Resource adjustment device, resource adjustment method, and resource adjustment program

Abstract

To allow beam resources in a satellite communication system to be appropriately allocated.SOLUTION: A resource allocation unit 121 allocates resources to each of multiple beams in accordance with request information which is given to each beam for each of the multiple beams and which indicates items of a beam pattern indicating polarization, phase, and amplitude excitation coefficients, beam frequencies which are upper and lower limit frequencies, and frequency bandwidth. A resource adjustment unit 123 adjusts resources allocated to a beam to be adjusted by adjusting at least one of the items indicated by the request information, for the beam to be adjusted among the multiple beams so as to satisfy allowable interference indicating an allowable value of interference given to each beam for each of the multiple beams.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a technology for adjusting resources allocated to each beam in a satellite communication system that can flexibly control the frequency of the beam or the position and shape of the coverage area so that the amount of interference experienced by the beam is kept within a range acceptable for the service. [Background technology]

[0002] In response to demands for increased capacity in satellite communications, multi-beam satellites called HTS are being developed that use multiple beams to improve the frequency utilization efficiency of the entire satellite communications system. HTS stands for High Throughput Satellite. Furthermore, by equipping HTS with functions such as digital channelizer or DBF, satellite communications systems are being developed that can flexibly change the frequency of each beam, the position and shape of the coverage area, and the connection configuration between beams. DBF stands for Digital Beam Forming.

[0003] Multi-beams are being used to improve frequency utilization efficiency. Specifically, while narrowing the coverage area of ​​one beam, interference is avoided by irradiating nearby areas with beams of different frequencies or polarization, while areas some distance away where the effects of interference are small are irradiated with beams of the same frequency and polarization. This allows for repeated use of frequency and polarization radio resources, thereby increasing the capacity of the entire service area of ​​the satellite communications system.

[0004] The improvement of frequency utilization efficiency through frequency reuse has been put to more practical use in terrestrial mobile communication systems such as mobile phone services than in satellite communication systems. The basic idea of ​​a mobile communication system is to use radio resources allocated to a base station to create a "cell" that is part of the service area, and to cover the entire service area by installing a large number of base stations. Here, determining the radio resources to be allocated to base stations requires determining radio resource information for a large number of base stations so that each cell appropriately covers the borders with adjacent cells, which makes manual determination difficult.

[0005] One known technique for addressing these issues is cell design for terrestrial mobile communications, as disclosed in Non-Patent Document 1. This cell design is a resource allocation method that determines the radio wave irradiation range and the allocation of frequencies to be used, and appropriately constructs a service area for a mobile communication system. In this cell design, the number of base stations required and the information to be set for each base station are calculated based on required information such as the service area range, frequency band, communication capacity, and required communication quality. As an example of the information to be set for a base station, as disclosed in Patent Document 1, a method that uses a list of neighboring cells involved in handover and a threshold value for the difference in radio wave quality between the neighboring cells is considered. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent No. 5626219 [Non-patent literature]

[0007] [Non-Patent Document 1] NTT DoCoMo Technical Journal Vol.2 No.4 pp.28-34 Summary of the Invention [Problem to be solved by the invention]

[0008] The radio resource allocation method based on cell design in mobile communication systems is thought to be applicable to the beam resource allocation method in satellite communication systems, in that it allocates radio resources to each cell so as to satisfy the required communication quality taking interference into account. The cell design for mobile communications shown in Non-Patent Document 1 is based on the idea of ​​optimizing the overall service area that can be commonly used for various service requests by adding base stations, which are physical resources that radiate radio waves, as needed when request information changes. However, this idea is not suitable for beam resource allocation in satellite communications systems. Specifically, there are the following first and second problems.

[0009] (First issue) There is a limit to how much physical resources a satellite can allocate to beams as needed, so beam resource allocation in satellite communication systems requires resource allocation within the limited beam resources.

[0010] (Second issue) The service requirements for satellite communication systems include the formation of service-specific beams, in addition to cases where multiple beams deployed across the entire service area are used commonly by various services. Service-specific beams include, for example, beams for defense applications or beams for aircraft service applications. When multiple such service-specific beams are simultaneously formed, beam resources must be allocated to satisfy the independent requirements for each service. The requirements include the acceptable level of interference, service area, frequency, etc.

[0011] The present disclosure aims to enable appropriate allocation of beam resources in a satellite communication system. [Means for solving the problem]

[0012] A resource adjustment device according to the present disclosure includes: A resource adjustment device for adjusting resources allocated to each of a plurality of beams in a satellite communication system capable of controlling the plurality of beams, a resource allocation unit that allocates resources to each of the plurality of beams in accordance with request information given for each of the plurality of beams, the request information indicating items such as a beam pattern indicating polarization, phase, and amplitude excitation coefficients, beam frequencies indicating upper and lower limit frequencies, and frequency bandwidth; a resource adjustment unit that adjusts resources allocated to a beam to be adjusted by adjusting at least one item indicated by the request information for a beam to be adjusted among the plurality of beams so that the beam satisfies an allowable interference indicating an allowable value of interference given to each beam; Equipped with. [Effects of the Invention]

[0013] In the present disclosure, the resources allocated to the beam to be adjusted are adjusted by adjusting at least one item indicated by the request information for the beam to be adjusted so as to satisfy the allowable interference, which indicates the allowable value of interference given to each beam. This makes it possible to allocate appropriate resources to each beam without increasing physical resources. In addition, in the present disclosure, resources are allocated according to the request information while adjusting resources to satisfy the allowable interference, which makes it possible to allocate resources to each beam so as to satisfy the independent requirements of each service. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a diagram showing an example of a satellite communication system 100 to which satellite beam resource allocation according to a first embodiment is applied. [Figure 2] FIG. 1 is a configuration diagram of a resource adjustment device 101 according to a first embodiment. [Figure 3] FIG. 1 is a diagram showing an example of a case in which satellite beam resource allocation according to the first embodiment is performed by superimposing it on a multi-beam for shared services. [Figure 4]FIG. 10 is a diagram showing an example of beam resource allocation with multiple beams when satellite beam resource allocation according to the first embodiment is performed by superimposing it on a service-sharing multiple beam. [Figure 5] FIG. 2 is a diagram showing request information 20 according to the first embodiment. [Figure 6] FIG. 2 is a diagram showing an example of a method for extracting beams that may cause inter-beam interference according to the first embodiment. [Figure 7] FIG. 4 is a diagram showing information for extracting beams that may cause inter-beam interference according to the first embodiment. [Figure 8] FIG. 3 is a diagram showing the mutual interference relationship of inter-beam interference according to the first embodiment. [Figure 9] 4 is a flowchart of a satellite beam resource allocation process performed by the resource adjustment device 101 according to the first embodiment. [Figure 10] FIG. 2 is an explanatory diagram of bandwidth adjustment according to the first embodiment. [Figure 11] FIG. 2 is an explanatory diagram of bandwidth adjustment according to the first embodiment. [Figure 12] FIG. 10 is a configuration diagram of a resource adjustment device 101 according to a second embodiment. [Figure 13] FIG. 10 is an explanatory diagram of residual interference after satellite beam resource allocation according to the second embodiment. [Figure 14] FIG. 10 is an explanatory diagram of interference distribution within a beam after satellite beam resource allocation according to the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0015] Embodiment 1 ***Configuration Description*** An example of a satellite communication system 100 to which satellite beam resource allocation according to the first embodiment is applied will be described with reference to FIG. The communications satellite 1 forms service link beams 4-1 to 4-3 and a feeder link beam 7 to perform communications between any of the user earth stations 5-1 to 5-3 and the feeder link earth station 6. The communications satellite 1 is equipped with a repeater that relays signals received from the earth stations and transmits them to the earth stations. The communications satellite 1 performs beam formation using the DBF function. Therefore, the service link beams 4-1 to 4-3 are formed in any shape at any position within the service area of ​​the satellite communications system 100. The feeder link beam 7 may also be formed using the DBF function. However, since the installation position of the feeder link earth station 6 is generally fixed, the DBF function is not used to form the feeder link beam 7 here, and a beam with a fixed position and shape is applied.

