JP7774652B2 - Resource adjustment device, resource adjustment method, and resource adjustment program - Google Patents

Description

This disclosure relates to a technology for adjusting resources allocated to each beam in a satellite communications system that allows for flexible control of beam frequencies 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.

In response to demand for increased satellite communications capacity, 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 channelizers 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.

Multi-beams are being used to improve frequency utilization efficiency. Specifically, while narrowing the coverage area of a single 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 less affected are irradiated with beams of the same frequency and polarization. This allows for repeated use of frequency and polarization radio resources, increasing capacity across the entire service area of the satellite communications system.

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.

One known technique for addressing these issues is cell design for terrestrial mobile communications, as described 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 the service area of a mobile communications 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. One example of the information to be set for a base station is a method that uses a list of neighboring cells involved in handover and a threshold value for the difference in radio wave quality between neighboring cells, as described in Patent Document 1.

Patent No. 5626219

NTT DoCoMo Technical Journal Vol. 2 No. 4 pp. 28-34

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 described 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 communication systems. Specifically, there are the following first and second problems.

(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.

(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.

The present disclosure aims to enable appropriate allocation of beam resources in a satellite communications system.

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;
and a resource adjustment unit that 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 an allowable interference value that indicates an allowable interference value given to each beam for the plurality of beams.

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.

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. FIG. 1 is a configuration diagram of a resource adjustment device 101 according to a first embodiment. FIG. 10 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. FIG. 10 is a diagram showing an example of beam resource allocation with multi-beams when satellite beam resource allocation according to the first embodiment is performed by superimposing it on a service-sharing multi-beam. FIG. 2 is a diagram showing request information 20 according to the first embodiment. FIG. 10 is a diagram showing an example of a method for extracting beams that may cause inter-beam interference according to the first embodiment. FIG. 10 is a diagram showing information for extracting beams that may cause inter-beam interference according to the first embodiment. 4A and 4B are diagrams showing mutual interference relationships of inter-beam interference according to the first embodiment; 6 is a flowchart of a satellite beam resource allocation process performed by the resource adjustment device 101 according to the first embodiment. FIG. 1 is an explanatory diagram of bandwidth adjustment according to the first embodiment. FIG. 1 is an explanatory diagram of bandwidth adjustment according to the first embodiment. FIG. 10 is a configuration diagram of a resource adjustment device 101 according to a second embodiment. FIG. 10 is an explanatory diagram of residual interference after satellite beam resource allocation according to the second embodiment. FIG. 10 is an explanatory diagram of interference distribution within a beam after satellite beam resource allocation according to the second embodiment.

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 communicate 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.

Note that each of the service link beams 4-1 to 4-3 and the feeder link beam 7 requires a transmission beam and a reception beam. However, for simplicity, the transmission beam and reception beam are collectively shown here as service link beams 4-1 to 4-3 and feeder link beam 7.

Communications satellite 1 is equipped with a channelizer function, which allows it to change the frequency bandwidth allocated to each beam and the connection settings between beams.

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.

In Figure 1, the coverage areas of service link beams 4-1 to 4-3 partially overlap. This indicates that if the same polarization and frequency are assigned to service link beams 4-1 to 4-3, inter-beam interference will occur. Therefore, in order to avoid inter-beam interference in the case of the same polarization, different frequencies must be assigned, as in frequency assignments 8-1 to 8-3.

In this embodiment, a method for allocating beam resources so that inter-beam interference falls within a tolerable value will be described. A device that implements the satellite beam resource allocation method described below will be referred to as 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 equipment connected via a terrestrial network.

The results of the satellite beam resource allocation determined by the satellite beam resource allocation method are also required for the line control function, which 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 part of the feeder link earth station 6. Therefore, the control earth station 2 and feeder link earth station 6 are assumed to be connected by a terrestrial network.

The configuration of the resource adjustment device 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 the 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.

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

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

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 Disk.
It is an abbreviation for Disk.

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.

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 programs that realize the functions of the respective functional components of the resource adjustment device 101. These programs are loaded into the memory 112 by the processor 111 and executed by the processor 111. In this way, the functions of the respective functional components of the resource adjustment device 101 are realized.

In FIG. 2, only one processor 111 is shown. However, there may be multiple processors 111, and the multiple processors 111 may work together to execute programs that realize each function.

***Explanation of Operation***
The operation of the 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.

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.

