the interference wave. Note that the communication plan may include various information other than the operating frequency fu, such as the strength, frequency, and duration of use of the signals used by each earth station 300.

[0025] The frequency identification unit 210 calculates a spectral image of all communication signals at a predetermined timing based on, for example, a communication plan, and then compares it with the spectral image generated by the synthesis unit 270 as the unprocessed signal information 610 to identify the frequency of the interference wave (interference wave frequency fi).

[0026] The beam identifying unit 220 identifies a beam 510 including the source of the interference wave as the source beam among the multi-beams 500. In this embodiment, the beam identifying unit 220 identifies the beam 510 based on the interference wave frequency fi identified by the frequency identifying unit 210.

[0027] As described above, a communication frequency band fc is assigned to each beam 510. Using this information, the beam identifying unit 220 identifies the source beam. For example, the beam identifying unit 220 first identifies the beam 510 whose communication frequency band fc includes the interference wave frequency fi as a source beam candidate. Then, using beam signal information 650, the beam 510 that is most affected by the interference wave is identified as the source beam from among the source beam candidates. Note that the beam area 520 corresponding to the source beam is the region that includes the source of the interference wave.

[0028] [Source identification process] Here, the flow of the generation source identification process by the control station 200 of this embodiment will be described. Fig. 2(b) shows the processing flow of the generation source identification process of this embodiment. This process is started at a predetermined time interval or in response to an instruction from the user.

[0029] First, the combining unit 270 combines the received signal information 601 of each antenna element received from the artificial satellite 400 to generate unprocessed signal information 610 (step S1101).

[0030] Then, the frequency identifying unit 210 identifies the interference wave frequency fi (step S1102). As described above, the frequency identifying unit 210 compares the communication plan with the unprocessed signal information 610 to identify the interference wave frequency fi.

[0031] Thereafter, the beam identifying unit 220 identifies the source beam, which is the beam 510 including the source of the interference wave (step S1103), and ends the process. Note that here, the source beam is identified using the previously identified interference wave frequency fi and the predetermined communication frequency band fc of each beam 510.

[0032] As described above, according to the communication system 100 of this embodiment, the control station 200 identifies the beam that is the source of the interference wave. That is, the control station 200 can grasp that the source of the interference wave is in the beam area 520 corresponding to the beam 510. Based on this information, the control station 200 can take action such as issuing a command to the artificial satellite 400 to form a null in the beam area 520.

[0033] In this way, according to this embodiment, it is possible to contribute to reducing the influence of interference waves without increasing the processing load on the artificial satellite 400 side.

[0034] That is, according to this embodiment, communication quality can be maintained without increasing the processing load on the device equipped with array antenna 410 having DBF function.

[0035] <<Second embodiment>> Next, a second embodiment of the present disclosure will be described. This embodiment is an embodiment that embodies the first embodiment in more detail. In this embodiment, components with the same names as those in the first embodiment basically have the same functions as those in the first embodiment. Hereinafter, this embodiment will be described, focusing on the differences from the first embodiment.

[0036] The communication system 100 of this embodiment has basically the same configuration as that of the first embodiment. That is, as shown in Fig. 1(a), the communication system 100 includes a control station 200, an earth station 300, and an artificial satellite 400. The number of earth stations 300 is not limited to one.

[0037] [Control station] 3(a) is a functional block diagram of the control station 200 of this embodiment. As shown in this figure, the control station 200 of this embodiment includes a synthesis unit 270, a frequency identification unit 210, a beam identification unit 220, a position estimation unit 230, a planning unit 240, an antenna control unit 250, and a control communication unit 260. In addition, the control station 200 further includes a storage unit 290 that stores data used in processing and data generated by processing.

[0038] The storage unit 290 stores, for example, a communication plan, the latest information (DBF information) of the multi-beams 500 formed by the array antenna 410, etc. The DBF information includes, for example, a communication frequency band fc, which is a frequency band used for communication with the earth station 300 in each beam 510, and position information of the beam area 520 formed by each beam 510.

[0039] The synthesis unit 270, frequency identification unit 210, and beam identification unit 220 basically have the same functions as the configurations with the same names in the first embodiment. Note that the frequency identification process by the frequency identification unit 210 and the beam identification process by the beam identification unit 220 will be described later.

[0040] The position estimation unit 230 identifies the position of the source of the interference wave within the source beam identified by the beam identification unit 220. The method of identifying the position will be described later.

[0041] The planning unit 240 receives communication requests from each earth station 300, allocates an operating frequency fu to each earth station 300, and formulates a communication plan. The planning unit 240 allocates an operating frequency fu to each earth station 300 using the latest DBF information stored in the storage unit 290.

[0042] Antenna control unit 250 generates a control command to control the operation of array antenna 410. For example, when position estimation unit 230 identifies the position of the source of an interference wave, it generates a control command to form a null in the direction of that position.

