JP2017208679A - Reception power estimation device, reception power estimation method and reception power estimation program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reception power estimation device capable of estimating reception power at a desired observation position, including a position of low spatial correlation with a receiver.SOLUTION: The reception power estimation device includes a first estimation circuit for receiving information about the reception power of electromagnetic waves transmitted from a transmitter of an observation object system from at least one radio wave sensor, and estimating transmission antenna gain and transmission power of the transmitter by using the reception power, on the basis of a radio propagation model considering the terrain characteristics, and a second estimation circuit for acquiring the estimates of transmission antenna gain and transmission power of the transmitter from the first estimation circuit, and estimating reception power at the desired observation position by using the estimates of transmission antenna gain and transmission power of the transmitter, on the basis of the radio propagation model considering the terrain characteristics.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a received power estimation apparatus, a received power estimation method, and a received power estimation program.

  As a countermeasure for the rapidly increasing mobile traffic, it is considered to use a frequency band (referred to as white space) that is not used spatially and temporally among frequency bands allocated to primary users. If the white space can be utilized, the secondary user can effectively use the idle frequency resource. In order for a secondary user to use idle frequency resources, it is required to detect a white space.

  By the way, when the white space is detected excessively, the secondary user interferes with the primary user. On the other hand, if the white space is detected too small, the frequency use opportunity by the secondary user is reduced. Therefore, it is required to detect the white space accurately in the secondary use of the frequency.

  Patent Document 1 discloses an apparatus for detecting white space. The apparatus of Patent Literature 1 detects a white space using the position of the wave source, the estimated transmission power of the wave source, and the attenuation characteristics of the radio wave from the estimated wave source.

Japanese Patent Laying-Open No. 2015-165616

  According to the apparatus of Patent Document 1, it is possible to estimate the attenuation characteristics and detect the white space using the estimated attenuation characteristics. However, since the apparatus of Patent Document 1 estimates received power using the attenuation characteristics of radio waves in consideration of only the distance and angle dependence between the wave source and the receiving apparatus, the place where the spatial correlation with the receiving apparatus is low However, there is a problem that the received power cannot be estimated accurately. For example, the apparatus of Patent Document 1 may underestimate the received power between the wave source and the shielding object when the shielding object is positioned between the wave source and the receiving apparatus.

  In order to solve the above-described problems, an object of the present invention is to provide a received power estimation apparatus that can estimate received power at a desired observation position including a position having a low spatial correlation with the receiving apparatus.

  The received power estimation device of one aspect of the present invention receives information on the received power of radio waves transmitted from the transmission device of the observation target system from at least one radio wave sensor, and is based on a radio wave propagation model considering terrain characteristics. A first estimation circuit that estimates the transmission antenna gain and transmission power of the transmission device using the received power, and an estimated value of the transmission antenna gain and transmission power of the transmission device from the first estimation circuit, and a radio wave that takes into account terrain characteristics And a second estimation circuit that estimates received power at a desired observation position using a transmission antenna gain of the transmission device and an estimated value of transmission power based on the propagation model.

  In the reception power estimation method of one aspect of the present invention, information on reception power of radio waves transmitted from a transmission device of an observation target system is received from at least one radio wave sensor, and is based on a radio wave propagation model that takes into account terrain characteristics. , Estimating the transmission antenna gain and transmission power of the transmission device using the received power, and using the estimated value of the transmission antenna gain and transmission power of the transmission device based on the radio wave propagation model considering terrain characteristics at the desired observation position Estimate the received power.

  The received power estimation program according to one aspect of the present invention is based on a process of receiving information on the received power of a radio wave transmitted from a transmission device of an observation target system from at least one radio wave sensor, and a radio wave propagation model considering terrain characteristics. Based on the process of estimating the transmission antenna gain and transmission power of the transmission device using the received power and the radio wave propagation model considering the terrain characteristics, the estimated value of the transmission antenna gain and transmission power of the transmission device is used. And causing the computer to execute processing for estimating the received power at the observation position.

  According to the present invention, it is possible to estimate received power at a desired observation position including a position having a low spatial correlation with the receiving apparatus.

It is a conceptual diagram which shows the structural example of the radio | wireless communications system which concerns on the 1st Embodiment of this invention. It is a block diagram which shows the structural example of the received power estimation apparatus which concerns on the 1st Embodiment of this invention. It is a block diagram which shows the structural example of the transmission antenna gain estimation circuit of the received power estimation apparatus which concerns on the 1st Embodiment of this invention. It is a block diagram which shows the structural example of the transmission antenna gain conversion circuit contained in the transmission antenna gain estimation circuit of the received power estimation apparatus which concerns on the 1st Embodiment of this invention. It is a schematic diagram for demonstrating the example of calculation of the transmission antenna gain in the 1st Embodiment of this invention. It is a schematic diagram which shows an example of the range which sets a desired observation position in the 1st Embodiment of this invention. It is a schematic diagram for demonstrating the reception power in the 1st Embodiment of this invention. It is a schematic diagram for demonstrating the relationship between the reception power and the 1st propagation loss estimated value in the 1st Embodiment of this invention. It is a schematic diagram for demonstrating the relationship between the received power, the 1st propagation loss estimated value, and the addition result in the 1st Embodiment of this invention. It is a schematic diagram for demonstrating the relationship between the received power, the 1st propagation loss estimated value, the addition result, and the received power estimated value in the 1st Embodiment of this invention. It is a flowchart which shows an example of the reception power estimation process which concerns on the 1st Embodiment of this invention. It is a schematic diagram for demonstrating the example of a weighting coefficient setting of the transmission power estimation circuit which concerns on the 1st Embodiment of this invention. In related technology, it is a schematic diagram for demonstrating the received power estimated value when there exists an obstruction between a transmitter and a radio wave sensor. In the 1st Embodiment of this invention, it is a schematic diagram for demonstrating the reception power estimated value when there exists an obstruction between a transmitter and a radio wave sensor. It is a block diagram which shows the structural example of the received power estimation apparatus which concerns on the 2nd Embodiment of this invention. It is a block diagram which shows the structural example of the transmission antenna height estimation circuit of the received power estimation apparatus which concerns on the 2nd Embodiment of this invention. It is a schematic diagram for demonstrating the transmission antenna height estimation method in the transmission antenna height estimation circuit of the received power estimation apparatus which concerns on the 2nd Embodiment of this invention. It is a conceptual diagram which shows the structural example of the received power estimation system which concerns on the 3rd Embodiment of this invention. It is a block diagram which shows the structural example of the received power estimation apparatus which concerns on the 3rd Embodiment of this invention. FIG. 10 is a block diagram illustrating a configuration example of an information communication system disclosed in Patent Document 1. It is a block diagram which shows the structural example of the white space detection apparatus disclosed by patent document 1. FIG. It is a block diagram which shows an example of the hardware of the received power estimation apparatus which concerns on each embodiment of this invention.