[0016] It should be noted that a transmission beam and a reception beam are required for each of the service link beams 4-1 to 4-3 and the feeder link beam 7. However, for simplicity, the transmission beam and the reception beam are collectively shown as the service link beams 4-1 to 4-3 and the feeder link beam 7.

[0017] The communications satellite 1 is equipped with a channelizer function, and is capable of changing the frequency bandwidth allocated to each beam and the connection settings between beams.

[0018] The control earth station 2 is an earth station that controls the DBF function and channelizer function of the communication satellite 1. The control earth station 2 monitors the status of the communication satellite 1 by receiving telemetry. The control earth station 2 also transmits operational setting information for the DBF function and channelizer function by telecommand to set them. The control earth station beam 3 is a beam with a fixed position and shape that is used by the control earth station 2 to receive telemetry and transmit commands. As described above, the control earth station beam 3 also shows both the transmission beam and the reception beam. The control earth station 2 and the feeder link earth station 6, and the control earth station beam 3 and the feeder link beam 7 are shown separately, but the same earth station and the same beam may be used.

[0019] In Figure 1, the coverage areas of the service link beams 4-1 to 4-3 partially overlap each other. This indicates that if the same polarization and frequency are assigned to the service link beams 4-1 to 4-3, interference between beams will occur. Therefore, in order to avoid interference between beams in the case of the same polarization, it is necessary to assign different frequencies, as in frequency assignments 8-1 to 8-3.

[0020] In this embodiment, a method for allocating beam resources so that inter-beam interference falls within a tolerance will be described. A device that implements the satellite beam resource allocation method described below will be called a resource coordination device 101. Here, the satellite beam resource allocation method is implemented in a control earth station 2, and operation setting information for the DBF function and channelizer function is transmitted and set by telecommand. In other words, here, the control earth station 2 or a device provided in the control earth station 2 corresponds to the resource coordination device 101. However, the present invention is not limited to this, and the satellite beam resource allocation method described below may be implemented by the control earth station 2 and devices connected via a terrestrial network.

[0021] The result of the satellite beam resource allocation determined by the satellite beam resource allocation method is also required for the line control function that determines the frequencies to be assigned to the communication channels used by each user earth station 5 within the beam. This line control function is assumed to exist as a part of the function of the feeder link earth station 6. Therefore, it is assumed that the control earth station 2 and the feeder link earth station 6 are connected by a terrestrial network.

[0022] The configuration of resource adjustment apparatus 101 according to the first embodiment will be described with reference to FIG. The resource adjustment device 101 is a computer that adjusts resources to be allocated to each of a plurality of beams in a satellite communication system 100 that can control a plurality of beams. The resource adjustment device 101 includes the following hardware components: a processor 111, a memory 112, a storage 113, and a communication interface 114. The processor 111 is connected to other hardware components via signal lines and controls the other hardware components.

[0023] The processor 111 is an IC that performs processing. The processor 111 is, for example, a CPU, a DSP, or a GPU. The CPU stands for Central Processing Unit. The DSP stands for Digital Signal Processor. The GPU stands for Graphics Processing Unit.

[0024] The memory 112 is a storage device that temporarily stores data. Specific examples of the memory 112 include SRAM and DRAM. SRAM stands for Static Random Access Memory. DRAM stands for Dynamic Random Access Memory.

[0025] The storage 113 is a storage device that stores data. Specific examples of the storage 113 include an SSD or an HDD. SSD stands for Solid State Drive. HDD stands for Hard Disk Drive. The storage 113 may also be a portable recording medium such as an SD (registered trademark) memory card, CompactFlash (registered trademark), NAND flash, a flexible disk, an optical disk, a compact disk, a Blu-ray (registered trademark) disk, or a DVD. SD stands for Secure Digital. DVD stands for Digital Versatile. It is an abbreviation for Disk.

[0026] The communication interface 114 is an interface for communicating with external devices. Specific examples of the communication interface 114 include Ethernet (registered trademark), USB, and HDMI (registered trademark) ports. USB stands for Universal Serial Bus. HDMI stands for High-Definition Multimedia Interface.

[0027] The resource adjustment device 101 includes, as functional components, a resource allocation unit 121, a combination specification unit 122, and a resource adjustment unit 123. The functions of the functional components of the resource adjustment device 101 are realized by software. The storage 113 stores a program that realizes the function of each functional component of the resource adjustment device 101. This program is read into the memory 112 by the processor 111 and executed by the processor 111. In this way, the function of each functional component of the resource adjustment device 101 is realized.

[0028] 2 shows only one processor 111. However, there may be multiple processors 111, and the multiple processors 111 may cooperate to execute programs that realize the respective functions.

[0029] ***Explanation of Operation*** The operation of resource adjustment apparatus 101 according to the first embodiment will be described with reference to FIGS. The operation procedure of the resource adjustment device 101 according to the first embodiment corresponds to the resource adjustment method according to the first embodiment. Moreover, the program that realizes the operation of the resource adjustment device 101 according to the first embodiment corresponds to the resource adjustment program according to the first embodiment.

[0030] With reference to FIG. 3, a beam arrangement required for the satellite communication system 100 according to the first embodiment will be described. 3 shows that when a multi-beam 10 is deployed over the entire service area so that various services can be used in common, service link beams 4-1 to 4-3 are requested to be deployed as service-dedicated beams used for specific services. In such a case, it is necessary to prevent inter-beam interference between the multi-beam 10 and the service link beams 4-1 to 4-3.

[0031] In such a case, frequency allocation is performed as shown in FIG. Fig. 4(a) shows an example in which four beams 10-1 to 10-4 with two polarizations and two frequencies form clusters, which are units of frequency repetition, and the clusters are regularly arranged to form the multi-beam 10 of Fig. 3. In Fig. 4(a), frequency bands 11-1 to 11-4 are assigned to the beams 10-1 to 10-4 within the range of the system allocation band 12, which is the frequency band assigned to the satellite communication system 100. 4(b) shows an example of frequency allocation when a request is made to allocate a service link beam 4-4, which is a service-dedicated beam, from the state shown in FIG. 4(a). In FIG. 4(b), the frequency bands 11-3 and 11-4 in polarization 2 are narrowed to frequency bands 11-5 and 11-6, thereby ensuring an allocation allowable band 13. The frequency band 11-7 of the service link beam 4-4 is allocated within the allocation allowable band 13. Here, the allocation allowable band 13 is allocated for only one polarization (polarization 2). However, depending on the polarization of the service link beam requested to be allocated, the allocation allowable band 13 may be allocated for only another polarization (polarization 1) or for two polarizations (polarization 1 and polarization 2). In the following description, satellite beam resource allocation is performed within the allocation allowable band 13.

[0032] With reference to FIG. 5, the request information 20 input to the resource adjustment apparatus 10 according to the first embodiment will be described. The request information 20 is set for each service link beam for which placement is requested. Each request information 20 is given information on beam information 21, request value 22, priority 23, and adjustment possibility 24. The beam information 21 is given four pieces of information: allowable interference, beam pattern, beam frequency, and bandwidth. Of the four pieces of information, allowable interference is required information that must always be specified. The decibel value of the carrier power to interference power ratio (C / I) is given as the required value 22 for the allowable interference. The priority 23 and the adjustment possibility 24 for the allowable interference are information that is not included in the allowable interference (information that is not given). The identification number of the beam pattern formed by the DBF is assigned to the beam pattern requirement value 22. The beam pattern indicates a set of polarization, phase and amplitude excitation coefficients, and gain information for each frequency interval of the beam formed by the DBF using the set. The beam frequency is information that limits the range of frequencies that can be assigned to a beam. For example, a lower limit and an upper limit of the frequency are given as the required value 22 for the beam frequency. The bandwidth is the frequency bandwidth allocated to the beam. The required value 22 for the bandwidth is given as a bandwidth within the range of the lower limit to the upper limit indicated by the frequency. In other words, there is a relationship of "bandwidth≦upper limit frequency−lower limit frequency".