In such a case, frequency allocation is performed as shown in FIG.
Figure 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 shown in Figure 3. In Figure 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.
Figure 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 Figure 4(a). In Figure 4(b), the frequency bands 11-3 and 11-4 for polarization 2 are reduced to frequency bands 11-5 and 11-6, thereby ensuring an allocation allowable band 13. The frequency band 11-7 for 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.

Referring 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 provided with beam information 21, a request value 22, a priority 23, and an adjustment possibility 24. The beam information 21 includes four pieces of information: an allowable interference, a beam pattern, a beam frequency, and a bandwidth. Of the four pieces of information, the allowable interference is essential 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 tolerable interference. The priority 23 and the adjustable/unadjustable 24 for the tolerable interference are information that is not included in the target of the tolerable interference (information that is not given).
The identification number of the beam pattern formed by the DBF is assigned to the required value 22 for the beam pattern. 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 from 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."

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 a priority related to the adjustment of the beam pattern, beam frequency, and bandwidth. The priority is the priority between each beam information closed within a beam. In Figure 5, the larger the priority value, the lower the priority of the beam information, and the lower the priority, the earlier the order in which the requested value is adjusted or changed in satellite beam resource allocation.
The adjustable/unadjustable 24 indicates whether the required value can be adjusted or changed in the satellite beam resource allocation. In Fig. 5, only the bandwidth is adjustable, and the beam pattern and beam frequency are designated as not adjustable. The adjustable/unadjustable 24 may be expressed by the value of the priority 23. For example, when the priority of the bandwidth 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 not adjustable.

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

In embodiment 1, we will explain an example in which only the bandwidth of each beam is given as adjustable, while the beam pattern and beam frequency are given as non-adjustable, as shown in Figure 5.

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 request information 20 for each beam. The possibility of inter-beam interference means that, for beams of the same polarization, inter-beam interference occurs when the same frequency is assigned, but inter-beam interference does not occur when different frequencies are assigned, without taking into account the beam frequency and bandwidth given as the request information 20.
6A shows how beams that may cause inter-beam interference are identified using gain information for each beam at interference definition points 30, which define the coordinates of the entire service area as seen from the antenna using grid-like points. Here, as an example, we will explain inter-beam interference between downlink beams 31-1 and 31-2 (transmitted from the satellite).
In Downlink, radio waves of the frequency used are emitted to the entire coverage area of the beam. In contrast, Uplink (received by satellite) differs from Downlink in that the amount of interference when received from the satellite varies depending on the combination of the location and frequency of the earth station that emits the interfered radio waves. However, if we consider the amount of interference as the worst case scenario, interference calculations can be performed using a similar approach.

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, assume 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 Figure 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 wave is a stronger radio wave than the interference wave from beam 31-2. On the other hand, in an earth station belonging to beam 31-2, the desired wave is a weaker radio wave than the interference wave 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.

In Figure 6(a), 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 Figure 6(a), interference specification point 30-3 is outside the coverage area of beam 31-1 and beam 31-2, but taking into account the possibility of additional beams not shown here, it is possible to calculate the interference wave power I shown below.

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 interference reference points, polarizations, and frequency intervals (F1 to Fk). The reason for breaking down the gain into frequency intervals is that beam gain generally has frequency characteristics, and even if gain adjustment is performed to achieve as flat a characteristic as possible, slight 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, evaluation is performed for each frequency interval.

7, it is possible to calculate the C/I assuming that each beam uses frequency F1. For example, suppose that a desired signal is to be received on beam 1 of polarization 1 at interference reference point n. In this case, to evaluate the C/I of 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 obtain the interference signal power I.
The reason why the gain is treated as power is that the same transmission power is assumed to be input to each beam. However, if the power allocated to each beam differs in addition to 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 are polarized waves different from beam 1, can be added to the interference wave power I in consideration of 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.

In this way, the C/I for each frequency calculated for each beam is compared with the allowable interference for each beam described in Fig. 5. This determines whether or not 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 Fig. 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 as not to overlap. Here, according to the C/I calculation method described in Figure 7, the beam to be evaluated is subject to some interference from other beams of the same polarization. Therefore, it is advisable to allocate frequency bands so that all beams of the same polarization do not overlap.

However, when there is excessive interference in the beam being 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 being evaluated that do not result in excessive interference, and it is considered acceptable to allocate overlapping frequency bands in such combinations. Therefore, in embodiment 1, to further improve the efficiency of frequency band allocation, combinations of two or more beams that will result in excessive interference are identified, and frequency bands are allocated so that they do not overlap among the combinations of beams that will result in excessive interference.

