JP6538365B2 - measuring device - Google Patents

Description

  The present invention relates to a technique for estimating an azimuth in which a transmission source device exists using a wireless communication signal.

  Conventionally, the wireless communication signal in the high UHF band (several GHz) transmitted from the system under test is received by each element of the array antenna of the measurement system, and the system under test is based on the reception strength and phase information of the received signal. There is known a technique for obtaining an arrival direction of a wireless communication signal from the sensor and a relative position of a measurement system and a measurement system. Then, if there is a reflector that reflects radio waves around these measured systems and measurement systems, in the measurement system, not only direct waves coming directly from the measured systems but also reflections that are reflected from the reflectors and then come I also receive waves. At this time, as shown in FIG. 11 and FIG. 12, due to interference between the direct wave and the reflected wave, depending on the positional relationship between the measurement system and the measurement system, the reception intensity obtained by the measurement system is significantly reduced. It may be impossible.

  On the other hand, there is known a technique of switching the frequency used for wireless communication, measuring the reception strength, and performing positioning using the maximum value or the average value of the measurement results at each frequency (see Patent Document 1). .

JP, 2008-224489, A

  In the prior art, the maximum value and the average value of the measurement results at each frequency are used. This means that the results measured in the state where the direct wave and the reflected wave interfere with each other are the maximum value and the average value. It means that it may be reflected. As a result, there is a problem that the S / N of the direct wave required for accurate positioning is degraded, and the positioning error is increased.

  The present invention has been made in view of these problems, and an object of the present invention is to provide a technique for stably and accurately measuring the arrival direction of a direct wave even in an environment where the direct wave and the reflected wave interfere with each other.

  The arrival direction estimation system of the present invention includes a device under test that transmits a preset designated wave, and a measurement device that estimates the arrival direction of the designated wave. The device under test sequentially switches a plurality of frequencies and repeatedly transmits a designated wave. The measuring device extracts, for each frequency used for transmitting the designated wave, incoming wave information which is information on each incoming wave obtained from the received signal at the frequency, and directly arrives from the device under test according to the incoming wave information. Selection of a direct wave that is a designated wave, selection of a target frequency that is a frequency suitable for estimation of the direction of arrival of the direct wave, and estimation of the direction of arrival of the direct wave using a received signal at the target frequency are performed.

  According to such a configuration, since the interference state between the direct wave and the reflected wave changes for each frequency, the frequency in which the direct wave has a sufficiently large reception intensity is selected as the target frequency and the estimation of the arrival direction is performed. By doing this, stable positioning results can be obtained. Moreover, since the target frequency is determined to estimate the direction of arrival, it is possible to obtain accurate positioning results without deteriorating the S / N of the direct wave by the received signal of the frequency where the direct wave is greatly degraded. it can.

  The measuring apparatus according to the present invention receives a designated wave from a device under test which sequentially switches a plurality of frequencies and repeatedly transmits a designated wave which has been set in advance, and estimates the arrival direction of the designated wave. , A signal extraction unit, a frequency switching unit, an incoming wave information extraction unit, and an estimation unit. An array antenna is comprised of a plurality of antenna elements. The signal extraction unit extracts a signal of a designated frequency that is designated from the reception signals output from the respective antenna elements constituting the array antenna. The frequency switching unit switches the designated frequency in synchronization with the switching of the frequency in the device under test. The incoming wave information extraction unit extracts, from the signal extracted by the signal extraction unit, incoming wave information that is information related to each incoming wave detected at the specified frequency for each specified frequency. The estimation unit is a direct wave that is a designated wave that directly arrives from the device under test according to the arrival wave information extracted by the arrival wave information extraction unit, and a target frequency that is a frequency suitable for estimating the arrival direction of the direct wave. Selection and estimation of the direction of arrival of the direct wave using the received signal at the target frequency are performed.

According to the measuring apparatus configured as described above, it can be suitably used when configuring the above-described arrival direction estimation system.
In addition, the code | symbol in the parentheses described in the claim shows correspondence with the specific means as described in embodiment mentioned later as one aspect, Comprising: The technical scope of this invention is limited. is not.