[0033] For the beam pattern, beam frequency, and bandwidth, information on priority 23 and whether or not adjustment is possible 24 is also given. Priority 23 is the priority related to the adjustment of beam pattern, beam frequency, and bandwidth. Priority is the priority between each beam information closed within a beam. In Figure 5, the higher the priority value, the lower the priority of the beam information, and the lower the priority, the earlier the order of adjustment and change of the requested value in satellite beam resource allocation. Adjustability 24 indicates whether the requested value can be adjusted or changed in satellite beam resource allocation. In FIG. 5, only the bandwidth is adjustable, and the beam pattern and beam frequency are designated as non-adjustable. Adjustability 24 may be expressed by the value of priority 23. For example, when the bandwidth priority is designated as a two-digit decimal number such as "10," it may be designated as adjustable, and when a single-digit decimal number such as the beam pattern and beam frequency is designated as non-adjustable.

[0034] Furthermore, unlike the allowable interference, the beam pattern, beam frequency, and bandwidth are information that are not necessarily provided as the request information 20. If the beam pattern, beam frequency, and bandwidth are not provided, predetermined values ​​are applied.

[0035] In the first embodiment, an example will be described in which only the bandwidth of each beam is given as adjustable, and the beam pattern and beam frequency are given as non-adjustable, as shown in FIG.

[0036] A method for extracting beams that may cause inter-beam interference according to the first embodiment will be described with reference to FIG. Here, beams that may cause inter-beam interference are extracted using gain information of beams linked to the beam pattern given as the requirement information 20 for each beam. The possibility of inter-beam interference means that, for beams of the same polarization, inter-beam interference will occur if the same frequency is assigned, but will not occur if different frequencies are assigned, regardless of the beam frequency and bandwidth given as the requirement information 20. 6(a) shows how beams that may cause inter-beam interference are identified using gain information for each beam at interference determination point 30, which defines the coordinates of the entire service area as seen from the antenna using grid points. As an example, we will explain inter-beam interference between downlink (transmitted from the satellite) beam 31-1 and beam 31-2. In the case of downlink, radio waves of the frequency used are emitted over the entire coverage area of ​​the beam. In contrast, the uplink (received by satellite) differs from the downlink in that the amount of interference when received by the satellite varies depending on the combination of the location and frequency of the earth station that emits the interference and the interfered with radio waves. However, if we consider the amount of interference as the worst case scenario, it is possible to calculate interference using a similar approach.

[0037] In Figure 6(a), one of the interference specification points 30, interference specification point 30-1, is located at a position where the cover areas of beams 31-1 and 31-2 overlap. When viewed from beam 31-1, interference specification point 30-1 is located near the center of the beam, so a relatively strong radio wave is received. On the other hand, when viewed from beam 31-2, interference specification point 30-1 is located at the edge of the cover area, so a relatively weak radio wave is received. Here, it is assumed that beam 31-1 and beam 31-2 are of the same polarization. In this case, if frequency band 40-1 is assigned to beam 31-1 and frequency band 40-2 is assigned to beam 31-2 as shown in (b) of Fig. 6, the frequency bands overlap, resulting in inter-beam interference. However, at interference reference point 30-1, in an earth station belonging to beam 31-1, the desired signal is stronger than the interference signal from beam 31-2. On the other hand, in an earth station belonging to beam 31-2, the desired signal is weaker than the interference signal from beam 31-1. Therefore, the C / I value varies depending on the beam to be evaluated and the location of the evaluation point. Therefore, in order to evaluate whether service can be provided within the coverage area of ​​each beam, it is necessary to evaluate the C / I for each beam to be evaluated and each interference reference point using information on each beam pattern.

[0038] In FIG. 6(a), the interference specification point 30-2 is within the coverage area of ​​beam 31-1 but outside the coverage area of ​​beam 31-2. Even in this case, beam 31-1 is subject to interference from beam 31-2. Therefore, it is subject to C / I evaluation. Furthermore, in FIG. 6(a), the interference specification point 30-3 is outside the coverage area of ​​beam 31-1 and beam 31-2, but considering the possibility of additional beams not shown here, it is possible to calculate the interference wave power I described below.

[0039] A method of C / I evaluation according to the first embodiment will be described with reference to FIG. 7 shows the gain obtained from the information of each beam pattern, broken down into each interference reference point, polarization, and frequency interval (F1 to Fk). The reason for breaking down the gain into each frequency interval is that the gain of a beam generally has frequency characteristics, and even if gain adjustment is performed to achieve as flat a characteristic as possible, some differences will occur. Although it is possible to reduce the amount of evaluation calculation described below by ignoring such frequency characteristics, in the first embodiment, the evaluation is performed for each frequency interval.

[0040] Using the information decomposed as shown in Figure 7, it is possible to calculate the C / I assuming that each beam uses frequency F1. For example, suppose you want to receive a desired signal on beam 1 of polarization 1 at interference reference point n. In this case, to evaluate the C / I for frequency F1, the F1 gain 50-1 of beam 1 is set as the desired signal power C, and the F1 gain 50-2 of beam 2 of the same polarization, and the F1 gain 50-3 of beam m are added together to determine the interference signal power I. The reason why the gain is treated as power is because it is assumed that the same transmission power is input to each beam. However, if the power allocated to each beam differs apart from the gain according to the DBF phase and amplitude excitation coefficients, the difference in power allocation can be taken into account. Also, in Figure 7, the F1 gains 50-4 and 50-5 of beam p and beam q, which have polarizations different from beam 1, can be added to the interference power I taking into account the cross polarization discrimination XPD of beam 1. However, satellite communication systems are generally designed so that the effect of XPD is negligible, so it will be ignored here.

[0041] In this way, the C / I for each frequency calculated for each beam is compared with the allowable interference for each beam described in Figure 5. This determines whether there is inter-beam interference (excessive interference) that exceeds the allowable interference. Note that this determination does not take into account the frequency and bandwidth described in Figure 5. If the result of the inter-beam interference determination indicates excessive interference in one or more frequency sections, allocating frequency bands as shown in Figure 6(b) may result in inter-beam interference. Therefore, frequency bands are allocated so that they do not overlap. Here, according to the C / I calculation method explained in Figure 7, the beam being evaluated is subject to some interference from other beams of the same polarization. Therefore, it is best to allocate frequency bands so that they do not overlap among all beams of the same polarization.

[0042] However, when there is excessive interference in the beam to be evaluated, the method of allocating frequency bands so that they do not overlap among all beams of the same polarization results in inefficient frequency band allocation. The above method also includes combinations other than the beam to be evaluated that do not result in excessive interference, and it is considered that there is no problem with allocating frequency bands so that they overlap in such combinations. Therefore, in the first embodiment, in order to further improve the efficiency of frequency band allocation, combinations of two or more beams that will cause excessive interference are identified, and frequency bands are allocated so that they do not overlap among the combinations of beams that will cause excessive interference.

[0043] When the following two conditions, Condition 1 and Condition 2, are simultaneously satisfied, it is determined that there is excessive interference between the beam to be evaluated and the beam to be compared. (Condition 1) The C / I exceeds the allowable interference in one or more frequency sections at one or more interference specification points in the beam being evaluated. (Condition 2) At the interference specification point and frequency interval where the C / I exceeds the allowable interference, the individual comparison value indicating the interference from the beam being compared to the beam being evaluated exceeds the individual allowable value obtained by subtracting the reference value M from the allowable interference for the beam being evaluated. In other words, interference from the beam being compared is greater than or equal to allowable interference - M. Here, the comparison beam is one beam other than the evaluation beam. The interference from the comparison beam to the evaluation beam is C / I, where the gain of the evaluation beam is the desired signal power C and the gain of the comparison beam is the interference signal power I. The reference value M is a predetermined value.