[0043] The control communication unit 260 communicates with external devices. In this embodiment, it receives communication requests from each earth station 300. It also transmits a communication plan generated in response to the communication request to each earth station 300. It also transmits and receives various data and signals to and from the artificial satellite 400. For example, it transmits a request for received signal information 601 to the artificial satellite 400 at predetermined time intervals, and receives the received signal information 601 of each antenna element transmitted in response to the request. Furthermore, during the beam identification process by the beam identification unit 220, it transmits a request for beam signal information 650, and receives the beam signal information 650 transmitted in response to the request. It also transmits control commands generated by the antenna control unit 250 to the artificial satellite 400.

[0044] [Earth station] The earth station 300 basically has the same functions as those in the first embodiment. Fig. 3(b) is an example of a functional block diagram of functions related to this embodiment of the earth station 300. As shown in this diagram, the earth station 300 of this embodiment includes a transceiver unit 310, a station communication unit 320, and a storage unit 390.

[0045] The transceiver 310 transmits and receives data to and from the control station 200. In this embodiment, as described above, a communication request is transmitted to the control station 200. The communication request includes, for example, the location of the source earth station 300, the communication volume, the communication schedule, the communication speed, and the like. This communication request is transmitted, for example, when the earth station 300 is initially set up and / or when the configuration, settings, and the like are changed. The transceiver 310 also receives the operating frequency fu transmitted from the control station 200 in response to the communication request. The received operating frequency fu is stored in the storage unit 390.

[0046] The station communication unit 320 communicates with the array antenna 410. At this time, the communication is performed using the operating frequency fu stored in the storage unit 390.

[0047] As described above, the use frequency fu is stored in the storage unit 390. When a new use frequency fu is received, it is overwritten. In other words, only the latest use frequency fu is stored.

[0048] [Artificial satellite] 3(c) is a diagram showing an example of functional blocks of functions related to this embodiment of the control unit 420 provided in the artificial satellite 400. The control unit 420 includes an information acquisition unit 430, a DBF control unit 440, and a satellite communication unit 450.

[0049] The information acquisition unit 430 acquires received signal information 601 in response to a request from the control station 200. Specifically, as described above, the information acquisition unit 430 first acquires received signal information 601 of each antenna element before DBF from the array antenna 410. Then, the information acquisition unit 430 transmits the acquired received signal information 601 of each antenna element to the requesting control station 200 via the satellite communication unit 450.

[0050] Furthermore, in this embodiment, during the beam identification process described below, a spectral image of a specific beam decomposed by DBF is acquired as beam signal information 650. The acquired beam signal information 650 is transmitted to the requesting control station 200 via the satellite communication unit 450. The specific beam is each beam that is determined to be a source beam candidate during the beam identification process.

[0051] The DBF control unit 440 controls the operation of the array antenna 410. In this embodiment, for example, in accordance with preset data or in response to a control command from the control station 200, the DBF control unit 440 controls each antenna element constituting the array antenna 410 to achieve a desired DBF.

[0052] The satellite communication unit 450 communicates with the control station 200. In this embodiment, it receives requests from the control station 200 and transmits received signal information 601 and beam signal information 650. It also receives various control commands, including control commands related to DBF.

[0053] [Communication plan creation process] The details of the communication plan creation process by the earth station 300 and the control station 200 will be described. FIG. 4(a) shows the processing flow of the communication plan creation process of this embodiment. As described above, when a communication request is transmitted from each earth station 300, the planning unit 240 of the control station 200 generates a communication plan accordingly. The communication request is transmitted when starting new communication, for example, when an earth station 300 is opened. For example, when there are multiple earth stations 300, the communication requests are transmitted at different times. However, the communication requests may be transmitted approximately simultaneously. Here, an example in which a communication request is transmitted from one earth station 300 will be described.

[0054] The earth station 300 creates a communication request 620 and transmits it to the control station 200 (step S2101). An example of the communication request 620 created and transmitted here is shown in Fig. 4(b). As shown in this figure, the communication request 620 includes an identifier (ID) 621 that uniquely identifies the earth station 300 that sent it, a current position 622 of the earth station 300, a requested communication volume 623, a requested communication speed 624, a communication schedule 625 that indicates the time for communication, etc.

[0055] When the communication request 620 is received (step S2102), the planning unit 240 of the control station 200 creates a communication plan 630 and stores it in the storage unit 290 (step S2103). The communication plan 630 created here assigns a frequency fu to each earth station 300 and specifies information related to communication such as the communication volume of each earth station.

[0056] An example of the communication plan 630 generated at this time is shown in Figure 4(c). As shown in this figure, the communication plan 630 defines the frequency fu to be used, the band, the communication volume, etc. for each earth station 300 that has transmitted a communication request 620. In this figure, A to F are IDs 621 of the earth stations 300. Also, 511, 512, and 513 respectively indicate the communication frequency band fc of the beam 510 used by each earth station 300.