  EMBODIMENT OF THE INVENTION Below, the form for implementing this invention is demonstrated using drawing. However, the preferred embodiments described below are technically preferable for carrying out the present invention, but the scope of the invention is not limited to the following. In addition, in all the drawings used for description of the following embodiments, the same reference numerals are given to the same parts unless there is a particular reason. In the following embodiments, repeated description of similar configurations and operations may be omitted. Moreover, the direction of the arrow in the drawing shows an example, and does not limit the direction of the signal between the blocks.

(First embodiment)
First, a wireless communication system according to a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a conceptual diagram showing the configuration of the wireless communication system of the present embodiment. The wireless communication system according to the present embodiment includes a reception power estimation device 1, a transmission device 40, and a radio wave sensor group 50.

  The reception power estimation apparatus 1 estimates reception power at a desired observation position using radio waves transmitted from a transmission apparatus 40 (also referred to as a wave source) that is an observation target. The reception power estimation apparatus 1 detects a frequency white space using the estimated reception power.

  The transmission device 40 is an observation target by the reception power estimation device 1. The reception power estimation device 1 estimates reception power at a desired observation position using the radio wave transmitted from the transmission device 40. The received power estimation apparatus 1 verifies whether or not the desired observation position is included in the white space using the received power at the desired observation position.

  The radio wave sensor group 50 measures reception power of radio waves transmitted from the transmission device 40. Each radio wave sensor constituting the radio wave sensor group receives, for example, IQ data of a baseband signal, complex amplitude, or the like as a received signal (I: In Phase; Q: Quadrature Phase).

  The radio wave sensor group 50 outputs the measured received power to the received power estimation apparatus 1. As the radio wave sensors constituting the radio wave sensor group 50, a fixed radio wave sensor may be used, or a movable portable radio wave sensor may be used. Further, the receiving antenna gain of the radio wave sensor may be non-directional. Further, the received power information output from the radio wave sensor group 50 may be added with the position information of the radio wave sensor that has performed the received power measurement or an identifier corresponding to the position information.

  The reception power estimation device 1 receives a radio wave transmitted by the transmission device 40 from a radio wave sensor group 50 including at least one radio wave sensor by a reception circuit (not shown). The reception power estimation device 1 is connected to at least one radio wave sensor included in the radio wave sensor group 50 via a wired or wireless communication line. For example, the Internet, an intranet, a public telephone line, or the like may be used as a communication line. Note that the radio wave sensor group 50 may be included in the received power estimation apparatus 1.

[Received power estimation device]
As shown in FIG. 1, the received power estimation apparatus 1 includes a first estimation circuit 10, a second estimation circuit 20, and a detection circuit 30.

  The 1st estimation circuit 10 acquires the information regarding the reception power of the electromagnetic wave which the transmitter 40 which is an observation object transmitted from the radio wave sensor group 50 containing at least 1 radio wave sensor.

  The first estimation circuit 10 estimates a propagation loss (first propagation loss estimated value) between each radio wave sensor included in the radio wave sensor group 50 and the transmission device 40. Note that the first estimation circuit 10 estimates the first propagation loss estimated value by taking into account the diffraction loss of radio waves due to topography and features.

  The first estimation circuit 10 estimates the transmission antenna gain (also referred to as a transmission antenna gain estimation value) of the transmission device 40 using the received power and the first propagation loss estimation value.

  Further, the first estimation circuit 10 adds the reception power and the first propagation loss estimation value, and subtracts the transmission antenna gain estimation value from the addition result, thereby obtaining the transmission power (the transmission power estimation value) of the transmission device 40. Estimated).

  The first estimation circuit 10 outputs the transmission antenna gain estimation value and the transmission power estimation value to the second estimation circuit 20.

  The second estimation circuit 20 receives the transmission antenna gain estimation value and the transmission power estimation value from the first estimation circuit 10.

  The second estimation circuit 20 estimates the propagation loss (also referred to as a second propagation loss estimated value) between the transmitter 40 and the desired observation position by taking into account the diffraction loss of radio waves due to topography and features. The second estimation circuit 20 adds the transmission power estimation value and the transmission antenna gain estimation value, and subtracts the second propagation loss estimation value from the addition result, thereby receiving the reception power (also called reception power estimation value) at the desired observation position. ).

  The second estimation circuit 20 outputs the received power estimation value at the desired observation position to the detection circuit 30.

  The detection circuit 30 inputs the received power estimation value at the desired observation position from the second estimation circuit 20.

  The detection circuit 30 compares the received power estimated value at the desired observation position with a predetermined threshold, and detects a position where the received power estimated value is smaller than the predetermined threshold. The detection circuit 30 determines that an area including a position where the received power estimation value is smaller than a predetermined threshold is white space. Whether or not the position where the received power estimation value is equal to the predetermined threshold is a white space may be set in advance.

  The detection circuit 30 outputs information regarding the detected white space. Information regarding the white space output from the detection circuit 30 is registered in a database to be stored or output to other devices.

  According to the reception power estimation apparatus of the present embodiment, white space can be accurately detected even in a place where the spatial correlation with the reception apparatus is low.

  FIG. 2 is a block diagram including a detailed configuration of the reception power estimation apparatus 1 included in the wireless communication system of the present embodiment.

[First estimation circuit]
First, details of the first estimation circuit 10 will be described. As shown in FIG. 2, the first estimation circuit 10 includes a reception circuit 11, a first propagation loss estimation circuit 12, a transmission antenna gain estimation circuit 13, and a transmission power estimation circuit 14.

  The receiving circuit 11 receives from the radio wave sensor group 50 information related to the reception power of the radio wave transmitted from the transmission device 40. The reception circuit 11 outputs information on the received reception power to the transmission antenna gain estimation circuit 13 and the transmission power estimation circuit 14.

