Radio wave arrival direction estimation device, radio wave arrival direction estimation method, and radio wave arrival direction estimation program

Abstract

A radio-wave-arrival-direction estimation device according to an embodiment of the present invention comprises: an antenna angle acquisition unit for acquiring antenna angles representing the plurality of different directions that an antenna having an uneven antenna pattern is sequentially directed toward; a reception intensity measurement unit for measuring the reception intensities of radio wave reception by the antenna at each antenna angle acquired by the antenna angle acquisition unit; a degree of coincidence calculation unit for calculating, for each antenna angle acquired by the antenna angle acquisition unit, the degree of coincidence between the antenna pattern of the antenna and the antenna angle acquired by the antenna angle acquisition unit as well as the reception intensity measured by the reception intensity measurement unit; and an estimation unit for estimating that the radio wave arrival direction is the antenna angle for which the degree of coincidence calculated by the degree of coincidence calculation unit is the greatest.

Description

[Technical field]

[0001] The present invention relates to a radio wave arrival direction estimation device, a radio wave arrival direction estimation method, and a radio wave arrival direction estimation program. [Background technology]

[0002] Many methods have been proposed for estimating the direction of arrival of radio waves in wireless communication systems. For example, a method for estimating the direction of arrival of radio waves from a correlation matrix obtained using an array antenna having multiple antenna elements is well known.

[0003] Also, Non-Patent Document 1 discloses a method of estimating the direction of arrival of radio waves using an array antenna, by using the MUSIC algorithm (MUltiple SIgnal Classification). [Prior art documents] [Non-patent literature]

[0004] [Non-Patent Document 1] Minseok Kim, "Basics and Examples of Direction of Arrival Estimation Systems", Design Wave Magazine, CQ Publishing Co., Ltd., December 2007, pp.112-118 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the past, it was assumed that an array antenna with a freely configurable main lobe and null point was used. In addition, in wireless communication systems using low frequency bands such as the VHF (Very High Frequency) band, the size of the antenna elements becomes large, and preparing an array antenna using multiple antenna elements is a heavy burden and can be difficult to install.

[0006] An object of the present invention is to provide a radio wave arrival direction estimation device, a radio wave arrival direction estimation method, and a radio wave arrival direction estimation program that are capable of estimating the arrival direction of radio waves even without using a highly directional array antenna. [Means for solving the problem]

[0007] According to one aspect of the present invention, there is provided a radio wave arrival direction estimation device for estimating a direction of arrival of a radio wave having an antenna with a non-uniform antenna pattern. Any an antenna angle acquisition unit that acquires antenna angles indicating a plurality of different directions that are sequentially directed; a reception strength measurement unit that measures the reception strength at which the antenna receives radio waves at each of the antenna angles acquired by the antenna angle acquisition unit; a coincidence calculation unit that calculates a degree of coincidence between the antenna angle acquired by the antenna angle acquisition unit and the reception strength measured by the reception strength measurement unit, and an antenna pattern of the antenna, for each antenna angle acquired by the antenna angle acquisition unit; and an antenna angle at which the degree of coincidence calculated by the coincidence calculation unit is maximum, estimating the direction from which the radio waves arrive. The apparatus includes an estimation unit and a separation unit that separates components of an arriving wave or a delayed wave from the receiving strength measured by the receiving strength measurement unit, and the coincidence calculation unit calculates a coincidence between the antenna angle acquired by the antenna angle acquisition unit and the receiving strength of the arriving wave or the delayed wave separated by the separation unit, and an antenna pattern of the antenna, for each antenna angle acquired by the antenna angle acquisition unit, and the separation unit separates each arriving wave or delayed wave having the same propagation time from a transmitting station based on a correlation with a known pattern transmitted by the transmitting station. It is characterized by:

[0008] In addition, the radio wave arrival direction estimation method according to one aspect of the present invention is applicable to an antenna having a non-uniform antenna pattern. Any An antenna angle acquisition step of acquiring antenna angles indicating a plurality of different directions that are sequentially directed, a reception strength measurement step of measuring the reception strength of radio waves received by the antenna at each of the acquired antenna angles, a coincidence calculation step of calculating the degree of coincidence between the acquired antenna angle, the measured reception strength, and the antenna pattern of the antenna for each acquired antenna angle, and an estimation step of estimating the antenna angle with the maximum calculated degree of coincidence as the direction of arrival of the radio waves. and a separation step of separating components of an arriving wave or a delayed wave from the measured reception strength, in which the degree of coincidence calculation step calculates the degree of coincidence between the acquired antenna angle and the reception strength of the separated arriving wave or delayed wave and the antenna pattern of the antenna for each acquired antenna angle, and the separation step separates the arriving wave or delayed wave having the same propagation time from the transmitting station based on a correlation with a known pattern transmitted by the transmitting station. It is characterized by: Effect of the Invention

[0009] According to the present invention, the arrival direction of radio waves can be estimated without using an array antenna with high directivity. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 illustrates an example of the configuration of a communication device. [Diagram 2] (a) is a diagram illustrating the reception strength of radio waves received by an antenna at three different antenna angles, and (b) is a diagram illustrating three antenna angles and radio wave strength after separating delayed wave components and noise, etc. [Diagram 3] 1A is a diagram illustrating an example of an antenna pattern of an antenna, and FIG. 1B is a diagram illustrating a schematic diagram of a result of an estimation unit estimating the arrival direction of a radio wave using the antenna pattern. [Figure 4] 4 is a flowchart illustrating an example of the operation of the radio wave arrival direction estimation device according to an embodiment. [Diagram 5] (a) is a diagram illustrating an example of antenna pattern data stored in an antenna pattern storage unit. (b) is a diagram illustrating an example of the correspondence between the antenna angle acquired by the antenna angle acquisition unit when the antenna rotates and the reception strength measured by the reception strength measurement unit. (c) is a diagram illustrating a process performed by the coincidence calculation unit when calculating the coincidence. (d) is a diagram illustrating a result of estimation of the arrival direction of the radio wave by the estimation unit. [Figure 6] FIG. 2 is a diagram illustrating an example of a hardware configuration of a radio wave arrival direction estimation device according to an embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, a radio wave direction estimation device according to an embodiment will be described with reference to the drawings. Fig. 1 is a diagram showing a configuration example of a communication device 1. The communication device 1 includes an antenna 2, a rotary drive unit 3, a control unit 4, and a radio wave direction estimation device 5 according to an embodiment, and functions as a receiving station.

[0012] The antenna 2 is provided so as to be freely rotatable, for example, in the horizontal direction, receives radio waves (signals) transmitted from a transmitting station in a low frequency band such as the VHF band, and outputs the received signals to the radio wave arrival direction estimation device 5. The antenna pattern (radiation pattern) of the antenna 2 is non-uniform (see FIG. 4). Note that a non-uniform antenna pattern does not mean that the antenna pattern is omnidirectional, but that it has weak directionality.

[0013] The rotation drive unit 3 drives the antenna 2 to rotate, for example, in the horizontal direction under the control of the control unit 4, and sequentially points the antenna 2 in all directions of 360 degrees.

[0014] The control unit 4 controls the rotation drive unit 3 and the radio wave arrival direction estimation device 5 in response to an operation of an operation unit (not shown) by an operator. The antenna 2 may be oriented in any direction by hand of an operator, without being controlled by the rotation drive unit 3 and the control unit 4.

[0015] The radio wave arrival direction estimation device 5 has an antenna angle acquisition unit 50, a reception strength measurement unit 51, a separation unit 52, an acquired information storage unit 53, an antenna pattern storage unit 54, a coincidence calculation unit 55, and an estimation unit 56.