[0057] For example, as described above, the beam area 520 of each beam 510 formed by the array antenna 410 using DBF is determined in advance. The planning unit 240 identifies the beam area 520 in which the earth station 300 is included, for example, according to the position 622 within the communication request 620. Then, it identifies the communication frequency band fc of the beam area 520. Note that this information necessary for processing is stored in the storage unit 290 in advance.

[0058] The planning unit 240 determines an unused frequency (band) within the identified communication frequency band fc as the frequency fu to be used by the source earth station 300. Then, the frequency fu to be used by the newly added (or changed) earth station 300 is added to the existing communication plan 630 to create a new communication plan 630. At this time, other information (communication volume, communication speed, communication schedule, etc.) included in the communication request 620 may be added to the communication plan 630.

[0059] The required communication volume may vary from time to time. Furthermore, if the earth station 300 is mounted on a mobile object, the location of the earth station 300 may vary from time to time. For this reason, the communication plan 630 may be created for each predetermined time (interval). For example, the communication plan 630 shown in FIG. 4(c) is the communication plan 630 for the period from time T1 to time T2.

[0060] Then, the planning unit 240 transmits the operating frequency fu assigned to the requesting earth station 300 in the communication plan 630 to the earth station 300 (step S2104). The earth station 300 receives the operating frequency fu and stores it in the storage unit 390 (step S2105). Thereafter, the earth station 300 communicates with the artificial satellite 400 using the operating frequency fu. That is, it transmits an uplink signal (UL signal) to the artificial satellite 400.

[0061] [Frequency specific processing] Next, details of the frequency identification process performed by the frequency identification unit 210 will be described. As described above, the frequency identification unit 210 of this embodiment compares the unprocessed signal information 610 generated by the synthesis unit 270 from the received signal information 601 of each antenna element received from the artificial satellite 400 with the communication plan 630, and identifies the interference wave and its frequency (interference wave frequency fi).

[0062] As described above, in order to determine whether or not there is an interference wave, the control station 200 requests the satellite 400 to transmit received signal information 601 at predetermined time intervals via the control communication unit 260. The frequency identification unit 210 executes frequency identification processing upon receiving from the combining unit 270 the unprocessed signal information 610 obtained by combining the received signal information 601 of each antenna element transmitted from the satellite 400 in response to this request.

[0063] Fig. 5(a) shows an example of a spectral image generated as raw signal information 610. Note that the spectral image shown in this figure is a composite of received signal information 601, which is the input signal to each antenna element. Fig. 5(b) shows a communication plan 630 at this timing.

[0064] The frequency identification unit 210, for example, detects and converts into data the center frequency and frequency band (bandwidth) of each signal from the raw signal information 610. For example, the frequency identification unit 210 extracts a spectrum having an intensity equal to or greater than a predetermined value from the spectral image generated as the raw signal information 610 by image recognition or the like, and identifies the center frequency and bandwidth of the spectrum.

[0065] 5(c) shows an example of the digitized information 611. The numbers assigned to No. are assigned for convenience to distinguish between the spectra (signal waveforms defined by a center frequency and a bandwidth) of the unprocessed signal information 610.

[0066] Thereafter, the frequency identification unit 210 compares the digitized information 611 with the data on the center frequency and bandwidth of the frequencies fu (hereinafter simply referred to as the frequencies A to F) used by each earth station (A to F) in the communication plan 630, and identifies the interference wave frequency fi. A predetermined tolerance may be set for the comparison.

[0067] FIG. 6(a) shows a communication plan 630, and FIG. 6(b) shows an example of the determination results for each data item in the digitized information 611. For example, in the example of FIG. 6(b), the center frequency and bandwidth of No. 1 match the operating frequency A (ID is A) of the communication plan 630 within the allowable range. Nos. 2, 3, 5, and 6 also match the operating frequencies B, C, D, and E, respectively, within the allowable range. On the other hand, for No. 4, there is no data in the communication plan 630 that matches within the allowable range. The frequency identification unit 210 identifies the data item No. 4 as an interference wave, and sets the center frequency and bandwidth of the digitized information 611 as the center frequency fi and bandwidth of the interference wave.

[0068] If there is no data between the unprocessed signal information 610 and the communication plan 630 that deviates beyond the allowable range (no mismatch), the frequency identification unit 210 determines that there is no interference wave and ends the process.

[0069] [Beam specific processing] Next, we will explain the beam identification process performed by the beam identifying unit 220. First, the beam identifying unit 220 identifies a group of beams 510 to which the communication frequency band fc including the interference wave frequency fi is assigned as source beam candidates. Then, if there are multiple source beam candidates, the beam identifying unit 220 identifies the source beam from among them.

[0070] As described above, in DBF, the same communication frequency band fc is generally assigned to multiple beams 510. This is shown in Figure 7. Here, as in Figure 5(b), it is assumed that three communication frequency bands 511, 512, and 513 are assigned to each beam 510 of the multi-beam 500. Each is shown with a different shaded area. First, the beam identifying unit 220 identifies as source beam candidates 540 the group of beams 510 whose communication frequency band fc includes the interference wave frequency fi identified by the frequency identifying unit 210.