[0044] In order to reduce the amount of calculation, a method of determining whether or not there is excessive interference between two beams may be used in which the gain contours of each beam are used and it is determined that there is inter-beam interference when the contours between two beams intersect or touch.For simplicity, the state of beam interference will be represented schematically using contours below.

[0045] In addition to extracting excessive interference between two beams, there is also the possibility of excessive interference between multiple beams other than two beams. Therefore, combinations of beams that have excessive interference with each other are identified and grouped. Fig. 8 shows an example of beams that interfere with each other. Fig. 8(a) shows an image of the beam arrangement. Fig. 8(a) also shows a schematic diagram of the excessive interference that occurs when contours intersect or touch, and shows that not only is there excessive interference between beam 60-1 and beam 60-2, but also that beams 60-2, 60-3, and 60-4 interfere with each other. On the other hand, Fig. 8(a) shows that there is no excessive interference between beam 60-1 and beams 60-3 and 60-4. Such a group of beams that interferes excessively with one another is called a combination with a mutual interference relationship and is shown in Figure 8(b). Figure 8(b) shows that, for example, if beam 60-2 is viewed as an interfered beam, beams 60-1, 60-3, and 60-4 are interfering beams. Looking at this in terms of mutual interference relationships, as mentioned above, beams 60-1 and 60-2 form combination 61-1, and beams 60-2, 60-3, and 60-4 form combination 61-2. In other words, the beam arrangement in Figure 8(a) shows that only two combinations, 61-1 and 61-2, exist. The resource adjustment device 101 extracts combinations of beams that have such a mutual interference relationship and allocates frequency bands so that there is no overlap between beams in the combinations that have the mutual interference relationship. This makes it possible to allocate frequency bands efficiently without restricting the allocation of frequency bands more than necessary.

[0046] With reference to FIG. 9, the satellite beam resource allocation process performed by the resource adjustment apparatus 101 according to the first embodiment will be described. 9 shows the process of allocating frequency bands after the above-described C / I calculation and identification of combinations with mutual interference relationships. As a premise for the process in FIG. 9, the resource allocation unit 121 acquires request information 20. Then, the resource allocation unit 121 allocates resources to each of a plurality of beams in accordance with the beam pattern, beam frequency, and bandwidth indicated by the request information 20.

[0047] In step S1, the combination identifying unit 122 performs the C / I calculation described above to identify combinations that have a mutual interference relationship, thereby identifying combinations of beams that have excessive interference with each other. In step S2, the resource adjustment unit 123 sets the state to "Bandwidth reduction in progress." At this point, all beams are set as indicated in the request information 20. Therefore, 100% of the bandwidth in the request information 20 is set as the bandwidth for all beams.

[0048] In step S3, the resource adjustment unit 123 selects a combination to be adjusted from among the combinations identified in step S1 that have not yet been selected. In step S4, the resource adjustment unit 123 provisionally allocates the beam with the lowest frequency in the combination to be adjusted to the currently allocated frequency band. In step S5, the resource adjustment unit 123 attempts to provisionally allocate the remaining beam in the combination to be adjusted to the currently allocated frequency band. For example, the resource adjustment unit 123 attempts to provisionally allocate beams in the currently allocated frequency band in order from the beam with the lowest frequency. In step S6, the resource adjustment unit 123 determines whether or not the beam has been tentatively arranged. If there is frequency interference with an already arranged beam, the resource adjustment unit 123 determines that the beam cannot be tentatively arranged. If the resource adjustment unit 123 has tentatively arranged, the process proceeds to step S7. On the other hand, if the resource adjustment unit 123 has not tentatively arranged, the process proceeds to step S11. In step S7, the resource adjustment unit 123 determines whether or not the temporary arrangement of all beams in the combination to be adjusted has been completed. If the temporary arrangement of all beams has been completed, the resource adjustment unit 123 proceeds to step S8. On the other hand, if there are beams for which the temporary arrangement has not been completed, the resource adjustment unit 123 returns the process to step S5 and attempts to perform the temporary arrangement of the next beam.

[0049] In step S8, the resource adjustment unit 123 determines whether all of the combinations identified in step S1 have been selected as combinations to be adjusted in step S3. If all of the combinations have been selected as combinations to be adjusted, the resource adjustment unit 123 proceeds to step S9. At this time, the resource adjustment unit 123 sets the status to bandwidth reduction completed. On the other hand, if there are any combinations that have not been selected as combinations to be adjusted, the resource adjustment unit 123 returns the process to step S3 and selects a new combination.

[0050] In step S9, the resource adjustment unit 123 determines whether there is sufficient bandwidth. If there is sufficient bandwidth, the resource adjustment unit 123 proceeds to step S16. On the other hand, if there is not sufficient bandwidth, the resource adjustment unit 123 proceeds to step S10 and ends the adjustment process.

[0051] In step S11, the resource adjustment unit 123 determines whether the state is set to "bandwidth reduction in progress." If the state is set to "bandwidth reduction in progress," the resource adjustment unit 123 proceeds to the process in step S13. On the other hand, if the state is not set to "bandwidth reduction in progress," the resource adjustment unit 123 proceeds to the process in step S12. If the state is not set to "bandwidth reduction in progress," the process in step S11 is executed when the bandwidth is increased in step S16, which will be described later. In step S12, the resource adjustment unit 123 returns the bandwidth to the state before the increase, proceeds to the process in step S10, and ends the adjustment process. In step S13, since it is determined that tentative allocation is not possible, the resource adjustment unit 123 reduces the bandwidth to be allocated. Here, the resource adjustment unit 123 reduces the bandwidth by the reference rate for not only the beam included in the combination to be adjusted but also all beams. In step S14, the resource adjustment unit 123 determines whether the reduction in step S13 has resulted in a reduction exceeding a predetermined reduction rate. If the reduction has occurred beyond the reduction rate, the resource adjustment unit 123 proceeds to step S15, determines that bandwidth cannot be allocated, and determines that the adjustment has failed. If the adjustment has failed, the resource adjustment unit 123 prompts the user to reconsider the contents of the request information 20, etc. On the other hand, if the reduction has not occurred beyond the reduction rate, the resource adjustment unit 123 proceeds to step S3, and starts over from selecting the combination to be adjusted.

[0052] In step S16, since there is a surplus in the bandwidth, the resource adjustment unit 123 increases all beams or beams whose bandwidth can be increased by the reference amount. Then, the resource adjustment unit 123 returns the process to step S3 and redoes the tentative allocation for each combination.

[0053] The processing from step S2 to step S16 in FIG. 9 will be specifically described with reference to FIGS. FIG. 10(a) shows a state in which the frequency and bandwidth are set for each of the four beams 60-1 to 60-4 shown in FIG. 8 in accordance with the request information 20 described in FIG. 5. The frequency and bandwidth requested for beam 60-1 correspond to the lower and upper frequency limits indicated by requested frequency band 62-1, and the bandwidth shown is, for example, the entire band between the lower and upper frequency limits. Similarly, the frequency and bandwidth requested for beam 60-2 are indicated by requested frequency bandwidth 62-2. Similarly, the frequency and bandwidth requested for beam 60-3 are indicated by requested frequency bandwidth 62-3. Similarly, the frequency and bandwidth requested for beam 60-4 are indicated by requested frequency bandwidth 62-4. Note that these four beams will be described assuming that only the bandwidth is adjustable, as shown in Fig. 5. Furthermore, Fig. 10(a) shows that beam 60-1 and beam 60-2 belong to combination 61-1, which has a mutual interference relationship, as explained in Fig. 8, and that required frequency bands 62-1 and 62-2 thereof cause frequency interference, so that the allocation of frequency bands needs to be adjusted.