[0016] The antenna angle acquisition unit 50 acquires antenna angles indicating a plurality of different directions in which the antenna 2 rotated by the rotation drive unit 3 is sequentially pointed, and outputs the antenna angles to the reception strength measurement unit 51 and the acquired information storage unit 53. The antenna angle acquisition unit 50 may receive data indicating the antenna angle from the antenna 2, or may acquire the data from the control unit 4. The antenna angle acquisition unit 50 may also acquire the antenna angles from data input by an operator to an operation unit (not shown).

[0017] The reception strength measuring unit 51 measures the reception strength of radio waves received by the antenna 2 at each of the antenna angles acquired by the antenna angle acquisition unit 50 in association with each other, and outputs the measurement results to the separation unit 52.

[0018] For example, the reception strength measuring unit 51 measures the reception strength at a plurality of antenna angles spaced at equal intervals. The reception strength measuring unit 51 may measure the reception strength of radio waves by setting all or part of the antenna angles at which the reception strength is measured to both ends (maximum angle and minimum angle) of the settable antenna angles and to antenna angles spaced at equal intervals in the remaining range. The reception strength measuring unit 51 may obtain the reception strength for each antenna angle from the measurement data of the reception strength input by the operator to an operation unit (not shown).

[0019] The separator 52 separates, for example, delayed wave components and noise from the reception strength measured by the reception strength measuring unit 51, and outputs data associating the reception strength of a predetermined arriving wave or delayed wave with the antenna angle to the acquired information storage unit 53. For example, the separator 52 separates the arriving wave and delayed wave so as not to include interference waves or noise, based on the correlation between the received signal and a known pattern such as a synchronization signal transmitted by a transmitting station.

[0020] Fig. 2 is a diagram illustrating an example of data that the separator 52 separates delayed wave components, noise, etc., and outputs to the acquired information storage unit 53. Fig. 2(a) is a diagram illustrating the reception strength (vertical axis) of radio waves received by the antenna 2 at three different antenna angles. Fig. 2(b) is a diagram illustrating three antenna angles and radio wave strength after the delayed wave components, noise, etc. have been separated.

[0021] The radio waves transmitted by the transmitting station and propagated through multiple paths are measured at the receiving station as arriving waves and delayed waves coming from a certain direction with a certain strength. At this time, the direction from which the arriving waves and delayed waves arrive is constant (true value / constant value).

[0022] If the antenna receiving the radio waves has directionality, the measured reception strength will be larger or smaller depending on the characteristics (directivity) of the angle at which the antenna is pointed. In other words, the reception strength is distorted differently depending on the direction the antenna is pointed, and is not uniform.

[0023] Therefore, since the directivity (distortion characteristics: antenna pattern) of the antenna 2 is stored in the antenna pattern storage unit 54 described later, the radio wave arrival direction estimation device 5 estimates the arrival direction (true value) using the antenna pattern.

[0024] As shown in FIG. 2(a), for example, at three different antenna angles A, B, and C, the antenna 2 receives arriving waves and delayed waves with different reception intensities.

[0025] Then, the separation unit 52 separates the arriving waves or delayed waves (or delayed waves from the second delayed wave onwards) having the same propagation time received at each of the antenna angles A, B, and C of the antenna 2 based on the propagation time from the transmitting station to the antenna 2, etc. (Figure 2(a)).

[0026] 2(b), the separator 52 outputs the reception intensity separated for each arriving wave with the same propagation time (or delayed wave with the same propagation time) at antenna angles A, B, and C due to the rotation of the antenna 2 to the acquired information storage unit 53. In other words, the data that the separator 52 outputs to the acquired information storage unit 53 is a combination of the values ​​of the antenna angles A, B, and C and the reception intensity at each antenna angle, and therefore corresponds to the three vectors shown in FIG. 2(b).

[0027] However, when the distance from the transmitting station to the antenna 2 is long, the data output from the separation unit 52 to the acquired information storage unit 53 has a low reception strength at any antenna angle. Therefore, the coincidence calculation unit 55 described later generally expands or reduces the combinations of the antenna angles A, B, and C and the reception strength at each antenna angle, based on the origin, to facilitate comparison with the antenna pattern. In other words, by rotating the combinations of the reception strength at each antenna angle for the same propagation time after expanding or reducing them based on the origin, it becomes possible to estimate the true arrival direction of the radio wave.