[0071] 5(b), for example, among different communication frequency bands 511, 512, and 513 assigned to each beam 510, the interference wave frequency fi is included in the communication frequency band 512. Therefore, the beam identifying unit 220 designates the group of beams 510 to which the communication frequency band 512 is assigned as source beam candidates 540.

[0072] For example, in the example of Figure 7, beam 510 forming beam area BA1, beam 510 forming beam area BA2, and beam 510 forming beam area BA3 (hereinafter simply referred to as beams BA1, BA2, and BA3) are identified as source beam candidates 540.

[0073] Here, if there is one source beam candidate 540, the beam identifying unit 220 determines that source beam candidate 540 as the source beam 541, and ends the beam identifying process.

[0074] On the other hand, if there are multiple source beam candidates 540, the beam identifying unit 220 requests the satellite 400 for a spectral image (beam signal information 650) of each source beam candidate 540. Then, the beam signal information 650 transmitted in response to the request is analyzed using a spectrum analyzer or the like to identify the source beam 541. Specifically, the beam identifying unit 220 identifies the beam in the spectral image having the strongest spectrum in a spectrum centered on the interference wave frequency fi as the source beam 541.

[0075] For example, in the example of Fig. 7, 651, 652, and 653 are spectral images (beam signal information 650) of beams BA1, BA2, and BA3, respectively. When comparing the intensities of spectrum 655 of interference wave frequency fi, beam BA2 has the highest intensity. Therefore, the beam identifying unit 220 identifies beam BA2 as the source beam 541. In this figure, 656 is the spectrum of the signal of the operating frequency fu set in each beam 510.

[0076] [Location estimation processing] Next, the position estimation process by the position estimation unit 230 will be described in detail. Figures 8(a) and 8(b) are diagrams for explaining the position estimation process by the position estimation unit 230 of this embodiment. As shown in Figure 8(a), it is assumed that a source beam 541 has been identified among source beam candidates 540. Furthermore, spectral images 651, 652, and 653 are beam signal information 650 for each of the source beam candidates 540 (BA1, BA2, and BA3).

[0077] 8(b), the position estimation unit 230 extracts at least three beams 510, including a source beam 541, from the source beam candidates 540. Here, an example will be described in which beams BA1, BA2, and BA3 are extracted.

[0078] The position estimation unit 230 then identifies the level (intensity, input power) of a spectrum (interference wave) 655 having the interference wave frequency fi as its center frequency in each of the spectral images 651, 652, and 653. Then, as shown in FIG. 7(b), the position estimation unit 230 identifies the position 542 of the source of the interference wave using the ratio of the levels of the respective spectrums (interference waves) 655 based on the relationship between intensity and distance.

[0079] The antenna control unit 250 generates a control command to form a null in the antenna pattern in the direction of a predetermined area including the position 542 of the interference wave source. Then, the control command is output to the satellite 400 via the control communication unit 260. At this time, the size (area) of the predetermined area is set smaller than the beam area BA2. The size may be determined in advance. Alternatively, it may be determined according to the calculated maximum strength of the interference wave. For example, the communication system 100 may form a null of a predetermined size to perform communication, and if the influence of the interference wave remains, the null area may be expanded.

[0080] [Interference source identification and reduction processing] Here, a flow of the interference wave source identification and reduction process by the control station 200 and the control unit 420 of the artificial satellite 400 after the communication plan 630 has been created will be described. Fig. 9 shows the processing flow of this process. This process is executed at predetermined time intervals.

[0081] In order to determine whether or not there is an interference wave, control station 200 transmits a received signal information request to satellite 400 requesting received signal information 601 (step S2200).

[0082] When the control unit 420 of the artificial satellite 400 receives the received signal information request (step S2301), it collects the received signal information 601 and transmits it to the control station 200 that has made the request (step S2302).

[0083] When the frequency identification unit 210 of the control station 200 receives the received signal information 601 of each antenna element (step S2201), it combines the received received signal information 601 of each antenna element to generate raw signal information 610 (step S2202). Then, the frequency identification unit 210 performs frequency identification processing using the raw signal information 610. At this time, first, the frequency identification unit 210 compares the raw signal information 610 with the communication plan 630 (step S2203). Here, if there is no mismatch (S2204; No), this processing ends.

[0084] On the other hand, if there is a mismatch (S2204; Yes), the frequency identifying unit 210 executes the above-described frequency identifying process to identify the interference wave frequency fi (step S2205).

[0085] Thereafter, the beam identifying unit 220 identifies source beam candidates 540 that may include the source of the interference wave, based on the interference wave frequency fi and the communication frequency band fc set for each beam 510 (step S2206).

[0086] Here, if the number of beams (number of candidates) of the source beam candidate 540 is 1 (S2207; Yes), the beam identifying unit 220 designates the source beam candidate 540 as the source beam 541, and proceeds to step S2211 described later.