[0054] Fig. 10(b) shows that the provisional reduction bands 63-1 and 63-2 are allocated in accordance with the flowchart shown in Fig. 9. In step S2 of Fig. 9, the combination identification unit 122 applies the requested values ​​as they are and sets the operating state to a bandwidth reduction in progress state in order to confirm whether the requested frequency bands 62-1 and 62-2 can be allocated as they are. In step S3, the resource adjustment unit 123 selects the combination 61-1 and thereafter adjusts the frequency bands for the beams of this combination 61-1. In step S4, the resource adjustment unit 123 temporarily allocates the request frequency band 62-1, which has the lower frequency, of the request frequency band 62-1 and the request frequency band 62-2. Subsequently, in step S5, the resource adjustment unit 123 attempts temporary allocation of the request frequency band 62-2. Since the request frequency band 62-2 interferes with the request frequency band 62-1 as shown in (a) of FIG. 10, the resource adjustment unit 123 determines in step S6 that temporary allocation is not possible and proceeds to step S11. In step S11, the resource adjustment unit 123 is in the bandwidth reduction state set in step S2, so the process proceeds to step S13. In step S13, the resource adjustment unit 123 reduces the bandwidth for all beams, not just the requested frequency bands 62-1 and 62-2, by a predetermined reference rate, and retries from step S3. However, if the reduction in step S13 exceeds the reduction rate predetermined in step S14, the bandwidth adjustment fails as allocation is not possible. If this fails, the satellite beam resource allocation method determines that adjustment is not possible, so the request information 20 is reviewed on the requesting side of each beam. By retrying from step S3, bandwidth reduction via step S13 is performed until it is determined that all requested beams are tentatively arranged in step S6. The determination that tentative arrangement is possible here means that all requested beams are tentatively arranged after also executing steps S7 and S8, which will be described later.

[0055] Figure 10(b) shows that it is determined in step S6 that provisional placement is possible by reducing the required frequency band of each beam by, for example, 30%. Steps S3, S4, S5, S6, and S7 at this time will be explained using Figures 9 and 10(b). Since the retry is from step S3, similarly to the above, combination 61-1 is selected, and provisional reduction bands 63-1 and 63-2 corresponding to beams 60-1 and 60-2 are provisionally arranged. The bandwidths of provisional reduction bands 63-1 and 63-2 are assumed to be bandwidths reduced to 30% of the requested frequency band, as described above. In step S4, because the frequency range of the requested frequency band 62-1 includes lower frequencies than the frequency range of the requested frequency band 62-2, the resource adjustment unit 123 provisionally allocates the provisional reduction band 63-1 from the lower limit frequency 70-1, which corresponds to the lower limit of the frequencies provided in the request information 20, and the frequencies up to the upper limit frequency 70-2 have been provisionally allocated. As a result, in the combination 61-1, the provisional reduction band is allocated to frequencies higher than the upper limit frequency 70-2. In the next step S5, the resource adjustment unit 123 allocates the temporary reduction band 63-2 within the frequency range of the requested frequency band 62-2. This corresponds to the frequencies (lower limit, upper limit) in the request information 20 in Fig. 5 being given as non-adjustable, and the given frequency lower limit and upper limit being observed. Here, the frequency lower limit of the requested frequency band 62-2 corresponds to the lower limit frequency 70-3, which is a higher frequency than the already allocated upper limit frequency 70-2, so the resource adjustment unit 123 temporarily allocates the temporary reduction band 63-2 from the lower limit frequency 70-3, and its upper limit frequency 70-4 is determined. At this point, the determination in step S6 is that tentative allocation is possible. In the following step S7, the resource adjustment unit 123 proceeds to step S8 because there are no more beams in combination 61-1. In step S8, the resource adjustment unit 123 returns the process to step S3 because combination 61-2 remains and tentative allocation has not yet been completed, and therefore tentative allocation is performed on the tentative reduced band of the beams belonging to combination 61-2.

[0056] FIG. 11 is a diagram illustrating the operation from step S-3 for the provisional reduction band of the beams belonging to combination 61-2. The operation will be described using FIGS. 9 and 11. (a) of FIG. 11 shows that combination 61-2 is selected in step S3. Beams 60-2, 60-3, and 60-4, which are described in FIG. 8, belong to combination 61-2, and their requested frequency bands 62-2, 62-3, and 62-4 are also shown. (b) of FIG. 11 shows provisional reduction bands 63-2, 63-3, and 63-4 in combination 61-2, in which the provisional reduction bands of all beams have been reduced as described in step S13 of FIG. 9. In step S4, as described above, the resource adjustment unit 123 provisionally allocates provisional reduction band 63-3 for requested frequency band 62-3, which has a low frequency, from the lower limit frequency 71-1, and determines its upper limit frequency 71-2. In the next step S5, the resource adjustment unit 123 temporarily allocates the provisional reduction band 63-4 for the requested frequency band 62-4, which has the next lowest frequency, from the frequency adjacent to the upper limit frequency 71-2 to obtain the upper limit frequency 71-3. However, as mentioned above, the upper limit frequency 71-3 exceeds the lower limit frequency 70-3 of the provisional reduction band 63-2 that has already been temporarily allocated in another combination 61-1 in FIG. 10(b). Therefore, if left as is, the frequencies will overlap and interfere. To resolve this interference, provisional allocation is attempted while moving the provisionally allocated provisional reduction band.

[0057] FIG. 11(c) shows that the provisionally allocated provisional reduction band 63-2 is moved (relocated) to the higher frequency side to eliminate interference, resulting in a new provisional reduction band 63-2-1. The resource adjustment unit 123 determines the upper limit frequency 71-3 by tentatively allocating the tentative reduction band 63-4. At this time, the resource adjustment unit 123 rearranges the tentative reduction band 63-2, and determines in step S6 that the tentative allocation is possible. In step S7, the resource adjustment unit 123 returns the process to step S5 to rearrange the remaining tentative reduction band 63-2, and temporarily allocates the tentative reduction band 63-2 as the tentative reduction band 63-2-1 starting from the frequency consecutive to the upper limit frequency 71-3. As a result, in step S6, the resource adjustment unit 123 determines that the tentative allocation of the tentative reduction band 63-2-1, the tentative reduction band 63-3, and the tentative reduction band 63-4 of all three beams belonging to the combination 61-2 has been completed. In step S8, it is determined that all beams belonging to all two combinations shown in Figure 10(a) and Figure 11(a) have been provisionally arranged, and the operating state set in step S2 is set to bandwidth reduction complete.