  The first propagation loss estimation circuit 12 estimates the propagation loss between the radio wave sensor included in the radio wave sensor group 50 and the transmission device 40 by taking into account the diffraction loss of the radio wave due to topography and features. The propagation loss estimated by the first propagation loss estimation circuit 12 is also referred to as a first propagation loss estimated value. The propagation loss estimation model used by the first propagation loss estimation circuit 12 is a radio wave propagation model considering terrain characteristics. For example, ITU-R P.1546 may be used as the propagation loss estimation model (International Telecommunication Union Radiocommunication Sector). In addition, the Ministry of Posts and Telecommunications Notification No. 640 may be used as the propagation loss estimation model. The topographic characteristics used when the first propagation loss estimation circuit 12 estimates the first propagation loss estimation value may be registered in advance in a database or storage circuit (not shown). In addition, if it is configured to detect a change in terrain characteristics from a change in received power received by the radio wave sensor group 50, a moving body other than a fixed object can be included in the terrain characteristics.

  For example, the antenna height (hereinafter referred to as antenna height) of the transmitter 40 used for propagation loss estimation may be estimated from the type of system to be observed. A preset value may be used for the antenna height of the radio wave sensor group 50.

  When the position of the transmission device 40 is fixed, known information registered in a database or the like may be used as the position information of the transmission device 40. When the position of the transmission device 40 is unknown, the position information of the transmission device 40 may be estimated by a time difference of arrival (TDoA) or a direction of arrival (DoA) method using a radio wave sensor. The number of radio wave sensors is three or more when position information is estimated by the TDoA method, and is two or more when position information is estimated by the DoA method. When the DoA method is used, the radio wave sensors constituting the radio wave sensor group are configured so that the directivity of radio wave reception can be changed.

  The first propagation loss estimation circuit 12 uses the transmission antenna gain estimation circuit 13 and the transmission power estimation to determine the propagation loss (first propagation loss estimated value) between the radio wave sensor constituting the estimated radio wave sensor group 50 and the transmission device 40. Output to the circuit 14.

  The transmission antenna gain estimation circuit 13 receives the received power of the radio wave from the radio wave sensor group 50 and receives the first propagation loss estimation value from the first propagation loss estimation circuit 12. The transmission antenna gain estimation circuit 13 estimates the transmission antenna gain of the transmission device 40 using the received power and the first propagation loss estimated value. The detailed configuration of the transmission antenna gain estimation circuit 13 will be described later. The transmission antenna gain estimation circuit 13 outputs the estimated transmission antenna gain (also referred to as a transmission antenna gain estimation value) to the transmission power estimation circuit 14 and the reception power estimation circuit 22.

  The transmission power estimation circuit 14 inputs information related to reception power from the radio wave sensor group 50. Further, the transmission power estimation circuit 14 receives the first propagation loss estimation value from the first propagation loss estimation circuit 12. Further, the transmission power estimation circuit 14 inputs the transmission antenna gain estimation value of the transmission device 40 from the transmission antenna gain estimation circuit 13.

  The transmission power estimation circuit 14 adds the reception power and the first propagation loss estimation value, and subtracts the transmission antenna gain estimation value from the addition result to estimate the transmission power of the transmission device 40. The transmission power estimation circuit 14 outputs the estimated transmission power (also referred to as a transmission power estimation value) to the reception power estimation circuit 22.

  In general, the propagation loss estimated value acquired by the radio wave propagation model is used to estimate the received power of the radio wave transmitted from the transmission device 40. On the other hand, the transmission power estimation circuit 14 according to the present embodiment uses the propagation loss estimation value to estimate the transmission power, not the reception power of the radio wave transmitted from the transmission device 40.

  Here, a method for calculating the transmission power estimation value will be described. In the following description, it is assumed that the radio wave sensor group 50 includes M radio wave sensors (hereinafter, radio wave sensors 50-m) (M is a natural number; m = 0, 1,..., M-1).

First, R _m (t) is the received power of the radio wave sensor 50-m at time t (t = 0, 1,...), And the first propagation loss estimated value between the transmission device 40 and the radio wave sensor 50-m. Is Pl _m ′, and the transmission antenna gain estimation value of the transmission apparatus 40 is G ′ (θ _m ). At this time, the transmission power estimated value T ′ (t) estimated from the radio wave sensor 50-m is expressed by, for example, Equation 1 below.

The transmission power estimation value may be obtained by weight combining values estimated from the plurality of radio wave sensors 50-m. Assuming that the weight coefficient w _m of the transmission power estimation value estimated from the radio wave sensor 50-m, the transmission power estimation value T ′ (t) estimated from the M radio wave sensors is expressed by, for example, Equation 2 below. .

By weight combining the transmission power estimation values estimated from the plurality of radio wave sensors 50-m, it is possible to obtain the transmission power estimation value according to the propagation loss estimation accuracy of the radio wave propagation model and the performance of the radio wave sensor. An example of setting the weighting coefficient w _m will be described later.

[Second estimation circuit]
Next, details of the second estimation circuit 20 will be described. As shown in FIG. 2, the second estimation circuit 20 includes a second propagation loss estimation circuit 21 and a received power estimation circuit 22.

  The second propagation loss estimation circuit 21 estimates the propagation loss between the transmitter 40 and the desired observation position by taking into account the diffraction loss of radio waves due to topography and features. Note that the desired observation position is an arbitrary position within a range for verifying whether or not it is a white space. Similar to the first propagation loss estimation circuit 12, the propagation loss estimation model used by the second propagation loss estimation circuit 21 is a radio wave propagation model considering terrain characteristics. The topographic characteristics used when the second propagation loss estimation circuit 21 estimates the second propagation loss estimated value may be registered in advance in a database or storage circuit (not shown). In addition, if it is configured to detect a change in terrain characteristics from a change in received power received by the radio wave sensor group 50, a moving body other than a fixed object can be included in the terrain characteristics.

  The antenna height of the transmission device 40 used for propagation loss estimation may be estimated from the type of system to be observed, for example. In addition, a predetermined value or an arbitrary value may be used for the receiving antenna height at the desired observation position. The second propagation loss estimation circuit 21 outputs the estimated propagation loss (also referred to as a second propagation loss estimated value) between the transmitter 40 and the desired observation position to the reception power estimation circuit 22.

  The reception power estimation circuit 22 receives the transmission antenna gain estimation value from the transmission antenna gain estimation circuit 13, receives the transmission power estimation value from the transmission power estimation circuit 14, and receives the second propagation loss estimation circuit 21 from the second propagation loss estimation circuit 21. Enter a value. The reception power estimation circuit 22 adds the transmission power estimation value and the transmission antenna gain estimation value, and subtracts the second propagation loss estimation value from the addition result to estimate the reception power at the desired observation position. The reception power estimation circuit 22 outputs the estimated reception power to the white space detection circuit 31.

