JP2020113856A - Management device, program to be executed by computer, and computer-readable recording medium having recorded program - Google Patents

Abstract

To provide a management device capable of accurately setting an exclusive area of a primary user.SOLUTION: Calculation means 102 of a management device 10 calculates interference power greater than a threshold value that a receiving station receives from all transmitting stations of secondary users as an interference probability to the receiving station which is a function of a percentage of the secondary user's transmitting stations allowed to transmit in each region that constitutes a 3D region with the receiving station of a primary user as an origin. Determination means 104 determines a transmission permission percentage in each region for minimizing the number of transmission stations for secondary users whose interference probability is less than a target value and whose transmissions are prohibited. Creation means 105 creates an exclusive region in which only the primary user can communicate wirelessly based on the determined transmission permission percentage. The calculation means 102 calculates the interference power by approximating a shape of each region to a three-dimensional shape represented in cylindrical coordinates having the same volume as each region.SELECTED DRAWING: Figure 3

Description

The present invention relates to a management device, a program to be executed by a computer, and a computer-readable recording medium recording the program.

With the expansion of applications of unmanned aerial vehicles (UAVs), the unlicensed frequency band currently used as the frequency band used by communication by unmanned aerial vehicles (hereinafter referred to as “UAV communication”). Secondary use of a certain high frequency band has been studied (Non-Patent Document 1).

This enables high-speed and large-capacity communication such as video shooting and delivery. As an example, in Japan, the use of the 5.7 GHz band currently used by radar is considered. In that case, it is necessary to analyze the interference given to the radar by the UAV communication and use it within a range that does not adversely affect the laser.

For such a problem of frequency sharing, a design of an exclusive area of a primary user has been proposed (Non-Patent Document 2). This is a method of avoiding interference with the primary user by prohibiting communication of the secondary user within the range defined in the exclusive area.

In Non-Patent Document 3, a two-dimensional space is finely divided by a grid, and information such as a primary user's antenna gain is distinguished for each grid to design an exclusive area having a complicated shape, and to increase the number of secondary areas. It indicates that the user can communicate.

Further, Non-Patent Document 4 proposes an exclusive area design method applicable to UAV communication by analyzing interference power in a three-dimensional space.

In the analysis of the interference power in Patent Document 2 to Non-Patent Document 4 described above, stochastic geometry (Non-Patent Documents 5 and 6) that handles spatial point processes is used.

Japanese Unexamined Patent Application Publication No. 2018-142956

The Information and Communication Council, “Technical requirements for upgrading of use of radio waves for robots, etc. (in Japanese),” Mar. 2016. M. Vu, N. Devroye, and V. Tarokh, “On the primary exclusive region of cognitive networks,” IEEE Trans. Commun., vol.8, no.7, pp3380-3385, Jul. 2009. S. Yamashita, K. Yamamoto, T. Nishio, and M. Morikura, “Optimization of primary exclusive region in spatial grid-based spectrum database using stochastic geometry,” Proc. IEEE ICC2017, Paris, France, May 2017. K. Yoshikawa, S. Yamashita, K. Yamamoto, T. Nishio, and M. Morikura, “Resource allocation for 3rd drone networks sharing spectrum bands,” Proc. IEEE VTC2017-fall, Toront, Canada, Sept. 2017. M. Haenggi, Stochastic Geometry for Wireless Networks, Cambridge Univ. Pr., Nov. 2012. H. ElSawy, E. Hossain, and M. Haenggi, “Stochastic geometry for modeling, analysis, and design of multi-tier and cognitive cellular wireless networks: A survey,” IEEE Commun. Surv. Tuts., vol. 15, no .3, pp. 996-1019, 2013. D. Schleher, “Generalized gram-charlier series with application to the sum of log-normal variates (corresp.),” IEEE Trans. Inf. Theory, vol.23, no.2, pp.275-280, May 1977. K.W.Sung, M. Tercero, and J. Zander, “Aggregate interference in secondary access with interference protection,” IEEE Commun. Lett., vol.15, no.6, pp.629-631, April 2011. M.K.Simon and M.-S.Alouini, Digital Communication over Fading Channels, John Wiley & Sons, Inc., 2004. P. Li, C. Zhang, and Y. Fang, “The capacity of wireless ad hoc networks using directional antennas,” IEEE Trans. Mobile Comput., vol.10, no.10, pp.1374-1387, Oct. 2011 . W.E.Hart, C. Laird, J.-P. Watson, and D.L. Woodruff, Pyomo Optimization Modeling in Python, vol.67, Springer Science & Business Media, 2012. A. W ¨achter and LT Biegler, “On the implementation of an interior-point filter line-search algorithm for large-scale nonlinear programming,” Math. Program., vol.106, no.1, pp.25-27, Mar. 2006.

However, it is difficult to accurately design the exclusive area with the exclusive area design methods in Non-Patent Documents 2 to 4.

According to the embodiment of the present invention, there is provided a management device capable of accurately setting an exclusive area of a primary user.

Further, according to the embodiment of the present invention, there is provided a program for causing a computer to accurately set the exclusive area of the primary user.

Further, according to the embodiment of the present invention, there is provided a computer-readable recording medium in which a program for causing a computer to accurately set the exclusive area of the primary user is recorded.

(Structure 1)
According to the embodiment of the present invention, the management device includes a calculation unit, a determination unit, and a creation unit.

The calculation means is distributed according to the non-uniform Poisson point process of the secondary user in each of the plurality of regions forming the three-dimensional region with the receiving station of the primary user as the origin, where the ratio of the coverage data is a constant value. Transmitting power of transmitting station, antenna gain at receiving station of primary user, fading coefficient between receiving station of primary user and transmitting station of secondary user, position and origin of transmitting station of secondary user Using the Euclidean distance between and, and the propagation loss index, the interference power in each of the plurality of regions is larger than the threshold value that the receiving station of the primary user receives from all the transmitting stations of the secondary user. It is calculated as the probability of interference with the receiving station of the primary user, which is a function of the transmission permission ratio of the transmitting station of the secondary user.

The deciding means sets a plurality of transmission permission ratios of the transmitting stations of the secondary user that minimizes the number of transmitting stations of the secondary user whose calculated interference probability is equal to or less than the target value and whose transmission is prohibited. Determine in each of the areas.

The creating means creates an exclusive area in which only the primary user can perform wireless communication based on the transmission permission ratio of the transmitting station of the secondary user in each of the plurality of determined areas.

Then, the calculation means calculates the interference power by approximating the shape of each of the plurality of regions to the three-dimensional shape represented by the cylindrical coordinates, which has the same volume as each of the plurality of regions.

(Configuration 2)
In the configuration 1, the calculation means includes the transmission power of the transmitting station of the secondary user, the antenna gain of the receiving station of the primary user, and the receiving station of the primary user and the secondary user in each of the plurality of regions. Using the fading coefficient with the transmitting station, the Euclidean distance between the position of the transmitting station of the secondary user and the origin, and the propagation loss index, the transmitting station of the secondary user in each of the plurality of areas uses the primary The first interference power given to the receiving station of the second person is calculated, and the n th (n is a positive integer) n th cumulant of the first interference power is calculated by using the Laplace transform of the first interference power. Is calculated as a function of the transmission permission ratio, and based on the calculated n-th order cumulant, the second is the interference power from all the transmitting stations of the secondary user to the receiving station of the primary user in a plurality of areas. An n-th order cumulant of the interference power is calculated, a probability density function of the second interference power is calculated based on the calculated n-th order cumulant of the interference power, and the parameter of the calculated probability density function is used. Calculate the interference probability.

(Structure 3)
In the configuration 2, the calculating means calculates the n-th order cumulant of the second interference power by calculating the sum of the first-order cumulant of the second interference power to the n-th order cumulant.

(Structure 4)
In any one of Configurations 1 to 3, the determining unit multiplies the number of transmitting stations transmitted by the secondary user in each of the plurality of regions by a probability that transmission by the transmitting station of the secondary user is prohibited. The addition result obtained by adding the results for a plurality of areas is used as the objective function, and transmission of the secondary user transmission station that minimizes the objective function is performed under the constraint condition that the calculated interference probability is smaller than the interference allowable value. By determining the permission ratio in each of the plurality of areas, the transmission permission ratio of the transmission station of the secondary user that minimizes the number of transmission stations of the secondary user whose transmission is prohibited is determined.

