JP2020184739A - Wireless system capable of using shared frequency, wireless resource allocation method in radio communication using shared frequency, and base station - Google Patents

Abstract

To ensure the utilization efficiency of a shared frequency by adaptively controlling the transmission power depending on the direction of radio communication when an SU (Secondary User) system uses at least a part of shared frequency which a PU (Primary User) system may preferentially use.SOLUTION: An SU system 3 includes: an antenna Ant1 that performs radio communication with terminals TL1-TLn included in the communication area; at least one sensor WS1-WS5 that is disposed around the communication area to measure the reception power of a signal transmitted from the communication area; a memory M1 storing beam data representing the correspondence between the direction of the signal beam and measurement result by the sensor; a processor PRC2 as determination part for determining the maximum allowable transmission power of signal for each beam direction based on the shared condition and beam data; and a processor PRC2 as an allocation part that allocates wireless resources to the terminal based on the maximum allowable transmission power for each beam direction and a piece of line state information reported from the terminal.SELECTED DRAWING: Figure 6

Description

The present disclosure relates to a wireless system that can use a shared frequency, a radio resource allocation method in wireless communication using a shared frequency, and a base station.

The existing wireless system has been used almost exclusively between the existing wireless system (see PU system described later) and other wireless systems other than the existing wireless system (see SU system described later). Sharing a specific frequency band under predetermined conditions contributes to effective use of frequencies. For this reason, 5G (5th generation mobile communication system) communication specifications are being studied recently, but the frequency bands that are expected to be used in this 5G are the existing wireless system and the new wireless system (that is, that is). , Other wireless systems other than the existing wireless systems mentioned above) are being considered for sharing. In other words, a mechanism is being studied to improve the overall frequency utilization efficiency by encouraging new wireless systems to partially use the frequency band that is almost exclusively used by existing wireless systems. In the following specification, the existing wireless system is referred to as a "PU (Primary User) system", and the new wireless system is referred to as a "SU (Secondary User) system". As a condition for frequency sharing, it is conceivable that the radio communication of the PU system is not affected by interference due to the use of the frequency of the SU system.

In order to satisfy this condition, for example, a third-party shared frequency management mechanism performs interference calculation by frequency sharing based on the position information of the PU system radio and the SU system radio (FIG. 10). (See), a method of determining conditions for permitting use in the SU system based on the calculation result and notifying the SU system is disclosed (see, for example, Non-Patent Document 1).

Takeo FUJII et al., “Smart Spectrum for Future Wireless World”, The Institute of Electronics, Information and Communication Engineers, IEICE TRANS. COMMUN., VOL.E100-B, NO.9 September 2017

The radio parameters given to permit the use described above are considered to include, for example, carrier frequency and radio bandwidth, transmission power, and transmission directional gain. Therefore, the upper limit of the transmission power value including the transmission directivity gain for the SU system in the direction in which the boundary of the allowable interference level is closest to the SU system so that the allowable interference level for the PU system is minimized. It is conceivable to give permission to use the frequency to the SU system so as not to exceed this upper limit. Here, the closest direction is not limited to the concept of simply being close in distance, and may include the concept that the degree of interference due to radio wave radiation from the SU system is small.

However, in the above-mentioned usage permission method, in the radio resource control when using radio waves in the SU system, the transmission power including the transmission directional gain in the direction in which the interference from the SU system reaches the PU system most. The upper limit of the value of is similarly applied in all directions of 360 degrees when viewed from the SU system. Therefore, for example, when there is a direction in which the interference from the SU system does not reach the PU system so much, the use of the transmission power exceeding the upper limit of the transmission power value including the transmission directivity gain is used in that direction as well. It was not allowed and could be a limiting factor in the effective use of frequencies within the SU system.

The present disclosure has been devised in view of the above-mentioned conventional circumstances, and when the SU system uses at least a part of the shared frequencies that can be preferentially used by the PU system, the transmission power is adaptively applied according to the direction of wireless communication. It is an object of the present invention to provide a wireless system capable of using a shared frequency, a method for allocating wireless resources in wireless communication using a shared frequency, and a base station, which are controlled to the above and suppress a decrease in utilization efficiency of the shared frequency.

The present disclosure is a wireless system in which a shared frequency mainly used by an existing first wireless system can be used under predetermined shared conditions, and the present disclosure includes at least one terminal housed in the communication area of the wireless system. A communication unit that wirelessly communicates between the two, at least one sensor that is arranged around the communication area and measures the received power of a signal transmitted from within the communication area via the communication unit, and a beam of the signal. A determination unit that determines the maximum allowable transmission power of the signal for each beam direction based on a memory that stores beam data indicating a correspondence relationship between the direction and the measurement result of the sensor, and the shared condition and the beam data. Provided is a wireless system including an allocation unit for allocating wireless resources to the terminal based on the allowable maximum transmission power for each beam direction and line state information reported from the terminal.

Further, the present disclosure is a method for allocating wireless resources in wireless communication of a wireless system in which a shared frequency mainly used by an existing first wireless system can be used under predetermined shared conditions, and is within the communication area of the wireless system. The step of wireless communication with at least one terminal accommodated in the communication area and the reception power of a signal arranged around the communication area and transmitted from within the communication area via the communication unit are received by at least one unit. Based on the step of measuring by the sensor, the step of storing the beam data indicating the correspondence between the beam direction of the signal and the measurement result of the sensor in the memory, and the shared condition and the beam data, for each beam direction. A step of determining the allowable maximum transmission power of the signal and a step of allocating wireless resources to the terminal based on the allowable maximum transmission power for each beam direction and the line state information reported from the terminal. Provide a wireless resource allocation method to have.

Further, the present disclosure is a base station in a wireless system in which a shared frequency mainly used by an existing first wireless system can be used under predetermined shared conditions, and is at least accommodated in the communication area of the wireless system. Measurement result of received power of a signal transmitted from within the communication area via the communication unit by a communication unit that wirelessly communicates with one terminal and at least one sensor arranged around the communication area. A determination unit that determines the maximum allowable transmission power of the signal for each beam direction based on the memory that stores the beam data indicating the correspondence relationship between the signal and the beam direction, and the shared condition and the beam data. Provided is a base station including an allocation unit for allocating radio resources to the terminal based on the allowable maximum transmission power for each beam direction and line state information reported from the terminal.

Further, the present disclosure is a wireless system in which a shared frequency mainly used by an existing first wireless system can be used under predetermined shared conditions, and at least one unit accommodated in the communication area of the wireless system. Communication of the wireless system using the communication unit that wirelessly communicates with the terminal, the acquisition unit that acquires the information regarding the reception sensitivity boundary of the first wireless system, and the information regarding the reception sensitivity boundary of the first wireless system. A direction determining unit that derives the transmission direction of the signal that minimizes the distance from the area to the reception sensitivity boundary of the first wireless system, and a power source that derives the maximum allowable transmission power of the signal in the transmission direction of the derived signal. Provided is a wireless system including a determination unit and an allocation unit that allocates wireless resources to the terminal based on the allowable maximum transmission power and line state information reported from the terminal.

Further, the present disclosure is a wireless system in which a shared frequency mainly used by an existing first wireless system can be used under predetermined shared conditions, and at least one unit accommodated in the communication area of the wireless system. Includes the permissible transmission power of the signal calculated from the communication unit that wirelessly communicates with the terminal and the shared frequency management device connected to the first wireless system to the extent that interference with the first wireless system is avoided. An acquisition unit that acquires the shared conditions, and a direction determining unit that derives a signal transmission direction that minimizes the distance from the communication area of the wireless system to the reception sensitivity boundary of the first wireless system using the shared conditions. And the derivation unit that derives the difference between the allowable maximum transmission power of the signal in the transmission direction of the derived signal and the allowable transmission power of the signal, and the difference and the line state information reported from the terminal. Based on this, a wireless system is provided that includes an allocation unit that allocates wireless resources to the terminal.

Further, the present disclosure is a method for allocating wireless resources in wireless communication of a wireless system in which a shared frequency mainly used by an existing first wireless system can be used under predetermined shared conditions, and is within the communication area of the wireless system. Using the step of wirelessly communicating with at least one terminal housed in the first wireless system, the step of acquiring information on the reception sensitivity boundary of the first wireless system, and the information on the reception sensitivity boundary of the first wireless system. The step of deriving the transmission direction of the signal that minimizes the distance from the communication area of the wireless system to the reception sensitivity boundary of the first wireless system, and the allowable maximum transmission power of the signal in the transmission direction of the derived signal. Provided is a radio resource allocation method having a step of deriving the radio resource and a step of allocating the radio resource to the terminal based on the allowable maximum transmission power and the line state information reported from the terminal.

Further, the present disclosure is a base station in a wireless system in which a shared frequency mainly used by an existing first wireless system can be used under predetermined shared conditions, and is at least accommodated in the communication area of the wireless system. The radio is used by using a communication unit that wirelessly communicates with one terminal, an acquisition unit that acquires information on the reception sensitivity boundary of the first wireless system, and information on the reception sensitivity boundary of the first wireless system. A direction determining unit that derives the transmission direction of the signal that minimizes the distance from the communication area of the system to the reception sensitivity boundary of the first wireless system, and the maximum allowable transmission power of the signal in the transmission direction of the derived signal. Provided is a base station including a power determination unit to be derived, an allocation unit for allocating radio resources to the terminal based on the allowable maximum transmission power and line state information reported from the terminal.

Further, the present disclosure is a method for allocating wireless resources in wireless communication of a wireless system in which a shared frequency mainly used by an existing first wireless system can be used under predetermined shared conditions, and is within the communication area of the wireless system. A signal calculated from a step of wireless communication with at least one terminal accommodated in the above and a shared frequency management device connected to the first wireless system to the extent of avoiding interference with the first wireless system. The transmission direction of the signal that minimizes the distance from the communication area of the wireless system to the reception sensitivity boundary of the first wireless system by using the step of acquiring the shared condition including the allowable transmission power of the above and the shared condition. The step of deriving the difference between the allowable maximum transmission power of the signal in the transmission direction of the derived signal and the allowable transmission power of the signal, and the line state reported from the difference and the terminal. Provided is a radio resource allocation method comprising a step of allocating a radio resource to the terminal based on the information.

Further, the present disclosure is a base station in a wireless system in which a shared frequency mainly used by an existing first wireless system can be used under predetermined shared conditions, and is at least accommodated in the communication area of the wireless system. Allowable transmission power of a signal calculated from a communication unit that wirelessly communicates with one terminal and a shared frequency management device connected to the first wireless system to the extent that interference with the first wireless system is avoided. By using the acquisition unit that acquires the shared condition including the above and the shared condition, the transmission direction of the signal that minimizes the distance from the communication area of the wireless system to the reception sensitivity boundary of the first wireless system is derived. The direction determination unit, the derivation unit that derives the difference between the allowable maximum transmission power of the signal in the transmission direction of the derived signal and the allowable transmission power of the signal, and the line state reported from the difference and the terminal. Provided is a base station comprising an allocation unit that allocates radio resources to the terminal based on information.

According to the present disclosure, when the SU system uses at least a part of the shared frequency that can be preferentially used by the PU system, the transmission power is adaptively controlled according to the direction of wireless communication, and the utilization efficiency of the shared frequency is improved. The decrease can be suppressed.

The figure which shows the concept of the 1st border B1, the 2nd border B2, and the 3rd border B3. Block diagram showing an internal configuration example of the shared frequency management system according to the first embodiment A sequence diagram showing the operation procedure of the shared frequency management system according to the first embodiment in chronological order. A flowchart showing the detailed operation procedure of step St6 of FIGS. 3 and 6 in chronological order. The figure which shows typically the arrangement example of the SU system which concerns on Embodiment 2 and at least one PU system around it. A block diagram showing in detail an example of the internal configuration of the SU system according to the second embodiment. The figure explaining the received power by the radio wave sensor for each beam direction A table showing an example of the received power by the radio wave sensor for each beam direction measured in advance before actual operation. A flowchart showing an operation procedure of a base station of the SU system according to the second embodiment. Configuration diagram of the conventional shared frequency management system The figure which shows typically the arrangement example of the SU system which concerns on Embodiment 3 and two PU systems around it. A block diagram showing in detail an example of the internal configuration of the SU system according to the third embodiment. A flowchart showing an operation procedure of a base station of the SU system according to the third embodiment. A flowchart showing the operation procedure of the base station of the SU system according to the modified example of the third embodiment.

(Background to the contents of the first embodiment)
First, the concept of shared frequency management will be described with reference to FIG. 10 as a conventional technique that is a prerequisite for a wireless system that can use the shared frequency according to the present disclosure. FIG. 10 is a configuration diagram of a conventional shared frequency management system.

The shared frequency management system shown in FIG. 10 includes a PU system 101, a shared frequency management device 102, and a plurality of SU systems 1031, ..., 103N (for example, N: an integer of 2 or more). The PU system 101 and the shared frequency management device 102 can transmit and receive data or information to and from each other. Similarly, the shared frequency management device 102 and the respective SU systems 1031 to 103N can transmit and receive data or information to and from each other.

The PU system 101 is a wireless system whose operation is controlled by a system operator (so-called primary user) who is assigned to use a frequency in a predetermined shared frequency band mainly or almost exclusively. The PU system 101 has one or more transmitters (not shown) and receivers (not shown) necessary for the operation of the PU system 101, and holds the PU system information necessary for the operation of the PU system 101. ing. Here, the PU system information includes, for example, information related to transmission such as transmitter position, carrier frequency (center frequency), bandwidth, and transmission power, and information related to reception such as receiver position and reception sensitivity.

The shared frequency management device 102 includes a PU system transmitter information storage unit 201, a PU system receiver information storage unit 202, a terrain building geography data storage unit 203, a SU system transmitter information storage unit 204, and a SU system receiver. Information storage unit 205, PU-TX → PU-RX interference calculation unit 206, PU-TX → SU-RX interference calculation unit 207, SU-TX → PU-RX interference calculation unit 208, SU-TX → SU -The configuration includes the RX interference calculation unit 209 and the permission target frequency sharing condition determination unit 210.

Each of the SU systems 1031 to 103N applies to the shared frequency management device 102 to conditionally use a part of the frequency of a predetermined shared frequency band that can be used mainly or almost exclusively by the PU system 101. It is a system. The SU systems 1031 to 103N have one or more transmitters (not shown) and receivers (not shown) necessary for the respective operations of the SU systems 1031 to 103N, and each of the SU systems 1031 to 103N. It holds SU system information necessary for operation. Here, the SU system information includes, for example, information related to transmission such as transmitter position, carrier frequency (center frequency), bandwidth and transmission power, and information related to reception such as receiver position and reception sensitivity.