[0028] The separator 52 may separate the data for each arriving wave with the same propagation time for each antenna angle, or may separate the data for each delayed wave with the same propagation time. For example, when it is not easy to separate the first arriving wave, the separator 52 outputs data separated for each delayed wave with the same propagation time to the acquired information storage unit 53. That is, the radio wave arrival direction estimation device 5 can estimate the arrival direction of the radio wave at the measurement time of the reception strength for each arriving wave with the same propagation time or each delayed wave with the same propagation time.

[0029] The acquired information storage unit 53 (FIG. 1) stores, for example, data indicating the antenna angle acquired by the antenna angle acquisition unit 50, and data associating the reception strength of a predetermined incoming wave separated by the separation unit 52 with the antenna angle, and outputs the data in response to an access from the coincidence calculation unit 55.

[0030] The antenna pattern storage unit 54 stores data indicating the antenna pattern of the antenna 2 (gain for each antenna angle), and outputs the data in response to an access from the coincidence calculation unit 55.

[0031] The coincidence calculation unit 55 reads and acquires the data stored in the acquired information storage unit 53 and the data stored in the antenna pattern storage unit 54, and performs matching (comparison of the degree of coincidence).

[0032] For example, the coincidence calculation unit 55 calculates the coincidence between the antenna angle acquired by the antenna angle acquisition unit 50 and the reception strength measured by the reception strength measurement unit 51 and the antenna pattern of the antenna 2 for each antenna angle acquired by the antenna angle acquisition unit 50, and outputs the calculated coincidence to the estimation unit 56.

[0033] More specifically, the coincidence calculation unit 55 calculates the degree of coincidence between the antenna angle acquired by the antenna angle acquisition unit 50 and the receiving strength after the separation unit 52 separates the delayed wave components and noise, and the antenna pattern of antenna 2, for each antenna angle acquired by the antenna angle acquisition unit 50, and outputs the calculated degree of coincidence to the estimation unit 56.

[0034] Furthermore, in order to adjust the strength of the received power due to the transmission distance, etc., the coincidence calculation unit 55 may correct the received strength at other antenna angles based on the received strength at an arbitrary antenna angle, the received strength at an antenna angle close to the average value of the received power, the received strength at the antenna angle with the maximum received power, or the received strength at a predetermined antenna angle, etc. Furthermore, the coincidence calculation unit 55 may compare the combinations of the values ​​of antenna angles A, B, and C and the received strength at each antenna angle by generally expanding or contracting them based on the origin, and comparing them with the antenna pattern.

[0035] In this way, the coincidence calculation unit 55 compares the reception strength of the incoming wave (or delayed wave) at each antenna angle with the same propagation time with the antenna pattern to calculate the degree of coincidence. For example, the coincidence calculation unit 55 rotates a combination of reception strengths at each antenna angle, which is generally enlarged or reduced with respect to the origin, with the origin as the base, to calculate the degree of coincidence with the antenna pattern for each direction.

[0036] At this time, the coincidence calculation unit 55 does not need to use all data of the reception strength measured in the same propagation time. For example, as in a specific operation example of the radio wave arrival direction estimation device 5 described later with reference to Fig. 5, the coincidence calculation unit 55 calculates the coincidence with the antenna pattern without using data of reception strength that is significantly different from the antenna pattern as an exclusion target.

[0037] However, if the distance from the transmitting station to the antenna 2 is long, the reception strength at each antenna angle will be small, which may result in a decrease in accuracy when comparing with the antenna pattern to calculate the degree of match.

[0038] Therefore, the coincidence calculation unit 55 first performs a process of enlarging (or reducing) the combination of reception strengths at each antenna angle as a whole with respect to the origin, and bringing the magnitude of the reception strength at each antenna angle to be compared closer to the size of the antenna pattern. At this time, the coincidence calculation unit 55 excludes data estimated to be an abnormal value with a large deviation, as will be described later with reference to FIG. 5.