(Structure 5)
In any one of the configurations 1 to 4, the transmitting stations of the secondary users existing in the plurality of areas are in the first frequency band shared by the primary user and the secondary user based on the transmission permission ratio. Communication is permitted, and communication of only control information in the second frequency band, which is a lower frequency band than the first frequency band, is permitted based on the transmission prohibition rate determined from the transmission permission rate.

(Structure 6)
In any one of Configuration 1 to Configuration 5, each of the plurality of regions has a cubic shape. The computing means has a cubic shape in a three-dimensional shape having the same volume as that of the cube and having two arc-shaped curved surfaces protruding in a direction parallel to the ground and two planes arranged in the direction perpendicular to the ground. To approximate the interference power.

(Structure 7)
According to the embodiment of the present invention, the program is
The computing means distributes according to the non-uniform Poisson point process of the secondary user in each of the plurality of regions forming the three-dimensional region with the receiving station of the primary user as the origin, where the ratio of the interference data is a constant value. Transmitting power of transmitting station, antenna gain at receiving station of primary user, fading coefficient between receiving station of primary user and transmitting station of secondary user, position and origin of transmitting station of secondary user Using the Euclidean distance between and, and the propagation loss index, the interference power in each of the plurality of regions is larger than the threshold value that the receiving station of the primary user receives from all the transmitting stations of the secondary user. A first step of calculating as a probability of interference with the receiving station of the primary user, which is a function of the transmission permission ratio of the transmitting station of the secondary user,
The determining means minimizes the number of secondary user transmitting stations whose transmission is prohibited and the calculated interference probability is equal to or less than the target value, and sets a plurality of transmission permission ratios of the secondary user transmitting stations to a plurality of transmission permitting ratios. A second step of determining in each of the regions,
A third step in which the creating means creates an exclusive area in which only the primary user can perform wireless communication based on the transmission permission ratio of the transmitting station of the secondary user in each of the determined plurality of areas. And make the computer execute.

Then, in the first step, the calculating means has the same volume as each volume of the plurality of areas, and approximates each shape of the plurality of areas to the three-dimensional shape represented by the cylindrical coordinates to obtain the interference power. Is calculated.

(Structure 8)
In the configuration 7, in the first step, the calculating means is the transmission power of the transmitting station of the secondary user in each of the plurality of regions, the antenna gain in the receiving station of the primary user, and the receiving station of the primary user. Of the secondary user in each of the plurality of regions by using the fading coefficient between the transmission station of the secondary user and the transmission station of the secondary user, the Euclidean distance between the position of the transmission station of the secondary user and the origin, and the propagation loss index. The first interference power that the transmitting station gives to the receiving station of the primary user is calculated, and the nth (n is a positive integer)-order cumulant of the first interference power is calculated by using the Laplace transform of the first interference power. Calculate as a function of the transmission permission ratio of the transmitting station of the secondary user, and based on the calculated nth order cumulant, interference from all transmitting stations of the secondary user to the receiving station of the primary user in multiple areas. The n-th cumulant of the second interference power, which is electric power, is calculated, the probability density function of the second interference power is calculated based on the calculated n-th cumulant of the second interference power, and the calculated probability density The interference probability is calculated using the function parameters.

(Configuration 9)
In the configuration 8, the calculating means calculates the n-th order cumulant of the second interference power by calculating the sum of the first-order cumulant of the second interference power to the n-th order cumulant in the first step.

(Configuration 10)
In any one of the configurations 7 to 9, in the second step, the determining unit prohibits the transmission of the transmission station of the secondary user to the number of transmission stations of the secondary user in each of the plurality of areas. The secondary use that minimizes the objective function under the constraint that the calculated interference probability is smaller than the interference tolerance, and the addition result obtained by adding the multiplication result obtained by multiplying the probability of The transmission permission ratio of the secondary user's transmission station is determined in each of the plurality of areas to determine the transmission permission ratio of the secondary user's transmission station that minimizes the number of secondary user transmission stations whose transmission is prohibited. To do.

(Configuration 11)
In any one of the configurations 7 to 10, the transmitting stations of the secondary users existing in the plurality of areas are in the first frequency band shared by the primary user and the secondary user based on the transmission permission ratio. Communication is permitted, and communication of only control information in the second frequency band, which is a lower frequency band than the first frequency band, is permitted based on the transmission prohibition rate determined from the transmission permission rate.

(Configuration 12)
In any one of Configuration 7 to Configuration 11, each of the plurality of regions has a cubic shape. In the first step, the computing means has the same volume as the cube and has two curved arc-shaped curved surfaces protruding in a direction parallel to the ground and two planes arranged in a direction perpendicular to the ground. The interference power is calculated by approximating a cubic shape to a three-dimensional shape.

(Configuration 13)
Further, according to the embodiment of the present invention, the recording medium is a computer-readable recording medium in which the program according to any one of configurations 7 to 12 is recorded.

The exclusive area of the primary user can be set accurately.

It is the schematic which shows the communication apparatus in embodiment of this invention. It is a figure which shows an example of the system which has a space grid in embodiment of this invention. It is a block diagram of the management apparatus shown in FIG. It is a figure which shows the memory|storage method in the memory|storage means shown in FIG. It is a schematic diagram of a cylindrical grid. FIG. 6 is a plan view of surfaces S3 and S4 shown in FIG. 5. 6 is a flowchart for explaining a method of creating an exclusive area PER. 8 is a flowchart for explaining a detailed operation of step S1 shown in FIG. 7. 8 is a flowchart for explaining a detailed operation of step S2 shown in FIG. 7. 8 is a flowchart for explaining a detailed operation of step S3 shown in FIG. 7. It is a schematic diagram of a keyhole antenna. It is a figure which shows the antenna gain in each grid, and the transmission permission ratio of UAV which is a solution of an optimization problem. It is a figure which shows the relationship between an empirical cumulative distribution function and total interference electric power _Iijk . It is a figure which shows another relationship between an empirical cumulative distribution function and total interference electric power _Iijk . It is a diagram showing the relationship between the CCDF and total interference power _{I total.} It is a figure which shows the relationship between the number of UAVs transmitted, and the volume of each grid.

Embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts will be denoted by the same reference characters and description thereof will not be repeated.

FIG. 1 is a schematic diagram showing a communication device according to an embodiment of the present invention. Referring to FIG. 1, there are wireless communication systems WLC1 and WLC2. The wireless communication system WLC1 is a licensed wireless communication system and is called a "primary user". The wireless communication system WLC1 includes a wireless station 1 and terminals 2 and 3. The wireless station 1 is a primary user wireless station, and the terminals 2 and 3 are primary user terminals. The wireless station 1 and the terminals 2 and 3 wirelessly communicate with each other in the licensed frequency band.

The wireless communication system WLC2 is a wireless communication system that performs wireless communication in the frequency band of the primary user, and is called a "secondary user". The wireless communication system WLC2 includes a wireless station 11 and terminals 121 to 12s (s is an integer of 2 or more). The wireless station 11 is a wireless station of a secondary user, and the terminals 121 to 12s are terminals of a secondary user. The wireless station 11 and the terminals 121 to 12s wirelessly communicate with each other in the frequency band of the primary user. Further, the wireless station 11 and the terminals 121 to 12s perform wireless communication of only control information in a low frequency band that is a lower frequency band than the frequency band of the primary user. The frequency band of the primary user is, for example, the 5.7 GHz band, and the low frequency band is, for example, the 169 MHz band.

Each of the terminals 2 and 3 may receive a radio signal from the terminals 121 to 12s. Each of the terminals 2 and 3 detects its own position by using, for example, GPS (Global Positioning System), and transmits the detected own position to the wireless station 1.

The wireless station 1 receives the positions of the terminals 2 and 3 from the terminals 2 and 3, and transmits the received positions of the terminals 2 and 3 to the wireless station 11.

The management device 10 is arranged in the wireless station 11. Then, the management device 10 receives the positions of the terminals 2 and 3 from the wireless station 1. Further, the management device 10 receives the positions and transmission powers of the terminals 121 to 12s from the terminals 121 to 12s.

The management device 10 uses the positions of the terminals 2 and 3, the positions of the terminals 121 to 12s, and the transmission power of the terminals 121 to 12s, and an exclusive area in which only the primary user can perform wireless communication by a method described later. Create a PER (Primary Exclusive Region).