In the prior art shown in FIG. 10, the shared frequency management device 102 stores information about the transmitter in the PU system from the PU system 101 in the PU system transmitter information storage unit 201, and in the PU system from the PU system 101. Information about the receiver of is stored in the PU system receiver information storage unit 202. Similarly, the shared frequency management device 102 stores information about transmitters in the SU system from each of the SU systems 1031 to 103N in the SU system transmitter information storage unit 204, and SUs from each of the SU systems 1031 to 103N. Information about the receiver in the system is stored in the SU system receiver information storage unit 205. The shared frequency management device 102 reads out geographic information from the topographical building geographic data holding unit 203, and uses this geographic information to perform various interference calculations, PU-TX → PU-RX interference calculation unit 206, PU-TX → SU-. It is executed in each of the RX interference calculation unit 207, the SU-TX → PU-RX interference calculation unit 208, and the SU-TX → SU-RX interference calculation unit 209.

For example, the PU-TX → PU-RX interference calculation unit 206 performs interference calculation in the signal propagation path from the transmitter of the PU system 101 to the receiver of the PU system 101. Similarly, the PU-TX → SU-RX interference calculation unit 207 performs interference calculation in the signal propagation path from the transmitter of the PU system 101 to each receiver of the SU systems 1031 to 103N. Similarly, the SU-TX → PU-RX interference calculation unit 208 performs interference calculation in the signal propagation path from each transmitter of the SU system 1031 to 103N to the receiver of the PU system 101. Similarly, the SU-TX → SU-RX interference calculation unit 209 performs interference calculation in the signal propagation path from each transmitter of the SU system 1031 to 103N to each receiver of the SU system 1031 to 103N.

In the permission target frequency sharing condition determination unit 210, the frequency sharing condition (permission information) relating to the use of the frequency of the shared frequency band that can be used in each of the SU systems 1031 to 103N is based on the results of various huge interference calculations described above. Is notified to each SU system.

In such a conventional technique, between the radio of the PU system 101 (for example, a transmitter or a receiver; the same applies hereinafter) and the respective radios of the SU systems 1031 to 103N (for example, a transmitter or a receiver; the same applies hereinafter). The amount of interference calculation becomes enormous, and a considerably high load is applied to the calculation processing of the shared frequency management device 102. Further, in order to obtain the amount of interference while suppressing the error from the actual measurement to a small value, the existence of a building or the like between or around the radio of the PU system 101 and each of the radios of the SU systems 1031 to 103N is considered. It is necessary, but considering the existence of buildings, etc., the interference calculation becomes even larger, which is not realistic. On the other hand, in order to avoid considering the existence of buildings and the like and not to underestimate the amount of interference from each radio of SU system 1031 to 103N to the radio of PU system 101, the radio wave path between the radios. It is also conceivable to calculate the interference by assuming that is a line-of-sight propagation path (that is, free space propagation). In this method, each of the SU systems 1031 to 103N is allowed to exist only at a position very far from the PU system 101, so that the degree of effective frequency utilization by frequency sharing, which is the original purpose, is reduced. It ends up. Further, when determining the conditions for permitting the use of the shared frequency for each SU system so as to avoid interference between a plurality of SU systems existing in the suburbs, the frequencies permitted for use for each of the SU systems 1031 to 103N. By increasing the possibility that the frequency is finely divided, a division loss occurs regardless of how the operation of using the permitted frequency in each of the SU systems 1031 to 103N is actually performed. For this reason, the degree of effective frequency utilization by frequency sharing, which is the original purpose, is also reduced by the division loss.

Therefore, in the following embodiment 1, complicated interference calculation is not required, and the permission to use at least a part of the shared frequencies that can be preferentially used by the PU system is managed for the SU system, and the shared frequencies are used. An example of a shared frequency management system and a shared frequency management method that suppresses a decrease in utilization efficiency will be described.

Hereinafter, embodiments in which the shared frequency management system and the shared frequency management method according to the present disclosure are specifically disclosed will be described in detail with reference to the drawings as appropriate. However, more detailed explanation than necessary may be omitted. For example, detailed explanations of already well-known matters and duplicate explanations for substantially the same configuration may be omitted. This is to avoid unnecessary redundancy of the following description and to facilitate the understanding of those skilled in the art. It should be noted that the accompanying drawings and the following description are provided for those skilled in the art to fully understand the present disclosure, and are not intended to limit the subject matter described in the claims.

(Embodiment 1)
Hereinafter, the frequency band in which the frequency is shared by the shared frequency management system (hereinafter referred to as "shared frequency band") is, for example, a frequency of 20 GHz or higher, for example, a fixed wireless access system (FWA:) which is currently only about several thousand in Japan. 25 to 27 GHz band, which is a high frequency band assigned for Fixed Wireless Access), or 27 to 29.5 GHz, which is a high frequency band assigned to the fixed satellite telecommunications service, is exemplified. These frequencies have a characteristic that the reach of radio waves is small, for example, about 100 m, and it is difficult to diffract or transmit a shield such as a building. These shared frequency bands are currently expected to be used in 5G (5th generation mobile communication system), and are wireless in the communication area of the SU system (for example, on the premises of the SU system) operated by the secondary user who is a latecomer user. It can be considered as a frequency band suitable for communication. For example, in a fixed wireless access system in the 26 GHz band, the bandwidth (BW: band width) is 60 MHz, and there are 26 carrier frequencies. In this case, _k indicating the ordinal number of the carrier frequency f k is any of an integer value from 1 to 26.

In the following embodiment, the shared frequency management system grasps the received power distribution for each time zone and location of the radio signal based on the transmission power of the PU system. When using a shared frequency, the transmission power of the SU system is the reception sensitivity of the PU system with respect to the inside of the boundary (first border, see FIG. 1) where the reception power of the transmitted radio signal is the reception sensitivity of the PU system. Not giving the above interference is a restriction to be observed. The details of the first border will be described later, but it differs for each carrier frequency f _k .

In addition, for example, in a SU system that plans to use a frequency in the 26 GHz band indoors or on the premises, the area where transmitters and receivers (including access points) capable of wireless communication compatible with the SU system can exist is the SU system. This is the default limited area where you can receive the wireless service of (3rd border, see Fig. 1). Such limited areas are, for example, company premises, university campuses, hospitals, amusement parks, factories, construction sites, train stations, or smart towns where hundreds of households live, and these are exemplary and limited. Not done. The details of the third border will be described later, but the third border indicates a boundary line of a limited area (in other words, a closed space area) which is a communication area where the wireless service of the SU system can be received.

Therefore, the shared frequency management system sets the received power for each time zone and place of the radio signal based on the transmission power of the SU system existing in the third border to one or more installed around the closed space area of the SU system. By constructing the database as the measurement result of the radio wave sensor (see FIG. 1), it is possible to determine by calculation whether or not there is a frequency in the common frequency band for which the SU system can be used. The radio wave sensor is preferably arranged near the third border. Further, in the shared frequency management system, in the above calculation, the boundary of the position where the reception power of the radio signal based on the transmission power of the SU system is the reception sensitivity of the PU system in each time zone and place (see the second border, FIG. 1). ), It is possible to perform efficient calculations. That is, in the first embodiment, by introducing the above-mentioned concepts of the first border, the second border, and the third border, the frequency of the shared frequency band allocated so that the PU system can be used mainly or almost exclusively can be used. It is possible to determine whether or not a part of the above can be permitted to be used in the SU system, which is considerably simpler than that of the above-mentioned conventional technique.

FIG. 1 is a diagram showing the concepts of the first border B1, the second border B2, and the third border B3. In FIG. 1, two types of PU systems PU1 and PU2 are shown for the sake of clarity, but it goes without saying that the number of PU systems in the first embodiment is not limited to two.

First, the first border B1 will be described.

The shared frequency management system according to the first embodiment has information on the radio system (for example, transmission point position, carrier frequency (f _k ) or carrier frequency (f _k )) used in each of the PU systems PU1 and PU2 shown in FIG. The reception power of the radio signal (an example of the first radio signal) transmitted from each of the transmitters of the PU systems PU1 and PU2 is the reception sensitivity based on the number, the bandwidth, and the transmission power including the transmission directional gain). Always keep track of the positions of multiple receiving points. Here, the reception sensitivity (an example of a specified value) is the minimum received power at which wireless communication is established, and the same applies hereinafter. When a radio signal having a carrier frequency of f _k is transmitted from the PU system, the boundary line connecting the plurality of adjacent reception point positions described above is referred to as a "first border", and for convenience, "B1 (f _k )". May be written as.

Next, the second border B2 will be described.

The shared frequency management system according to the first embodiment has information on a radio system to be used in the SU system SU1 (for example, limited area position information, carrier frequency (f _k ) or carrier frequency (f _k ) number, bandwidth, transmission orientation). Based on the transmission power including the sex gain and the reception power measured by the radio wave sensor described later, the reception power of the radio signal (an example of the second radio signal) transmitted from the transmitter Tx of the SU system SU1 is the PU system (an example of the second radio signal). For example, the positions of a plurality of receiving points, which are the receiving sensitivities of the PU system PU2), are constantly grasped. When a radio signal having a carrier frequency f _k is transmitted from the SU system SU1, the boundary line connecting the plurality of adjacent reception point positions described above is referred to as a "second border", and for convenience, "B2 (f _k)". ) ”May be written. Here, the propagation distance of the radio wave from the transmitter Tx of the SU system SU1 to the reception point position Ci described above is referred to as “d ₂ ”.

In FIG. 1, there is an overlapping crossing area S between the area surrounded by the second border B2 and the area surrounded by the first border B1 corresponding to the PU system PU2, but the second border B2 The above-mentioned intersection area S does not exist between the area surrounded by the PU system and the area surrounded by the first border B1 corresponding to the PU system PU1.

Finally, the third border B3 will be described.

The third border B3 is a boundary line of a limited area (for example, a university campus exemplified above) which is a communication area where the wireless service of the SU system SU1 can be received. In the first embodiment, one or more radio wave sensors 341, 342, 343, and 344 are arranged around the third border B3, respectively. Each of the radio wave sensors 341 to 344 measures the received power of the radio signal based on the transmission power from the transmitter Tx of the SU system SU1 and reports it to the SU system SU1. Further, in each of the radio wave sensors 341 to 344, the reception power of the radio signal using the carrier frequency _fk actually granted to the SU system SU1 is the reception power specified by the common frequency usage condition permission. Monitor whether or not the compliance is observed. Here, the propagation distance of the radio wave from the transmitter Tx of the SU system SU1 to the radio wave sensor (for example, the radio wave sensor 344) is referred to as "d ₁ ". This propagation distance "d ₁ " will be described in detail later, but is used in the calculation of the propagation distance "d ₂ " corresponding to the second border B2.

Next, a configuration example of the shared frequency management system according to the first embodiment will be described with reference to FIG. FIG. 2 is a block diagram showing an internal configuration example of the shared frequency management system according to the first embodiment. The shared frequency management system according to the first embodiment has a configuration including a PU system 1, a shared frequency management device 2, a SU system 3, and one or more radio wave sensors 341 to 344 (see FIG. 1). Each of the radio wave sensors 341 to 344 may be included in the SU system 3. The PU system 1 and the shared frequency management device 2 can transmit and receive data or information to and from each other. Similarly, the shared frequency management device 2 and the SU system 3 can transmit and receive data or information to and from each other. Although only one SU system 3 is shown in FIG. 1 for the sake of clarity, a plurality of SU systems may be provided.

The PU system 1 as an example of the first wireless system is provided by a system operator (so-called primary user) who is assigned to use a frequency in a predetermined shared frequency band (for example, 20 GHz to 30 GHz band) mainly or almost exclusively. It is a wireless system whose operation is controlled. The PU system 1 has one or more PU transmitters 11, a memory 12, and a PU receiver 13 necessary for the operation of the PU system 1. That is, each of the PU transmitter 11 and the PU receiver 13 is used to execute the wireless service provided by the PU system 1. The memory 12 stores PU system information necessary for operating the PU system 1. Here, the PU system information includes, for example, information related to transmission such as a transmitter position indicating the installation position of the PU transmitter 11, a carrier frequency (center frequency), a bandwidth, and transmission power, and the installation position of the PU receiver 13. Includes information related to reception such as the receiver position and reception sensitivity shown.

The shared frequency management device 2 includes a B1 derivation unit 21, a B2 derivation unit 22, a permission target frequency sharing condition determination unit 23, a memory 24, a terrain / building geography data holding unit 25, and a communication interface circuit 26. Is. The B1 derivation unit 21, the B2 derivation unit 22, and the permission target frequency sharing condition determination unit 23 include, for example, a processor PRC1 such as a CPU (Central Processing Unit), a DSP (Digital Signal Processor), or an FPGA (Field Programmable Gate Array). It is functionally configured by the processor PRC1 reading and executing a program stored in the memory 24. Details of the configuration of the shared frequency management device 2 will be described later. The processor PRC1 functions as a controller that controls the operation of the shared frequency management device 2, controls processing for overall control of the operation of each part of the shared frequency management device 2, and data between each part of the shared frequency management device 2. Input / output processing, data calculation (calculation) processing, and data storage processing. The processor PRC1 operates according to the program stored in the memory 24. The processor PRC1 uses the memory 24 during operation, and stores the data generated by the processor PRC1 in the memory 24.

The SU system 3 as an example of the second wireless system conditionally uses a part of a predetermined shared frequency band (for example, 20 GHz to 30 GHz band) that the PU system 1 can mainly or almost exclusively use. This is a wireless system that applies to the shared frequency management device 2. The SU system 3 has one or more SU transmitters 31, a memory 32, and a SU receiver 33 necessary for each operation of the SU system 3. That is, each of the SU transmitter 31 and the SU receiver 33 is used to execute the wireless service provided by the SU system 3. The memory 32 holds SU system information necessary for the operation of the SU system 3. Here, the SU system information includes at least transmission power including, for example, carrier frequency (center frequency), bandwidth, and transmission directional gain. Further, the SU system information further includes the measurement result of the received power by the radio wave sensor (for example, the radio wave sensor 344) and the third border B3 indicating the boundary line of the limit area which is the communication area where the radio service of the SU system 3 can be received. It's fine.

Each of the radio wave sensors 341 to 344 as an example of the sensor measures the received power of the radio signal based on the transmission power from the SU transmitter 31 of the SU system 3 and reports it to the SU system 3. Further, the measurement of the received power by each of the radio wave sensors 341 to 344 is, for example, the reception power of the radio signal using the carrier frequency _{fk in} which the shared frequency management device 2 actually gives the SU system 3 permission to use. May be used to monitor whether or not the received power specified in the shared frequency usage conditions (see below) is observed. The number of radio wave sensors arranged may be one or more.

Here, the details of the configuration of the shared frequency management device 2 will be described.