[0087] Then, the beam identifying unit 220 requests the satellite 400 to send a spectral image (beam signal information 650) of the source beam candidate 540 (step S2208).

[0088] Upon receiving the request (step S2303), the control unit 420 of the satellite 400 generates the beam signal information 650 and transmits it to the control station 200 that sent it (step S2304).

[0089] Upon receiving the beam signal information 650 (step S2209), the beam identifying unit 220 identifies the source beam 541 from among the source beam candidates 540 using the beam signal information 650 (step S2210).

[0090] Thereafter, the position estimation unit 230 identifies the position 542 of the source in the source beam 541 (step S2211). Through the above process, the communication system 100 of this embodiment identifies the position 542 of the source of the interference wave.

[0091] After identifying position 542 of the interference wave source, antenna control unit 250 generates a control command to form a null in the direction of identified position 542 of the source, and instructs satellite 400 to form the null (step S2212).

[0092] On the satellite 400 side, the DBF control unit 440 performs null formation in accordance with the control command (step S2305) to reduce the influence of the interference wave.

[0093] As described above, this embodiment has the same configuration as the first embodiment, and therefore has the same effects as the first embodiment.

[0094] Generally, in satellite communications, the available frequency band is limited. Therefore, it is desirable to narrow the band to be stopped as much as possible to ensure continuous operation of the communication system 100. According to this embodiment, after identifying the source beam 541, the position 542 of the interference wave source is further narrowed down within the beam area 520 formed by the source beam 541. Then, the array antenna 410 is controlled to form a null only in the direction of that area. Therefore, the area in which the null is formed can be minimized, and accordingly, the suspension of satellite communications by the earth station 300 and changes in the frequency band used can be minimized. Furthermore, since such processing is also performed by the control station 200, the processing load on the artificial satellite 400 is not increased.

[0095] That is, according to the communication system 100 of this embodiment, communication quality can be maintained without increasing the processing load on the artificial satellite 400 equipped with a DBF antenna.

[0096] <Variation 1> In the second embodiment, the position estimation unit 230 estimates the position 542 of the source using the ratio of the levels of the interference waves. However, the position estimation method is not limited to this.

[0097] For example, the position estimation unit 230 may estimate the position 542 of the source by changing the directivity of the source beam 541. Changing the directivity means, for example, changing the radius of the beam area 520 formed by the beam 510, changing the center position of the beam area 520, or a combination of these. Each of these is achieved by generating a control command in the antenna control unit 250 and transmitting it to the artificial satellite 400. Every time the position estimation unit 230 changes the directivity, it checks the level of the spectrum 655 of the interference wave using the spectral image of the beam area 520 (beam signal information 650 (see FIG. 10(d))), and identifies the position 542 of the source. A specific example will be described below.

[0098] 10(a), for example, a beam area 551 of a small beam with a smaller radius is formed within a beam area 550 of a source beam 541. Then, scanning is performed by changing the center position of the beam area 551 within the beam area 550. In this case, the position estimation unit 230 estimates the location in the spectral image (beam signal information 650) where the level of the spectrum 655 of the interference wave is highest as the position 542 of the source.

[0099] Furthermore, when beam area 520 moves away from the source, the level of spectrum 655 of the interference wave decreases. Furthermore, when the source of the interference wave moves outside beam area 520, the level of spectrum 655 of the interference wave decreases. Using this, position estimation unit 230 may estimate position 542 of the source.

[0100] For example, as shown in Fig. 10(b), it is possible to move only the center position of a beam area 550 formed by a source beam 541 without changing the radius of the beam area 550. For example, first, the center position of the beam area 550 is moved in a predetermined angular direction. Then, the outer periphery of the beam area 550 where the level of the interference wave is equal to or lower than a predetermined value is determined as a position candidate. The position estimation unit 230 repeats this process at multiple different angles to narrow down the source position 542 to one.

[0101] 10(c), scanning may be performed by reducing the radius of beam area 550. A beam area 552, which is the beam area 550 with a reduced radius, is formed at a position obtained by shifting the center position of the beam area 550 by a predetermined angle. As above, the outer periphery of beam area 552 where the level of the interference wave is below a predetermined value is determined as a position candidate. The position estimation unit 230 repeats this process at multiple different angles to narrow down the source position 542 to one.

[0102] The method of this modification is particularly effective when, for example, the number of beam areas 520 in which interference waves are observed in the second embodiment is two or less.

[0103] <Variation 2> Although the above-described embodiments have been described with reference to an example in which the source of the interference wave is one location, the present invention is not limited to this. For example, the above-described embodiments and modifications can be applied even when interference waves are generated from multiple sources.

[0104] First, the interference wave frequency fi of each interference wave is identified, and then, for each frequency, the source beam 541 and the source position 542 are identified.

[0105] <Variation 3> After identifying the source position 542, the control station 200 transmits a control command to the satellite 400 to form a null in the direction of the source position 542. This may affect the formation of other beam areas 520. In such a case, the control station 200 may reconstruct the communication plan 630.