The terminals 121 to 12s, for example, detect their own positions using GPS and transmit the detected own positions to the management device 10. In addition, the terminals 121 to 12s detect the transmission power when wireless communication is performed, and transmit the detected transmission power to the management device 10.

FIG. 2 is a diagram showing an example of a system having a spatial grid according to the embodiment of the present invention. Referring to FIG. 2, the receiving station PR (Primary Receiver) of the primary user (either the terminal 2 or 3) is set as the origin O, and the space is divided into a plurality of grids GR by the orthogonal coordinates (x, y, z). To divide.

Each of the plurality of grids GR has a cubic shape with one side having a length of l, and is divided into N _x +1, N _y +1, N _z + 1 planes in the x, y, and z directions, respectively. At this time, the volume of each grid GR is l ³ , and each plane has x=x _i , i=0,..., N _x , y=y _j , j=0,..., N, respectively. It is expressed as _y , z=z _k , k=0,..., N _z .

One grid GR is represented by the following equation.

The volume of one grid GR is expressed as |V _ijk |. In the grid V _ijk , the UAV density is λ _ijk , the UAV transmission power is p _ijk , and the radar (primary user) antenna gain is g _ijk . Then, λ _ijk , p _ijk , and g _ijk are assumed to be constant values.

The distribution of the UAV is assumed to follow a non-uniform Poisson point process having an intensity function Λ _ijk (x, y, z) represented by the following equation.

Further, the transmission permission ratio of the UAV in the grid V _ijk is a _ijk . That is, in the UAV existing in the grid V _ijk , only the transmission permission ratio a _ijk is permitted to communicate in the high frequency band (=frequency band shared with the primary user), and only the ratio (1-a _ijk ) is control information. Communication in the low frequency band that allows only communication is permitted (that is, communication in the high frequency band (=frequency band shared with primary users) is prohibited).

By determining the transmission permission ratio a _ijk for all grid V _ijk, designing an exclusive area of the complex shape. In this case, in the grid V _ijk , the UAV communicating using the high frequency band follows a non-uniform Poisson point process with a strength function a _ijk Λ _ijk (x, y, z). This point process is described as Φ _ijk .

Secondary user of the transmission station ST (Secondary Transmitter) (1 single transmission station ST consists of either a terminal 121～12S) is assumed to be located at random in a plurality of grid _{V ijk.}

FIG. 3 is a block diagram of the management device 10 shown in FIG. With reference to FIG. 3, the management device 10 includes a reception unit 101, a calculation unit 102, a storage unit 103, a determination unit 104, and a creation unit 105.

The receiving means 101 receives the positions of the terminals 2 and 3 from the wireless station 1 and outputs the received positions of the terminals 2 and 3 to the calculating means 102. Further, the receiving unit 101 receives the positions and transmission powers of the terminals 121 to 12s from the terminals 121 to 12s, and outputs the received positions and transmission powers of the terminals 121 to 12s to the computing unit 102.

The calculating means 102 receives from the receiving means 101 the positions of the terminals 2 and 3, the positions of the terminals 121 to 12s, and the transmission power of the terminals 121 to 12s.

The calculation means 102 holds in advance the volume |V _ijk | of the grid V _ijk described in FIG.

The calculating means 102 arranges one of the terminals 2 and 3 as the receiving station PR of the primary user at the origin O of the three-dimensional space grid.

The arithmetic unit 102 based on the position of the terminal 121～12S, calculates the density lambda _ijk transmission station ST of the secondary user that is present in each grid _{V ijk.} Then, the calculating means 102 stores the calculated density λ _ijk of the transmitting stations ST of the secondary users in the storing means 103.

Further, the calculation means 102 stores the transmission power of the terminals 121 to 12s received from the reception means 101 in the storage means 103.

Further, the calculating means 102 uses the method described later to determine the probability of interference with the receiving station PR of the primary user, which is a function of the transmission permission ratio a _ijk of the transmitting station ST of the secondary user in each of the plurality of grids V _ijk. P(I _total >I _th ) is calculated, and the calculated interference probability P(I _total >I _th ) is output to the determination unit 104.

The storage means 103 receives the density λ _ijk of the transmitting stations ST of the secondary users and the transmission power of the terminals 121 to 12 s from the computing means 102, and receives the received density λ _ijk of the transmitting stations ST of the secondary users and the terminal 121. Store 12 s of transmit power.

The storage unit 103 also stores the antenna gain g _ijk in advance. The antenna gain g _ijk is a constant that affects the directivity of the antenna of the receiving station PR of the primary user and the antenna height of the receiving station PR of the primary user or the transmitting station ST of the secondary user, and is used for each grid. It is a value unique to _Vijk .

The determination unit 104 receives the interference probability P (I _total >I _th ) from the calculation unit 102. Then, the determining unit 104 minimizes the number of transmitting stations ST of secondary users whose transmission is prohibited because the interference probability P (I _total >I _th ) becomes smaller than the target value β _target. The transmission permission ratio a _ijk (0≦a _ijk ≦1) of the transmitting station ST of is determined in each of the plurality of grids V _ijk . Then, determination unit 104 outputs a transmission permission ratio _{a ijk} transmission station ST of the secondary user at each grid _{V ijk} to creation means 105.

The creating unit 105 receives from the determining unit 104 the transmission permission ratio a _ijk of the transmitting station ST of the secondary user in each grid V _ijk . Then, the creating unit 105 sets the grid V _{ijk in} which the transmission permission ratio a _ijk of the transmission station ST of the secondary user is zero as an exclusive area, and the transmission permission ratio a _ijk of the transmission station ST of the secondary user is not zero. An exclusive area PER is created on the three-dimensional space grid with the grid V _ijk as a non-exclusive area.

FIG. 4 is a diagram showing a storage method in the storage means 103 shown in FIG. With reference to FIG. 4, the storage unit 103 stores the density λ _ijk of the transmitting stations ST of the secondary users, the position Ps of the transmitting stations ST of the secondary users, the transmission power p _ijk of the secondary users, and the antenna gain g. _ijk , the radio wave loss index α, and the fading coefficient h _ijk are stored corresponding to each grid V _ijk .

Density lambda _ijk is the calculation means 102, the number of the transmitting station ST of the secondary user that exists in the grid _{V ijk} grid _{V ijk} volume _| is obtained by dividing the | _{V ijk.}

The position Ps of the transmitting station ST of the secondary user is determined by the cylindrical coordinates (r, θ, z). The transmission power p _ijk is an average value of the transmission power in the transmission stations ST existing in each grid V _ijk and is a constant value.

The antenna gain g _ijk is a constant value specific to each grid V _ijk . The fading coefficient h _ijk corresponds to the position Ps of the transmitting station ST of the secondary user. The radio wave loss index α is α>2.

A method of determining the transmission permission ratio a _ijk of the transmitting station ST of the secondary user in each of the plurality of grids V _ijk will be described.

The transmitting stations ST of secondary users transmitting on the grid V _ijk are distributed according to the non-uniform Poisson point process Φ _ijk having the intensity function a _ijk Λ _ijk (x, y, z).

As for interference to the primary user, total interference power I _total received from all transmitting secondary user's transmitting stations ST in the receiving station PR of the primary user exceeds the threshold value Ith. The threshold value I _th is set to a value 10 dB lower than the noise power, for example. At this time, the probability of interference with the primary user can be expressed as P(I _total >I _th ).

The total interference power I _total given to the radar (primary user) by the UAV that communicates using the high frequency band is represented by the following equation.

In Expression (3), I _ijk is the total interference power from the UAVs existing in the grid V _ijk and is represented by the following expression.

In Expression (4), h _x is a fading coefficient (average 1) between the UAV of the coordinate sεΦ _Vijk and the radar (first-order user), and ||d|| is the coordinate dεR ² Is the Euclidean distance between the origin and the origin O, and α is the propagation loss index (α>2).

To determine the distribution of the total interference power _{I total,} to calculate the n-th order cumulant of the total interference power _{I total.} For that purpose, first, the nth order cumulant of the total interference power I _ijk is calculated.

The Laplace transform of the total interference power I _ijk can be calculated using the Campbell's theorem (Non-Patent Document 5) as in the following equation.

Using the equation (5), the n-th order cumulant κ _n (I _ijk ) of the total interference power I _ijk can be expressed as the following equation for n=1, 2 _,.

E in the formula (6) ^{(h n)} is expressed by the following equation.