The B1 out-licensing unit 21 acquires and grasps the PU system information sent from the PU system 1 via the communication interface circuit 26. The B1 derivation unit 21 reads out the geographic information from the topographical building geographic data holding unit 25, and uses this geographic information and the PU system information as an example of the first border information regarding the first border corresponding to the carrier frequency f _k . B1 (f _k ) is derived. As described above, in B1 (f _k ), when a radio signal having a carrier frequency f _k is transmitted from the PU system 1, the reception power of the radio signal becomes the reception sensitivity of the PU system 1 (see above). The boundary line connecting the points is shown. In other words, the B1 out-licensing unit 21 can derive the position information of the region (an example of the first region) surrounded by the first border B1. The B1 derivation unit 21 outputs the derived first border information to the permission target frequency sharing condition determination unit 23.

The B2 out-licensing unit 22 as an example of the out-licensing unit acquires and grasps the SU system information sent from the SU system 3 via the communication interface circuit 26. The SU system information includes, for example, carrier frequency (center frequency), bandwidth, transmission power including transmission directivity gain, third border B3 indicating a boundary line of a limit area where the radio service of SU system 3 can be received, and radio waves. The measurement result of the received power by the sensor (for example, the radio wave sensor 344) is included. The B2 derivation unit 22 uses the SU system information to calculate (see later) B2 (f _k ) as an example of the second border information regarding the second border corresponding to the carrier frequency f _k . As described above, in the B2 (f _k ), when a radio signal having a carrier frequency f _k is transmitted from the SU system 3, the reception power of the radio signal becomes the reception sensitivity (see above) of the PU system 1. The boundary line connecting the points is shown. In other words, the B2 derivation unit 22 can derive the position information of the region surrounded by the second border B2 (an example of the second region). The B2 derivation unit 22 outputs the derived second border information to the permission target frequency sharing condition determination unit 23.

The permission target frequency sharing condition determination unit 23 as an example of the input unit has the first border information (B1 (f _k )) from the B1 out-licensing unit 21 and the second border information (B2 (f _k )) from the B2 out-licensing unit 22. ) And enter. The permission target frequency sharing condition determination unit 23 uses the first border information (B1 (f _k )) and the second border information (B2 (f _k )) from the B2 derivation unit 22 to share the frequency with respect to the SU system 3. Determine the shared frequency usage conditions (an example of shared permission conditions) related to the band frequency. That is, the permission target frequency sharing condition determination unit 23 as an example of the permission condition determination unit determines, via the communication interface circuit 26, whether or not the permission to use the carrier frequency _{fk to} the SU system 3 may be granted. Is transmitted to the SU system 3.

The memory 24 is configured by using a RAM (Random Access Memory) and a ROM (Read Only Memory), and stores a program necessary for executing the operation of the shared frequency management device 2 and data or information generated during the operation. Temporarily save. The RAM is, for example, a work memory used during the operation of the processor PRC1. The ROM stores, for example, a program for controlling the processor PRC1 in advance.

Topography as an example of the geographic data holding unit The building geographic data holding unit 25 is configured by using an HDD (Hard Disk Drive) or an SSD (Solid State Drive), and the topography in the area where the PU system 1 and the SU system 3 are installed. Stores geographic information, including information and building information.

The communication interface circuit 26 is configured by using a communication circuit for transmitting / receiving data or information to / from a network (for example, an intranet or the Internet) to which the shared frequency management device 2 is connected. The communication interface circuit 26 transmits / receives data or information to / from the PU system 1 and the SU system 3 connected to the above-mentioned network. The communication interface circuit 26 as an example of the notification unit notifies the corresponding SU system 3 of the shared frequency usage condition determined by the permission target frequency sharing condition determination unit 23.

Here, a calculation example for deriving the second border information (B2 (f _k )) in the B2 deriving unit 22 will be described in detail. In the first embodiment, deriving the second border information (B2 (f _k )) is a transmission in which a position in the third border B3 corresponding to the communication area of the SU system 3 (for example, the SU transmitter 31 is arranged). It is synonymous with deriving the propagation distance d _{2 in} which the received power of the radio signal (an example of the second radio signal) from the point position) is reduced to the reception sensitivity of the PU system 1. The following four methods can be considered for the B2 derivation unit 22 to derive the propagation distance d ₂ . In the following description of the calculation examples, as the parameter to be used commonly, 60 bandwidth B used in the wireless service in the PU systems 1 [MHz], the carrier frequency _{f k} 26000 [MHz], the propagation distance _{d 2} The received CNR (Carrier to Noise ratio) is set to 0 [dB], and the noise figure N _{f is set} to 6 [dB].

(First calculation method) Method of applying the radio wave propagation loss equation in an ideal radio wave propagation environment Since the first calculation method assumes an ideal radio wave propagation environment, the B2 derivation unit 22 is a radio wave sensor. The measurement result of the received power in is not used. The transmission power P of the radio signal (an example of the second radio signal) from the SU system 3 is 30 [dBm].

As the radio wave propagation loss equation, the propagation loss L is expressed by the equation (1). In formula (1), α is the radio wave propagation attenuation coefficient, which is about 2.0 in the LOS (Line Of Sight) environment (that is, the line-of-sight environment) and about 3.0 to 4.0 in the NLOS (Non Line Of Sight) environment. It becomes. f is the carrier frequency [MHz]. A is an additional loss [dB]. In order not to underestimate the propagation distance d2, it can be assumed that α = 2.0 and A = 0.

Further, as shown in the equation (2), the difference between the transmission power P and the propagation loss L can be evaluated as the reception CNR and the noise level of the received signal at the position of the SU receiver 33.

Therefore, the B2 derivation unit 22 has a carrier frequency f _k = 26000 [MHz], a radio wave propagation attenuation coefficient α = 2.0, an additional loss A = 0 [dB], respectively, in the mathematical formulas (1) and (2). Substituting the bandwidth B at 60 [MHz], the reception CNR = 0 [dB], kT = -174 [dBm / Hz], and the noise figure N _f at 6 [dB], the propagation distance d ₂ ≈ 1000 [m]. Can be calculated. That is, unless the radio wave propagation attenuation coefficient α = 2.0 and the additional loss A = 0 [dB] are underestimated, the propagation distance d ₂ becomes such a large value.

(Second calculation method) A method of calculating by applying the measured value of the received power by the radio wave sensor in the actual environment to the radio wave propagation loss equation In the second calculation method, the B2 derivation unit 22 receives by the radio wave sensor in the actual environment. Use the measured value (measurement result) of the electric wave. The received power at the position on the third border B3 corresponding to the position of the propagation distance d ₁ from the transmission point position of the SU transmitter 31 (for example, the installation position of the radio wave sensor 344 in FIG. 1) is transmitted by R ₁ and the SU transmitter 31. Let R ₂ be the received power at the position on the second border B2 (for example, the reception point position Ci in FIG. 1) corresponding to the position of the propagation distance d ₂ from the point position.

In this case, when the mathematical formulas (1) and (2) are applied to the received powers R ₁ and R ₂ , the following mathematical formulas (3) and (4) are established. In Equation (4), and the received power R ₂ assuming noise level. The B2 derivation unit 22 has the same constant value for both the additional loss A ₁ in the formula (3) and the additional loss A _{2 in the} formula (4) (that is, A = 0 is not set as in the (first calculation method)). By assuming that, the propagation distance d ₂ that is more suitable for the actual real environment than the assumption of (first calculation method) can be estimated.

That is, by assuming that the additional loss A ₁ = the additional loss A ₂ in the mathematical formulas (3) and (4), the following mathematical formula (5) can be obtained. In equation (5), the radio wave propagation attenuation coefficients α ₁ and α ₂ for not underestimating the propagation distance d ₂ are assumed as follows, and α ₂ = 2.0 and α ₁ > 2.0 (for example, α _1). = 3.0).

Therefore, assuming that the received power R ₁ measured by the radio wave sensor at the propagation distance d ₁ = 10 [m] is −70 [dBm] as a calculation example, the B2 derivation unit 22 propagates by substituting it into the mathematical formula (5). It can be calculated that the distance d ₂ ≈ 324 [m].

(Third and fourth calculation methods) A method of calculating the radio wave propagation attenuation coefficients α ₁ and α ₂ by applying a value different from the assumed value of (second calculation method) In the third and fourth calculation methods, the B2 derivation unit For 22, an assumed value that is more realistic than the assumed values of the radio wave propagation attenuation coefficients α ₁ and α ₂ in the second calculation method is used. For example, the propagation loss L ₁ is (in other words, relatively short distance) within a limited area of the SU system 3 for the propagation loss of the radio wave, the radio wave propagation attenuation coefficient alpha ₁ corresponding to the propagation loss L ₁ is 3. It can be considered as a value smaller than 0 (in other words, close to the line-of-sight propagation path). On the other hand, the propagation loss L ₂ is (in other words, a relatively long distance) limited outside the area SU system 3 for the propagation loss of the radio wave, the radio wave propagation attenuation coefficient alpha ₂ corresponding to the propagation loss L ₂ is 2 It can be considered as a value larger than .0.

Therefore, in the third calculation method, assuming that α ₁ = 3.0 and α ₂ = 3.0, the B2 derivation unit 22 receives the received power R measured by the radio wave sensor at the propagation distance d ₁ = 10 [m]. _By substituting −70 [dBm] for ₁ into the mathematical formula (5) (see the second calculation method), the propagation distance d ₂ ≈ 47 [m] can be calculated.

Similarly, in the fourth calculation method, assuming that α ₁ = 2.0 and α ₂ = 3.0, the B2 derivation unit 22 receives the measurement measured by the radio wave sensor at the propagation distance d ₁ = 10 [m]. By substituting −70 [dBm] for the power R ₁ into the mathematical formula (5) (see the second calculation method), the propagation distance d ₂ ≈ 22 [m] can be calculated.

In this way, in order for the B2 derivation unit 22 to calculate the propagation distance d ₂ , the measured values are used for the propagation distance d ₁ and the received power R _1, and the radio wave propagation attenuation coefficients α ₁ and α ₂ are both assumed. The value may be used and assigned to the formula (5). Here, in Table (1), the propagation distance d ₁ [m], the received power R ₁ [dBm], the radio wave propagation attenuation coefficient α ₁ , α ₂ , the propagation distance d ₂ [m], and the power (PA _1). ) The relationship with [dBm] is shown. As shown in Table (1), it can be seen that the value of the propagation distance d ₂ largely depends on the combination of the hypothetical values of the radio wave propagation attenuation coefficients α ₁ and α ₂ . The electric power (PA ₁ ) can be derived from the mathematical formula (3), and is an image of a value obtained by subtracting the loss when a shield is inserted into the propagation path from the transmitted electric power.

That is, the radio wave propagation attenuation coefficient α of the propagation distance d ₁ from the transmission point, which is the location of the transmitter Tx of the SU system 3, which is a relatively short-range radio wave propagation, to the installation position of the radio wave sensor (for example, the radio wave sensor 344). ₁ adopts 2.0 as the LOS environment, and the propagation distance at which the received power of the radio wave is attenuated to the noise level from the transmission point where the transmitter Tx of the SU system 3 is arranged for the radio wave propagation over a relatively long distance. It is assumed that 3.0 is adopted as the radio wave propagation attenuation coefficient α ₂ of d ₂ as the NLOS environment.

In this case, the propagation distance d ₂ derived by the B2 derivation unit 22 is calculated as the smallest value among (first calculation method) to (fourth calculation method). This value seems to be the most realistic value, but it is not always appropriate to adopt this smallest value as the propagation distance d ₂ depending on the usage environment of the wireless service assumed by the founder of SU system 3. It is quite possible that there is no such thing. Therefore, the founder of the SU system 3 should measure, for example, at least before the start of the wireless service, which of the calculated propagation distances d ₂ is most suitable for the actual environment by actual measurement or simulation. Is preferable. On this basis, when the B2 derivation unit 22 calculates the propagation distance d _{2 in} order to derive the second border B2, each of one or more radio wave sensors 341 to 344 is used around the limited area of the SU system 3. It is more appropriate to determine the radio wave propagation attenuation coefficients α ₁ and α ₂ by measuring the received power used by measuring the propagation distance from the transmission point where the transmitter Tx is arranged as a parameter.

In practice, measuring the received power R ₁ (measured value) at the location where the radio wave sensor is installed (that is, the propagation distance d ₁ from the transmission point where the transmitter Tx is located) is periodically (for example, once an hour). ) Is not a big task, but it is a transmitter that attenuates to the received power that does not affect the PU system 1 and the propagation distance d ₂ required to realize the existence of the second border B2. Measuring the distance from the transmitting point, which is the location of Tx, is a fairly difficult task. Furthermore, since it is a considerably difficult task to periodically perform the propagation distance d ₂ , in the first embodiment, the propagation distance d ₂ is calculated using the above-mentioned calculation formula instead of the measurement using a radio wave sensor or the like. In particular, the fact that it has been reduced is a characteristic technical element.

However, the calculation formula for deriving the propagation distance d _2, the propagation distance greater wave propagation attenuation coefficient alpha ₁ effects the calculation of d _2, assume suitably a alpha ₂ (e.g., α _{1 =} 2.0, α ₂ At = 3.0), there are the following risks. Specifically, the risk of underestimating the propagation distance d ₂ (that is, assuming that α ₁ is smaller than the value corresponding to the actual environment and α ₂ is larger than the value suitable for the actual environment), There is a risk of waste overestimating the propagation distance d ₂ (that is, assuming that α ₁ is larger than the actual environment value and α ₂ is smaller than the actual environment value).

Therefore, as described above, the founder of the SU system 3 determines the propagation distance from the transmission point, which is the location of the transmitter Tx in the limited area of the SU system 3 (in other words, in the area surrounded by the third border B3). It is possible to carry out the work of measuring the received power at least once by changing as a parameter, and to obtain the values of the radio wave propagation attenuation coefficients α ₁ and α _{2 in} the actual measurement based on the measurement results. Appropriate.

Thus, the underestimation risk aversion to the propagation distance d _2, the propagation distance because d ₂ waste to overestimate it should be emphasized than risk aversion generated, radio wave propagation attenuation coefficient alpha ₁ than the value obtained by measuring Should be a little larger and the radio wave propagation attenuation coefficient α ₂ should be a little smaller. For example, when α ₁ = 2.08 and α ₂ = 3.23 in the measurement, instead of substituting it into the mathematical formula (5) as it is, α ₁ = 2.2 and α ₂ = 3.0 are mathematical formulas ( If it is used in 5), the propagation distance d ₂ will be calculated to be larger than the actual value. In other words, this leads to more reliable adherence to the precondition that interference from the SU system 3 should not adversely affect the PU system 1.