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 of one or more interference-specified 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 to be compared to the beam to be evaluated exceeds the individual allowable value obtained by subtracting the reference value M from the allowable interference for the beam to be evaluated. In other words, interference from the beam to be compared ≧ 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.

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

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 have mutual excessive interference. (a) of FIG. 8 shows an image of the beam arrangement. (a) of FIG. 8 also shows a schematic diagram of excessive interference caused by contours crossing or touching, 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 have mutual excessive interference. On the other hand, (a) of FIG. 8 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 a mutual interference relationship, 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 the 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.

Referring 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. As a prerequisite 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 in the request information 20.

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.

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 assigned 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 assigned frequency band. For example, the resource adjustment unit 123 attempts to provisionally allocate beams in the currently assigned 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 beam, the process proceeds to step S7. On the other hand, if the resource adjustment unit 123 has not tentatively arranged the beam, the process proceeds to step S11.
In step S7, the resource adjustment unit 123 determines whether or not the temporary placement of all beams in the combination to be adjusted has been completed. If the temporary placement 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 placement has not been completed, the resource adjustment unit 123 returns the process to step S5 and attempts the temporary placement of the next beam.

In step S8, the resource adjustment unit 123 determines whether all of the combinations identified in step S1 were 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 remaining that have not been selected as combinations to be adjusted, the resource adjustment unit 123 returns to step S3 and selects a new combination.

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.

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 step S13. On the other hand, if the state is not set to "bandwidth reduction in progress," the resource adjustment unit 123 proceeds to step S12. If the state is not set to "bandwidth reduction in progress," the process of 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 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 beams 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.

In step S16, since there is sufficient 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 provisional placement for each combination.

The processing from step S2 to step S16 in FIG. 9 will be specifically described with reference to FIGS.
10A 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 a requested frequency band 62-1, and the bandwidth shown is, as an example, the entire band between the lower and upper frequency limits. Similarly, the frequency and bandwidth requested for beam 60-2 are indicated by a requested frequency bandwidth 62-2. Similarly, the frequency and bandwidth requested for beam 60-3 are indicated by a requested frequency bandwidth 62-3. Similarly, the frequency and bandwidth requested for beam 60-4 are indicated by a 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.

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 provisionally allocates the request frequency band 62-1, which has the lower frequency, of the request frequency bands 62-1 and 62-2. Subsequently, in step S5, the resource adjustment unit 123 attempts provisional allocation of the request frequency band 62-2. Because the request frequency band 62-2 causes frequency interference with the request frequency band 62-1 as shown in (a) of FIG. 10, the resource adjustment unit 123 determines in step S6 that provisional allocation is not possible, and the process 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.

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 FIGS. 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 frequencies lower 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 frequency 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 provisional 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 Figure 5 being given as non-adjustable, and the given frequency lower limit and upper limit must be 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 provisionally allocates the provisional 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 provisional 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 to step S3 because combination 61-2 remains and provisional allocation has not yet been completed, and therefore provisional allocation is performed on the provisional reduced band of the beams belonging to combination 61-2.

Figure 11 is a diagram explaining the operation from step S-3 for the provisional reduction band of beams belonging to combination 61-2. The explanation will be made using Figures 9 and 11. Figure 11 (a) shows that combination 61-2 was selected in step S3. Beams 60-2, 60-3, and 60-4 described in Figure 8 belong to combination 61-2, and their required frequency bands 62-2, 62-3, and 62-4 are also shown. Figure 11 (b) 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 Figure 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 its upper limit frequency 71-2 is determined. In the following 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 frequencies 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 Figure 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.

FIG. 11C shows that the provisionally allocated provisional reduction band 63-2 is moved (relocated) to a 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 continuous with 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, tentative reduction band 63-3, and 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.

In the next step S9, the resource adjustment unit 123 determines whether there is a surplus of 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 reduce the remaining allocatable bandwidth as much as possible and optimize the frequency band allocation as a whole. In step S16, the resource adjustment unit 123 increases the bandwidth for 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 the 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.

***Effects of First Embodiment***
As described above, the resource adjustment device 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 that 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.