Further, A _n (V) in the equation (6) is represented by the following equation.

Here, f _h (h) in the equation (7) is a probability density function of the fading coefficient h. Further, since V _ijk is a random variable independent of each other, the n th order cumulant of the _total interference power I _total is obtained as the sum of each cumulant by the following equation.

Next, formula (8) is calculated. When the shape of the grid V _ijk is a cube, because it is difficult to determine the integral of A n _(V) directly calculates the integral of A _{n (V)} based on the following approximation.

FIG. 5 is a schematic diagram of a cylindrical grid. The cubic grid V _ijk is approximated to a cylindrical grid as shown in FIG. 5 to allow integration.

With reference to FIG. 5, the cylindrical grid Cy has the same volume as the volume of the grid _Vijk shown in FIG. 2, and is formed of a three-dimensional shape surrounded by six surfaces S1 to S6. The surface S1 is a curved surface having vertices A, B, C, D, the surface S2 is a curved surface having vertices E, F, G, H, and the surface S3 has vertices A, E, H, D. It is a plane. The surface S4 is a plane having vertices B, F, G, C, the surface S5 is a plane having vertices A, E, F, B, and the surface S6 is a vertex C, D, H, G. Is a plane having.

The surfaces S1 and S2 are arranged along the z-axis direction and face each other. The surfaces S3 and S4 are arranged parallel to the xy plane and face each other. The surfaces S5 and S6 are arranged along the z-axis direction. Each of the surfaces S5 and S6 has a square shape with a side length of l.

FIG. 6 is a plan view of the surfaces S3 and S4 shown in FIG. Since the grid V _ijk shown in FIG. 2 has a cubic shape, the bottom surface and the top surface of the cube have a square planar shape.

On the other hand, the cylindrical grid Cy has an annular fan-shaped planar shape in which the length of the arc increases in the direction away from the origin O.

The cylindrical grid Cy satisfies the following conditions on the xy plane.
(1) The intersection that connects the midpoints in the radial direction and the circumferential direction is equal to the intersection of the diagonal lines in the square. The coordinates are (x _io , y _jo )=((2 _i +1)l/2, (2 _j +1)l/2) in _Cartesian coordinates, and (r _{ij o} , θ _ijo )=((x _io ² +y _jo ² ) ^1/2 , arctan(2 _i +1)/(2 _j +1)).
(2) The radial length is l.
(3) The central angle of the arc is 1/r _ijo .

By approximating the shape of the grid V _ijk shown in FIG. 2 to the shape of the cylindrical grid Cy shown in FIGS. 5 and 6, the integral of the equation (8) is approximated by the following equation.

The expression (10) can be integrated because (r ² +z ² ) ^1/2 representing the distance from the origin to each grid V _ijk is included in the integration. Then, the expression (10) includes (r ² +z ² ) ^1/2 in the integral because the grid coordinates V _ijk are represented by cylindrical coordinates (r, θ, z) as shown in FIGS. 5 and 6. Because it was represented by.

Further, the equation (10) can be calculated when α>2. As a simple example, when α=3, the first-order cumulant and the second-order cumulant become as shown in Expression (11) and Expression (12), respectively.

B(r) in the equation (11) is represented by the following equation.

Further, c(r) in the equation (12) is represented by the following equation.

From the above, the cumulant κ _n (I _total ) can be analytically obtained.

The distribution of total interference power I _total is approximately calculated using cumulant matching. Cumulant matching is a method of approximating the distribution by matching an nth-order cumulant of a desired distribution with an n-th order cumulant of a well-known distribution (Non-Patent Document 7).

In the embodiment of the present invention, as described in Non-Patent Document 8, the distribution of the total interference power I _total is obtained by matching with the lognormal distribution. In this case, the probability density function pdf _{f Itotal} of the total interference power _{I total} is expressed by the following equation.

Μ ₁ in Expression (15) is represented by the following expression.

Further, sigma ₁ ² of the formula (15) is expressed by the following equation.

Note that the expression “κ ₁ (I _total ) ² ” in Expressions (16) and (17) means the square of κ ₁ (I _total ).

The interference probability is defined as P (I _total >I _th ) as the probability that the _total interference power I _total given to the radar (primary user) by all the UAVs communicating in the high frequency band exceeds the threshold value I _th. .. As a result, the interference probability P (I _total >I _th ) is expressed by the following equation.

Q(·) in the equation (18) is a Q function and is represented by the following equation.

The interference probability P (I _total >I _th ) with respect to the threshold value I _th is the same as the complementary cumulative distribution function (CCDF) of the total interference power I _total .

The threshold value I _th of the equation (18) is known, μ ₁ of the equation (18) is represented by the equation (16), and σ ₁ of the equation (18) is represented by the equation (17), Since κ ₁ (I _total ) and κ ₂ (I _total ) in equations (16) and (17) are represented by equations (11) and (12), respectively, the interference probability P(I _total >I). It can be seen that _th ) is a function of the transmission permission ratio a _ijk . Therefore, the interference probability P(I _total >I _th ) can be calculated by the equations (11), (12), (16) to (19).

In order to set the exclusive area, an optimization problem for determining the transmission permission ratio a _ijk in each grid V _ijk is formulated.

The objective function is the number of UAVs UAV _p whose transmission is prohibited in the high frequency band, and is defined by the following equation.

Then, the transmission permission ratio a _ijk in each grid V _ijk is determined so as to minimize the number UAV _p of UAVs.

Further, a value that allows the interference probability P(I _total >I _th ) to be β _target , and the constraint condition is that the interference probability P (I _total >I _th ) be _less than the allowable value β _target .

From the above, the optimization problem is formulated as shown in equations (21) and (22).

That is, the transmission permission ratio a _ijk satisfying the expression (21) under the constraint condition of the expression (22) is obtained for each grid V _ijk .

The calculating means 102 calculates the interference probability P(I _total >I _th ) by the above-described method, and outputs the calculated interference probability P(I _total >I _th ) to the determining means 104.

The determining means 104 receives the interference probability P(I _total >I _th ) from the calculating means 102, and uses the equations (21) and (22) based on the received interference probability P (I _total >I _th ). Then, the transmission permission ratio a _ijk that minimizes the number UAV _{p of} which transmission is prohibited is obtained for each grid V _ijk , and the obtained transmission permission ratio a _ijk (V _ijk )(=transmission permission in each grid V _ijk Ratio) to the creating means 105.

The creation unit 105 receives the transmission permission ratio a _ijk (V _ijk ) in each grid V _ijk from the determination unit 104, and based on the received transmission permission ratio a _ijk (V _ijk ), in the spatial grid shown in FIG. Create an exclusive area where only the primary user can communicate. More specifically, creation means 105, by the transmission permission ratio _{a ijk} is a grid _{V ijk} exclusive area is zero, the grid _{V ijk} transmission permission ratio _{a ijk} is not zero and nonexclusive region, FIG. 2 In the spatial grid shown in, an exclusive area where only the primary user can communicate is created.

FIG. 7 is a flowchart for explaining a method of creating the exclusive area PER. With reference to FIG. 7, when the operation of creating the exclusive area PER is started, the arithmetic means 102 outputs 2 in each of the plurality of grids forming the three-dimensional spatial grid with the receiving station of the primary user as the origin. Transmit power of transmitting station distributed according to non-uniform Poisson point process of secondary user, antenna gain at receiving station of primary user, fading between receiving station of primary user and transmitting station of secondary user A threshold value that the receiving station of the primary user receives from all transmitting stations of the secondary user using the coefficient, the Euclidean distance between the position of the transmitting station of the secondary user and the origin, and the propagation loss index. A larger interference power is calculated as an interference probability to the receiving station of the primary user, which is a function of the transmission permission ratio of the transmitting station of the secondary user in each of the plurality of grids (step S1).

Then, the calculating means 102 outputs the calculated interference probability to the determining means 104. The determining unit 104 receives the interference probability from the calculating unit 102. Then, the determining unit 104 minimizes the number of transmitting stations of the secondary user whose calculated interference probability is smaller than the target value and which prohibits the use of the high frequency band. The transmission permission ratio of the station is determined in each of the plurality of grids (step S2).

After that, the determining unit 104 outputs the transmission permission ratio determined in each grid to the creating unit 105. The creation unit 105 receives the transmission permission ratio determined in each grid from the determination unit 104, and creates an exclusive area in which only the primary user can perform wireless communication based on the received transmission permission ratio (( Step S3). This completes the operation of creating the exclusive area PER.