On the other hand, when the first border B1 of the PU system 1 and the second border B2 of the SU system 3 are clearly separated (for example, the intersection area S shown in FIG. 1 does not occur), the propagation distance d ₂ is overestimated. The propagation distance d ₂ may be calculated by adopting α ₁ = 3.0 and α ₂ = 2.0, knowing that there is a risk of waste. In this case, the measurement work for deriving the radio wave propagation attenuation coefficient α becomes unnecessary.

Next, the operation procedure of the shared frequency management system according to the first embodiment will be described with reference to FIGS. 3 and 4. FIG. 3 is a sequence diagram showing the operation procedure of the shared frequency management system according to the first embodiment in chronological order. FIG. 4 is a flowchart showing the detailed operation procedure of step St6 of FIG. 3 in chronological order.

In FIG. 3, the PU system 1 includes PU system information (for example, transmitter position indicating the installation position of the PU transmitter 11, carrier frequency (center frequency), bandwidth, transmission power, and other information related to transmission, and a PU receiver. Information related to reception such as the receiver position indicating the installation position of 13 and the reception sensitivity) is sent to the shared frequency management device 2 (St1).

The shared frequency management device 2 receives the PU system information sent in step St1 and reads out the geographic information from the topographical building geographic data holding unit 25. The shared frequency management device 2 uses this geographic information and the PU system information to derive B1 (f _k ) as an example of the first border information regarding the first border corresponding to the carrier frequency f _k in the B1 out-licensing unit 21. (St2).

The SU system 3 is described above in each of the one or more radio wave sensors 341-344 arranged in the vicinity in the limited area in response to the transmission of the radio signal based on the transmission power from the SU transmitter 31 of the SU system 3. The received power of the radio signal is measured (St3). The SU system 3 manages the shared frequency of SU system information (for example, carrier frequency, bandwidth, transmission power, and third border information indicating the boundary line of the limit area of the SU system 3) including the measurement result of the received power in step St3. Send to device 2 (St4).

The shared frequency management device 2 receives the SU system information sent in step St4, and uses this SU system information to calculate B2 (f _k ) as an example of the second border information corresponding to the carrier frequency f _k. (For example, refer to any one of the first calculation method to the fourth calculation method described above) to derive the information in the B2 derivation unit 22 (St5). The shared frequency management device 2 uses the first border information (B1 (f _k )) and the second border information (B2 (f _k )) from the B2 derivation unit 22, and the frequency of the shared frequency band with respect to the SU system 3. Determine the shared frequency usage conditions for (St6). The shared frequency management device 2 notifies the SU system 3 of the shared frequency usage conditions determined in step St6 (St7).

The SU system 3 can use the shared frequency in the wireless service of the SU system 3 according to the shared frequency usage condition notified from the shared frequency management device 2 in step St7 (St8).

Next, the details of the operation of the shared frequency management device 2 regarding the determination of the shared frequency usage condition in step St6 will be described with reference to FIG. The process shown in FIG. 4 is executed by, for example, the permission target frequency sharing condition determination unit 23 of the shared frequency management device 2, and is a process for determining the shared frequency usage condition corresponding to the carrier frequency _fk of interest in the shared frequency band. The process of determining the shared frequency usage conditions corresponding to other carrier frequencies in the same shared frequency band is repeatedly executed in the same manner. That is, the shared frequency management device 2 repeats the process of determining the shared frequency usage conditions shown in FIG. 4 so as to sweep the carrier frequencies of the shared frequency band in order.

In FIG. 4, the shared frequency management device 2 uses the PU system information and the SU system information inside the first border B1 (f _k ) (that is, in the communication area where the wireless service of the PU system 1 is enjoyed). It determines whether or not the second border B2 _{(f k)} is present (ST6-1). When the shared frequency management device 2 determines that the second border B2 (f _k ) does not exist inside the first border B1 (f _k ) (St6-1, NO), the carrier frequency currently being focused on. It is determined that f _k can be used within the range of the third border B3 (St6-2). This provides a wireless service using the carrier frequency f _k , which the SU system 3 is currently paying attention to because the second border B2 (f _k ) does not exist inside the first border B1 (f _k ). This is also because it is considered that interference higher than the reception sensitivity of the PU system 1 wireless service is unlikely to occur. Thereafter, determination process of shared frequency use condition corresponding to the carrier frequency f _k of interest currently is terminated, processing for determining the shared frequency use condition corresponding to the carrier frequency f _k of interest then is similarly Will be executed.

On the other hand, when the shared frequency management device 2 determines that the second border B2 (f _k ) exists inside the first border B1 (f _k ) (St6-1, YES), the first border B1 (St6-1, YES) the second border B2 present inside the f _k) a _{(f k)} and intersection area (overlapping area) is set to S _{(f k)} (ST6-3).

The shared frequency management device 2 uses the PU system information and the SU system information to determine whether or not the PU receiver 13 of the PU system 1 exists in the intersection area S (f _k ) (St6-4). .. When the shared frequency management device 2 determines that the PU receiver 13 of the PU system 1 does not exist in the intersection area S (f _k ) (St6-4, NO), the carrier frequency of interest is also present. It is determined that f _k can be used within the range of the third border B3 (St6-2). This is because the PU receiver 13 that receives the radio signal from the PU transmitter 11 of the PU system 1 does not exist in the intersection area S (f _k ) during the operation of the PU system 1, so that the SU system 3 has the SU system 3. This is because it is considered that even if the wireless service using the carrier frequency _fk , which is currently the focus of attention, is provided, it is unlikely to cause interference higher than the reception sensitivity of the wireless service of the PU system 1. Thereafter, determination process of shared frequency use condition corresponding to the carrier frequency f _k of interest currently is terminated, processing for determining the shared frequency use condition corresponding to the carrier frequency f _k of interest then is similarly Will be executed.

On the other hand, shared frequency management device 2, in the case of determining that PU receiver 13 of the PU system 1 is present in the intersection area _{S (f k) (St6-4,} YES), intersection area S _{(f k)} the shortening of the propagation distance _{d 2} to the position of the PU system 1 PU receiver 13, by referring to the equation (3) and equation (4), to any position outside the first border B1 _{(f k)} The transmission power (P−ΔP) required for this is calculated (St6-5). The shared frequency management device 2 is premised on the use of the reduced transmission power (P−ΔP) calculated in step St6-5 within the range of the third border B3 for the carrier frequency _fk currently being focused on. If it is possible (St6-6). This is because the PU receiver 13, which receives the radio signal from the PU transmitter 11 of the PU system 1 during the operation of the PU system 1, exists in the intersection area S (f _k ) in the first place, so that the SU system 3 When providing a radio service using the carrier frequency _fk, which is currently the focus of attention, the SU transmission of the SU system 3 is performed so that the radio wave of the SU system 3 does not interfere with the radio service of the PU system 1 more than the reception sensitivity. This is because it is considered that the transmission power from the machine 31 must be reduced. After that, the process of determining the shared frequency usage condition corresponding to the carrier frequency f _k of interest is completed, and the process of determining the shared frequency usage condition corresponding to the carrier frequency f _k of interest next is completed in the same manner. Will be executed.

As described above, in the shared frequency management system according to the first embodiment, the shared frequency management device 2 manages the sharing of the frequency of the shared frequency band mainly used by the PU system 1 with the SU system 3. The shared frequency management device 2 relates to a first border B1 indicating a boundary of a first region in which a reception level based on transmission of a radio signal using a frequency in the shared frequency band by the PU system 1 becomes a specified value (for example, reception sensitivity). 1 Derivation of border information. The shared frequency management device 2 relates to a second border B2 indicating a boundary of a second region in which a reception level based on transmission of a radio signal using a frequency in the shared frequency band by the SU system 3 becomes a specified value (for example, reception sensitivity). 2 Derivation of border information. The shared frequency management device 2 determines the shared frequency usage condition of the frequency of the shared frequency band with respect to the SU system 3 based on the first border information and the second border information.

As a result, the shared frequency management device 2 does not require the complicated interference calculation shown in the first approach according to the prior art described above, and the SU system 3 of at least a part of the shared frequencies that the PU system 1 can preferentially use. You can easily manage the usage permission for. Further, the shared frequency management device 2 is set in the shared frequency band by the PU system 1 and the SU system 3 without constructing the received power map which is very difficult to construct as shown in the second approach by the above-mentioned prior art. The procedure for sharing frequencies can be simplified to improve the feasibility of sharing frequencies. Further, since the shared frequency management device 2 can suppress that the SU system 3 interferes with the PU system 1 more than the reception sensitivity of the radio waves of the PU system 1, the frequency of the shared frequency band used by the PU system 1 By permitting the SU system 3 to use a part of the system openly, it is possible to suppress a decrease in the utilization efficiency of the frequency in the shared frequency band between the PU system 1 and the SU system 3.

Further, the shared frequency management device 2 determines the shared frequency usage conditions for each frequency in the shared frequency band. As a result, the shared frequency management device 2 can determine whether or not the SU system 3 is granted permission to use each of the plurality of carrier frequencies in the shared frequency band (for example, 20 GHz to 30 GHz band), so that the SU is relatively SU. It is possible to easily guarantee the existence of a carrier frequency that can be permitted to be used by the system 3.

Further, the shared frequency management device 2 includes the received power of the radio signal from the SU system 3 in each of the radio wave sensors 341 to 344 installed around the local area (for example, a limited area) in which the SU system 3 is used. , The second border information is derived by using the information about the communication method of the SU system 3. As a result, the shared frequency management device 2 uses the measured value of the received power measured in the vicinity of the boundary of the limited area of the SU system 3 for the radio waves radiated from the SU system 3, so that the PU system 1 is not interfered with. The propagation distance of radio waves suitable for the actual operating environment of the SU system 3 can be derived.

Further, the shared frequency management device 2 is based on the first border information and the second border information corresponding to any specific frequency (for example, the carrier frequency _{fk of} interest) in the shared frequency band. When it is determined that the overlapping region between the 1st border B1 and the 2nd border B2 does not exist, it is determined that the SU system 3 permits the use of a specific frequency in the local area (for example, the limited area) where it is used. As a result, the shared frequency management device 2 can determine that the radio waves radiated from the SU system 3 are unlikely to have an adverse effect such as interference on the PU receiver 13 existing in the communication area of the PU system 1. Therefore, even if the shared frequency management device 2 permits the SU system 3 to use the carrier frequency of interest, the shared frequency management device 2 does not interfere with the use of the shared frequency of the PU system 1, and the shared frequency is shared with the SU system 3. Can be effectively promoted.

Further, the shared frequency management device 2 is based on the first border information and the second border information corresponding to any specific frequency (for example, the carrier frequency _{fk of} interest) in the shared frequency band. A local area where the SU system 3 is used when it is determined that there is an overlapping area between the 1st border B1 and the 2nd border B2 and the PU receiver 13 corresponding to the PU system 1 is not arranged in the overlapping area. It is determined that the use of a specific frequency within (for example, a limited area) is permitted. As a result, in the shared frequency management device 2, even if the intersection area S (f _k ) exists, the PU receiver 13 does not exist in the intersection area, so that the radio waves radiated from the SU system 3 communicate with the PU system 1. It can be determined that the possibility of adverse effects such as interference on the PU receiver 13 existing in the area is substantially low. Therefore, even if the shared frequency management device 2 permits the SU system 3 to use the carrier frequency of interest, the shared frequency management device 2 does not substantially interfere with the use of the shared frequency of the PU system 1, and the SU system 3 is not affected. Frequency sharing can be effectively promoted.

Further, the shared frequency management device 2 is based on the first border information and the second border information corresponding to any specific frequency (for example, the carrier frequency _{fk of} interest) in the shared frequency band. A local area where the SU system 3 is used when it is determined that there is an overlapping area between the 1st border B1 and the 2nd border B2 and the PU receiver 13 corresponding to the PU system 1 is arranged in the overlapping area. It is determined that the use of a specific frequency in (for example, a limited area) is permitted on the premise that the transmission power of the radio signal from the SU system 3 in the local area is reduced by a predetermined amount. As a result, the shared frequency management device 2 can reduce the transmission power to such that the radio wave radiated from the SU system 3 propagates only to the outside of the first border B1, so that the radio wave radiated from the SU system 3 can be reduced to the PU system 1. It is possible to reduce the possibility of adverse effects such as interference on the PU receiver 13 existing in the communication area of the above. Therefore, the shared frequency management device 2 permits the use of the carrier frequency of interest on the condition that the SU system 3 uses a transmission power that allows radio waves to propagate only to the outside of the first border B1. However, it does not substantially interfere with the use of the shared frequency of the PU system 1, and can effectively promote the sharing of the frequency with respect to the SU system 3.

Further, the shared frequency management device 2 further includes a terrain building geographic data holding unit 25 that holds terrain and geographic information indicating the presence or absence of a building in an area where a radio signal from the PU system 1 is received. The shared frequency management device 2 derives the first border information by using the information regarding the communication method of the PU system 1 and the geographic information read from the topographical building geographic data holding unit 25. As a result, the shared frequency management device 2 actually realizes the first border B1 in which the received power becomes the receiving sensitivity in consideration of the geographical information such as the terrain and the building existing in the propagation path where the radio wave radiated from the PU system 1 propagates. It can be derived adaptively according to the environment of.

Further, the shared frequency management device 2 notifies the SU system 3 of the shared frequency usage conditions. As a result, the SU system 3 is defined in the shared frequency usage conditions to the extent that the PU system 1 is not interfered with the reception power equal to or higher than the reception sensitivity based on the shared frequency usage conditions determined by the shared frequency management device 2. It becomes possible to use the shared frequency (carrier frequency).

(Background to the contents of the second and subsequent embodiments)
The radio parameters assigned to the SU system 103 for permission to use the shared frequency from the shared frequency management device 102 (see FIG. 10) described as the prior art include, for example, carrier frequency and radio bandwidth, transmission power, and transmission directivity. Gain is considered to be included. Therefore, the transmission power including the transmission directional gain with respect to the SU system 103 in the direction in which the boundary of the allowable interference level is closest to the SU system 103 so that the allowable interference level for the PU system 101 is minimized. It is conceivable to set an upper limit of the value and give permission to use the frequency to the SU system 103 so as not to exceed this upper limit. Here, the closest direction is not limited to the concept of simply being close in distance, and may include the concept that the degree of interference due to radio wave radiation from the SU system is small.

However, in the above-mentioned usage permission method, in the radio resource control when using radio waves in the SU system 103, the transmission directional gain in the direction in which the interference from the SU system 103 reaches the PU system 101 most is included. The upper limit of the value of the transmitted power is similarly applied to all directions of 360 degrees when viewed from the SU system 103. Therefore, for example, when there is a direction in which the interference from the SU system 103 does not reach the PU system 101 so much, the transmission power exceeding the upper limit of the transmission power value including the transmission directivity gain also in that direction. It was not allowed to be used and could be a limiting factor in the effective use of frequencies within the SU system 103.