[0039] The matching degree calculation unit 55 then rotates the matching target, the size of which has been made closer, around the origin and calculates the degree of matching with the antenna pattern for each direction, thereby improving the accuracy of calculating the degree of matching.

[0040] As a method of comparing the degree of match between the angle and reception strength of the arriving wave and the antenna pattern, the coincidence calculation unit 55 may select a combination that minimizes the sum of the absolute values ​​of the gain differences, or may select a combination that minimizes the sum of the squares of the absolute values.

[0041] The estimation unit 56 estimates that the antenna angle for which the degree of coincidence calculated by the degree of coincidence calculation unit 55 is the maximum is the direction from which the radio wave arrives for the communication device 1. Here, the degree of coincidence is maximum, for example, a combination for which the difference between the antenna angle and reception strength and the antenna pattern is minimum.

[0042] Fig. 3 is a diagram illustrating an example of the arrival direction of a radio wave estimated by the estimation unit 56. Fig. 3(a) is a diagram illustrating an example of an antenna pattern of the antenna 2. Fig. 3(b) is a diagram typically illustrating a result of the estimation unit 56 estimating the arrival direction of a radio wave using the antenna pattern.

[0043] The estimation unit 56 rotates the reception strength (see Figure 2(b)) for each antenna angle calculated by the similarity calculation unit 55, for example, by enlarging (or reducing) the size of the antenna pattern to approximate it, around the origin, and estimates that the antenna angle (Figure 3(b)) which has the highest similarity to the antenna pattern (Figure 3(a)) is the direction from which the radio waves arrive at the communication device 1.

[0044] Fig. 4 is a flowchart showing an example of the operation of the radio wave arrival direction estimation device 5 according to an embodiment. As shown in Fig. 4, the radio wave arrival direction estimation device 5 receives a signal transmitted by a transmitting station via a rotating antenna 2 (S100), and obtains an arriving wave as reception strength for a plurality of antenna angles (S102).

[0045] Next, the radio wave arrival direction estimation device 5 selects (extracts) arriving waves that arrive in the same order at each antenna angle (S104), and calculates the degree of match between the antenna angle and reception strength and the antenna pattern for each antenna angle (S106).

[0046] Then, the radio wave arrival direction estimation device 5 estimates the antenna angle with the highest degree of agreement as the arrival direction of the radio wave for the communication device 1 (S108). That is, the radio wave arrival direction estimation device 5 estimates the arrival direction of the radio wave by combining the antenna pattern and the actually measured antenna angle.

[0047] Next, a specific operation example when the radio wave arrival direction estimation device 5 estimates the radio wave arrival direction will be described. Fig. 5 is a diagram showing a specific operation example when the radio wave arrival direction estimation device 5 estimates the arrival direction of the radio wave. Here, it is assumed that only one wave arrives.

[0048] Fig. 5(a) is a diagram illustrating an example of antenna pattern data stored in the antenna pattern storage unit 54 (Fig. 1). Fig. 5(b) is a diagram illustrating the correspondence between the antenna angle acquired by the antenna angle acquisition unit 50 when the antenna 2 rotates and the reception intensity measured by the reception intensity measurement unit 51. Fig. 5(c) is a diagram illustrating the process performed by the coincidence calculation unit 55 when calculating the coincidence. Fig. 5(d) is a diagram illustrating the result of the estimation of the arrival direction of the radio wave by the estimation unit 56.

[0049] As shown in FIG. 5(a), the antenna pattern storage unit 54 stores data indicating antenna patterns represented by combinations of a plurality of angles (directions) and gains in the range of, for example, −179 degrees to +180 degrees.

[0050] The coincidence calculation unit 55 extracts, for example, combinations of measurement angles (for example, three points: angle E at the center, the difference between angle D and angle E, and the difference between angle E and angle F) from the data stored in the antenna pattern storage unit 54.