FIG. 8 is a flowchart for explaining the detailed operation of step S1 shown in FIG. With reference to FIG. 8, when the operation of creating the exclusive area PER is started, the calculation means 102 sets i=0, j=0, and k=0 (step S11).

Then, the calculating means 102 calculates the Euclidean distance d between the position Ps of the secondary user existing in the grid V _ijk and the origin (step S12). More specifically, the calculation unit 102 reads the position Ps (see FIG. 4) of the secondary user associated with the grid V _ijk from the storage unit 103, and based on the read position Ps of the secondary user. Then, the Euclidean distance d is calculated.

After step S12, the arithmetic unit 102, the transmission power _{p ijk} in the grid _{V ijk,} antenna gain _{g ijk,} fading coefficients _{h ijk,} using the Euclidean distance d and the propagation loss exponent alpha, the interference power _{I ijk} in the grid _{V ijk} Calculate (step S13). More specifically, the calculation means 102 reads out the transmission power p _ijk , the antenna gain g _ijk and the fading coefficient h _ijk (see FIG. 4) associated with the grid V _ijk from the storage means 103, and the read transmission power. The interference power I _ijk is calculated by substituting p _ijk , the antenna gain g _{ijk, the} fading coefficient h _ijk , the Euclidean distance d, and the propagation loss index α into the equation (4).

After step S13, the arithmetic unit 102, the shape of the grid _{V ijk} consisting cubic approximates the shape of a cylinder grid, interference power n order cumulant of the interference power _{I ijk} using Laplace transform _{L ijk} of _{I ijk} kappa _n (I _ijk ) is calculated (step S14). More specifically, the calculation means 102 calculates the nth-order cumulant κ _n (I _ijk ) of the interference power I _ijk using the formulas (5) to (7) and (10).

Then, the calculation means 102 determines whether i=N _r −1 (step S15). When it is determined in step S15 that i=N _r -1 is not established, the calculation means 102 sets i=i+1 (step S16).

After that, the series of operations proceeds to step S12, and steps S12 to S16 are repeatedly executed until it is determined in step S15 that i=N _r −1.

Then, in step S15, when it is determined that i=N _r −1, the calculation means 102 determines whether j=N _θ −1 (step S17).

When it is determined in step S17 that j=N _θ −1 is not established, the calculation means 102 sets j=j+1 (step S18).

After that, the series of operations proceeds to step S12, and steps S12 to S18 are repeatedly executed until it is determined in step S17 that j=N _θ −1.

Then, when it is determined in step S17 that j=N _θ −1, the calculation means 102 determines whether k=N _z −1 (step S19).

When it is determined in step S19 that k=N _z -1 is not established, the calculation means 102 sets k=k+1 (step S20). After that, the series of operations proceeds to step S12, and steps S12 to S20 are repeatedly executed until it is determined in step S19 that k=N _z −1.

Then, in step S19, when it is determined that k=N _z −1, the calculation unit 102 determines, based on the nth-order cumulant κ _n (I _ijk ), all of the secondary users in the plurality of grids V _ijk . The n-th order cumulant κ _n (I _total ) of the total interference power I _total , which is the interference power from the transmitting station to the receiving station of the primary user, is analytically obtained (step S21). More specifically, the arithmetic means 102 analytically obtains the nth order cumulant κ _n (I _total ) of the total interference power I _total using the equations (10) and (11) to (14).

After that, the calculating means 102 calculates the probability density function of the _total interference power I _{total according} to the equations (15) to (17) based on the nth order cumulant κ _n (I _total ), and the calculated probability density function of The interference probability P (I _total >I _th ) is calculated using the parameters μ ₁ and σ ₁ (step S22). More specifically, the interference probability P (I _total >I _th ) is calculated by substituting the parameters μ ₁ and σ ₁ into the equations (18) and (19). Then, after step S22, the series of operations proceeds to step S2 in FIG.

FIG. 9 is a flowchart for explaining the detailed operation of step S2 shown in FIG.

With reference to FIG. 9, after step S1 shown in FIG. 7, the determination unit 104 determines the number (λ _ijk |V _ijk |) of transmitting stations ST transmitted by the secondary user in each of the plurality of grids V _ijk. , The addition result obtained by adding the multiplication result obtained by multiplying the ratio (1-a _ijk ) of the transmission stations ST of the secondary users who are prohibited from transmitting in the high frequency band for a plurality of grids V _ijk is calculated as an objective function (step S31). More specifically, the determining unit 104 calculates the objective function by the equation (20).

Then, the determining unit 104 sets the constraint condition shown in Expression (22) based on the interference probability P (I _total >I _th ) received from the calculating unit 102 (step S32).

After that, the determining unit 104 determines the transmission permission ratio a _ijk that minimizes the objective function under the set constraint condition (step S33). More specifically, the determining unit 104 determines the transmission permission ratio a _ijk satisfying the expression (21) under the constraint condition shown in the expression (22). The determined transmission permission ratio a _ijk is the transmission permission ratio in each grid V _ijk , and is composed of “0” or “1”. Then, the series of operations moves to step S3 in FIG.

FIG. 10 is a flowchart for explaining the detailed operation of step S3 shown in FIG.

With reference to FIG. 10, after step S2 shown in FIG. 7, the creating unit 105 sets i=0, j=0 and k=0 (step S41).

Then, the creating unit 105 determines whether or not the transmission permission ratio a _ijk is zero (=0) (step S42).

When it is determined in step S42 that the transmission permission ratio a _ijk is zero (=0), the creating unit 105 sets the grid V _ijk as an exclusive area (step S43).

On the other hand, when it is determined in step S42 that the transmission permission ratio a _ijk is not zero (=0), the creating unit 105 sets the grid V _ijk as a non-exclusive area (step S44).

After step S43 or step S44, the creating unit 105 determines whether i=N _r −1 (step S45). When it is determined in step S45 that i=N _r -1 is not established, the creating unit 105 sets i=i+1 (step S46).

Thereafter, the series of operations proceeds to step S42, and steps S42 to S46 are repeatedly executed until it is determined in step S45 that i=N _r −1.

Then, when it is determined in step S45 that i=N _r −1, the creating unit 105 determines whether j=N _θ −1 (step S47 ).

When it is determined in step S47 that j=N _θ −1 is not satisfied, the creating unit 105 sets j=j+1 (step S48).

After that, the series of operations proceeds to step S42, and steps S42 to S48 are repeatedly executed until it is determined in step S47 that j=N _θ −1.

Then, when it is determined in step S47 that j=N _θ −1, the creating unit 105 determines whether k=N _z −1 (step S49).

When it is determined in step S49 that k=N _z -1 is not established, the creating unit 105 sets k=k+1 (step S50). After that, the series of operations proceeds to step S42, and steps S42 to S50 are repeatedly executed until it is determined in step S49 that k=N _z −1.

Then, when it is determined in step S49 that k=N _z −1, the creating unit 105 creates the exclusive area of the primary user including the grid V _{ijk as} the exclusive area in the three-dimensional space grid ( Step S51). After that, the series of operations shifts to "end" in FIG.

As described above, the management device 10 determines whether each of the plurality of grids V _ijk is an exclusive area or a non-exclusive area according to the flowchart shown in FIG. 7 (including the flowcharts shown in FIGS. 8 to 10 ), The exclusive area PER of the primary user, which is composed of the grid V _{ijk as} the exclusive area, is created in the three-dimensional space grid. Therefore, the exclusive area PER of the primary user having a complicated shape can be created.

FIG. 16 of Patent Document 1 shows a three-dimensional space grid having a cylindrical shape, but the plurality of regions forming this three-dimensional space grid do not have the same volume as each other, and the volume of one region is the origin. It increases as it moves away from O in the radial direction.

As a result, the region existing at a position distant from the origin O in the radial direction has a larger volume than the region existing at a position close to the origin O, and thus the entire region having a larger volume is set as the exclusive region.

Therefore, in Patent Document 1, the exclusion area is finely set at a position close to the origin O, and the exclusion area is roughly set at a position far from the origin O in the radial direction. Therefore, the accuracy of the exclusion area in Patent Document 1 varies depending on the distance from the origin O in the radial direction, and the accuracy of the exclusion area decreases as the distance from the origin O in the radial direction increases.