(Embodiment 2)
In the second embodiment, when the SU system uses at least a part of the shared frequency that can be preferentially used by the PU system, the transmission power is adaptively controlled according to the direction of wireless communication to improve the utilization efficiency of the shared frequency. An example of a wireless system that can use a shared frequency and a wireless resource allocation method in wireless communication using a shared frequency that suppresses a decrease will be described.

In the configuration of the shared frequency management system according to the second embodiment, the same reference numerals are given to the same configuration as the configuration of the shared frequency management system according to the first embodiment to simplify or omit the description, and different contents are described. explain.

FIG. 5 is a diagram schematically showing an arrangement example of the SU system 3 according to the second embodiment and at least one PU system 1 around the SU system 3. In FIG. 5, for example, three base stations TX1, TX2, and TX3 are arranged in the third border B3 corresponding to the communication area SU2 of the SU system 3. The radio signals (so-called radio waves) transmitted from each of the base stations TX1, TX2, and TX3 are reflected by the reflective object RL1, the ceiling, and the reflective object RL2 arranged in the SU system 3, and are reflected by the receiving points RX1 and RX2. , RX3 respectively. Each of the receiving points RX1 to RX3 is, for example, a wireless terminal (an example of a terminal) such as a smartphone housed in each of the base stations TX1, TX2, and TX3 in the SU system 3.

A plurality of (for example, five) radio wave sensors WS1, WS2, WS3, WS4, WS5 are arranged around the third border B3 corresponding to the communication area SU2 of the SU system 3.

Each of the radio wave sensors WS1 to WS5 as an example of the sensor has the same role as each of the radio wave sensors 341 to 344 according to the first embodiment, and the base stations 351 and ... 35k arranged in the SU system 3 ( Refer to FIG. 6, k: The received power of the radio signal (an example of the signal) from (k: an integer of 2 or more) is measured and reported to each of the base stations 351 to 35k via the SU system management device 36. Each of the radio wave sensors WS1 to WS5 sends the measurement result of the received power (reception level) to each of the base stations 351 to 35k. The measurement result of the received power (reception level) by each of the radio wave sensors WS1 to WS5 is input to each processor of the base stations 351 to 35k. Further, the measurement of the received power by each of the radio wave sensors WS1 to WS5 is, for example, the reception power of the radio signal using the carrier frequency _{fk in} which the shared frequency management device 2 actually gives permission to use the SU system 3. May be performed for monitoring whether or not the received power specified in the shared frequency usage conditions is observed.

In FIG. 5, a boundary line (for example, a first border) in which reception point positions that serve as reception sensitivity of radio signals from the PU systems PU1 and PU3 are connected to each other so as not to physically overlap with the communication area SU2 of the SU system 3 See B1) is shown. Here, also in the second embodiment, the shared frequency management device 2 to the SU system 3 are provided with, for example, a carrier frequency, a bandwidth, and a transmission directivity gain as common frequency usage conditions (see permission information S2 described later). The included transmission power or the maximum allowable reception level Ps (see below) is notified. Therefore, the SU system 3 cannot determine in which direction the PU systems PU1 and PU3 physically exist when viewed from the SU system 3.

However, the maximum transmission power for keeping the radio wave level radiated outside the communication area SU2 below a predetermined allowable value by transmitting a radio signal (radio wave) in the communication area SU2 (see the third border B3) of the SU system 3 is , Can be varied depending on the transmission directional beam direction (for example, 64 directions). Here, the radio wave level radiated outside the communication area SU2 is, for example, a measured value (monitor value) of the reception level of each of the radio wave sensors WS1 to WS5 installed around the third border B3.

In particular, in the case where the SU system 3 is an indoor space such as a factory and the reflection path of the reflective objects RL1 and RL2 such as ceilings and walls can be utilized, the radiation of radio waves outside the communication area SU2 (see the third border B3) is emitted. It is likely that there is a transmit directional beam direction that can suppress the level. In other words, the value of the transmission power including the transmission directivity gain in the direction in which the interference from the SU system 3 reaches the PU system most is set for each beam direction of the transmission directivity of the radio wave seen from the SU system 3. If it can be set variably, radio resources can be adaptively allocated to the terminals accommodated by the base station of the SU system 3 depending on the direction, and it is assumed that the shared frequency usage conditions notified from the shared frequency management device 2 are observed. It is considered that the carrier frequency can be effectively used.

FIG. 6 is a block diagram showing in detail an example of the internal configuration of the SU system 3 according to the second embodiment. The SU system 3 shown in FIG. 6 has a configuration including at least a SU system management device 36, radio wave sensors WS1 to WS5, and base stations 351 to 35k. Each of the base stations 351 to 35k accommodates at least one of the terminals TL1 to TLn. n is an integer of 2 or more. Here, in order to make the explanation easy to understand, each of the terminals TL1 to TLn is accommodated by the base station 351 and is, for example, a wireless terminal such as a smartphone that wirelessly communicates with the base station 351. Each of the terminals TL1 to TLn may not be limited to those having the same internal configuration as long as they can wirelessly communicate with the base station 351. Further, each of the terminals TL1 to TLn uses radio resources (for example, a resource block, see below) allocated by the base station 351 based on the permission information S2 (see below) notified from the shared frequency management device 2. Wireless communication is performed with the base station 351.

The SU system management device 36 may be configured by using, for example, a PC (Personal Computer). The SU system management device 36 conditionally uses a part of a predetermined shared frequency band (for example, 20 GHz to 30 GHz band) that can be used mainly or almost exclusively by the PU system 1. Apply to 2. The application information S1 sent to the shared frequency management device 2 at the time of application includes at least transmission power including, for example, carrier frequency, bandwidth, and transmission directivity gain. The application information S1 further includes the measurement result of the received power by the radio wave sensor (for example, radio wave sensors WS1 to WS5) and the third border B3 indicating the boundary line of the limit area which is the communication area where the wireless service of the SU system 3 can be received. It's fine.

Further, the SU system management device 36 as an example of the acquisition unit receives and acquires the permission information S2 indicating the shared frequency usage condition determined by the shared frequency management device 2 according to the application information S1 from the shared frequency management device 2. To do. The permission information S2 includes the carrier frequency, the bandwidth, the transmission power including the transmission directional gain, or the maximum allowable reception level Ps. The transmission power including the transmission directional gain indicates, for example, "Please suppress the transmission power of the radio signal (radio wave) transmitted from the SU system 3 to a maximum of 30 dBi including the transmission directional gain". On the other hand, the allowable maximum reception level Ps is measured in each of the radio wave sensors WS1 to WS5, for example, based on the arrangement position of the radio wave sensors WS1 to WS5 in the SU system 3 and the transmission power including the transmission directivity gain. The maximum received power of the radio signal is -70 dBm. " The transmission power including the transmission directivity gain is the gain (gain) at the time of forming the transmission directivity of the radio signal transmitted from the base station (for example, base station 351) of the SU system 3 and the transmission of the radio signal in the carrier frequency band. It is the sum of the electric power and is calculated by the shared frequency management device 2. On the other hand, the allowable maximum reception level Ps is the maximum reception level allowed to minimize the interference with the PU system among the reception levels of radio waves measured by the radio wave sensors WS1 to WS5, and the radio wave sensors WS1 to WS1. It is calculated by the permission target frequency sharing condition determination unit 23 of the shared frequency management device 2 capable of grasping the arrangement position information of the WS5. The SU system management device 36 sends the calculation result of the allowable maximum reception level Ps to each of the base stations 351 to 35k. The maximum allowable reception level Ps is input to each processor of the base stations 351 to 35k.

Since the internal configurations of the base stations 351 to 35k are the same, the base station 351 will be described here as an example. The base station 351 includes an IF unit 51, a transmission BB (Base Band) signal processing unit 52, a DAC (Digital Analog Converter) 53, a modulation unit 54, an upconverter 55, a PA (Power Amplifier) 56, and the like. BPF (Band Pass Filter) 57, duplexer 58, antenna Ant1, BPF61, downconverter 62, demodulation unit 63, ADC64, reception BB signal processing unit 65, IF unit 66, processor PRC2. , And the memory M1.

The IF unit 51 acquires DL (Down Link) data from, for example, a higher-level device (not shown) of the base station 351 and sends it to the transmission BB signal processing unit 52. The host device includes, for example, an RNC (Radio Network Controller) and an S-GW (Serving Gateway).

The transmission BB signal processing unit 52 performs various signal processing (baseband signal processing) in a predetermined baseband band on the DL data from the IF unit 51 based on the control signal from the processor PRC2. Baseband signal processing includes, for example, coding processing and transmission directivity control processing (for example, beamforming processing).

The DAC 53 converts the DL data processed by the transmission BB signal processing unit 52 into a baseband signal from digital data to an analog signal to generate a transmission signal.

The modulation unit 54 modulates the transmission signal from the DAC 53 according to a predetermined modulation method corresponding to the radio (see below) selected by the processor PRC2. Modulation schemes include, for example, quadrature modulation. Quadrature modulation includes, for example, QPSK (Quadrature Phase Shift Keying) and QAM (Quadrature Amplified Modulation).

The upconverter 55 raises the frequency band of the transmission signal in the baseband band modulated by the modulation unit 54, and the transmission signal in the carrier frequency band (RF band) included in the permission information S2 notified from the shared frequency management device 2. To generate.

The PA56 amplifies the signal power of the RF band transmission signal from the upconverter 55 according to the beam direction according to the transmission power control signal generated by the processor PRC2 based on the radio parameters selected by the processor PRC2 (see below). The transmission power of this transmission signal is maintained so as to be equal to or less than the maximum allowable reception level Ps.

The BPF 57 is filtered to pass transmission signals in a predetermined frequency range and block signals outside the predetermined frequency range based on the carrier frequency and bandwidth used in wireless communication between the base station 351 and the terminal. To do.

The duplexer 58 as an example of the communication unit separates the input signal (specifically, the transmission signal or the reception signal) and separates the transmission system (for example, the transmission BB signal processing unit 52, the DAC 53, the modulation unit 54, and the upconverter). 55, PA56, BPF57) or the receiving system (for example, BPF61, downconverter 62, demodulation unit 63, ADC64, receiving BB signal processing unit 65). For example, the duplexer 58 transmits (radiates) a transmission signal from the transmission system (see above) from the antenna Ant1. The duplexer 58 outputs the received signal received by the antenna Ant1 to the receiving system (see above).

The antenna Ant1 as an example of the communication unit is composed of a plurality of antenna elements, and transmits (radiates) a transmission signal from the transmission system (see above) of the base station 351 toward the communication area SU2 of the SU system 3.

The BPF 61 passes a reception signal in a predetermined frequency range (see above) based on the carrier frequency and bandwidth used in wireless communication between the base station 351 and the terminal, and transmits a signal outside the predetermined frequency range. Filter to block. Although not shown in FIG. 6, an LNA (Low Noise Amplifier) may be provided between the BPF 61 and the down converter 62. This LNA amplifies the received signal in the carrier frequency band (RF band) from the BPF 61.

The down converter 62 lowers the frequency band of the received signal in the carrier frequency band from the BPF 61 or LNA (see above) to generate a received signal in the default baseband band (see above).

The demodulation unit 63 demodulates the baseband band received signal from the down converter 62 according to a predetermined demodulation method corresponding to the radio parameters (see below) selected by the processor PRC2. The demodulation method includes, for example, quadrature demodulation (eg, QPSK, QAM) corresponding to the modulation method.

The ADC 64 converts the received signal from the demodulation unit 63 from an analog signal to digital data to generate UL (Up Link) data.

The receiving BB signal processing unit 65 performs various signal processing (baseband signal processing) in a predetermined baseband band on the UL data from the ADC 64. Baseband signal processing includes, for example, decoding processing and reception directivity control processing (for example, beamforming processing). Further, the reception BB signal processing unit 65 outputs the line state information (CSI: Channel State Information) reported from the terminal to the processor PRC2.

The IF unit 66 sends UL data from the receiving BB signal processing unit 65 to a higher-level device (see above).

The processor PRC2 controls the operation of each part of the base station 351 and is configured by using, for example, a CPU (Central Processing Unit), a DSP (Digital Signal Processor), an FPGA (Field Programmable Gate Array), or the like. The processor PRC2 controls the operation of each part of the base station 351 and executes processing related to wireless communication in an integrated manner. The processor PRC2 functions as a control unit of the base station 351, and controls processing for overall control of the operation of each unit of the base station 351, data input / output processing with and from each unit of the base station 351, and data calculation. Performs processing and data storage processing. The processor PRC2 operates according to the execution of the program stored in the ROM in the memory M1. For example, the processor PRC2 generates and outputs a transmission power control signal for controlling the transmission power of the transmission signal to the PA56 based on the selected radio parameter (see below).

The processor PRC2 manages radio resources (also referred to as “radio resources”) allocated during wireless communication with each of the terminals TL1 to TLn accommodated in the base station 351 (RRM: Radio Resource Management). Specifically, the processor PRC2 executes each process of reception control (RRC: Radio Resource Control), scheduling (MAC: Media Access Control), and wireless transmission parameter selection (PHY: Physical Layer). The reception control is a function of setting an upper limit of the number of wireless connections (connections) with the base station 351 and controlling access to the terminal so that the number of connections from the terminal does not exceed the upper limit. Scheduling is a function of mapping (allocating) subcarriers in two dimensions of a downlink (DL) frequency axis and a time axis based on line state information (CSI) reported from each of a plurality of terminals. The wireless transmission parameter selection is a function of selecting a predetermined wireless parameter required for wireless communication (transmission) based on the permission information S2 sent from the shared frequency management device 2. The radio parameters include, for example, carrier frequency, bandwidth, transmission power including transmission directivity gain or maximum allowable reception level Ps, minimum TTI (Transmission Time Interval), subcarrier frequency interval, and cyclic prefix length. , A subcarrier modulation method, and a subcarrier demodulation method.

The memory M1 is configured by using, for example, a RAM (Random Access Memory) and a ROM (Read Only Memory), and temporarily stores a program necessary for executing the operation of the base station 351 and data or information generated during the operation. Save as. The RAM is, for example, a work memory used during the operation of the processor PRC2. The ROM stores, for example, a program for controlling the processor PRC2 in advance. The memory M1 stores beam data indicating the correspondence between each of the plurality of beam directions of the radio signal (radio wave) transmitted from the base station 351 and the measurement result of the reception level of each of the radio wave sensors WS1 to WS5 (the memory M1). (See FIG. 8).

Here, the beam data will be described with reference to FIGS. 7 and 8. FIG. 7 is a diagram for explaining the received power of the radio wave sensor for each beam direction. FIG. 8 is a table showing an example of the received power of the radio wave sensor for each beam direction, which was measured in advance before the actual operation. Although an example in which five (that is, a plurality of) radio wave sensors WS1 to WS5 are provided as radio wave sensors is described here, there are five (that is, a plurality of) reception positions for measuring the reception level of the radio wave sensor. Therefore, it is not necessary that the required number of radio wave sensors is a plurality.