[0058] In the next step S9, the resource adjustment unit 123 determines whether there is a surplus in the allocatable bandwidth in each combination. This is because, in step S13, the bandwidth is reduced in units of the reference ratio, and the provisional reduced bandwidth is allocated as described above, so there is a possibility that the reduction amount is greater than the minimum unit of frequency allocation. In other words, there is a possibility that there is an allocatable bandwidth remaining. For example, in (c) of FIG. 11, there is an allocatable bandwidth remaining in the high frequency portion of the requested frequency bandwidth 62-2. If there is no allocatable bandwidth remaining, the resource adjustment unit 123 proceeds to step S10 and completes the adjustment. On the other hand, if there is an allocatable bandwidth remaining after the provisional reduced-band allocation, the resource adjustment unit 123 proceeds to step S16 to minimize the remaining allocatable bandwidth and optimize the frequency band allocation as a whole. In step S16, the resource adjustment unit 123 increases the bandwidth of each provisional reduced band by a predetermined reference amount. Then, the resource adjustment unit 123 returns to step S3 and allocates the provisional reduced band. However, in step S16, the bandwidth for each provisional reduced band is increased for all beams. However, even if the bandwidth of a specific beam within a combination cannot be increased, if the bandwidth of other beams can be increased, the bandwidth of the beams that can be increased is increased. For example, as shown in FIG. 11(c), the allocatable bandwidth remaining in the high-frequency portion of the requested frequency bandwidth 62-4 is smaller than the allocatable bandwidth remaining in the high-frequency portion of the requested frequency bandwidth 62-2. By increasing the provisional reduction band 63-3 and the provisional reduction band 63-4 by the reference amount, even if there is no remaining band in the high frequency portion of the requested frequency bandwidth 62-4 and it becomes impossible to increase the bandwidth of the provisional reduction band 63-3 and the provisional reduction band 63-4, if the provisional reduction band 63-2 can be increased, the provisional reduction band 63-3 and the provisional reduction band 63-4 are not increased, and the increase of the provisional reduction band 63-2 continues, and the process returns to step S3. In this case, the same is applied to beams in other combinations, i.e., the provisional reduction band 63-1 in (b) of Figure 10, and after returning to step S3, a determination is made in step S6 as to whether the provisional reduction band can be increased as an overall resource adjustment across each combination. If it is determined in step S6 that increasing the provisional reduction bandwidth makes provisional allocation impossible, the resource adjustment unit 123 proceeds to step S11. Here, unlike the description of step S11 above, the resource adjustment unit 123 proceeds to step S12 because the operating state is bandwidth reduction complete. In step S12, the resource adjustment unit 123 cancels the bandwidth increase of the provisional reduction bandwidth performed immediately before in step S16, and applies the allocation of the provisional reduction bandwidth that was provisionally possible before, thereby completing the adjustment.

[0059] ***Effects of the First Embodiment*** As described above, the resource adjustment apparatus 101 according to the first embodiment adjusts the resources allocated to the beam to be adjusted by adjusting at least one of the items indicated by the request information for the beam to be adjusted so as to satisfy the allowable interference indicating the allowable value of interference given to each beam. This makes it possible to allocate appropriate resources to each beam without increasing physical resources.

[0060] The resource adjustment device 101 according to the first embodiment adjusts the items of beam pattern, beam frequency, and bandwidth in descending order of priority for the beam to be adjusted. Also, the resource adjustment device 101 according to the first embodiment adjusts the items of beam pattern, beam frequency, and bandwidth that are adjustable for the beam to be adjusted. This makes it possible to adjust resources as intended.

[0061] The resource adjustment apparatus 101 according to the first embodiment adjusts resources for each combination of two or more beams that cause excessive interference, thereby enabling efficient resource adjustment.

[0062] ***Other Configurations*** <Variation 1> In the first embodiment, an example has been shown in which only the bandwidth is "adjustable" and the provisional reduced bandwidth of each beam is adjusted, as shown in Fig. 5. However, it is also possible to adjust not only the bandwidth but also the frequency. For example, assume that there is a beam for which the priority of beam frequency is higher than that of bandwidth, as shown in Fig. 5, but for which request information 20 has been given that not only bandwidth but also beam frequency is "adjustable." For this beam, the resource adjustment unit 123 initially attempts temporary allocation as the requested frequency bandwidth shown in Figs. 10 and 11 within the range of the given lower and upper limits of frequency. However, when the resource adjustment unit 123 determines that temporary allocation of the temporary reduced bandwidth of each beam cannot be performed by simply adjusting the bandwidth as shown in the flow of Fig. 9, rather than determining that the adjustment has failed, the resource adjustment unit 123 replaces the lower and upper limits of the allocatable frequency with the lower and upper limits of the allocation allowable band shown in Figs. 10 and 11 and attempts temporary allocation again. Also, assume that there is a beam for which the priority of the beam frequency is lower than the bandwidth, and the bandwidth and beam frequency are set as "adjustable" and the request information 20 is given. For this beam, the resource adjustment unit 123 attempts a tentative allocation by replacing the lower and upper limits of the frequency with the lower and upper limits of the allocation allowable band before reducing the bandwidth as in step S13.

[0063] <Variation 2> In the first modification, an example was shown in which the bandwidth and the beam frequency are "adjustable." However, it is also possible to adjust the beam pattern indicated by the request information 20. In order to adjust the beam pattern, a plurality of selectable beam patterns must be provided as the beam pattern in the request information 20. The resource adjustment unit 123 preferentially selects and adjusts the pattern that has the largest coverage area among the plurality of provided beam patterns. When changing the beam pattern in adjusting the beam pattern, the resource adjustment unit 123 performs calculations by returning to the method of extracting beams that may cause inter-beam interference shown in FIG. 6. It is also possible to increase the priority of adjusting the beam pattern of the request information 20. The resource adjustment unit 123 may adjust the beam pattern, beam frequency, and bandwidth in order according to the priority given to each beam.

[0064] <Variation 3> In the first embodiment, no priority is applied between beams, and it is assumed that all requested beams have the same priority. However, it is also possible to allocate satellite beam resources taking into account the priority between beams. For example, if one of the required beams is for defense purposes, it is conceivable that beam resource allocation will be prioritized over other beams. Also, satellite communications may be used as a means of communication when terrestrial communication networks are unavailable during disasters, etc. In such emergencies, satellite communications will be used as a means of communication for lifesaving purposes, so it is conceivable that beam resource allocation will be prioritized over other beams. Furthermore, it is conceivable that beam usage fees may be set in stages for services that provide beams, and when a beam with a higher usage fee is used, beam resource allocation will be given a higher priority. For this reason, the resource adjustment device 101 is able to set priorities for the request information 20 in Fig. 5. The resource allocation unit 121 allocates beam resources starting with the beam with the highest priority so that the allocation of resources for a beam with a lower priority does not affect the results of the allocation of resources for a beam with a higher priority. That is, for beams with a lower priority, the resource allocation unit 121 allocates resources within the range of beam resources remaining as a result of the resource allocation for beams with a higher priority. That is, for beams with a lower priority, the resource allocation unit 121 allocates resources within the range of beam resources remaining after adjustment by the resource adjustment unit 123 for beams with a higher priority is completed. If the resource adjustment unit 123 determines that allocation is not possible within the range of the remaining beam resources, it reviews the request for the beams with the priority levels that cannot be allocated.

[0065] <Variation 4> In the first embodiment, each functional component is realized by software. However, as a fourth modification, each functional component may be realized by hardware. The following describes the differences between the first embodiment and the fourth modification.

[0066] When each functional component is realized by hardware, the resource adjustment device 101 includes an electronic circuit instead of the processor 111, the memory 112, and the storage 113. The electronic circuit is a dedicated circuit for realizing the functions of each functional component, the memory 112, and the storage 113.

[0067] Possible electronic circuits include single circuits, composite circuits, programmed processors, parallel programmed processors, logic ICs, GAs, ASICs, and FPGAs. GA stands for Gate Array. ASIC stands for Application Specific Integrated Circuit. FPGA stands for Field-Programmable Gate Array. Each functional component may be realized by one electronic circuit, or each functional component may be realized by distributing it among a plurality of electronic circuits.

[0068] <Variation 5> As a fifth modification, some of the functional components may be realized by hardware, and other functional components may be realized by software.

[0069] The processor 111, memory 112, storage 113, and electronic circuitry are collectively referred to as a processing circuit. In other words, the functions of the respective functional components are realized by the processing circuit.

[0070] Furthermore, the term "unit" in the above description may be read as a "circuit," "step," "procedure," "process," or "processing circuit."

[0071] Embodiment 2 The second embodiment differs from the first embodiment in that the amount of remaining interference is specified. In the second embodiment, this difference will be explained, and explanation of the same points will be omitted.

[0072] ***Configuration Description*** The configuration of resource adjustment apparatus 101 according to the second embodiment will be described with reference to FIG. 2 in that the resource adjustment device 101 includes a residual interference identifying unit 124 as a functional component. The residual interference identifying unit 124 identifies a distribution of residual interference, which is interference that remains when using resources adjusted by the resource adjustment unit 123. The function of the residual interference identifying unit 124 is realized by software or hardware, like the other functional components.