On the other hand, in embodiments of the present invention, a plurality of grid V _ijk constituting the three-dimensional spatial grid has mutually the same volume (= l ^3), as shown in FIG. As a result, the exclusion area can be set with a constant accuracy regardless of the distance from the origin O in both the radial direction and the height direction. If the length l of one side of one grid V _ijk is shortened, the exclusion area can be set with higher accuracy and with a constant accuracy regardless of the distance from the origin O.

Therefore, the exclusion area setting method according to the embodiment of the present invention is a method capable of setting the exclusion area with higher accuracy than the exclusion area setting method described in Patent Document 1.

The management device 10 creates the exclusive area PER of the primary user by the method described above. Then, when the secondary user existing outside the created exclusive area PER of the primary user makes a communication availability inquiry, the management device 10 sends a notification indicating that communication is possible to the secondary user. It may be transmitted to.

Numerical evaluation of the transmission permission ratio a _ijk as the optimum solution obtained under the constraint condition will be described. Further, the interference probability of the radar with respect to the set exclusive area PER is evaluated by Monte Carlo simulation.

[Evaluation specifications]
As fading, composite fading of Nakagami m fading and logarithmic normal shadowing (Non-Patent Document 9) is assumed. In this case, E ^{(h n),} considering E (h) = 1, it is expressed by the following equation (Non-Patent Document 9).

In Expression (23), Γ(·) is a gamma function, m _N is a parameter for Nakagami m fading, σ _S,dB is a parameter in dB unit of lognormal shadowing, and ξ= It is 10/ln(10).

FIG. 11 is a schematic diagram of a keyhole antenna. As a radar antenna pattern, the keyhole antenna shown in FIG. 11 (Non-Patent Document 10) is used.

When the gains of the main lobe and the side lobes are G _m and G _S , respectively, and the beam width is θ _d , the antenna gain g(r, θ, φ) is represented by the following equation.

Then, the following equation holds between the gain G _{m of the} main lobe and the gain G _{S of the} side lobe.

When calculating g _ijk , the maximum value of the antenna gain in grid V _ijk is used as the roast case. That is, g _ijk is determined by the following equation.

Further, in order to pay attention to the influence of the antenna gain on the exclusion area, constant values are used for the density λ _ijk and the transmission power p _ijk .

The optimization problem (equation (21)) is implemented in Python using a modeling framework Pyomo (Non-Patent Document 11), and solved using an Interior Point Optimizer (IPOPT) solver (Non-Patent Document 12). Table 1 shows the evaluation specifications.

[Exclusive area design]
FIG. 12 is a diagram showing the antenna gain in each grid and the transmission permission ratio of the UAV which is the solution of the optimization problem. In FIG. 12, for comparison, the antenna gain and the transmission permission ratio are shown for some heights.

With reference to FIG. 12, an exclusion area is designed according to the distance to the radar (primary user) at a low altitude, and an exclusion area considering antenna gain is designed at a high altitude.

About the approximation in the shape of the grid mentioned above, the error is verified by Monte Carlo simulation.

FIG. 13 is a diagram showing the relationship between the empirical cumulative distribution function and the total interference power I _ijk . In FIG. 13, the vertical axis represents the empirical cumulative distribution function, and the horizontal axis represents the total interference power I _ijk . The solid line shows the relationship between the empirical cumulative distribution function and the total interference power I _ijk when the grid shape is a cube, and the dotted line shows the empirical cumulative distribution function and total interference when the grid shape is an approximate shape. The relationship with the electric power I _ijk is shown. Note that FIG. 13 shows an empirical cumulative distribution function (ECDF) of interference power from a grid near the radar (a grid in which the distance from the origin to the center of the grid is 1.56 km).

FIG. 14 is a diagram showing another relationship between the empirical cumulative distribution function and the total interference power I _ijk . In FIG. 14, the vertical axis represents the empirical cumulative distribution function, and the horizontal axis represents the total interference power I _ijk . The solid line shows the relationship between the empirical cumulative distribution function and the total interference power I _ijk when the grid shape is a cube, and the dotted line shows the empirical cumulative distribution function and total interference when the grid shape is an approximate shape. The relationship with the electric power I _ijk is shown. Note that FIG. 14 shows an empirical cumulative distribution function (ECDF) of the interference power from a grid far from the radar (a grid in which the distance from the origin to the center of the grid is 2.83 km).

As shown in FIGS. 13 and 14, it can be seen that the error is small when the grid shape is a cube and when the grid shape is an approximate shape, regardless of whether the grid is near or far from the origin.

In the designed exclusive area, the CCDF of the total interference power represented by the equation (18) is evaluated by Monte Carlo simulation. FIG. 15 is a diagram showing the relationship between CCDF and total interference power I _total . In FIG. 15, the vertical axis represents CCDF and the horizontal axis represents total interference power I _total . Further, the solid line shows the CCDF by the analytical formula, and the dotted line shows the CCDF by the simulation.

With reference to FIG. 15, it can be confirmed that the interference power is below the set threshold value. As the cause of the error with the analytical expression, in addition to the approximation in the grid shape, the approximation error due to cumulant matching and the error due to the worst case of the antenna gain are considered.

The comparison with the cylindrical grid will be described. FIG. 16 is a diagram showing the relationship between the number of UAVs to be transmitted and the volume of each grid. In FIG. 16, the vertical axis represents the number of UAVs to be transmitted, and the horizontal axis represents the volume of each grid. The white circles indicate the relationship between the number of UAVs to be transmitted and the volume of each grid when the grid shape is a cube, and the black circles are the number of UAVs to be transmitted and each grid when the grid shape is a cylinder. Shows the relationship with the volume of.

An exclusive area PER was designed for each of the cubic grid division according to the embodiment of the present invention and the grid division based on the cylindrical coordinates as disclosed in Patent Document 1, and the number of transmittable UAVs was compared.

As the antenna pattern, the keyhole antenna shown in FIG. 11 was used in which the direction of the main lobe was inclined by π/4 in the θ direction.

With reference to FIG. 16, it was confirmed that in both cases, the smaller the grid volume, that is, the larger the number of divisions, the larger the number of UAVs that can be transmitted.

It was also confirmed that, in the same volume, the cubic grid can transmit more UAVs than the cylindrical grid. It is considered that this is due to the difference in grid shape. The cubic grid has the same grid shape at all coordinates, whereas the cylindrical grid changes its shape as it moves away from the center. It can be approximated by a shape close to the antenna pattern of. Therefore, the area treated as the main lobe becomes smaller and the exclusive area PER becomes smaller, so that the number of transmittable UAVs increases.

As described above, it can be demonstrated that the number of UAVs that can be transmitted can be increased by using the cubic grid according to the embodiment of the present invention as compared with the case where the grid shape is a cylinder.

In the embodiment of the present invention, the operation of management device 10 may be executed by software. In this case, the management device 10 includes a CPU (Central Processing Unit), a ROM (read only memory), and a RAM (Random Access Memory).

The ROM stores a program Prog_A including the flowchart shown in FIG. 7 (including the flowcharts shown in FIGS. 8 to 10). In addition, the density λ _ijk of the transmitting station ST of the secondary user, the position Ps of the transmitting station ST of the secondary user, the transmission power p _ijk of the secondary user, the antenna gain g _ijk , and the propagation loss index α shown in FIG. And the fading coefficient h _ijk is stored in the ROM in association with the grid V _ijk .

The CPU reads the program Prog_A from the ROM, executes the read program Prog_A, and creates the exclusive area PER by the method described above.

In this case, the RAM temporarily stores the calculation result in the middle of the calculation of the interference probability P (I _total >I _th ). Further, the RAM temporarily stores the determined transmission permission ratio a _ijk .

Therefore, the program Prog_A is a program for causing the computer (CPU) to execute the creation of the exclusive area PER.

The program Prog_A may be recorded in a recording medium such as a CD and a DVD and distributed. In this case, the computer (CPU) reads the program Prog_A from the recording medium and executes it to create the exclusive area PER. Therefore, a CD, a DVD, or the like having the program Prog_A recorded therein is a computer (CPU) readable recording medium having the program Prog_A recorded therein.

In the above description, it is explained that the management device 10 is arranged in the wireless station 11, but the embodiment of the present invention is not limited to this, and the management device 10 is arranged in a place different from the wireless station 11. Alternatively, they may be arranged independently.