The resource adjustment device 101 according to embodiment 1 adjusts the beam pattern, beam frequency, and bandwidth items in descending order of priority for the beam to be adjusted. Furthermore, the resource adjustment device 101 according to embodiment 1 adjusts the beam pattern, beam frequency, and bandwidth items that are adjustable for the beam to be adjusted. This makes it possible to adjust resources as intended.

The resource adjustment device 101 according to embodiment 1 adjusts resources for each combination of two or more beams that causes excessive interference. This enables efficient resource adjustment.

***Other configurations***
<Modification 1>
In the first embodiment, an example is 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, as shown in Fig. 5, assume that there is a beam for which the priority of beam frequency is higher than that of bandwidth, but for which the request information 20 is given that not only the bandwidth but also the 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, if the resource adjustment unit 123 determines that temporary allocation of the temporary reduced bandwidth of each beam cannot be achieved 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.

<Modification 2>
In the first modification, an example is 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.

<Modification 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. Furthermore, satellite communications may be used as a means of communication when terrestrial communication networks are unavailable during disasters or other emergencies. Since satellite communications is also used as a means of communication for lifesaving in such emergencies, 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.

<Modification 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.

When each functional component is implemented in hardware, the resource adjustment device 101 includes an electronic circuit instead of the processor 111, memory 112, and storage 113. The electronic circuit is a dedicated circuit that implements the functions of each functional component, memory 112, and storage 113.

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.

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

The processor 111, memory 112, storage 113, and electronic circuitry are collectively referred to as the processing circuit. In other words, the functions of each functional component are realized by the processing circuit.

Furthermore, the word "part" in the above description may be interpreted as "circuit," "process," "procedure," "processing," or "processing circuit."

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.

***Configuration Description***
The configuration of a resource adjustment apparatus 101 according to the second embodiment will be described with reference to FIG.
The resource adjustment device 101 differs from the resource adjustment device 101 shown in Fig. 2 in that it includes a residual interference identification unit 124 as a functional component. The residual interference identification 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 identification unit 124 is realized by software or hardware, like the other functional components.

***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 a beam arrangement. In this example of beam arrangement, the mutual interference relationship between beams 60-1 and 60-3, which are different combinations, does 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 beams 60-1 and 60-3. Similarly, residual interference due to overlapping band 80-2 exists in the provisionally reduced band between beams 60-1 and 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 frequencies other than the overlapping bands, affecting communication quality.

FIG. 14 is a diagram showing the 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. Here, the interference distribution is depicted in a simplified form. However, as described in FIGS. 6 and 7, the C/I for each beam is calculated using the gain of each beam for each interference specification point and frequency interval. However, in the description of FIG. 6, the C/I for 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 the 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 for each beam. This makes it possible to evaluate interference when frequencies are assigned to communication channels. Since the calculation method is the same as described above, detailed description is omitted. However, the gain for the frequency interval of each beam in FIG. 6 can be treated as a valid value for the frequency interval of the provisional reduction band assigned to each beam, and recalculated.

Returning to the explanation of Figure 14, the residual interference identifying unit 124 identifies the distribution of residual interference using the recalculated C/I. Residual interference band 91-1 does not overlap with provisional reduction band 63-3 and provisional reduction band 63-4. Therefore, the residual interference identifying unit 124 identifies the residual interference as "none." Residual interference band 91-2 overlaps with provisional reduction band 63-3, but because beams 60-1 and 60-3 are the furthest apart, as shown in Figure 13(a), the impact of interference is considered to be small. Therefore, the residual interference identifying unit 124 identifies the residual interference as "small." Furthermore, residual interference band 91-3 overlaps with provisional reduction band 63-4, and beams 60-1 and 60-4 are slightly closer together, as shown in Figure 13(a). Therefore, the residual interference identifying unit 124 identifies the residual interference as "medium."

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 described 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 of each interference-specifying point may be extracted for each frequency section, and the average, maximum, or minimum value may be determined and used as the interference distribution.