In FIG. 7, the outer shape of the communication area SU2 of the SU system 3 is rectangular in order to make the explanation easy to understand, but the outer shape is not limited to the rectangular shape. As shown in FIG. 7, the base station 351 forms a transmission directivity in the beam direction #i (i: identification number indicating the beam direction) at the stage before the actual operation when the wireless communication with the terminal is started. (Hereinafter, abbreviated as "radio signal in beam direction # 1") is transmitted. Each of the radio wave sensors WS1 to WS5 measures the reception level (reception power) when the radio signal in the beam direction #i is received and outputs it to the base station 351 (see FIG. 6). Further, the base station 351 similarly transmits a radio signal in the next beam direction # (i + 1). Each of the radio wave sensors WS1 to WS5 measures the reception level (reception power) when the radio signal in the beam direction # (i + 1) is received, and outputs it to the base station 351. After that, the base station 351 transmits radio signals in all the beam directions (for example, 64) that can be transmitted, acquires the measurement results of the reception levels of the radio wave sensors WS1 to WS5 for each radio signal, and obtains the measurement results of FIG. The beam data table TBL1 shown in the above is generated and stored in the memory M1.

As shown in FIG. 8, the beam data includes each of all possible beam directions in which the radio signal (radio wave) transmitted from the base station 351 can be formed, and the radio signal (radio wave) corresponding to the beam direction. The correspondence relationship with the measurement result of the reception level at the time of reception by each of the radio wave sensors WS1 to WS5 is shown. For example, in the beam direction # 1, the reception power (reception level) of the radio wave sensor WS1 is RP11, the reception power (reception level) of each of the radio wave sensors WS2 to WS4 is ... (Omitted), and the reception of the radio wave sensor WS5. The power (reception level) is RP51. Similarly, in the beam direction # (i + 1), the received power (reception level) of the radio wave sensor WS1 is RP12, and the received power (reception level) of each of the radio wave sensors WS2 to WS4 is ... (Omitted). The received power (reception level) of WS5 is RP52.

Further, the processor PRC2 as an example of the determination unit is included in the permission information S2 (an example of the shared condition) from the shared frequency management device 2, and is a radio signal for each beam direction based on the beam data (see FIG. 8). The maximum allowable transmission power P (b) of (radio wave) is determined. b indicates the beam number. That is, the base station 351 has a radio wave sensor in which the beam direction of the radio signal (radio wave) radiated in the communication area SU2 of the SU system 3 includes the influence of reflective objects such as walls, ceilings, pillars, and windows. In consideration of the measurement result of reception at such a reception level, the allowable maximum transmission power P (b), which is an index for determining which direction of the terminal to allocate the radio wave to from the base station 351 is obtained, is obtained for each beam direction.

Further, the processor PRC2 as an example of the allocation unit allocates wireless resources to the terminal based on the allowable maximum transmission power P (b) for each beam direction and the line state information reported from the terminal (see CSI described above). .. Details of this allocation will be described in detail with reference to FIG.

Next, the operation procedure of the base station 351 of the SU system 3 according to the second embodiment will be described with reference to FIG. FIG. 9 is a flowchart showing an operation procedure of the base station 351 of the SU system 3 according to the second embodiment. Each operation procedure shown in FIG. 9 is executed, for example, at a timing immediately before the base station 351 starts wireless communication with the terminal.

In FIG. 9, the base station 351 transmits a radio signal (radio signal in the beam direction # 1) having a transmission directivity formed in the beam direction #i at the stage before the actual operation when the wireless communication with the terminal is started. To do. Each of the radio wave sensors WS1 to WS5 measures the reception level (reception power) when the radio signal in the beam direction #i is received and outputs it to the base station 351 (St11). Further, the base station 351 similarly transmits a radio signal in the next beam direction # (i + 1). Each of the radio wave sensors WS1 to WS5 measures the reception level (reception power) when the radio signal in the beam direction # (i + 1) is received, and outputs it to the base station 351 (St11). After that, the base station 351 transmits radio signals in all the beam directions (for example, 64) that can be transmitted, acquires the measurement results of the reception levels of the radio wave sensors WS1 to WS5 for each radio signal, and obtains the measurement results of FIG. The beam data table TBL1 shown in the above is generated and stored in the memory M1 (St11). The base station 351 may generate the beam data table TBL1 shown in FIG. 8 and store it in the memory M1 at the stage of the actual operation described above.

The base station 351 has a radio signal (radio wave) for each beam direction based on the allowable maximum reception level Ps and beam data (see FIG. 8) included in the permission information S2 (an example of sharing conditions) from the shared frequency management device 2. ) Is determined (St12). The base station 351 stores the determined allowable maximum transmission power P (b) in the memory M1. As a premise of step St12, the allowable maximum reception level Ps is calculated by the permission target frequency sharing condition determination unit 23 of the shared frequency management device 2 capable of grasping the arrangement position information of the radio wave sensors WS1 to WS5, and is calculated by the shared frequency management device. It is included in the permission information S2 notified from 2.

Each of the terminal groups (for example, TL1 to TLn) wirelessly connected to the base station 351 receives the radio signal (radio wave) for each beam direction transmitted by the base station 351 in step St11, and the downlink of the wireless signal leading to the reception is received. The line state information (see CSI described above) indicating the state of the propagation path of the line is measured.

Here, the downlink (DL) is targeted for the following reasons, and the same applies to the subsequent Embodiment 3 or its modified example. Specifically, assuming an uplink (UL), the terminal performs omni-transmission that evenly transmits radio waves that are not so strong in the direction of 360 degrees, and the base station 351 transmits radio waves toward the position of the terminal. The reception directivity of is formed by the reception beamforming and then received. For this reason, it is considered that there is little need to consider the interference from the SU system 3 to the PU system in the uplink (UL). On the other hand, in the downlink (DL), the terminal also receives omni in the direction of 360 degrees, and the base station 351 needs to radiate radio waves with strong transmission directivity, and it is necessary to consider the interference with the PU system. Because there is.

Each of the terminals TL1 to TLn reports to the base station 351 the measurement result of the line state information of the propagation path (downlink) leading to the reception of the radio signal (radio wave) for each beam direction. The base station 351 receives and acquires downlink line status information (see CSI described above) from each of the terminal groups (for example, terminals TL1 to TLn) that request DL (downlink) wireless communication (St13). ..

The base station 351 has the maximum allowable transmission power P (b) of the radio signal (radio wave) for each beam direction determined in step St12 and the line state information for each beam direction of the radio signal acquired in step St13 (CSI described above). (See) is used to calculate the MCS (Modulation and Coding Scheme) when wireless resources (for example, resource blocks) are allocated to each terminal connected wirelessly (St14). That is, the base station 351 calculates the existing radio parameter MCS based on the line state information of the downlink (DL) and the allowable maximum transmission power P (b) based on the consideration of interference, and after step St14. In each of the processes of Steps St15 and St16 of the above, the radio resources can be allocated to the terminal based on the known PF (Proportional Fairness) algorithm, and the compatibility with the existing radio resource allocation processes can be improved.

The base station 351 reads the past time-series MCS value for each terminal (in other words, the value of a plurality of MCS for a certain time in the past) from the memory M1 and acquires it (St15). The memory M1 stores past time-series MCS values for each terminal (in other words, a plurality of MCS values for a certain period of time in the past).

The base station 351 uses the instantaneous (most recent) MCS value for each terminal calculated in step St14 and the past time-series MCS value for each terminal acquired in step St15 according to the existing PF algorithm. A process of allocating a radio resource (for example, a resource block) to each corresponding terminal is performed (St16). That is, the base station 351 preferentially allocates wireless resources to terminals having a relatively large ratio between the instantaneous (most recent) MCS value for each terminal and the average value of a plurality of MCS values for a certain period of time in the past. assign. As a result, the base station 351 supplies wireless resources to each of the terminals TL1 to TLn that are wirelessly connected when performing wireless communication using a part of the shared frequency mainly or almost exclusively used by the PU system. Since the allocation frequency can be made uniform by the PF algorithm, wireless resources can be evenly allocated while ensuring fairness between terminals, and the shared frequency can be effectively used.

As described above, the SU system 3 (an example of a wireless system) according to the second embodiment can use the shared frequency mainly used by the existing PU system 1 (an example of the first wireless system) under predetermined shared conditions. is there. The SU system 3 wirelessly communicates with each of at least one terminals TL1 to TLn accommodated in the communication area SU2, is arranged around the communication area SU2, and is arranged from within the communication area SU2 via the communication unit. The received power of the transmitted wireless signal is measured, and beam data indicating the correspondence between the beam direction of the wireless signal and the measurement results of each of the plurality of radio wave sensors WS1 to WS5 is stored in the memory M1. The SU system 3 determines the allowable maximum transmission power P (b) of the radio signal for each beam direction based on the permission information S2 (an example of the shared condition) and the beam data, and determines the allowable maximum transmission power P (b) for each beam direction. Radio resources are allocated to the terminal based on (b) and the line status information reported from the terminal.

As a result, the SU system 3 according to the second embodiment has a direction of wireless communication (for example, a beam) when the SU system 3 uses at least a part of the shared frequencies that can be preferentially used by the PU system 1 in the communication area SU2. The transmission power can be adaptively controlled according to the direction). Therefore, even if the SU system 3 cannot grasp the physical positional relationship of the PU system 1, an incident (for example, a wave stop command) that causes excessive interference with the PU system 1 by wireless communication using a shared frequency in the communication area SU2. Can be reduced, and the decrease in utilization efficiency of the shared frequency in the communication area SU2 can be suppressed.

Further, in the SU system 3, the allowable maximum reception level Ps (an example of the allowable transmission power) of the radio signal calculated from the shared frequency management device 2 connected to the PU system 1 to the extent of avoiding interference with the PU system 1 is set. Acquire the included permission information S2. The SU system 3 determines the allowable maximum transmission power P (b) for each beam direction based on the allowable maximum reception level Ps and the beam data. As a result, the SU system 3 can obtain the upper limit of the transmission power permitted to the extent that the interference with the PU system 1 can be minimized for each beam direction of the radio wave radiated from the base station 351.

Further, the SU system 3 receives the line state information for each beam direction of the radio signal from the terminal, and based on the allowable maximum transmission power for each beam direction and the line state information for each beam direction reported from the terminal, the terminal Allocate wireless resources to. As a result, the SU system 3 becomes a terminal that can be expected to maximize the throughput while reducing the interference area with the PU system 1 in view of the line state information of the downlink (DL) between the base station 351 and the terminal. Radio resources can be preferentially allocated to it.

Further, the SU system 3 calculates the radio parameter (for example, MCS value) corresponding to the radio resource by using the allowable maximum transmission power for each beam direction and the line status information reported from the terminal, and the latest line in the terminal. Radio resources are allocated to the terminal based on the ratio of the MCS value based on the state information to the average value of the MCS value based on the average line state information for the past fixed time in the terminal. As a result, the SU system 3 is a terminal that can be expected to maximize the throughput while reducing the interference area with the PU system 1 in view of the line state information of the downlink (DL) between the base station 351 and the terminal. It is possible to efficiently allocate wireless resources to terminals while satisfying the fairness of allocation of wireless resources between them.

Further, the permission information S2 (an example of the shared condition) is the permission of the radio signal in each of the radio wave sensors WS1 to WS5 calculated to the extent that the carrier frequency, the bandwidth, and the interference with the PU system 1 are minimized. It includes the maximum reception level Ps (an example of the allowable maximum reception power). As a result, the SU system 3 can select the radio parameters (see above) for minimizing the interference with the PU system 1 even if the information indicating the physical position of the PU system 1 is not notified. Wireless communication using a shared frequency can be stably performed in the communication area SU2.

(Embodiment 3)
In the third embodiment, as in the second embodiment, when the SU system uses at least a part of the shared frequencies that can be preferentially used by the PU system, the transmission power is adaptively controlled according to the direction of wireless communication. An example of a wireless system that can use the shared frequency and a wireless resource allocation method in wireless communication using the shared frequency that suppresses a decrease in the utilization efficiency of the shared frequency will be described.

In the configuration of the shared frequency management system according to the third embodiment, the same reference numerals are given to the same configurations as the configurations of the shared frequency management system according to each of the first and second embodiments, and the description is simplified or omitted. , Explain the different contents.

FIG. 11 is a diagram schematically showing an arrangement example of the SU system 3A according to the third embodiment and the two PU systems PU3 and PU4 around the SU system 3A. Although not shown in FIG. 11, in FIG. 11, for example, three base stations TX1, TX2, TX3 (see FIG. 5) are included in the third border B3 corresponding to the communication area SU2 of the SU system 3A. Each of is arranged. The base stations TX1 to TX3 have the same configuration as any of the base stations 351 to 35k shown in FIG. 12, for example. The radio signals (so-called radio waves) transmitted from each of the base stations TX1, TX2, and TX3 are reflected by the reflective object and the ceiling arranged in the SU system 3A, and are reflected at each of the receiving points RX1, RX2, and RX3. Received (see FIG. 5). Each of the receiving points RX1 to RX3 is, for example, a wireless terminal (an example of a terminal) such as a smartphone housed in each of the base stations TX1, TX2, and TX3 in the SU system 3A.

The shared frequency management system according to the first embodiment has a second border around the communication area SU2 of the SU system 3A so as not to overlap each of the first borders B1 which can be the boundaries of the reception sensitivities of the PU systems PU3 and PU4. B2 is derived.

The first border B1 is a boundary (in other words, a reception sensitivity boundary) of the allowable interference levels of the PU systems PU3 and PU4. The shape of the first border B1 does not necessarily have to be circular, and is set in consideration of the terrain or features (for example, buildings) in each area of the PU systems PU3 and PU4.

The second border B2 is centered on the third border B3, assuming that the upper limit of "transmission power + transmission directivity gain" in the SU system 3A whose service area is within the third border B3 is permitted. It is a substantially circular boundary of the allowable interference level, and is derived by, for example, the method described in the first embodiment.

The third border B3 is a service area (so-called communication area) for wireless communication of the SU system 3A.

As shown in the upper part of FIG. 11, the second border B2 is directed from the communication area (for example, the center point) toward the directions DRC1 and DRC2 where the SU system 3A is closest to the first border B1 of each of the PU systems PU3 and PU4. When a signal is transmitted with the upper limit value of "transmission power + transmission directivity gain" corresponding to the above, there is a possibility that interference of an allowable interference level may reach each of the PU systems PU3 and PU4.