Further, in the above description, the primary user has been described as a licensed wireless communication system, but the embodiment of the present invention is not limited to this, and the primary user may interfere with the outside of the exclusion area. It suffices if the wireless communication system has a constant value of the data indicating the.

Furthermore, in the above description, each grid V _ijk has been described to have a cubic shape, but the embodiment of the present invention is not limited to this, and each grid V _ijk has two cubes in the height direction of the cube. The surface may have a three-dimensional shape having two curved surfaces that are convex upward or convex downward, or may have a rectangular parallelepiped shape. Generally, it is a three-dimensional shape represented by cylindrical coordinates. It may have any three-dimensional shape as long as it can approximate the shape.

According to the embodiment of the present invention, management device 10 may have the following configuration.

(Structure 1)
The management device includes a calculation unit, a determination unit, and a creation unit.

The calculating means is distributed according to the non-uniform Poisson point process of the secondary user in each of the plurality of regions forming the three-dimensional region with the receiving station of the primary user as the origin, where the ratio of the coverage data is a constant value. Transmission power of transmitting station, antenna gain at receiving station of primary user, fading coefficient between receiving station of primary user and transmitting station of secondary user, position and origin of transmitting station of secondary user Using the Euclidean distance with and the propagation loss index, the interference power in each of the plurality of regions is larger than the threshold value that the receiving station of the primary user receives from all the transmitting stations of the secondary user. It is calculated as the probability of interference with the receiving station of the primary user, which is a function of the transmission permission ratio of the transmitting station of the secondary user.

The deciding means sets a plurality of transmission permission ratios of the transmitting stations of the secondary user that minimizes the number of transmitting stations of the secondary user whose calculated interference probability is equal to or less than the target value and whose transmission is prohibited. Determine in each of the areas.

The creating means creates an exclusive area in which only the primary user can perform wireless communication based on the transmission permission ratio of the transmitting station of the secondary user in each of the plurality of determined areas.

Then, the calculation means calculates the interference power by approximating the shape of each of the plurality of regions to the three-dimensional shape represented by the cylindrical coordinates, which has the same volume as each of the plurality of regions.

(Configuration 2)
In the configuration 1, the calculation means includes the transmission power of the transmitting station of the secondary user, the antenna gain of the receiving station of the primary user, and the receiving station of the primary user and the secondary user in each of the plurality of regions. Using the fading coefficient with the transmitting station, the Euclidean distance between the position of the transmitting station of the secondary user and the origin, and the propagation loss index, the transmitting station of the secondary user in each of the plurality of areas uses the primary The first interference power given to the receiving station of the second person is calculated, and the n th (n is a positive integer) n th cumulant of the first interference power is calculated by using the Laplace transform of the first interference power. Is calculated as a function of the transmission permission ratio, and based on the calculated n-th order cumulant, the second is the interference power from all the transmitting stations of the secondary user to the receiving station of the primary user in a plurality of areas. An n-th order cumulant of the interference power is calculated, a probability density function of the second interference power is calculated based on the calculated n-th order cumulant of the interference power, and the parameter of the calculated probability density function is used. Calculate the interference probability.

(Structure 3)
In the configuration 2, the calculating means calculates the n-th order cumulant of the second interference power by calculating the sum of the first-order cumulant of the second interference power to the n-th order cumulant.

(Structure 4)
In any one of Configurations 1 to 3, the determining unit multiplies the number of transmitting stations transmitted by the secondary user in each of the plurality of regions by a probability that transmission by the transmitting station of the secondary user is prohibited. The addition result obtained by adding the results for a plurality of areas is used as the objective function, and transmission of the secondary user transmission station that minimizes the objective function is performed under the constraint condition that the calculated interference probability is smaller than the interference allowable value. By determining the permission ratio in each of the plurality of areas, the transmission permission ratio of the transmission station of the secondary user that minimizes the number of transmission stations of the secondary user whose transmission is prohibited is determined.

(Structure 5)
In any one of the configurations 1 to 4, the transmitting stations of the secondary users existing in the plurality of areas are in the first frequency band shared by the primary user and the secondary user based on the transmission permission ratio. Communication is permitted, and communication of only control information in the second frequency band, which is a lower frequency band than the first frequency band, is permitted based on the transmission prohibition rate determined from the transmission permission rate.

(Structure 6)
In any one of Configuration 1 to Configuration 5, each of the plurality of regions has a cubic shape. The computing means has a cubic shape in a three-dimensional shape having the same volume as that of the cube and having two arc-shaped curved surfaces protruding in a direction parallel to the ground and two planes arranged in the direction perpendicular to the ground. To approximate the interference power.

(Structure 7)
The program to make the computer execute is
The computing means distributes according to the non-uniform Poisson point process of the secondary user in each of the plurality of regions forming the three-dimensional region with the receiving station of the primary user as the origin, where the ratio of the interference data is a constant value. Transmitting power of transmitting station, antenna gain at receiving station of primary user, fading coefficient between receiving station of primary user and transmitting station of secondary user, position and origin of transmitting station of secondary user Using the Euclidean distance between and, and the propagation loss index, the interference power in each of the plurality of regions is larger than the threshold value that the receiving station of the primary user receives from all the transmitting stations of the secondary user. A first step of calculating as a probability of interference with the receiving station of the primary user, which is a function of the transmission permission ratio of the transmitting station of the secondary user,
The determining means minimizes the number of secondary user transmitting stations whose transmission is prohibited and the calculated interference probability is equal to or less than the target value, and sets a plurality of transmission permission ratios of the secondary user transmitting stations to a plurality of transmission permitting ratios. A second step of determining in each of the regions,
A third step in which the creating means creates an exclusive area in which only the primary user can perform wireless communication based on the transmission permission ratio of the transmitting station of the secondary user in each of the determined plurality of areas. And make the computer execute.

Then, in the first step, the calculating means has the same volume as each volume of the plurality of areas, and approximates each shape of the plurality of areas to the three-dimensional shape represented by the cylindrical coordinates to obtain the interference power. Is calculated.

(Structure 8)
In the configuration 7, in the first step, the calculating means is the transmission power of the transmitting station of the secondary user in each of the plurality of regions, the antenna gain in the receiving station of the primary user, and the receiving station of the primary user. Of the secondary user in each of the plurality of regions by using the fading coefficient between the transmission station of the secondary user and the transmission station of the secondary user, the Euclidean distance between the position of the transmission station of the secondary user and the origin, and the propagation loss index. The first interference power that the transmitting station gives to the receiving station of the primary user is calculated, and the nth (n is a positive integer)-order cumulant of the first interference power is calculated by using the Laplace transform of the first interference power. Calculate as a function of the transmission permission ratio of the transmitting station of the secondary user, and based on the calculated nth order cumulant, interference from all transmitting stations of the secondary user to the receiving station of the primary user in multiple areas. The n-th cumulant of the second interference power, which is electric power, is calculated, the probability density function of the second interference power is calculated based on the calculated n-th cumulant of the second interference power, and the calculated probability density The interference probability is calculated using the function parameters.

(Configuration 9)
In the configuration 8, the calculating means calculates the n-th order cumulant of the second interference power by calculating the sum of the first-order cumulant of the second interference power to the n-th order cumulant in the first step.

(Configuration 10)
In any one of the configurations 7 to 9, in the second step, the determining unit prohibits the transmission of the transmission station of the secondary user to the number of transmission stations of the secondary user in each of the plurality of areas. The secondary use that minimizes the objective function under the constraint that the calculated interference probability is smaller than the interference tolerance, and the addition result obtained by adding the multiplication result obtained by multiplying the probability of The transmission permission ratio of the secondary user's transmission station is determined in each of the plurality of areas to determine the transmission permission ratio of the secondary user's transmission station that minimizes the number of secondary user transmission stations whose transmission is prohibited. To do.

(Configuration 11)
In any one of the configurations 7 to 10, the transmitting stations of the secondary users existing in the plurality of areas are in the first frequency band shared by the primary user and the secondary user based on the transmission permission ratio. Communication is permitted, and communication of only control information in the second frequency band, which is a lower frequency band than the first frequency band, is permitted based on the transmission prohibition rate determined from the transmission permission rate.

(Configuration 12)
In any one of Configuration 7 to Configuration 11, each of the plurality of regions has a cubic shape. In the first step, the computing means has the same volume as the cube and has two curved arc-shaped curved surfaces protruding in a direction parallel to the ground and two planes arranged in a direction perpendicular to the ground. The interference power is calculated by approximating a cubic shape to a three-dimensional shape.