[0051] For example, the coincidence calculation unit 55 obtains a plurality of pairs (example 1, example 2, etc.) from the antenna pattern storage unit 54, with the following three points as pairs:

[0052] (Example 1) -45 degrees, -5dB 0 degrees, 0dB +45 degrees, -5dB (Example 2) 0 degrees, 0dB +45 degrees, -5dB +90 degrees, -20dB

[0053] Furthermore, the coincidence calculation unit 55 acquires the measured data as shown in Fig. 5(b) from the acquired information storage unit 53. Furthermore, as shown in Fig. 5(c), the coincidence calculation unit 55 calculates the relative power and inversion angle (± interchange) with respect to the maximum value for each measured antenna angle data as follows:

[0054] ·Angle D → 0 degrees, -5dB Angle E → -45 degrees, 0dB Angle F → -90 degrees, -6dB

[0055] Next, the coincidence calculation unit 55 calculates (antenna pattern dB)-(measurement result dB) in ascending order of antenna angle, and excludes data with a large ± difference as data that could not be measured. At this time, the coincidence calculation unit 55 expands (or reduces) the reception strength for each antenna angle based on the origin so as to compensate for the influence of attenuation of the reception power caused by the distance from the transmitting station, and excludes data that is estimated to deviate from the antenna pattern.

[0056] (Example 1) -45 degrees → (-5dB)-(-6dB)=1dB (exclusion) 0 degrees → (0dB)-(0dB)=0dB +45 degrees→(-5dB)-(-5dB)=0dB (Example 2) 0 degrees → (0dB)-(-6dB)=6dB +45 degrees→(-5dB)-(0dB)=-5dB +90 degrees → (-20dB)-(-5dB)=-15dB (Excluded)

[0057] The coincidence calculation unit 55 uses the results other than the excluded data to calculate and store the difference with respect to the antenna pattern.

[0058] (Example 1) 0 degrees → (0dB)-(0dB)=0dB +45 degrees→(-5dB)-(-5dB)=0dB Total difference value → |0dB|+|0dB|=0dB (Example 2) 0 degrees → (0dB)-(-6dB)=6dB +45 degrees→(-5dB)-(0dB)=-5dB Total difference value → |6dB|+|-5dB|=11dB

[0059] Then, the estimation unit 56 acquires each data stored in the coincidence calculation unit 55, and selects a combination that minimizes the difference between the antenna angle and reception strength and the antenna pattern (maximizes the coincidence). Here, the combination of Example 1 is selected.

[0060] In other words, the estimation unit 56 estimates the direction of arrival of each incoming wave by matching (comparing the degree of agreement) the reception strength at each antenna angle with the antenna pattern (antenna angle and gain) for the incoming waves measured at multiple antenna angles (Figure 5(d)).

[0061] In this way, the radio wave arrival direction estimation device 5 estimates the antenna angle at which the degree of coincidence calculated by the degree of coincidence calculation unit 55 is the maximum as the radio wave arrival direction, and therefore can estimate the radio wave arrival direction even without using a highly directional array antenna. That is, the radio wave arrival direction estimation device 5 can easily and at low cost estimate the arrival direction even for radio waves of a relatively low frequency such as the VHF band, even without preparing a highly directional array antenna for estimating the radio wave arrival direction.

[0062] In addition, in order to extract its own signal from the received signal, the radio wave arrival direction estimation device 5 may use the difference (C / N) between the state when the transmitting station stops transmitting a signal and the state when the transmitting station transmits a signal, instead of the reception strength.

[0063] In addition, each function of the radio wave arrival direction estimation device 5 may be configured in part or in whole by hardware such as a PLD (Programmable Logic Device) or an FPGA (Field Programmable Gate Array), or may be configured as a program executed by a processor such as a CPU.

[0064] For example, the radio wave arrival direction estimation device 5 according to the present invention can be realized using a computer and a program, and the program can be recorded on a storage medium or provided via a network.