For example, a desired observation position and the transmission device 40 n (n = 0,1, ··· ) and second propagation loss estimation value between the P2 _'n. At this time, the received power estimation value R ′ _n (t) is expressed by, for example, Equation 3.

[Detection circuit]
Next, details of the detection circuit 30 will be described. As shown in FIG. 2, the detection circuit 30 includes a white space detection circuit 31 and an output circuit 32.

  The white space detection circuit 31 inputs the received power estimation value at the desired observation position n from the received power estimation circuit 22. For example, the white space detection circuit 31 determines that an area where the estimated received power value is smaller than a predetermined threshold is a white space, and determines an area where the estimated received power value is greater than the threshold is a non-white space.

  The white space detection circuit 31 outputs the detected white space to the output circuit 32. Further, the white space detection circuit 31 may output an area not included in the detected white space to the output circuit 32 as a non-white space. It should be set in advance whether the portion where the estimated received power value matches the predetermined threshold is assigned to white space or non-white space.

  The output circuit 32 receives the white space detection result from the white space detection circuit 31 and registers it in a database storing information on the white space or outputs it to other devices.

[Transmission antenna gain estimation circuit]
Here, the details of the transmission antenna gain estimation circuit 13 will be described with reference to FIG. FIG. 3 is a detailed block diagram of the transmission antenna gain estimation circuit 13. The transmission antenna gain estimation circuit 13 includes an adder circuit 121, an interpolation circuit 122, and a transmission antenna gain conversion circuit 123.

The adder circuit 121 receives the received power from the radio wave sensor group 50 and receives the first propagation loss estimation value from the first propagation loss estimation circuit 12. The adder circuit 121 adds the first propagation loss estimated value to the received power. The adder circuit 121 outputs an addition result (hereinafter referred to as an addition result) of M received power and propagation loss corresponding to each radio wave sensor to the interpolation circuit 122. When the angle between the transmission device 40 and the radio wave sensor 50-m is θ _m , the addition result K ′ (θ _m ) is expressed by, for example, the following Equation 4.

The interpolation circuit 122 adds M reception power / propagation loss addition results K ′ (θ ₀ ), K ′ (θ ₁ ),..., K ′ (θ _M−1 ) corresponding to each radio wave sensor. Input from the circuit 121. For example, the interpolation circuit 122 converts the input discrete addition result into an addition result K ′ (θ) obtained by interpolating a continuous value in the angle direction by a linear interpolation method. The interpolation circuit 122 outputs the interpolated addition result K ′ (θ) to the transmission antenna gain conversion circuit 123.

  The transmission antenna gain conversion circuit 123 receives the addition result K ′ (θ) interpolated by the interpolation circuit 122. The transmission antenna gain conversion circuit 123 calculates a transmission antenna gain estimation value using the interpolated addition result K ′ (θ), and outputs the calculated transmission antenna gain estimation value to the transmission power estimation circuit 14 and the reception power estimation circuit 22. To do.

[Transmission antenna gain conversion circuit]
Here, the details of the transmission antenna gain conversion circuit 123 will be described with reference to FIG. FIG. 4 is a detailed block diagram of the transmission antenna gain conversion circuit 123. The transmission antenna gain conversion circuit 123 includes a closed curve area calculation circuit 231, an equivalent power circle radius calculation circuit 232, and a transmission antenna gain calculation circuit 233.

  The closed curve area calculation circuit 231 receives the interpolated addition result output from the interpolation circuit 122. The closed curve area calculation circuit 231 calculates the area of the closed curve as the interpolated addition result (hereinafter referred to as the closed curve area), and outputs the calculated closed curve area to the equivalent power circle radius calculation circuit 232.

  The equivalent power circle radius calculation circuit 232 receives the closed curve area from the closed curve area calculation circuit 231. The equivalent power circle radius calculation circuit 232 calculates a circle radius having an area equal to the closed curve area. The equivalent power circle radius calculation circuit 232 outputs the calculated circle radius to the transmission antenna gain calculation circuit 233. A circle having an area equal to the closed curve area is called an equivalent power circle.

  The transmission antenna gain calculation circuit 233 receives the radius information of the equivalent power circle from the equivalent power circle radius calculation circuit 232, the addition result interpolated from the interpolation circuit 122, and the position information of the transmission device 40. The transmission antenna gain calculation circuit 233 calculates the ratio (also referred to as transmission antenna gain) between the radius information of the equivalent power circle and the line segment connecting the position of the transmission device 40 and the interpolated addition result, and calculates the calculated transmission antenna gain. It outputs to the transmission power estimation circuit 14 and the reception power estimation circuit 22.

  Here, a calculation method of the transmission antenna gain will be described with reference to FIG. FIG. 5 is a schematic diagram for explaining a transmission antenna gain calculation example of the transmission antenna gain conversion circuit 123. FIG. 5 shows a transmission device 40, an equivalent power circle 320, and a closed curve 330 as an interpolated addition result.

A line segment connecting the interpolated addition result at θ _m that is an angle in the direction of the radio wave sensor 50-m from the position of the transmission device 40 is r ₁ (θ _m ), and the radius of the equivalent power circle is r ₀ . The transmission antenna gain G ′ (θ _m ) is expressed by the following formula 5, for example.

  6 to 10 are conceptual diagrams for explaining a procedure for estimating a received power estimated value using an actual value of received power received by the radio wave sensor 50-m included in the radio wave sensor group 50. FIG. 6 to 10 show a positional relationship in which the transmission device 40, the radio wave sensor 50-m included in the radio wave sensor group 50, and the shield 60 are arranged in the horizontal direction. 6 to 10 show examples in which the radio wave sensor 50-m is arranged in the horizontal direction, the radio wave sensor 50-m may be arranged in the vertical direction. 6 to 10 show an example in which five radio wave sensors 50-0 to 50-4 are used, the number of radio wave sensors 50-m is arbitrarily set, and the number is not limited.

  FIG. 6 is a conceptual diagram of a wireless communication system including a plurality of radio wave sensors 50-0 to 50-4 and a transmission device 40. Between the radio wave sensor 50-3 and the transmission device 40 constituting the wireless communication system, a shield 60 that lowers the spatial correlation between the radio wave sensor 50-3 and the transmission device 40 is located.