Therefore, in the third embodiment, the SU system 3A specifies a direction (that is, a transmission direction θ) for determining an upper limit value of “transmission power + transmission directivity gain” when transmitting a transmission signal (that is, a radio wave). , Derives the maximum allowable transmission power P (θ) when transmitting a transmission signal in the specified transmission direction θ. The SU system 3A manages radio resources in the base station 351 (see FIG. 12) of the SU system 3A based on the allowable maximum transmission power P (θ). As a result, when the SU system 3A transmits a transmission signal from the communication area (for example, the center point), the transmission direction is such that the interference of the allowable interference level does not affect the first border B1 of each of the PU systems PU3 and PU4. Wireless communication can be performed using the maximum allowable transmission power P (θ) for each θ. For example, as shown in the lower part of FIG. 11, in the SU system 3A, the transmission direction in which the distance D (θ) from the communication area (for example, the center point) to the first border B1 of each of the PU systems PU3 and PU4 is not minimized. It is possible to send a transmission signal to θ (that is, a direction different from the directions DRC1 and DRC2) with a transmission power exceeding the upper limit of “transmission power + transmission directivity gain”. In other words, the SU system 3A can pseudo-expand the size of the area area of the second border B2 from the area BFB2 to the area AFB2.

FIG. 12 is a block diagram showing in detail an example of the internal configuration of the SU system 3A according to the third embodiment. In the SU system 3A according to the third embodiment, the structural difference from the SU system 3 according to the second embodiment is that the radio wave sensors WS1 to WS5 are omitted (see FIG. 2), and other configurations. Since there is no difference above, detailed explanation is omitted. In the third embodiment, the operations of the base stations 351 to 35k are different from those of the base stations 351 to 35k according to the second embodiment.

Next, the operation procedure of the base station 351 of the SU system 3A according to the third embodiment will be described with reference to FIG. FIG. 13 is a flowchart showing an operation procedure of the base station 351 of the SU system 3A according to the third embodiment. In the description of FIG. 13, the same step number is assigned to the content that overlaps with the description of FIG. 9, and the description is simplified or omitted. Each operation procedure shown in FIG. 13 is executed, for example, at a timing immediately before the base station 351 starts wireless communication with the terminal.

In FIG. 13, the base station 351 (for example, the processor PRC2) acquires information about the first border B1 of each of the PU systems PU3 and PU4 sent from the shared frequency management device 2 via the SU system management device 36 ( St21). The base station 351 uses the information about the first border B1 of the PU systems PU3 and PU4 (for example, the position information of each area of the PU systems PU3 and PU4) to use the third border B3 (that is, the communication area of the SU system 3A). ) To the first border B1 of each of the PU systems PU3 and PU4, the minimum value of the distance D (θ) for each transmission direction θ is calculated (St21). The base station 351 stores information regarding the third border B3 (for example, position information of the area of the SU system 3A) in the memory M1. The transmission direction θ in which the distance D (θ) is the minimum value is the distance from the third border B3 to the first border B1 of each of the PU systems PU3 and PU4 in the directions DRC1 and DRC2 shown in FIG. (Minimum direction).

The base station 351 calculates and determines the allowable maximum transmission power P (θ) corresponding to the transmission direction θ at which the minimum value of the distance D (θ) calculated in step St21 is obtained (St22). Each of the terminals TL1 to TLn reports to the base station 351 the measurement result of the line state information of the propagation path (downlink) leading to the reception of the radio signal (radio wave) for each transmission direction θ from the base station 351. The base station 351 receives and acquires downlink line status information (see CSI described above) from each of the terminal groups (for example, terminals TL1 to TLn) that request DL (downlink) wireless communication (St13). ..

The base station 351 includes the allowable maximum transmission power P (θ) of the radio signal (radio wave) determined in step St22 and the line state information (see CSI described above) for each transmission direction θ of the radio signal acquired in step St13. Is used to calculate the MCS when wireless resources (for example, carrier frequency, resource block) are assigned to each terminal connected wirelessly (St24). That is, the base station 351 calculates the existing radio parameter MCS based on the line state information of the downlink (DL) and the allowable maximum transmission power P (θ) based on the consideration of interference, and after step St24. In each of the processes of Steps St15 and St16 of the above, the radio resource can be allocated to the terminal based on the known PF algorithm, and the compatibility with the existing radio resource allocation process can be improved.

The base station 351 reads the past time-series MCS value for each terminal (in other words, the value of a plurality of MCS for a certain time in the past) from the memory M1 and acquires it (St15). The memory M1 stores past time-series MCS values for each terminal (in other words, a plurality of MCS values for a certain period of time in the past).

The base station 351 uses the instantaneous (most recent) MCS value for each terminal calculated in step St24 and the past time-series MCS value for each terminal acquired in step St15 according to the existing PF algorithm. A process of allocating wireless resources (for example, carrier frequency, resource block) to each corresponding terminal is performed (St16). That is, the base station 351 preferentially allocates wireless resources to terminals having a relatively large ratio between the instantaneous (most recent) MCS value for each terminal and the average value of a plurality of MCS values for a certain period of time in the past. assign. As a result, the base station 351 supplies wireless resources to each of the terminals TL1 to TLn that are wirelessly connected when performing wireless communication using a part of the shared frequency mainly or almost exclusively used by the PU system. Since the allocation frequency can be made uniform by the PF algorithm, wireless resources can be evenly allocated while ensuring fairness between terminals, and the shared frequency can be effectively used.

As described above, the SU system 3A (an example of a wireless system) according to the third embodiment can use the shared frequency mainly used by the existing first wireless system under predetermined shared conditions. The SU system 3A wirelessly communicates with each of at least one terminals TL1 to TLn accommodated in the communication area SU2, and provides information on the reception sensitivity boundary (for example, the first border B1) of the PU systems PU3 and PU4. get. The SU system 3A uses information about the reception sensitivity boundaries of the PU systems PU3 and PU4 to transmit a signal in which the distance from the communication area SU2 of the SU system 3A to the reception sensitivity boundaries of the PU systems PU3 and PU4 is minimized. θ is derived in the base station 351 (for example, the processor PRC2 as an example of the direction determining unit). The SU system 3A derives the allowable maximum transmission power P (θ) in the transmission direction θ of the derived signal at the base station 351 (for example, the processor PRC2 as an example of the power determination unit). The SU system 3A allocates radio resources to the terminal based on the maximum allowable transmission power P (θ) and the line state information (for example, CSI) reported from the terminal.

As a result, the SU system 3A has a maximum allowable transmission power P (θ) in the transmission direction θ in which the distance D (θ) from the communication area SU2 (for example, the center point) to the first border B1 of each of the PU systems PU3 and PU4 is minimized. Taking θ) into consideration, it is possible to manage the radio resources in the base station 351 (see FIG. 12) of the SU system 3A. Therefore, when the SU system 3A transmits a transmission signal from the communication area SU2 (for example, the center point), the transmission direction is such that the interference of the allowable interference level does not affect the first border B1 of each of the PU systems PU3 and PU4. Wireless communication can be performed using the maximum allowable transmission power P (θ) for each θ. That is, the SU system 3A is different from the transmission direction θ (that is, the directions DRC1 and DRC2) in which the distance D (θ) from the communication area SU2 (for example, the center point) to the first border B1 of each of the PU systems PU3 and PU4 is not minimized. In the direction), it is possible to transmit a transmission signal with a transmission power exceeding the upper limit of “transmission power + transmission directional gain”. In other words, the SU system 3A can pseudo-expand the size of the area area of the second border B2 from the area BFB2 to the area AFB2.

Further, the SU system 3A calculates the radio parameter (for example, MCS value) corresponding to the radio resource by using the allowable maximum transmission power P (θ) and the line status information reported from the terminal, and the latest line in the terminal. Radio resources are allocated to the terminal based on the ratio of the MCS value based on the state information to the average value of the MCS value based on the average line state information for the past fixed time in the terminal. As a result, the SU system 3A is expected to maximize the throughput while reducing the interference area with respect to the PU systems PU3 and PU4 in view of the line state information of the downlink (DL) between the base station 351 and the terminal. At the same time, it is possible to efficiently allocate wireless resources to terminals while satisfying the fairness of allocation of wireless resources between terminals.

(Modified Example of Embodiment 3)
In the configuration of the shared frequency management system according to the modified example of the third embodiment, the same configuration as the configuration of the shared frequency management system according to each of the first, second, and third embodiments is given the same reference numerals and described. Simplify or omit, and explain different contents.

In the third embodiment, the SU system 3A can acquire information about the first border B1 of the PU systems PU3 and PU4 (for example, the position information of each area of the PU systems PU3 and PU4). However, the information about the first border B1 of each of the PU systems PU3 and PU4 may be confidential, and the information about the first border B1 is transmitted to the third party SU system 3A from the viewpoint of each of the PU systems PU3 and PU4. Being informed can actually be accompanied by security challenges. For example, depending on the PU system, the location of a transmitter / receiver such as a base station used in the PU system may be highly confidential information.

Therefore, in the modified example of the third embodiment, the SU system 3A cannot acquire the information regarding the first border B1 of the PU systems PU3 and PU4 (for example, the position information of each area of the PU systems PU3 and PU4). It is assumed that the shared frequency usage conditions (see above) sent from the shared frequency management device 2 can be acquired. Here, the shared frequency usage condition (see permission information S2) is the transmission power including, for example, the carrier frequency, the bandwidth, and the transmission directivity gain as a function of the transmission direction θ (that is, as in the second embodiment). , "Transmission power + transmission directivity gain"). In other words, in the modified example of the third embodiment, the shared frequency management device 2 calculates the transmission power including the transmission directivity gain as a function of the transmission direction θ as the shared frequency usage condition and notifies the SU system 3A. To do.

In the modification of the third embodiment, the SU system 3A has "transmission power + transmission directivity gain" (that is, maximum allowable transmission power P (θ)) as a function of the transmission direction θ included in the shared frequency usage condition. , The difference from the minimum allowable maximum transmission power P (θ0) corresponding to the transmission direction θ0 at which the allowable maximum transmission power P (θ) is minimized is derived. Further, the SU system 3A sets the above-mentioned difference (that is, “allowable maximum transmission power P (θ) − minimum allowable maximum transmission power P (θ0)”) between each of the terminals TL1 to TLn and the base station 351. The added SINR added to the signal-to-interference and noise ratio (SINR) [dB] is derived. The SU system 3A manages radio resources in the base station 351 (see FIG. 12) of the SU system 3A based on the added SINR. As a result, when the SU system 3A transmits a transmission signal from the communication area (for example, the center point), the transmission direction is such that the interference of the allowable interference level does not affect the first border B1 of each of the PU systems PU3 and PU4. Wireless communication can be performed using the maximum allowable transmission power P (θ0) for each θ. For example, as shown in the lower part of FIG. 11, in the SU system 3A, the transmission direction in which the distance D (θ) from the communication area (for example, the center point) to the first border B1 of each of the PU systems PU3 and PU4 is not minimized. It is possible to send a transmission signal to θ (that is, a direction different from the directions DRC1 and DRC2) with a transmission power exceeding the upper limit of “transmission power + transmission directivity gain”. In other words, the SU system 3A can pseudo-expand the size of the area area of the second border B2 from the area BFB2 to the area AFB2.

Next, the operation procedure of the base station 351 of the SU system 3A according to the modified example of the third embodiment will be described with reference to FIG. FIG. 14 is a flowchart showing the operation procedure of the base station of the SU system according to the modified example of the third embodiment. In the description of FIG. 14, the same step number is assigned to the content that overlaps with the description of FIG. 9 or 13, and the description will be simplified or omitted. Each operation procedure shown in FIG. 14 is executed, for example, at a timing immediately before the base station 351 starts wireless communication with the terminal.

In FIG. 14, the base station 351 (for example, processor PRC2) has a “transmission power + transmission orientation” as a function of the shared frequency usage conditions (for example, carrier frequency, bandwidth, and transmission direction θ) transmitted from the shared frequency management device 2. Sex gain ") is acquired (St31). The base station 351 calculates the difference between the maximum allowable transmission power P (θ) and the minimum allowable maximum transmission power P (θ0) included in the shared frequency usage condition (St32). Each of the terminals TL1 to TLn reports to the base station 351 the measurement result of the line state information of the propagation path (downlink) leading to the reception of the radio signal (radio wave) for each transmission direction θ from the base station 351. The base station 351 receives and acquires downlink line status information (see CSI described above) from each of the terminal groups (for example, terminals TL1 to TLn) that request DL (downlink) wireless communication (St13). ..

The base station 351 sets a difference calculated in step St32 (that is, “allowable maximum transmission power P (θ) − minimum allowable maximum transmission power P (θ0)”) between each of the terminals TL1 to TLn and the base station 351. Using the added SINR added to the SINR of the above and the line state information for each transmission direction θ of the wireless signal acquired in step St13 (see CSI described above), the wireless resource (for example, carrier) is used for each terminal in wireless connection. The MCS when the frequency (frequency, resource block) is assigned is calculated (St34). That is, the base station 351 calculates the MCS, which is an existing radio parameter, based on the line state information of the downlink (DL) and the added SINR based on the consideration of interference, so that the steps St15 and St36 after step St34 In each process, the terminal can be assigned a radio resource based on a known PF algorithm, and compatibility with the existing radio resource allocation process can be improved.

The base station 351 reads the past time-series MCS value for each terminal (in other words, the value of a plurality of MCS for a certain time in the past) from the memory M1 and acquires it (St15). The memory M1 stores past time-series MCS values for each terminal (in other words, a plurality of MCS values for a certain period of time in the past).

The base station 351 uses the instantaneous (most recent) and each MCS value for a certain time in the past based on the added SINR for each terminal calculated in step St34, or the added SINR, respectively, according to the existing PF algorithm. Performs a process of allocating wireless resources (for example, carrier frequency, resource block) to the corresponding terminal of (St36). That is, the base station 351 is a terminal in which the ratio of the instantaneous (most recent) MCS value or added SINR for each terminal to the average value of a plurality of MCS values or added SINRs for a certain period of time in the past is relatively large. Radio resources are preferentially allocated to them. As a result, the base station 351 supplies wireless resources to each of the terminals TL1 to TLn that are wirelessly connected when performing wireless communication using a part of the shared frequency mainly or almost exclusively used by the PU system. Since the allocation frequency can be made uniform by the PF algorithm, wireless resources can be evenly allocated while ensuring fairness between terminals, and the shared frequency can be effectively used.