(Configuration 13)
The recording medium is a computer-readable recording medium in which the program according to any one of configurations 7 to 12 is recorded.

The embodiments disclosed this time are to be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description of the embodiments but by the claims, and is intended to include meanings equivalent to the claims and all modifications within the scope.

The present invention is applied to a management device, a program to be executed by a computer, and a computer-readable recording medium recording the program.

1, 11 wireless stations, 2, 3, 121 to 12s terminals, 10 management device, 101 receiving means, 102 computing means, 103 storage means, 104 determining means, 105 creating means.

Claims (13)

Transmission of transmission stations distributed according to the non-uniform Poisson point process of the secondary user in each of a plurality of regions forming a three-dimensional region whose origin is the receiving station of the primary user where the ratio of the interference data is a constant value Power, antenna gain at the receiving station of the primary user, fading coefficient between the receiving station of the primary user and the transmitting station of the secondary user, position of the transmitting station of the secondary user, and Using the Euclidean distance from the origin and the propagation loss index, the interference power larger than the threshold received by the receiving station of the primary user from all the transmitting stations of the secondary users is Computing means for computing as a probability of interference to the receiving station of the primary user which is a function of the transmission permission ratio of the transmitting station of the secondary user in each of the regions;
The calculated interference probability is less than or equal to a target value, and the transmission permission ratio of the transmission station of the secondary user that minimizes the number of transmission stations of the secondary user whose transmission is prohibited is set to the plurality of areas. Determining means for each of the
Creating means for creating an exclusive area in which only the primary user can perform wireless communication based on the transmission permission ratio of the transmitting station of the secondary user in each of the determined plurality of areas. Prepare,
The calculation means calculates the interference power by approximating each shape of the plurality of areas to a three-dimensional shape represented by cylindrical coordinates, which has the same volume as each of the plurality of areas. Management device. The calculating means is a transmission power of a transmission station of a secondary user in each of the plurality of areas, an antenna gain in a reception station of the primary user, a reception station of the primary user and the secondary user. Transmission of the secondary user in each of the plurality of regions by using a fading coefficient between the secondary user and the transmission station of the secondary user, the Euclidean distance between the position of the transmission station of the secondary user and the origin, and a propagation loss index. A station calculates a first interference power given to the receiving station of the primary user, and uses an Laplace transform of the first interference power to calculate an n-th (n is a positive integer) cumulant of the first interference power. As a function of the transmission permission ratio of the transmitting station of the secondary user, and based on the calculated nth order cumulant, from all the transmitting stations of the secondary user in the plurality of areas to the primary user. Calculating an n-th order cumulant of the second interference power, which is the interference power to the receiving station, and calculating a probability density function of the second interference power based on the calculated n-th order cumulant of the second interference power. The management apparatus according to claim 1, wherein the interference probability is calculated using the calculated parameter of the probability density function. The management device according to claim 2, wherein the calculation unit calculates the n-th order cumulant of the second interference power by calculating the sum of the first-order cumulant to the n-th order cumulant of the second interference power. The determining means multiplies the number of transmitting stations transmitted by the secondary user in each of the plurality of regions by a probability that transmission by the transmitting station of the secondary user is prohibited, and multiplies the multiplication result by the plurality of regions. For the objective function, the transmission permission ratio of the transmitting station of the secondary user that minimizes the objective function under the constraint condition that the calculated interference probability is smaller than the allowable value of interference. The transmission permission ratio of the transmitting station of the secondary user that minimizes the number of transmitting stations of the secondary user whose transmission is prohibited is determined by determining the value in each of a plurality of areas. Item 5. The management device according to any one of items 3. The transmitting station of the secondary user existing in the plurality of areas is permitted to communicate in the first frequency band shared by the primary user and the secondary user based on the transmission permission ratio, The communication of only control information in a second frequency band, which is a lower frequency band than the first frequency band, is permitted based on the transmission prohibition ratio determined from the transmission permission ratio. The management device according to any one of 4 above. Each of the plurality of regions has a cubic shape,
The calculating means has a three-dimensional shape having the same volume as the cube and having two arc-shaped curved surfaces protruding in a direction parallel to the ground and two flat surfaces arranged in a direction perpendicular to the ground. The management device according to claim 1, wherein the interference power is calculated by approximating the shape of a cube. The computing means distributes according to the non-uniform Poisson point process of the secondary user in each of the plurality of regions forming the three-dimensional region with the receiving station of the primary user as the origin, where the ratio of the interference data is a constant value. Transmission power of transmitting station, antenna gain at receiving station of primary user, fading coefficient between receiving station of primary user and transmitting station of secondary user, transmitting station of secondary user Using the Euclidean distance between the position of the first user and the origin, and the propagation loss index, an interference power larger than a threshold value received by the receiving station of the primary user from all the transmitting stations of the secondary user is received. A first step of calculating as a probability of interference with the receiving station of the primary user, which is a function of a transmission permission ratio of the transmitting station of the secondary user in each of the plurality of regions,
The determining means sets the transmission permission ratio of the transmitting station of the secondary user that minimizes the number of transmitting stations of the secondary user whose calculated interference probability is equal to or less than the target value and whose transmission is prohibited. A second step of determining in each of the plurality of regions;
The creating means creates an exclusive area in which only the primary user can perform wireless communication based on the transmission permission ratio of the transmitting station of the secondary user in each of the determined plurality of areas. Let the computer perform the third step and
In the first step, the arithmetic means has the same volume as each volume of the plurality of areas, and approximates each shape of the plurality of areas to a three-dimensional shape represented by cylindrical coordinates. A program for causing a computer to calculate the interference power. In the first step, the calculating means transmits the transmission power of the transmitting station of the secondary user in each of the plurality of areas, the antenna gain of the receiving station of the primary user, and the reception of the primary user. In each of the plurality of regions by using a fading coefficient between a station and a transmitting station of the secondary user, a Euclidean distance between the position of the transmitting station of the secondary user and the origin, and a propagation loss index. The first interference power given to the reception station of the primary user by the transmission station of the secondary user is calculated, and n(n) of the first interference power is calculated using the Laplace transform of the first interference power. Is a positive integer) The next cumulant is calculated as a function of the transmission permission ratio of the transmitting station of the secondary user, and based on the calculated nth order cumulant, all transmissions of the secondary user in the plurality of regions are calculated. Calculating the nth-order cumulant of the second interference power, which is the interference power from the station to the receiving station of the primary user, and based on the calculated nth-order cumulant of the second interference power, the second interference A program for causing a computer to execute according to claim 7, which calculates a probability density function of electric power, and calculates the interference probability using a parameter of the calculated probability density function. The computing means computes the n-th order cumulant of the second interference power by computing the sum of the first-order cumulant to the n-th order cumulant of the second interference power in the first step. A program to be executed by the computer according to item 8. In the second step, the determining means multiplies the number of transmitting stations transmitted by the secondary user in each of the plurality of areas by a probability that transmission by the transmitting station of the secondary user is prohibited. The secondary user who minimizes the objective function under the constraint condition that the addition result obtained by adding the multiplication result for the plurality of regions is the objective function and the calculated interference probability is smaller than the interference tolerance value. The transmission permission ratio of the secondary user is determined by determining the transmission permission ratio of each of the plurality of regions in each of the plurality of areas, thereby minimizing the number of the transmission stations of the secondary user whose transmission is prohibited. A program to be executed by the computer according to any one of claims 7 to 9. The transmitting station of the secondary user existing in the plurality of areas is permitted to communicate in the first frequency band shared by the primary user and the secondary user based on the transmission permission ratio, The communication of only control information in a second frequency band, which is a lower frequency band than the first frequency band, is permitted based on the transmission prohibition ratio determined from the transmission permission ratio. 10. A program to be executed by the computer according to any one of 10. Each of the plurality of regions has a cubic shape,
In the first step, the calculating means has two arc-shaped curved surfaces that have the same volume as the cube and project in a direction parallel to the ground, and two planes that are arranged in a direction perpendicular to the ground. A program for causing a computer according to any one of claims 7 to 11 to execute the interference power by approximating a shape of the cube to a three-dimensional shape having. A computer-readable recording medium in which the program according to any one of claims 7 to 12 is recorded.

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