  FIG. 7 is a conceptual diagram showing a first propagation loss contour line 110 that is a guideline of the first propagation loss estimated value in the wireless communication system of FIG. The first propagation loss contour line 110 is a contour line formed by connecting points at which the first propagation loss estimated value is the same value on a line segment connecting each radio wave sensor 50-m and the transmission device 40. In addition, the position of the point on the line segment which connects between each radio wave sensor 50-m and the transmission apparatus 40 shows the relative magnitude | size of a 1st propagation loss estimated value.

  As shown in FIG. 7, since the shielding object 60 is located between the transmission device 40 and the radio wave sensor 50-3, compared with the other radio wave sensors 50-m, the radio wave sensor 50-3 and the transmission device 40 are not connected. The first propagation loss estimated value is estimated to be a large value.

  FIG. 8 is a diagram in which the received power contour line 120, which is a measure of the received power of the radio wave received by each radio wave sensor 50-m, is superimposed on the first propagation loss contour line 110 of FIG. The received power contour line 120 is a contour line formed by connecting points at which the actually measured received power has the same value on a line segment connecting the radio wave sensor 50-m and the transmission device 40. In addition, the position of the point on the line segment connecting between each radio wave sensor 50-m and the transmission device 40 indicates the relative magnitude of the received power.

  As shown in FIG. 8, since the shield 60 is located between the transmission device 40 and the radio wave sensor 50-3, the radio wave received by the radio wave sensor 50-3 is received as compared with the other radio wave sensors 50-m. Electric power is reduced.

  FIG. 9 shows an addition result contour line 200 that is a measure of the addition result of the first propagation loss estimated value and the reception power of each radio wave sensor 50-m on the first propagation loss contour line 110 and the reception power contour line 120 shown in FIG. FIG. The addition result contour line 200 is formed by connecting points where the addition result of the first propagation loss estimated value and the received power is the same value on a line segment connecting the radio wave sensor 50-m and the transmission device 40. It is. In the present embodiment, the addition result is obtained by adding the reception power obtained for each radio wave sensor 50-m and the first propagation loss estimated value.

  FIG. 10 is a diagram in which the estimated received power contour lines 500-1 to 500-3 are superimposed on the first propagation loss contour line 110, the received power contour line 120, and the addition result contour line 200 shown in FIG. The estimated received power contour lines 500-1 to 500-3 are contour lines formed by connecting points at which the received power estimated values are the same on the line segment connecting the radio wave sensor 50-m and the transmission device 40. In the estimated received power contour lines 500-1 to 500-3, the estimated received power contour line 500-1 is the contour line connecting the largest value, and the estimated received power contour line 500-3 is the contour line connecting the smallest value.

  In the present embodiment, the transmission antenna gain estimation value is obtained using the addition result of the received power and the first propagation loss. The received power estimated value is obtained using a transmission power estimated value (not shown), a transmission antenna gain estimated value, and a second propagation loss estimated value (not shown).

  As shown in FIGS. 6 to 10, according to the present embodiment, in order to calculate the received power estimation value by taking into account that the radio wave is blocked by the shielding object, a place having a low spatial correlation with the receiving device is used. In addition, the received power for accurately detecting the white space can be estimated.

[Operation]
Next, the operation of the received power estimation apparatus 1 of the present embodiment will be described using the drawings. FIG. 11 is a flowchart illustrating an operation example of the reception power estimation apparatus 1. The flowchart of FIG. 11 includes processing from step S11 to step S18. Note that the radio wave sensor group 50, which is the operation subject in step S11, may or may not be included in the configuration of the received power estimation apparatus 1.

  First, in FIG. 11, the radio wave sensor 50-m constituting the radio wave sensor group 50 measures the reception power of the radio wave transmitted from the transmission device 40 (step S11).

  The first propagation loss estimation circuit 12 estimates the propagation loss by calculating the diffraction loss of the radio wave due to the topography and the features between the transmission device 40 and the radio wave sensor 50-m (step S12).

  The transmission antenna gain estimation circuit 13 estimates the transmission antenna gain of the transmission device 40 using the received power and the first propagation loss estimation value (step S13).

  The transmission power estimation circuit 14 estimates the transmission power of the transmission device 40 using the reception power, the transmission antenna gain estimation value, and the first propagation loss estimation value (step S14).

  The second propagation loss estimation circuit 21 estimates the propagation loss by taking into account the diffraction loss of radio waves due to topography and features between the transmission device 40 and the desired observation position (step S15).

  The reception power estimation circuit 22 estimates the reception power at the desired observation position using the transmission antenna gain estimation value, the transmission power estimation value, and the second propagation loss estimation value (step S16).

  The white space detection circuit 31 determines whether the range corresponding to the received power estimated value is a white space using the received power estimated value, and detects the white space (step S17).

  The output circuit 32 registers the detected white space in the database or notifies other devices (step S18).

Here, an example of setting the weighting factor w _m by the transmission power estimation circuit 14 will be described. FIG. 12 is an example in which the weighting factor w _m is set using Equation 2 of the transmission power estimation circuit 14.

For example, the weighting factor w _m is set to a small value when the distance between the transmission device 40 and the radio wave sensor 50-m is long, and the weighting factor is set when the distance between the transmission device 40 and the radio wave sensor 50-m is short. a w _m may be set to a large value. When the terrain undulation between the transmission device 40 and the radio wave sensor 50-m is large, the weighting factor w _m is set to a small value, and the terrain undulation between the transmission device 40 and the radio wave sensor 50-m is small. In this case, the weight coefficient w _m may be set to a large value. Further, when the performance of the radio wave sensor 50-m is low, the weighting factor w _m may be set to a small value, and when the performance of the radio wave sensor 50-m is high, the weighting factor w _m may be set to a large value. . In the present embodiment, with such weighting, the transmission power according to the reliability of the radio wave propagation model and the performance of the radio wave sensor can be estimated with high accuracy.

  Here, the difference between the case where the propagation loss due to the shielding object 60 positioned between the transmission device 40 and the radio wave sensor 50-m is estimated and the case where it is not estimated will be described.

  FIG. 13 is a schematic diagram when the received power in the radio wave sensor 50-m is not estimated. FIG. 13 is an example in which the received power is estimated using the technique of Patent Document 1 (Japanese Patent Laid-Open No. 2015-165616), which is a related technique. Patent Document 1 discloses an example in which received power is estimated in consideration of the angle dependency of a radio wave emitted from a transmission device 40. According to the technique of Patent Document 1, since the influence of the propagation loss due to the shielding object 60 is reflected at all the angular positions where the shielding object 60 exists around the transmission apparatus 40, the transmission apparatus 40, the shielding object 60, The received power during is estimated too low.