[0073] ***Explanation of Operation*** As explained in the first embodiment, by adjusting the bandwidth of each beam within a combination that has a mutual interference relationship, frequency interference can be avoided within each combination. However, although there is no frequency interference exceeding the allowable interference between beams that do not have a mutual interference relationship, there is still some interference remaining. This remaining interference, or residual interference, will be explained using Figure 13. Figure 13(a) is the same as Figure 8(a) and shows an image of beam arrangement. In this example of beam arrangement, beam 60-1 and beam 60-3, which are different combinations that have a mutual interference relationship, do not exceed the allowable interference of each beam. However, as shown in Figure 13(b), residual interference due to overlapping band 80-1 exists in the provisionally reduced band between beam 60-1 and beam 60-3. Similarly, residual interference due to overlapping band 80-2 exists in the provisionally reduced band between beam 60-1 and beam 60-4. Therefore, when communication is performed at the frequency of these overlapping bands 80-1 or 80-2, the amount of interference is greater than when communication is performed at a frequency other than the overlapping band, affecting communication quality.

[0074] FIG. 14 is a diagram showing an interference distribution after the provisional reduction bands 63-1, 63-3, and 63-4 are assigned to the beams 60-1, 60-3, and 60-4. Interference distribution 90 shows the interference distribution in the provisional reduction band 63-1 of beam 60-1. While the interference distribution is depicted in a simplified form here, it is assumed that the C / I of each beam is calculated for each interference point and frequency interval using the gain of each beam. However, in the explanation of FIG. 6, the C / I of beams of the same polarization when the same frequency is assigned is calculated as the "possibility of inter-beam interference" without taking into account the frequency and bandwidth provided in request information 20. Therefore, when a provisional reduction band is assigned to each beam, as shown in FIG. 13(b), the C / I value changes. Therefore, when a provisional reduction band is assigned to each beam, the combination identification unit 122 recalculates the C / I of each beam. This enables interference evaluation when frequencies are assigned to communication channels. The calculation method is the same as described above, and therefore a detailed description is omitted. However, the gain of the frequency interval of each beam in FIG. 6 is treated as a valid value in the frequency interval of the provisional reduction band assigned to each beam, and recalculated.

[0075] Returning to the description of FIG. 14 , the residual interference identifying unit 124 identifies the distribution of residual interference using the recalculated C / I. The residual interference band 91-1 does not overlap with the provisional reduction band 63-3 and the provisional reduction band 63-4. Therefore, the residual interference identifying unit 124 identifies the residual interference as "none." The residual interference band 91-2 overlaps with the provisional reduction band 63-3, but since the beams 60-1 and 60-3 are the furthest apart as shown in FIG. 13( a), the influence of interference is considered to be small. Therefore, the residual interference identifying unit 124 identifies the residual interference as "small." Furthermore, the residual interference band 91-3 overlaps with the provisional reduction band 63-4, and the beams 60-1 and 60-4 are slightly closer to each other as shown in FIG. 13( a). Therefore, the residual interference identifying unit 124 identifies the residual interference as "medium."

[0076] The residual interference identification unit 124 provides the distribution of residual interference in the assigned frequency band for each beam and interference control point to the channel control function, which determines the frequency to be assigned to the communication channel used by each user earth station 5 within the beam. The channel control function is a function of the feeder link earth station 6, as explained in FIG. 1. As a result, if the position of the user earth station 5 can be identified, the channel control function can determine the C / I value at the interference control point closest to the user earth station 5. Therefore, the channel control function can select and determine the frequency of the communication channel to be assigned to the user earth station 5 in accordance with the QoS required for the communication channel of the user earth station 5. QoS stands for Quality of Service. If the position of the user earth station 5 cannot be identified, the C / I value at each interference-specifying point may be extracted for each frequency section, and the average, maximum, or minimum value may be calculated and used as the interference distribution.

[0077] ***Effects of the Second Embodiment*** As described above, the resource adjustment apparatus 101 according to the second embodiment specifies the distribution of residual interference in the assigned frequency band for each beam and interference control point, and provides the distribution to the channel control function. This makes it possible to select and determine the frequency of the communication channel to be assigned to the user earth station 5 in accordance with the QoS required for the communication channel of the user earth station 5.

[0078] Various aspects of the present disclosure are summarized below as appendices. (Appendix 1) A resource adjustment device for adjusting resources allocated to each of a plurality of beams in a satellite communication system capable of controlling the plurality of beams, a resource allocation unit that allocates resources to each of the plurality of beams in accordance with request information given for each of the plurality of beams, the request information indicating items such as a beam pattern indicating polarization, phase, and amplitude excitation coefficients, beam frequencies indicating upper and lower limit frequencies, and frequency bandwidth; a resource adjustment unit that adjusts resources allocated to a beam to be adjusted by adjusting at least one item indicated by the request information for a beam to be adjusted among the plurality of beams so that the beam satisfies an allowable interference indicating an allowable value of interference given to each beam; A resource adjustment device comprising: (Appendix 2) For each of the beams, a priority is set for the beam pattern, the beam frequency, and the bandwidth; The resource adjustment unit adjusts the items of the beam pattern, the beam frequency, and the bandwidth in order of decreasing priority for the beam to be adjusted. 2. A resource coordination device as described in Supplementary Note 1. (Appendix 3) For each of the beams, whether or not the beam pattern, the beam frequency, and the bandwidth are adjustable is set, The resource adjustment unit adjusts the adjustable item in the beam to be adjusted among the items of the beam pattern, the beam frequency, and the bandwidth. 3. A resource adjustment device according to claim 1 or 2. (Appendix 4) The resource adjustment device further a combination identifying unit that identifies a combination of two or more beams that interfere with each other from the plurality of beams; Equipped with The resource adjustment unit sets each combination identified by the combination identification unit as a target combination, and adjusts the bandwidth of at least one beam included in the target combination as the beam to be adjusted so that frequency bands assigned to beams included in the target combination do not overlap. 4. A resource adjustment device according to any one of claims 1 to 3. (Appendix 5) The combination identification unit sets each of the plurality of beams as an evaluation target beam and sets each beam other than the evaluation target beam as a comparison target beam, and identifies the evaluation target beam and the comparison target beam as beams that interfere with each other, satisfying Condition 1 that, for the evaluation target beam, C / I, which is a carrier power to interference power ratio, at at least any one of a plurality of interference specification points exceeds the allowable interference for the evaluation target beam, and Condition 2 that, at the interference specification point where the C / I exceeds the allowable interference, an individual comparison value, which is the C / I for the evaluation target beam from the comparison target beam, exceeds an individual allowable value obtained by subtracting a reference value M from the allowable interference for the evaluation target beam. 5. A resource coordination device as recited in claim 4. (Appendix 6) The resource adjustment device further a residual interference determination unit that determines a distribution of residual interference remaining when the resources adjusted by the resource adjustment unit are used; 6. The resource adjustment device according to claim 1, comprising: (Appendix 7) a priority level is set for each of the plurality of beams; The resource allocation unit allocates the remaining resources after adjustment by the resource adjustment unit to beams having a higher priority than the beam to be set as the beam to be set in order from the beam with the highest priority. 7. A resource adjustment device according to any one of claims 1 to 6. (Appendix 8) 1. A resource adjustment method for adjusting resources allocated to each of a plurality of controllable beams in a satellite communication system, the method comprising: a computer allocates resources to each of the plurality of beams in accordance with request information given for each of the plurality of beams, the request information indicating items including a beam pattern indicating polarization, phase, and amplitude excitation coefficients, beam frequencies indicating upper and lower limit frequencies, and frequency bandwidth; A resource adjustment method in which a computer adjusts resources allocated to a beam to be adjusted by adjusting at least one of the items indicated by the request information for the beam to be adjusted among the plurality of beams so that the beam satisfies the allowable interference indicated by the allowable interference value given to each beam for the plurality of beams. (Appendix 9) A resource adjustment program for adjusting resources allocated to each of a plurality of beams in a satellite communication system capable of controlling the plurality of beams, a resource allocation process for allocating resources to each of the plurality of beams in accordance with request information given for each of the plurality of beams, the request information indicating items such as a beam pattern indicating polarization, phase, and amplitude excitation coefficients, beam frequencies indicating upper and lower limit frequencies, and frequency bandwidth; a resource adjustment process for adjusting resources allocated to a beam to be adjusted by adjusting at least one item indicated by the request information for a beam to be adjusted among the plurality of beams so that the beam satisfies an allowable interference indicating an allowable value of interference given to each beam; A resource adjustment program that causes a computer to function as a resource adjustment device that performs the above.