[0106] <Variation 4> The control station 200 may be shared with one of the earth stations 300. Furthermore, the functions of the control station 200 may be distributed among different pieces of hardware. Furthermore, the application of the communication system 100 is not limited to satellite communications. For example, it may be an ETC system, a radar device, or the like.

[0107] [Hardware configuration] The control station 200 in each of the above embodiments may be realized by, for example, a general-purpose information processing device. The general-purpose information processing device includes, for example, a central processing unit (CPU) 191, a main storage device (memory) 192, an auxiliary storage device 193, a communication I / F 194, and an expansion I / F 195, which are interconnected by an internal bus, as shown in FIG. 11(a).

[0108] The CPU 191 realizes the above functions and comprehensively controls the entire device by, for example, loading a program stored in the auxiliary storage device 193 into the main storage device 192 and executing it. Note that the CPU 191 may be replaced by one or more processors such as an MPU (Micro Processing Unit).

[0109] The main storage device 192 is a memory such as a RAM (Random Access Memory), etc. The main storage device 192 is a work area when the CPU 191 processes programs executed by the installed devices.

[0110] The auxiliary storage device 193 is, for example, a read only memory (ROM), a hard disk drive (HDD), or a solid state drive (SSD). The auxiliary storage device 193 stores various programs executed by the control station 200. In addition, in each of the above embodiments and / or modifications, the storage unit 290 may be constructed in the auxiliary storage device 193. Note that data generated during processing may be stored in the main storage device 192.

[0111] The auxiliary storage device 193 may include a storage medium such as a flexible disk, a hard disk, an optical disk, a CD-ROM, a CD-R, a magnetic tape, a non-volatile memory card, or a DVD.

[0112] The above-mentioned functions of the control station 200 are realized by the CPU 191 loading a program stored in the auxiliary storage device 193 into the main storage device 192 and executing it.

[0113] The programs for realizing the above functions can be recorded on a computer-readable storage medium. The storage medium can be a non-transitory medium such as a semiconductor memory, a hard disk, a magnetic recording medium, or an optical recording medium. The present disclosure can also be embodied as a computer program product. Furthermore, the programs stored in the auxiliary storage device 193 can be provided as a program product recorded on a non-transitory computer-readable recording medium. The auxiliary storage device 193 can be used to store various programs recorded on a non-transitory computer-readable recording medium for the medium to long term.

[0114] The communication I / F 194 is an interface for inputting and outputting signals and data via wired or wireless communication. The communication I / F 194 may also include an antenna, a modem, etc. In this embodiment, the control communication unit 260 is realized by the communication I / F 194.

[0115] The expansion I / F 195 includes, for example, a USB interface and a memory slot, and is connected to an external storage unit, an input device, an output device, and the like. The input device is, for example, a device that accepts user operations, such as a keyboard or a mouse. The output device is a display device such as a monitor. The liquid crystal monitor may have a touch panel function that accepts instructions by touch operation by the user. The expansion I / F 195 may have a plurality of different types of interfaces.

[0116] For example, the user may make various settings, give instructions to start / end processing, etc. via an input device connected to this expansion I / F 195 .

[0117] Similarly, the control unit 420 of the earth station 300 and the artificial satellite 400 may also be realized by a general-purpose information processing device having the hardware shown in Fig. 11(a). As with the control station 200, each of the above functions is realized by the CPU 191 loading a program stored in the auxiliary storage device 193 into the main storage device 192 and executing it.

[0118] The hardware configuration of the control station 200, the earth station 300, and the control unit 420 of the artificial satellite 400 is not limited to this, but may be implemented, for example, as an integrated circuit (IC) dedicated to each process, an application specific integrated circuit (ASIC), a system on chip (SOC), a field programmable gate array (FPGA), or the like.

[0119] Furthermore, the array antenna 410 of each of the above embodiments includes, for example, N (N is an integer greater than or equal to 1) antenna elements 411, LNAs (Low Noise Amplifiers) 412 connected to each of the antenna elements 411, downconverters (D / C) 413, analog-to-digital converters (ADCs) 414, and channelizers DBFs 415, as shown in FIG. 11(b).

[0120] Each antenna element 411 receives a signal transmitted from a wireless terminal within each beam area 520. Furthermore, an LNA 412 amplifies the received signal, a D / C 413 converts the amplified received signal into direct current, and an ADC 414 samples the signal and converts it into a digital signal.

[0121] The channelizer DBF 415 assigns weights to the received signals, combines them, and outputs a beam signal. At this time, digital beamforming (DBF) is performed, which processes multiple different weight combinations in parallel to generate multiple different beam signals.

[0122] In the process flow used in the above explanation, multiple steps (processes) are described in order, but the order in which each step is performed is not limited to the order described. For example, the order of the steps shown in the figure can be changed to the extent that the content is not affected, such as performing each process in parallel.