  On the other hand, FIG. 14 is a schematic diagram for explaining an example of reception power estimation by the reception power estimation apparatus of the present embodiment. According to the present embodiment, by adding the first propagation loss estimated value considering the topographic characteristics and the received power, it is possible to estimate the transmission antenna gain excluding the influence of the diffraction loss due to the shield 60. Furthermore, in the present embodiment, the received power is estimated using the second propagation loss estimated value obtained by calculating the transmission power, the transmission antenna gain estimated value, and the terrain characteristics. As a result, according to the present embodiment, the received power between the transmission device 40 and the shield 60 can be correctly estimated.

  As described above, in the present embodiment, the received power is estimated using the estimated value of the propagation loss considering the terrain characteristics, so that the received power can be accurately estimated even in a place where the spatial correlation with the radio wave sensor is low. Therefore, according to the present embodiment, the white space can be accurately detected even in a place where the spatial correlation with the receiving device is low.

(Second Embodiment)
Next, a received power estimation apparatus according to the second embodiment of the present invention will be described with reference to the drawings.

  In the second embodiment, the transmission antenna height referred to by the first propagation loss estimation circuit 12 and the second propagation loss estimation circuit 21 is estimated using the distance attenuation of the received power measured by the radio wave sensor group 50.

  FIG. 15 is a configuration diagram of the received power estimation apparatus 2 of the present embodiment. The present embodiment is different from the first embodiment in that a first estimation circuit 10-2 in which a transmission antenna height estimation circuit 15 is added to the first estimation circuit 10 of the first embodiment is provided. In the following, description of the same parts as in the first embodiment will be omitted, and differences from the first embodiment will be described.

  The radio wave sensor group 50 transmits the received power received from the transmission device 40 of FIG. 1 to the first estimation circuit 10-2. The reception circuit 11 of the first estimation circuit 10-2 receives the received power from the radio wave sensor group 50. The reception circuit 11 outputs information regarding the received reception power to the transmission antenna gain estimation circuit 13, the transmission power estimation circuit 14, and the transmission antenna height estimation circuit 15.

  The transmission antenna gain estimation circuit 13 and the transmission power estimation circuit 14 perform the same processing as in the first embodiment.

  The transmission antenna height estimation circuit 15 receives received power from the radio wave sensor group 50. In addition, the received power input from the radio wave sensor group 50 may be added with the position information of the radio wave sensor that has been measured and an identifier corresponding to the position information.

  The transmission antenna height estimation circuit 15 estimates the transmission antenna height using the received power and the distance attenuation characteristics of the received power obtained from the positions of the transmission device 40 and the radio wave sensor group 50. The transmission antenna height estimation circuit 15 outputs the estimated transmission antenna height to the first propagation loss estimation circuit 12 and the second propagation loss estimation circuit 21.

[Transmission antenna height estimation circuit]
FIG. 16 is a detailed block diagram of the transmission antenna height estimation circuit 15. The transmission antenna height estimation circuit 15 includes a moving average circuit 151 and an attenuation characteristic recognition circuit 152.

  The moving average circuit 151 receives received power from the radio wave sensor group 50. The moving average circuit 151 performs a moving average of the input received power in the distance direction between the transmission device 40 and the radio wave sensor group 50 in order to smooth the fluctuation of the received power due to shadowing. The moving average circuit 151 outputs the calculated moving average result of the received power to the attenuation characteristic recognition circuit 152.

  The attenuation characteristic recognition circuit 152 receives the moving average result of the received power from the moving average circuit 151. The attenuation characteristic recognition circuit 152 estimates the transmission antenna height with reference to the distance attenuation characteristic of the received power. A method for estimating the transmission antenna height will be described later. The attenuation characteristic recognition circuit 152 outputs the estimated transmission antenna height to the first propagation loss estimation circuit 12 and the second propagation loss estimation circuit 21.

  Here, a method for obtaining the transmission antenna height will be described. FIG. 17 is an example of propagation loss characteristics according to distance when the reception antenna height of the radio wave sensor group 50 is 1.5 m and the transmission antenna height of the transmission device 40 is set to 3 m, 50 m, and 300 m. The attenuation characteristic recognition circuit 152 can estimate the height of the transmitting antenna by referring to the distance attenuation of the received power.

  For example, when the attenuation of received power within a predetermined distance from the transmission device 40 is large, it can be estimated that the height of the transmission antenna is low. On the other hand, when the attenuation amount of the received power within a predetermined distance from the transmission device 40 is small, it can be estimated that the height of the transmission antenna is high. For example, the attenuation characteristic recognition circuit 152 holds a correspondence relationship between the attenuation amount of the received power and the transmission antenna height within a predetermined distance from the transmission device 40 in a table or the like in advance, and refers to the table to determine the received power. The transmitting antenna height may be estimated from the attenuation.

  As described above, the reception power estimation apparatus of this embodiment estimates the antenna height of the transmission apparatus from the distance attenuation characteristics of the reception power of the radio wave sensor group. Therefore, according to the received power estimation apparatus of the present embodiment, the received power can be estimated with high accuracy even when the height of the transmitting antenna is unknown.

(Third embodiment)
Next, a radio communication system according to a third embodiment of the present invention will be described with reference to the drawings.

  FIG. 18 is a conceptual diagram showing a configuration of the reception power estimation apparatus 3 of the wireless communication system according to the present embodiment. As shown in FIG. 18, the received power estimation device 3 includes a first estimation circuit 10 and a second estimation circuit 20-3. The received power estimation apparatus 3 in FIG. 18 has a configuration in which the detection circuit 30 is omitted from the received power estimation apparatus 1 in FIG.

  The first estimation circuit 10 includes the first propagation loss estimation circuit 12, the transmission antenna gain estimation circuit 13, and the transmission power estimation circuit 14 of the first embodiment (FIG. 2).

  The second estimation circuit 20-3 includes the second propagation loss estimation circuit 21, the reception power estimation circuit 22, and the output circuit 23 of the first embodiment (FIG. 2). Since the first propagation loss estimation circuit 12, the transmission antenna gain estimation circuit 13, the transmission power estimation circuit 14, the second propagation loss estimation circuit 21, and the reception power estimation circuit 22 have the same configuration as that of the first embodiment, details are described. The detailed explanation is omitted.

  The output circuit 23 of FIG. 19 has a configuration corresponding to the output circuit 32 included in the detection circuit 30 of the first embodiment (FIG. 2). The output circuit 23 outputs the received power estimation value estimated by the received power estimation device 3.