[0079] The embodiments and modifications of the present disclosure have been described above. Some of these embodiments and modifications may be combined and implemented. Also, one or more of them may be implemented partially. Note that the present disclosure is not limited to the above embodiments and modifications, and various modifications are possible as needed. [Explanation of symbols]

[0080] 100 Satellite communications system, 1 Communications satellite, 2 Control earth station, 3 Beam for control earth station, 4 Beam for service link, 5 User earth station, 6 Feeder link earth station, 7 Beam for feeder link, 8 Frequency allocation, 101 Resource adjustment device, 111 Processor, 112 Memory, 113 Storage, 114 Communications interface, 121 Resource allocation unit, 122 Combination identification unit, 123 Resource adjustment unit, 124 Residual interference identification unit, 20 Request information.

Claims

1. A resource adjustment device for adjusting resources allocated to each of a plurality of beams in a satellite communication system capable of controlling the plurality of beams, a resource allocation unit that allocates, to each of the plurality of beams, a set of polarization, phase, and amplitude excitation coefficients indicated by the beam pattern, and allocates a frequency band of the allocation width between the upper limit and the lower limit indicated by the beam frequency, in accordance with request information given for each of the plurality of beams, the request information indicating items including a beam pattern indicating polarization, phase, and amplitude excitation coefficients, a beam frequency indicating an upper limit and a lower limit of a frequency that can be allocated to the beam, and an allocation width that is a bandwidth of the frequency to be allocated to the beam and is equal to or smaller than the bandwidth from the upper limit to the lower limit; a resource adjustment unit that calculates, for each of the plurality of beams, a value of interference from other beams in a coverage area of ​​the beam, and adjusts, for a beam to be adjusted among the plurality of beams by the resource allocation unit, a set of excitation coefficients of polarization, phase, and amplitude indicated by the beam pattern assigned to the beam to be adjusted by the resource allocation unit, or adjusts either the upper limit value or the lower limit value indicated by the beam frequency to change a frequency band to be assigned, or adjusts the allocation width of the frequency band to change a frequency band to be assigned, so that the calculated value of interference satisfies an allowable interference given to each of the plurality of beams and indicating an allowable value of interference in the coverage area of ​​the beam; A resource adjustment device comprising:

2. Priorities are set for the beam pattern, the beam frequency, and the allocation width for each of the beams, The resource adjustment unit adjusts information on the beam pattern, the beam frequency, and the allocation width in order of priority for the beam to be adjusted. The resource adjustment device according to claim 1 .

3. For each of the beams, whether or not the beam pattern, the beam frequency, and the allocation width are adjustable is set, The resource adjustment unit adjusts the adjustable item in the beam to be adjusted among the beam pattern, the beam frequency, and the allocation width. The resource adjustment device according to claim 1 .

4. The resource adjustment device further a combination identifying unit that identifies a combination of two or more beams that interfere with each other from the plurality of beams; Equipped with The resource adjustment unit sets each combination identified by the combination identification unit as a target combination, and adjusts the allocation width for at least one of the beams included in the target combination as the beam to be adjusted so that frequency bands assigned by the resource allocation unit to beams included in the target combination do not overlap, thereby changing the frequency band to be assigned. The resource adjustment device according to claim 1 .

5. The combination identification unit sets each of the plurality of beams as an evaluation target beam and sets each beam other than the evaluation target beam as a comparison target beam, and identifies the evaluation target beam and the comparison target beam as beams that interfere with each other, satisfying Condition 1 that, for the evaluation target beam, a carrier power to interference power ratio C / I at at least any one of a plurality of interference specification points exceeds the allowable interference for the evaluation target beam, and Condition 2 that, at the interference specification point where the C / I exceeds the allowable interference, an individual comparison value that is the C / I for the evaluation target beam from the comparison target beam exceeds an individual allowable value obtained by subtracting a reference value M from the allowable interference for the evaluation target beam. The resource adjustment device according to claim 4 .

6. The resource adjustment device further The resource adjustment device according to claim 1 , further comprising a residual interference specifying unit that specifies a distribution of residual interference remaining when the resources adjusted by the resource adjustment unit are used.

7. a priority level is set for each of the plurality of beams; The resource allocation unit allocates the remaining resources after adjustment by the resource adjustment unit to beams having a higher priority than the beam to be set as the beam to be set in order from the beam with the highest priority. The resource adjustment device according to claim 1 .

8. 1. A resource adjustment method for adjusting resources allocated to each of a plurality of controllable beams in a satellite communication system, the method comprising: a computer, according to request information given for each of the plurality of beams, the request information indicating items including a beam pattern indicating excitation coefficients of polarization, phase, and amplitude, a beam frequency indicating an upper limit value and a lower limit value of a frequency assignable to the beam, and an allocation width which is a bandwidth of the frequency to be assigned to the beam and is equal to or less than the bandwidth from the upper limit value to the lower limit value, assigning to each of the plurality of beams a set of excitation coefficients of polarization, phase, and amplitude indicated by the beam pattern, and assigning a frequency band of the allocation width between the upper limit value and the lower limit value indicated by the beam frequency; A resource adjustment method in which a computer calculates, for each of the plurality of beams, a value of interference from other beams in the beam's coverage area, and adjusts, for a beam among the plurality of beams to be adjusted, a set of polarization, phase, and amplitude excitation coefficients indicated by the beam pattern assigned to the beam to be adjusted so that the calculated value of interference satisfies an allowable interference given to each of the plurality of beams, which indicates the allowable value of interference in the beam's coverage area, or adjusts either the upper limit value or the lower limit value indicated by the beam frequency to change the frequency band to be assigned, or adjusts the allocation width of the frequency band to change the frequency band to be assigned.

9. A resource adjustment program for adjusting resources allocated to each of a plurality of beams in a satellite communication system capable of controlling the plurality of beams, a resource allocation process that allocates to each of the plurality of beams a set of polarization, phase, and amplitude excitation coefficients indicated by the beam pattern, and allocates a frequency band of the allocation width between the upper limit and lower limit values ​​indicated by the beam frequency, according to request information given for each of the plurality of beams, the request information indicating items including a beam pattern indicating polarization, phase, and amplitude excitation coefficients, a beam frequency indicating an upper limit value and a lower limit value of a frequency that can be allocated to the beam, and an allocation width that is a bandwidth of the frequency to be allocated to the beam and is equal to or smaller than the bandwidth from the upper limit value to the lower limit value; a resource adjustment process that calculates, for each of the plurality of beams, a value of interference from other beams in a coverage area of ​​the beam, and performs at least one of adjusting a set of polarization, phase, and amplitude excitation coefficients indicated by the beam pattern assigned to the beam to be adjusted by the resource allocation process, adjusting either the upper limit value or the lower limit value indicated by the beam frequency to change the frequency band to be assigned, or adjusting the allocation width of the frequency band to change the frequency band to be assigned, so that the calculated value of interference satisfies an allowable interference given to each of the plurality of beams and indicating an allowable value of interference in the coverage area of ​​the beam; A resource adjustment program that causes a computer to function as a resource adjustment device that performs the above.

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