As described above, the SU system 3A (an example of a wireless system) according to the modified example of the third embodiment can use the shared frequency mainly used by the existing first wireless system under a predetermined shared condition. The SU system 3A wirelessly communicates with each of at least one terminals TL1 to TLn accommodated in the communication area SU2, and from the shared frequency management device 2 communicably connected to the PU systems PU3 and PU4. Shared conditions (for example, shared frequency usage conditions) that include the allowable transmission power of the signal calculated to the extent that interference with the PU systems PU3 and PU4 (for example, the maximum allowable transmission power P (θ) as a function of the transmission direction θ) is included. ) To get. The SU system 3A uses the above-mentioned shared conditions to set the transmission direction θ0 of the signal that minimizes the distance from the communication area SU2 to the reception sensitivity boundaries of the PU systems PU3 and PU4 by the base station 351 (for example, the direction determination unit). It is derived in the processor PRC2) as an example. The SU system 3A has a maximum allowable transmission power of the signal in the transmission direction θ0 of the derived signal (for example, the minimum allowable maximum transmission power P (θ0)) and an allowable transmission power of the signal (for example, the maximum allowable transmission power P (θ)). The difference between the above and the base station 351 (for example, the processor PRC2 as an example of the direction determination unit) is derived. The SU system 3A allocates wireless resources to the terminal based on the above-mentioned difference and the line status information reported from the terminal.

As a result, the SU system 3A has a minimum allowable maximum transmission power P (θ0) in the transmission direction θ0 that minimizes the allowable maximum transmission power P (θ) included in the shared frequency usage condition notified from the shared frequency management device 2. The radio resource management in the base station 351 (see FIG. 12) of the SU system 3A can be executed in consideration of the difference from the maximum allowable transmission power P (θ). Therefore, when the SU system 3A transmits a transmission signal from the communication area SU2 (for example, the center point), the transmission direction is such that the interference of the allowable interference level does not affect the first border B1 of each of the PU systems PU3 and PU4. Wireless communication can be performed using the maximum allowable transmission power P (θ) for each θ. That is, even if the SU system 3A cannot acquire information about each of the PU systems PU3 and PU4 from the shared frequency management device 2 (see the third embodiment), the SU system 3A does not interfere with each of the PU systems PU3 and PU4. It is possible to send a transmission signal with the transmission power of. For example, the SU system 3A can pseudo-expand the size of the area area of the second border B2 from the area BFB2 to the area AFB2 (see FIG. 11).

Further, the SU system 3A adds the above-mentioned difference (that is, "allowable maximum transmission power P (θ) -minimum allowable maximum transmission power P (θ0)") to the SINR between the base station 351 and the terminal. And the line status information reported from the terminal are used to calculate the radio parameters (for example, MCS value) corresponding to the radio resources. The SU system 3A allocates radio resources to the terminal based on the ratio of the MCS value based on the latest line state information of the terminal and the average value of the MCS value based on the average line state information of the past fixed time in the terminal. .. As a result, the SU system 3A is expected to maximize the throughput while reducing the interference area with respect to the PU systems PU3 and PU4 in view of the line state information of the downlink (DL) between the base station 351 and the terminal. At the same time, it is possible to efficiently allocate wireless resources to terminals while satisfying the fairness of allocation of wireless resources between terminals.

The shared conditions (for example, shared frequency usage conditions) are the maximum allowable transmission as a function of the transmission direction θ, which is calculated to the extent that the carrier frequency, the bandwidth, and the interference with the PU systems PU3 and PU4 are minimized. Includes power P (θ). As a result, the SU system 3A has a radio parameter (which minimizes interference with each of the PU systems PU3 and PU4 even if the information indicating the physical position of each of the PU systems PU3 and PU4 is not notified. (See above) can be selected, and wireless communication using a shared frequency can be stably performed within the communication area SU2.

Although the embodiments have been described above with reference to the accompanying drawings, the present disclosure is not limited to such examples. It is clear that a person skilled in the art can come up with various modifications, modifications, substitutions, additions, deletions, and equality examples within the scope of the claims. It is understood that it belongs to the technical scope of the present disclosure. Further, each component in the above-described embodiment may be arbitrarily combined as long as the gist of the invention is not deviated.

In the second embodiment described above, the radio wave sensors installed around the third border B3 of the SU system 3 are the beam direction of the radio signal (radio wave) transmitted from each of the base stations 351 to 35k and the third border. The purpose of creating a table (see FIG. 8) showing the correspondence between the reception levels (reception power) at each position around B3 in advance and the shared frequency usage conditions notified by the SU system 3 from the shared frequency management device 2 are set. It has two purposes: to enable the SU system 3 itself to monitor compliance during operation. It is not always necessary to use a plurality of radio wave sensors at the same time in creating the above-mentioned table (see FIG. 8), and at least one radio wave sensor (for example, radio wave sensor WS1) is installed while being moved to each position to determine the beam direction. The reception level of is measured. Further, a plurality of radio wave sensors (for example, radio wave sensors WS1 to WS5) may be installed at a plurality of positions around the third border B3 during operation, but the position where the reception level of the radio wave sensor is highest is specified and the position thereof is specified. It may be said that only one radio wave sensor (for example, radio wave sensor WS1) is installed at the position (for example, the application for using the shared frequency is executed using the maximum reception level). This is because the SU system 3 can monitor and comply with the maximum value of radio wave emission outside the third border B3 area.

For example, the first border B1 and the second border B2 are defined and described as the boundary of the position where the reception power becomes the reception sensitivity of the PU systems 1, 1A. For example, the value is 10 dB smaller than the reception sensitivity of the PU systems 1, 1A. It is also within the technical scope of the present disclosure to obtain an interference margin of 10 dB by defining it as the boundary of the position.

In the present disclosure, when the SU system uses at least a part of the shared frequency that can be preferentially used by the PU system, the transmission power is adaptively controlled according to the direction of wireless communication, and the utilization efficiency of the shared frequency is reduced. It is useful as a wireless system that can use the shared frequency to be suppressed and as a wireless resource allocation method in wireless communication using the shared frequency.

1 PU system 2 Shared frequency management device 3 SU system 11 PU transmitter 12, 24, 32, M1 Memory 13 PU receiver 21 B1 Derivation unit 22 B2 Derivation unit 23 Permitted frequency sharing condition determination unit 25 Topography and building geography data retention unit 26 Communication interface circuit 31 SU transmitter 33 SU receiver 51, 66 IF unit 52 Transmission BB signal processing unit 53 DAC
54 Modulator 55 Upconverter 56 PA
57, 61 BPF
58 Duplexer 62 Down converter 63 Demodulator 64 ADC
65 Reception BB signal processing unit 341, 342, 343, 344, WS1, WS2, WS3, WS4, WS5 Radio sensor 351, 35k Base station Ant1 Antenna PRC1, PRC2 Processor TL1, TLn terminal

Claims (16)

A wireless system in which the shared frequency mainly used by the existing first wireless system can be used under predetermined shared conditions.
A communication unit that wirelessly communicates with at least one terminal housed in the communication area of the wireless system.
At least one sensor arranged around the communication area and measuring the received power of a signal transmitted from within the communication area via the communication unit, and
A memory that stores beam data indicating the correspondence between the beam direction of the signal and the measurement result of the sensor, and
A determination unit that determines the maximum allowable transmission power of the signal for each beam direction based on the shared condition and the beam data.
It includes an allocation unit that allocates radio resources to the terminal based on the allowable maximum transmission power for each beam direction and the line state information reported from the terminal.
Wireless system. Further, an acquisition unit that acquires the shared condition including the allowable transmission power of the signal calculated to the extent of avoiding interference with the first wireless system from the shared frequency management device connected to the first wireless system. Prepare,
The determination unit determines the allowable maximum transmission power for each beam direction based on the allowable transmission power and the beam data.
The wireless system according to claim 1. The communication unit receives the line state information for each beam direction of the signal from the terminal, and receives the line state information.
The allocation unit allocates radio resources to the terminal based on the allowable maximum transmission power for each beam direction and the line state information for each beam direction reported from the terminal.
The wireless system according to claim 1. The allocation unit calculates the radio parameter corresponding to the radio resource by using the allowable maximum transmission power for each beam direction and the line state information reported from the terminal, and calculates the radio parameter corresponding to the radio resource, and the latest line state in the terminal. Allocate radio resources to the terminal based on the ratio of the information-based radio parameter to the radio parameter based on the average line status information for the past fixed time in the terminal.
The wireless system according to claim 1. The shared condition includes a carrier frequency, a bandwidth, and a maximum permissible received power of a signal at the sensor calculated to the extent that interference with the first radio system is minimized.
The wireless system according to any one of claims 1 to 4. It is a wireless resource allocation method in wireless communication of a wireless system in which a shared frequency mainly used by an existing first wireless system can be used under predetermined shared conditions.
A step of wireless communication with at least one terminal housed in the communication area of the wireless system,
A step of measuring the received power of a signal transmitted from within the communication area, which is arranged around the communication area, by at least one sensor.
A step of storing beam data indicating the correspondence between the beam direction of the signal and the measurement result of the sensor in the memory, and
A step of determining the allowable maximum transmission power of the signal for each beam direction based on the shared condition and the beam data, and
It has a step of allocating radio resources to the terminal based on the allowable maximum transmission power for each beam direction and the line state information reported from the terminal.
Radio resource allocation method. A base station in a wireless system that can use the shared frequency mainly used by the existing first wireless system under predetermined shared conditions.
A communication unit that wirelessly communicates with at least one terminal housed in the communication area of the wireless system.
Beam data showing the correspondence between the measurement result of the received power of the signal transmitted from the communication area through the communication unit by at least one sensor arranged around the communication area and the beam direction of the signal. Memory to store and
A determination unit that determines the maximum allowable transmission power of the signal for each beam direction based on the shared condition and the beam data.
It includes an allocation unit that allocates radio resources to the terminal based on the allowable maximum transmission power for each beam direction and the line state information reported from the terminal.
base station. A wireless system in which the shared frequency mainly used by the existing first wireless system can be used under predetermined shared conditions.
A communication unit that wirelessly communicates with at least one terminal housed in the communication area of the wireless system.
An acquisition unit that acquires information about the reception sensitivity boundary of the first wireless system, and
A direction determining unit that derives a signal transmission direction that minimizes the distance from the communication area of the wireless system to the reception sensitivity boundary of the first wireless system by using the information regarding the reception sensitivity boundary of the first wireless system.
A power determination unit that derives the maximum allowable transmission power of the signal in the transmission direction of the derived signal, and a power determination unit.
An allocation unit for allocating radio resources to the terminal based on the allowable maximum transmission power and the line state information reported from the terminal.
Wireless system. The allocation unit calculates the radio parameter corresponding to the radio resource by using the allowable maximum transmission power and the line state information reported from the terminal, and the radio parameter based on the latest line state information in the terminal. And the radio resources are allocated to the terminal based on the ratio with the radio parameter based on the average line state information for the past fixed time in the terminal.
The wireless system according to claim 8. A wireless system in which the shared frequency mainly used by the existing first wireless system can be used under predetermined shared conditions.
A communication unit that wirelessly communicates with at least one terminal housed in the communication area of the wireless system.
An acquisition unit that acquires a shared condition including an allowable transmission power of a signal calculated to the extent of avoiding interference with the first wireless system from a shared frequency management device connected to the first wireless system.
Using the shared conditions, a direction determining unit that derives a signal transmission direction that minimizes the distance from the communication area of the wireless system to the reception sensitivity boundary of the first wireless system, and
A derivation unit for deriving the difference between the allowable maximum transmission power of the signal in the transmission direction of the derived signal and the allowable transmission power of the signal.
An allocation unit that allocates radio resources to the terminal based on the difference and the line status information reported from the terminal is provided.
Wireless system. The allocation unit calculates the radio parameter corresponding to the radio resource by using the difference and the line state information reported from the terminal, and the radio parameter and the terminal based on the latest line state information in the terminal. Allocate radio resources to the terminal based on the ratio to the radio parameter based on the average line state information for the past fixed time in
The wireless system according to claim 10. The shared condition includes a carrier frequency, a bandwidth, and the allowable transmission power calculated to the extent that interference with the first radio system is minimized.
The wireless system according to claim 10 or 11. It is a wireless resource allocation method in wireless communication of a wireless system in which a shared frequency mainly used by an existing first wireless system can be used under predetermined shared conditions.
A step of wireless communication with at least one terminal housed in the communication area of the wireless system,
The step of acquiring information on the reception sensitivity boundary of the first wireless system, and
Using the information about the reception sensitivity boundary of the first wireless system, a step of deriving the transmission direction of the signal that minimizes the distance from the communication area of the wireless system to the reception sensitivity boundary of the first wireless system, and
A step of deriving the maximum allowable transmission power of the signal in the transmission direction of the derived signal, and
It has a step of allocating radio resources to the terminal based on the allowable maximum transmission power and the line state information reported from the terminal.
Radio resource allocation method. A base station in a wireless system that can use the shared frequency mainly used by the existing first wireless system under predetermined shared conditions.
A communication unit that wirelessly communicates with at least one terminal housed in the communication area of the wireless system.
An acquisition unit that acquires information about the reception sensitivity boundary of the first wireless system, and
A direction determining unit that derives a signal transmission direction that minimizes the distance from the communication area of the wireless system to the reception sensitivity boundary of the first wireless system by using the information regarding the reception sensitivity boundary of the first wireless system.
A power determination unit that derives the maximum allowable transmission power of the signal in the transmission direction of the derived signal, and a power determination unit.
An allocation unit for allocating radio resources to the terminal based on the allowable maximum transmission power and the line state information reported from the terminal.
base station. It is a wireless resource allocation method in wireless communication of a wireless system in which a shared frequency mainly used by an existing first wireless system can be used under predetermined shared conditions.
A step of wireless communication with at least one terminal housed in the communication area of the wireless system,
A step of acquiring a shared condition including an allowable transmission power of a signal calculated to the extent of avoiding interference with the first wireless system from a shared frequency management device connected to the first wireless system.
Using the shared conditions, a step of deriving the transmission direction of the signal that minimizes the distance from the communication area of the wireless system to the reception sensitivity boundary of the first wireless system, and
A step of deriving the difference between the allowable maximum transmission power of the signal in the transmission direction of the derived signal and the allowable transmission power of the signal.
It has a step of allocating wireless resources to the terminal based on the difference and the line status information reported from the terminal.
Radio resource allocation method. A base station in a wireless system that can use the shared frequency mainly used by the existing first wireless system under predetermined shared conditions.
A communication unit that wirelessly communicates with at least one terminal housed in the communication area of the wireless system.
An acquisition unit that acquires a shared condition including an allowable transmission power of a signal calculated to the extent of avoiding interference with the first wireless system from a shared frequency management device connected to the first wireless system.
Using the shared conditions, a direction determining unit for deriving the transmission direction of the signal that minimizes the distance from the communication area of the wireless system to the reception sensitivity boundary of the first wireless system, and
A derivation unit for deriving the difference between the allowable maximum transmission power of the signal in the transmission direction of the derived signal and the allowable transmission power of the signal.
An allocation unit that allocates radio resources to the terminal based on the difference and the line status information reported from the terminal is provided.
base station.

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