  The received power estimation device 3 of the present embodiment estimates the received power estimated value at the desired observation position and outputs the received power estimated value to other systems and devices. The received power estimation value at the desired observation position output by the received power estimation device 3 in FIG. 18 can be used when other systems or devices detect white space.

(Related technology)
Next, a related technology (Patent Document 1) of the received power estimation apparatus according to the embodiment of the present invention will be described, and differences from the received power estimation apparatus according to the embodiment of the present invention will be described.

  FIG. 20 is a block diagram of an information communication system disclosed in Patent Document 1 (Japanese Patent Laid-Open No. 2015-165616).

  The information communication system includes a first receiving device 101, a second receiving device 102, and a white space detecting device 105. The white space detection device 105 uses the first reception device 101 and the second reception device 102 to observe radio waves transmitted from the wave source 103 corresponding to the primary user.

  FIG. 21 is a block diagram showing a configuration of the white space detection apparatus 105 according to the information communication system of Patent Document 1. The white space detection device 105 includes a reception unit 501, a position acquisition unit 502, a transmission power estimation unit 503, an attenuation characteristic estimation unit 504, a white space detection unit 505, and an output unit 506.

  The receiving unit 501 acquires observation data of the first receiving device 101 and the second receiving device 102 for the radio wave transmitted from the wave source 103.

  The position acquisition unit 502 acquires the position of the wave source 103 by observing radio waves transmitted from the wave source 103 received by the plurality of first receiving apparatuses 101.

  The transmission power estimation unit 503 estimates the transmission power of the wave source 103 using the reception power observed by the first reception device 101 and the distance between the wave source 103 and the first reception device 101.

  The attenuation characteristic estimation unit 504 uses the estimated transmission power, the reception power observed by the second reception device 102, and the distance between the wave source 103 and the second reception device 102, from the wave source 103. Estimate the attenuation characteristics of radio waves. The radio wave attenuation characteristic may have an angle dependency with the wave source 103 as the center.

  The white space detection unit 505 estimates the reach of radio waves from the wave source 103 using the estimated transmission power and radio wave attenuation characteristics, and detects the white space.

  The output unit 506 registers the detected white space in a database or outputs it to a display device.

  As described above, the white space detection device 105 of Patent Document 1 shows the estimated transmission power and radio wave attenuation characteristics even when the radio wave transmission path from the wave source 103 to the second reception device 102 is out of line of sight. The received power can be estimated using this. Therefore, according to the white space detection device 105 of Patent Document 1, white space can be detected even when the radio wave transmission path from the wave source 103 to the second reception device 102 is out of line of sight.

  By the way, the white space detection device 105 of Patent Document 1 estimates received power using the attenuation characteristics of radio waves in consideration of only the distance and angle dependence between the wave source and the receiving device. For this reason, the received power between the wave source and the shielding object at a location between the wave source and the shielding object where the spatial correlation with the receiving apparatus is low, such as when the shielding object is located between the wave source and the receiving apparatus. Is underestimated, and the received power cannot be estimated accurately.

  On the other hand, the received power estimation apparatus of this embodiment does not underestimate the received power between the wave source and the shielding object even when the shielding object is located between the wave source and the receiving apparatus. Therefore, according to the received power estimation apparatus of the present embodiment, the white space can be accurately detected even when the shielding object is located between the wave source and the receiving apparatus.

(hardware)
Here, the hardware 90 that implements the received power estimation apparatus according to the present embodiment will be described with reference to FIG. Note that the hardware 90 is an example for realizing the received power estimation apparatus of the present embodiment, and does not limit the scope of the present invention.

  As shown in FIG. 22, the hardware 90 includes a processor 91, a main storage device 92, an auxiliary storage device 93, an input / output interface 95, and a network adapter 96. The processor 91, main storage device 92, auxiliary storage device 93, input / output interface 95, and network adapter 96 are connected to each other via a bus 99. The processor 91, the main storage device 92, the auxiliary storage device 93, and the input / output interface 95 are connected to a network such as an intranet or the Internet via a network adapter 96. The hardware 90 is connected to another system or device via a network. Each of the components of the hardware 90 may be single or plural.

  The processor 91 is a central processing unit that expands a program stored in the auxiliary storage device 93 or the like in the main storage device 92 and executes the expanded program. In the present embodiment, a configuration using a software program installed in the hardware 90 may be used. The processor 91 executes various arithmetic processes and control processes.

  The main storage device 92 has an area where the program is expanded. The main storage device 92 may be a volatile memory such as a DRAM (Dynamic Random Access Memory). Further, a nonvolatile memory such as an MRAM (Magnetoresistive Random Access Memory) may be configured and added as the main storage device 92.

  The auxiliary storage device 93 is means for storing various data. The auxiliary storage device 93 is configured as a local disk such as a hard disk or a flash memory. The main storage device 92 may be configured to store data, and the auxiliary storage device 93 may be omitted.

  The input / output interface 95 is an interface (I / F) that connects the hardware 90 and peripheral devices based on a connection standard.

  You may connect input devices, such as a keyboard, a mouse | mouth, and a touch panel, to the hardware 90 as needed. These input devices are used for inputting information and settings. When a touch panel is used as an input device, the display screen of the display device may be a touch panel display that also serves as an interface of the input device. Data exchange between the processor 91 and the input device may be mediated by the input / output interface 95.

  You may connect output devices, such as a display device and a printer, to the hardware 90 as needed. These output devices are used for outputting information. For example, when using a display device that displays information about the detected white space, the display device may be connected to the input / output interface 95. Further, for example, when using a printing apparatus that prints information about the detected white space, the printing apparatus may be connected to the input / output interface 95.

  The network adapter 96 is an interface for connecting to a network such as the Internet or an intranet based on standards or specifications. The input / output interface 95 and the network adapter 96 may be shared as an interface for connecting to an external device.

  The hardware 90 may be provided with a reader / writer as necessary. The reader / writer is connected to the bus 99, reads a data program from the recording medium, writes a processing result of the hardware 90 to the recording medium, and the like between the processor 91 and a recording medium (program recording medium) (not shown). Mediate. The recording medium can be realized by a semiconductor recording medium such as an SD (Secure Digital) card or a USB (Universal Serial Bus) memory. The recording medium may be realized by a magnetic recording medium such as a flexible disk, an optical recording medium such as a CD (Compact Disc) or a DVD (Digital Versatile Disc), and other recording media.