[0065] Fig. 6 is a diagram showing an example of a hardware configuration of a radio wave arrival direction estimation device 5 according to an embodiment. As shown in Fig. 6, for example, the radio wave arrival direction estimation device 5 has an input unit 60, an output unit 61, a communication unit 62, a CPU 63, a memory 64, and a HDD 65 connected via a bus 66, and has a function as a computer. In addition, the radio wave arrival direction estimation device 5 is configured to input and output data to and from a computer-readable storage medium 67.

[0066] The input unit 60 is, for example, a keyboard and a mouse, etc. The output unit 61 is, for example, a display device, etc. The communication unit 62 is, for example, a wired or wireless network interface, etc.

[0067] The CPU 63 controls each unit constituting the radio wave arrival direction estimation device 5 and performs predetermined processing, etc. The memory 64 and the HDD 65 correspond to the acquired information storage unit 53 and the antenna pattern storage unit 54 described above, which store data, etc. The storage medium 67 is capable of storing programs, etc., for executing the functions of the radio wave arrival direction estimation device 5. Note that the architecture constituting the radio wave arrival direction estimation device 5 is not limited to the example shown in FIG. [Explanation of symbols]

[0068] 1 communication device, 2 antenna, 3 rotation drive unit, 4 control unit, 5 radio wave arrival direction estimation device, 50 antenna angle acquisition unit, 51 reception strength measurement unit, 52 separation unit, 53 acquired information storage unit, 54 antenna pattern storage unit, 55 match calculation unit, 56 estimation unit, 60 input unit, 61 output unit, 62 communication unit, 63 CPU, 64 memory, 65 HDD, 66 bus, 67 storage medium

Claims

1. an antenna angle acquisition unit that acquires antenna angles indicating a plurality of different directions in which an antenna having a non-uniform antenna pattern is directed in an arbitrary sequential order; a reception strength measuring unit that measures a reception strength of radio waves received by the antenna at each of the antenna angles acquired by the antenna angle acquisition unit; a coincidence calculation unit that calculates a coincidence between the antenna angle acquired by the antenna angle acquisition unit and the reception intensity measured by the reception intensity measurement unit, and an antenna pattern of the antenna, for each antenna angle acquired by the antenna angle acquisition unit; an estimation unit that estimates an antenna angle at which the degree of coincidence calculated by the degree of coincidence calculation unit is maximum as a direction of arrival of radio waves; a separation unit that separates an incoming wave or a delayed wave component from the reception intensity measured by the reception intensity measurement unit; having The coincidence calculation unit Calculating a degree of coincidence between the antenna angle acquired by the antenna angle acquisition unit and the reception strength of the arrival wave or the delayed wave separated by the separation unit, and an antenna pattern of the antenna, for each antenna angle acquired by the antenna angle acquisition unit; The separation unit is Separating incoming or delayed waves with the same propagation time from the transmitting station by correlation with a known pattern transmitted by the transmitting station A radio wave arrival direction estimation device comprising:

2. an antenna angle acquisition step of acquiring antenna angles indicating a plurality of different directions in which an antenna having a non-uniform antenna pattern is directed in an arbitrary sequential order; a reception strength measuring step of measuring the reception strength of radio waves received by the antenna at each of the acquired antenna angles; a coincidence calculation step of calculating a coincidence between the acquired antenna angle and the measured reception intensity and an antenna pattern of the antenna for each acquired antenna angle; an estimation step of estimating the antenna angle with the highest calculated degree of coincidence as the direction of arrival of the radio wave; A separation step for separating the components of the arriving wave or delayed wave from the measured reception strength. Including, In the matching degree calculation step, Calculating the degree of agreement between the acquired antenna angle and the reception strength of the separated arriving wave or delayed wave and the antenna pattern of the antenna for each acquired antenna angle; In the separation step, Separating incoming or delayed waves with the same propagation time from the transmitting station by correlation with a known pattern transmitted by the transmitting station A method for estimating direction of arrival of radio waves, comprising:

3. A radio wave direction estimation program for causing a computer to function as each part of the radio wave direction estimation device described in claim 1.

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