[0123] Although the embodiments and modifications of the present disclosure have been described above, the present disclosure is not limited to the above-described embodiments and can be modified in various ways that would be understandable to a person skilled in the art. Each embodiment and modification can be combined with other embodiments as appropriate. Furthermore, for example, the network configurations and element configurations shown in the drawings are examples intended to aid in understanding the present disclosure and are not limited to the configurations shown in these drawings.

[0124] Finally, preferred embodiments of the present disclosure will be summarized. Some or all of the above-described embodiments can be described as, but are not limited to, the following supplementary notes. (Appendix 1) The control station a combining unit that combines received signal information of each antenna element, which is a received signal received by each antenna element constituting an array antenna having a DBF (Digital Beam Forming) function and is a received signal before the DBF, to generate unprocessed signal information; a frequency identification unit that identifies an interference wave frequency, which is a frequency of an interference wave, from the unprocessed signal information; and a beam identifying unit that identifies, among a plurality of beams formed by performing the DBF processing on the received signal in the array antenna, a beam that includes the source of the interference wave as a source beam based on the interference wave frequency. (Appendix 2) In the control station described in Appendix 1, It is preferable that the system further comprises a position estimator for identifying the position of the source within the source beam. (Appendix 3) In the control station described in Appendix 1 or 2, It is preferable that the frequency identification unit compares the unprocessed signal information with a communication plan including frequencies used that are assigned to earth stations that communicate with the device equipped with the array antenna, and identifies the interference wave frequency. (Appendix 4) In any one of the control stations according to appendix 1 to 3, a frequency band used for communication is set as a communication frequency band for each of the plurality of beams; The beam specifying unit One or more of the beams to which the communication frequency band including the identified interference wave frequency is set are set as source beam candidates, It is preferable to identify the beam with the highest intensity of the interference wave among the source beam candidates as the source beam. (Appendix 5) In the control station described in Appendix 2, a frequency band used for communication is set as a communication frequency band for each of the plurality of beams; It is preferable that the position estimation unit identifies the position of the source using a ratio of the intensity of the interference wave of at least three beams, including the source beam, to which the communication frequency band is set that includes the identified interference wave frequency. (Appendix 6) In the control station described in Appendix 2, It is preferable that the position estimation unit specifies the position of the source by changing the directivity of the source beam. (Appendix 7) In the control station described in Appendix 2, It is preferable that the antenna device further comprises an antenna control unit that controls each of the antenna elements so as to form a null in the direction of the position of the source. (Appendix 8) The communication system a control station as set forth in any of appendices 1 to 7, 11, or 12; an antenna-mounted device that is equipped with the array antenna and transmits received signal information of each of the antenna elements to the control station; and an earth station that performs communication via the antenna-mounted equipment under the control of the control station. (Appendix 9) The method for identifying the source of interference waves is as follows: The computer in the control station generating unprocessed signal information by combining received signal information of each antenna element, which is a received signal received by each antenna element constituting an array antenna having a DBF (Digital Beam Forming) function and is a received signal before the DBF; Identifying an interference wave frequency, which is a frequency of an interference wave, from the unprocessed signal information; Among a plurality of beams formed by performing the DBF processing on the received signal in the array antenna, a beam including the source of the interference wave is identified as a source beam based on the frequency of the interference wave. (Appendix 10) The program is On the computer, generating unprocessed signal information by combining received signal information of each antenna element, which is a received signal received by each antenna element constituting an array antenna having a DBF (Digital Beam Forming) function and is a received signal before the DBF; a step of identifying an interference wave frequency, which is a frequency of an interference wave, from the unprocessed signal information; and a procedure of identifying, as a source beam, a beam including the source of the interference wave, among a plurality of beams formed by performing the DBF processing on the received signal in the array antenna, based on the frequency of the interference wave. (Appendix 11) In any one of the control stations described in appendix 1 to 7, It is preferable that the radio communication system further comprises a planning unit that receives a communication request from an earth station, formulates a communication plan in which a frequency fu to be used is assigned to the earth station, and transmits the plan to the earth station. (Appendix 12) In any one of the control stations described in Supplementary Notes 1 to 7 and 11, It is preferable that the device equipped with the array antenna further comprises a control communication unit that requests the received signal information at predetermined time intervals. (Appendix 13) 9. The communication system according to claim 8, the control station further comprises a planning unit that receives a communication request from the earth station, formulates a communication plan in which a frequency to be used is allocated to the earth station, and transmits the communication plan to the earth station; The earth station a transceiver unit that transmits the communication request to the control station and receives the use frequency transmitted from the control station in response to the communication request; It is preferable that the communication device further comprises a communication unit that communicates with the antenna-equipped device using the allocated operating frequency. Note that, like Supplementary Note 1, the forms of Supplementary Notes 8 to 10 can be developed into the forms of Supplementary Notes 2-7, 11, and 12.