  The above is an example of the hardware configuration for enabling the reception power estimation apparatus according to the embodiment of the present invention. Note that the hardware configuration of FIG. 22 is an example of a hardware configuration for enabling the received power estimation apparatus according to the present embodiment, and does not limit the scope of the present invention. A processing program that causes a computer to execute processing by the received power estimation apparatus according to the present embodiment is also included in the scope of the present invention. Furthermore, a program recording medium recording the processing program according to the present embodiment is also included in the scope of the present invention. Further, the processing program according to the present embodiment may be loaded into the received power estimation apparatus via a network.

DESCRIPTION OF SYMBOLS 10 1st estimation circuit 11 Reception circuit 12 1st propagation loss estimation circuit 13 Transmission antenna gain estimation circuit 14 Transmission power estimation circuit 20 2nd estimation circuit 21 2nd propagation loss estimation circuit 22 Reception power estimation circuit 23 Output circuit 30 Detection circuit 31 White space detection circuit 32 Output circuit 40 Transmitting device 50 Radio wave sensor group 60 Shield 15 Transmitting antenna height estimation circuit 151 Moving average circuit 152 Attenuation characteristic recognition circuit 121 Adder circuit 122 Interpolation circuit 123 Transmitting antenna gain conversion circuit 231 Closed curve area calculation circuit 232 Equivalent power circle radius calculation circuit 233 Transmitting antenna gain calculation circuit

Claims (10)

Information on reception power of radio waves transmitted from the transmission device of the observation target system is received from at least one radio wave sensor, and based on a radio wave propagation model considering terrain characteristics, the transmission antenna of the transmission device using the reception power A first estimation circuit for estimating a gain and transmission power;
Estimated values of the transmission antenna gain and transmission power of the transmission device are obtained from the first estimation circuit, and based on a radio wave propagation model taking into account the terrain characteristics, the estimation values of the transmission antenna gain and transmission power of the transmission device are obtained. And a second estimation circuit that estimates the received power at the desired observation position. The first estimation circuit includes:
A first propagation loss estimation circuit that estimates a first propagation loss estimation value that is a propagation loss between the transmission device and the radio wave sensor by a radio wave propagation model that takes into account the topographic characteristics;
Using the received power output from the radio wave sensor and the first propagation loss estimation value output from the first propagation loss estimation circuit, a transmission antenna gain estimation value that is an estimation value of the transmission antenna gain of the transmission device A transmit antenna gain estimation circuit for estimating
Transmission that estimates a transmission power estimation value that is an estimation value of the transmission power of the transmission device, using the reception power output from the radio wave sensor, the first propagation loss estimation value, and the transmission antenna gain estimation value A power estimation circuit,
The second estimation circuit is configured to estimate a second propagation loss estimation value, which is a propagation loss between the transmission device and the desired observation position, using a radio wave propagation model considering the terrain characteristics;
The transmission antenna gain estimation value output from the transmission antenna gain estimation circuit, the transmission power estimation value output from the transmission power estimation circuit, and the second propagation loss output from the second propagation loss estimation circuit The received power estimation apparatus according to claim 1, further comprising: a received power estimation circuit that estimates the received power at the desired observation position using an estimated value. The transmission antenna gain estimation circuit includes:
Received power propagation loss for outputting a first addition result calculated by adding the received power output from the radio wave sensor and the first propagation loss estimated value output from the first propagation loss estimation circuit. An adder circuit;
An addition result interpolation circuit that outputs a second addition result calculated by interpolating in an angular direction centered on the transmission device with respect to the first addition result output from the received power propagation loss adding circuit;
The reception power estimation apparatus according to claim 2, further comprising: a transmission antenna gain conversion circuit that converts the second addition result output from the addition result interpolation circuit into the transmission antenna gain of the transmission apparatus. The transmission antenna gain conversion circuit includes:
A closed curve area calculation circuit for calculating a closed curve area of the second addition result;
An equivalent power circle radius calculation circuit for calculating a radius of an equivalent power circle having an area equal to the closed curve area;
And a transmission antenna gain calculation circuit for calculating the transmission antenna gain by calculating a ratio between a length of a line segment connecting the position of the transmission device and the second addition result and a radius of the equivalent power circle. Item 4. The received power estimation apparatus according to Item 3. A transmission antenna height estimation circuit that estimates a transmission antenna height estimation value that is an estimation value of the antenna height of the transmission device using a distance attenuation characteristic of the reception power of the radio wave sensor;
The first propagation loss estimation circuit includes:
Estimating the first propagation loss estimate using the transmit antenna height estimate,
The second propagation loss estimation circuit includes:
5. The received power estimation apparatus according to claim 2, wherein the second propagation loss estimation value is estimated using the transmission antenna height estimation value output from the transmission antenna height estimation circuit. The transmission antenna height estimation circuit includes:
A moving average circuit that calculates a distance attenuation characteristic of the received power by moving and averaging the received power of the radio wave sensor in a distance direction between the transmission device and the radio wave sensor;
6. The received power according to claim 5, further comprising: a received power attenuation characteristic recognition circuit that refers to a distance attenuation characteristic of the received power calculated by the moving average circuit and estimates the height of the transmission antenna using an attenuation amount of the received power. Estimating device.   The estimated value of the received power at the desired observation position is input, the inputted estimated value of the received power is compared with a predetermined threshold, and a position where the estimated value of the received power is smaller than the predetermined threshold is white space. The received power estimation apparatus according to any one of claims 1 to 6, further comprising a detection circuit that detects the received signal.   The received power estimation apparatus according to any one of claims 1 to 7, comprising at least one radio wave sensor. Receives information on the received power of radio waves transmitted from the transmission device of the observation target system from at least one radio wave sensor,
Based on a radio wave propagation model considering terrain characteristics, estimate the transmission antenna gain and transmission power of the transmission device using the received power,
A received power estimation method for estimating the received power at a desired observation position using an estimated value of a transmission antenna gain and transmission power of the transmission device based on a radio wave propagation model considering the terrain characteristics. A process of receiving information about the received power of radio waves transmitted from the transmission device of the observation target system from at least one radio wave sensor;
Based on a radio wave propagation model considering terrain characteristics, a process of estimating the transmission antenna gain and transmission power of the transmission device using the reception power;
A received power estimation program for causing a computer to execute processing for estimating the received power at a desired observation position using estimated values of a transmission antenna gain and transmission power of the transmission device based on a radio wave propagation model considering the topographic characteristics .

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