***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.

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 device comprising: a resource adjustment unit that 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 an allowable interference value that indicates an allowable interference value given to each beam for the plurality of beams.
(Appendix 2)
For each of the beams, a priority is set for the beam pattern, the beam frequency, and the bandwidth;
The resource adjustment device described in Appendix 1, wherein the resource adjustment unit adjusts the beam pattern, the beam frequency, and the bandwidth in order of decreasing priority for the beam to be adjusted.
(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 device according to claim 1 or 2, wherein the resource adjustment unit adjusts the items that can be adjusted in the beam to be adjusted, among the items of the beam pattern, the beam frequency, and the bandwidth.
(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,
The resource adjustment unit is configured to adjust the bandwidth of at least one of the beams included in the target combination as the beam to be adjusted, so that the frequency bands assigned to the beams included in the target combination do not overlap, with each combination identified by the combination identification unit as a target combination.
(Appendix 5)
The combination identification unit identifies each of the multiple beams as a beam to be evaluated, and each beam other than the beam to be evaluated as a beam to be compared, and identifies the beam to be evaluated and the beam to be compared as beams that interfere with each other, satisfying condition 1 that, for the beam to be evaluated, the C/I, which is the carrier power to interference power ratio at at least one of multiple interference specification points, exceeds the allowable interference for the beam to be evaluated, 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 from the beam to be compared to the beam to be evaluated, exceeds an individual allowable value obtained by subtracting a reference value M from the allowable interference for the beam to be evaluated.A resource coordination device as described in Appendix 4, which identifies combinations of beams that interfere with each other.
(Appendix 6)
The resource adjustment device further
6. The resource adjustment device according to claim 1, further comprising: a residual interference specifying unit that specifies a distribution of residual interference remaining when using resources adjusted by the resource adjustment unit.
(Appendix 7)
a priority level is set for each of the plurality of beams;
A resource adjustment device described in any one of Appendices 1 to 6, in which the resource allocation unit allocates the remaining resources after adjustment by the resource adjustment unit to beams with a higher priority than the beam to be set as the beam to be set in order of the priority of the beam with the highest priority.
(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 program that causes a computer to function as a resource adjustment device that performs a resource adjustment process that 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 allowable interference indicating the allowable value of interference given to each beam for each of the plurality of beams is satisfied.

The above describes embodiments and variations of the present disclosure. Some of these embodiments and variations may be implemented in combination. Furthermore, one or more of them may be implemented partially. Note that the present disclosure is not limited to the above embodiments and variations, and various modifications are possible as needed.

100 Satellite communications system, 1 Communications satellite, 2 Control earth station, 3 Control earth station beam, 4 Service link beam, 5 User earth station, 6 Feeder link earth station, 7 Feeder link beam, 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 (9)

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 the beam's coverage area , and adjusts, for a beam among the plurality of beams to be adjusted by the resource allocation unit, a set of polarization and phase and amplitude excitation coefficients indicated by the beam pattern assigned to the beam to be adjusted by the resource allocation unit so that the calculated value of interference satisfies an allowable interference given to each of the plurality of beams, which indicates an 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 . Priorities are set for the beam pattern, the beam frequency, and the allocation width for each of the beams,
The resource adjustment device according to claim 1 , wherein the resource adjustment unit adjusts information on the beam pattern, the beam frequency, and the allocation width in descending order of priority for the beam to be adjusted. 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 device according to claim 1 , wherein 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 further
a combination identifying unit that identifies a combination of two or more beams that interfere with each other from the plurality of beams,
The resource adjustment unit adjusts the allocation width for each combination identified by the combination identification unit as a target combination, and changes the frequency band to be allocated by adjusting at least one of the beams included in the target combination as the beam to be adjusted so that the frequency bands assigned by the resource allocation unit for the beams included in the target combination do not overlap . The resource adjustment device of claim 4, wherein the combination identification unit identifies each of the plurality of beams as a beam to be evaluated, and each of the beams other than the beam to be evaluated as a beam to be compared, and identifies the beam to be evaluated and the beam to be compared as beams that interfere with each other, satisfying condition 1 that, for the beam to be evaluated, the C/I, which is the carrier power to interference power ratio at at least one of a plurality of interference specification points, exceeds the allowable interference for the beam to be evaluated, 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 from the beam to be compared to the beam to be evaluated, exceeds an individual allowable value obtained by subtracting a reference value M from the allowable interference for the beam to be evaluated. 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. 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 with a higher priority than the beam to be set as the beam to be set in order of the priority of the beam with the highest priority. 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 . 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 program that causes a computer to function as a resource adjustment device that performs resource adjustment processing that 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 that is to be adjusted by the resource allocation processing , a set of polarization and phase and amplitude excitation coefficients indicated by the beam pattern assigned to the beam to be adjusted by the resource allocation processing so that the calculated value of interference satisfies an allowable interference that indicates an allowable value of interference in the beam's coverage area given for each of the plurality of beams ;