[0125] The disclosures of the above-mentioned patent documents and other documents are incorporated herein by reference. Within the scope of this disclosure (including the claims), modifications and adjustments of the embodiments and variations are possible based on the basic technical concepts. Furthermore, within the scope of this disclosure, various combinations and selections of the various disclosed elements (including each element of each claim, each element of each embodiment or variation, each element of each drawing, etc.) are possible. In other words, this disclosure naturally includes various modifications and alterations that would be possible by a person skilled in the art in accordance with the entire disclosure, including the claims, and the technical concepts. In particular, with regard to the numerical ranges described herein, any numerical value or subrange included within the range should be construed as being specifically described, even if not otherwise specified. [Explanation of symbols]

[0126] 100: communication system, 191: CPU, 192: main memory device, 193: auxiliary memory device, 194: communication I / F, 195: expansion I / F, 200: control station, 210: frequency identification unit, 220: beam identification unit, 230: position estimation unit, 240: planning unit, 250: antenna control unit, 260: control communication unit, 270: synthesis unit, 290: memory unit, 300: Earth station, 310: Transmitter / receiver, 320: Station communication unit, 390: Memory unit, 400: artificial satellite, 410: array antenna, 411: antenna element, 412: LNA, 413: D / C, 414: ADC, 415: channelizer DBF, 420: control unit, 430: information acquisition unit, 440: DBF control unit, 450: satellite communication unit, 500: multi-beam, 510: beam, 511: communication frequency band, 512: communication frequency band, 513: communication frequency band, 520: beam area, 540: source beam candidate, 541: source beam, 542: source position, 550: beam area, 551: beam area, 552: beam area, 601: Received signal information, 610: Unprocessed signal information, 611: Digitized information, 620: Communication request, 621: ID, 622: Position, 623: Communication volume, 624: Communication speed, 625: Communication schedule, 630: Communication plan, 650: Beam signal information, 651: Spectral image, 652: Spectral image, 653: Spectral image, 655: Spectrum (interference wave), 656: Spectrum (used signal), BA1: Beam (beam area), BA2: Beam (beam area), BA3: Beam (beam area), fc: Communication frequency band, fi: Interference wave frequency, fu: Frequency used

Claims

1. a combining unit that combines received signal information of each antenna element, which is a received signal received by each antenna element constituting an array antenna having a DBF (Digital Beam Forming) function and is a received signal before the DBF, to generate unprocessed signal information; a frequency identification unit that identifies an interference wave frequency, which is a frequency of an interference wave, from the unprocessed signal information; a beam identifying unit that identifies a beam including a source of the interference wave as a source beam among a plurality of beams formed by performing the DBF processing on the received signal in the array antenna, based on a frequency of the interference wave.

2. 2. The control station according to claim 1, The control station further comprises a position estimator that identifies a position of the source within the source beam.

3. 2. The control station according to claim 1, The frequency identification unit of the control station compares the unprocessed signal information with a communication plan including frequencies used that are assigned to earth stations that communicate with the device equipped with the array antenna, and identifies the interference wave frequency.

4. 2. The control station according to claim 1, a frequency band used for communication is set as a communication frequency band for each of the plurality of beams; The beam specifying unit One or more of the beams to which the communication frequency band including the identified interference wave frequency is set are set as source beam candidates, A control station identifies the beam with the highest intensity of the interference wave as the source beam among the source beam candidates.

5. 3. The control station according to claim 2, a frequency band used for communication is set as a communication frequency band for each of the plurality of beams; The position estimation unit identifies the position of the source using the ratio of the intensity of the interference waves of at least three beams, including the source beam, to which the communication frequency band is set that includes the identified interference wave frequency.

6. 3. The control station according to claim 2, The position estimation unit changes the directivity of the source beam to identify the position of the source.

7. 3. The control station according to claim 2, The control station further includes an antenna control unit that controls each of the antenna elements to form a null in the direction of the position of the source.

8. A control station according to any one of claims 1 to 7; an antenna-mounted device that is equipped with the array antenna and transmits received signal information of each of the antenna elements to the control station; an earth station that performs communication via the antenna-equipped equipment under the control of the control station.

9. The computer in the control station generating unprocessed signal information by combining received signal information of each antenna element, which is a received signal received by each antenna element constituting an array antenna having a DBF (Digital Beam Forming) function and is a received signal before the DBF; Identifying an interference wave frequency, which is a frequency of an interference wave, from the unprocessed signal information; a beam including the source of the interference wave among a plurality of beams formed by performing the DBF processing on the received signal in the array antenna is identified as a source beam based on the interference wave frequency.

10. On the computer, generating unprocessed signal information by combining received signal information of each antenna element, which is a received signal received by each antenna element constituting an array antenna having a DBF (Digital Beam Forming) function and is a received signal before the DBF; a step of identifying an interference wave frequency, which is a frequency of an interference wave, from the unprocessed signal information; and a program for executing a procedure for identifying, as a source beam, a beam including a source of the interference wave, among a plurality of beams formed by performing the DBF processing on the received signal in the array antenna, based on the frequency of the interference wave.

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