It is a block diagram showing composition of a position estimating system of a 1st embodiment. It is a flowchart of the direct wave selection process in 1st Embodiment. It is a flow chart of direct wave selection processing in a 2nd embodiment. It is a flow chart of direct wave selection processing in a 3rd embodiment. It is a block diagram which shows the structure of the position estimation system of 4th Embodiment. It is explanatory drawing which shows the structure of the array antenna in 4th Embodiment, and the setting of a partial array antenna. It is a flowchart of the direct wave selection process in 4th Embodiment. It is a flow chart of angle difference calculation processing performed during direct wave selection processing of a 4th embodiment. It is an explanatory view showing each parameter used for classification of a direct wave and a reflected wave. It is explanatory drawing which shows the other setting method of a partial array antenna. It is explanatory drawing which shows a mode that a direct wave attenuates by interference of a direct wave and a reflected wave. (A) is explanatory drawing which shows the arrival direction of a direct wave and a reflected wave, (b) is a graph which illustrates the arrival direction estimation result calculated | required in the condition which the direct wave attenuated largely.

Embodiments to which the present invention is applied will be described below with reference to the drawings.
[1. First embodiment]
[1.1 configuration]
The position estimation system 1 includes a device to be measured (transmission side device) 2 and a measurement device (reception side device) 3 as shown in FIG. The device to be measured 2 includes, for example, a mobile phone, a smart key, and the like, and the measuring device 3 is configured as, for example, an on-vehicle device mounted on a vehicle.

  The device under test 2 includes an antenna 21, a transmitter 22, a communication controller 23, and a frequency switch 24. The transmitter 22 transmits a wireless communication signal according to a predetermined communication standard (for example, WiFi (registered trademark) or Bluetooth (registered trademark)) using the high UHF band (several GHz) through the antenna 21. The communication controller 23 controls communication using a wireless communication signal. The frequency switcher 24 sequentially switches the frequency used for transmission by the transmitter 22 in the high UHF band according to a predetermined schedule. In addition, since such switching of the frequency is a known technique in spread spectrum communication and the like using frequency hopping, the description is omitted here. Hereinafter, the radio wave transmitted by the device under test 2 is also referred to as a “designated wave”.

The measuring device 3 includes a first array antenna 31, a second array antenna 32, a first receiving unit 33, a second receiving unit 34, and a position estimating unit 35.
Each of the first and second array antennas 31 and 32 is composed of a plurality of antenna elements arranged in the horizontal direction. Further, both array antennas 31 and 32 are disposed at different positions at least in the horizontal direction.

  The first receiving unit 33 estimates the arrival direction of the received designated wave in accordance with the received signal from the first array antenna 31, and supplies the first estimated direction DR1 that is the estimation result to the position estimating unit 35. The second receiving unit 34 estimates the arrival direction of the received designated wave in accordance with the received signal from the second array antenna 32, and supplies the second estimated direction DR2 that is the estimation result to the position estimating unit 35.

  The position estimation unit 35 estimates the first estimated direction DR1 estimated by the first receiver 33, the second estimated direction DR2 estimated by the second receiver 34, and the installation interval of the first array antenna 31 and the second array antenna 32. The position of the device to be measured 2 which is the transmission source of the designated wave is estimated using a known triangulation method according to the above.

The first receiving unit 33 and the second receiving unit 34 have the same configuration, so only the configuration of the first receiving unit 33 will be described here.
The first receiver 33 includes a receiver 331, a direct wave selector 332, and a frequency switch 333. The receiver 331 extracts the signal component of the frequency (designated frequency) designated by the frequency switcher 333 from the reception signals supplied from the respective antenna elements constituting the first array antenna 31, and samples this to directly It supplies to the wave selection part 332. The frequency switch 333 switches the designated frequency in accordance with the instruction from the direct wave selection unit 332. The switching is performed in synchronization with the frequency switch 24 of the device under test 2 so that the same frequency becomes the designated frequency at the same timing. The direct wave selection unit 332 processes the sampled received signal (hereinafter, referred to as received data) supplied from the receiver 331 while switching the setting of the frequency switching unit 333 so that the direct wave is selected from the incoming waves. A direct wave selection process is performed to select and estimate the direction of arrival of the direct wave. The arrival direction of the direct wave estimated by the direct wave selection process is supplied to the position estimation unit 35 as the first estimated direction DR1. The direct wave selection unit 332 is realized by processing executed by a known microcomputer provided with a CPU, a ROM, and a RAM.

[1.2. processing]
Here, the details of the direct wave selection process executed by the direct wave selection unit 332 will be described using the flowchart shown in FIG. The present process is repeatedly activated while power is supplied to the measuring device 3.

When the present process is activated, the CPU functioning as the direct wave selection unit 332 initializes an arrival wave number counter for counting the number of arrival waves to 0 in S110.
In the following S120, the designated frequency of the frequency switch 333 is selected, and in the following S130, the process waits until the signal of the selected designated frequency is received, and when the signal of the designated frequency is received, the process proceeds to S140.

  In S140, high resolution azimuth estimation processing such as MUSIC is performed using the sampling values of the reception signals obtained from the respective antenna elements constituting the array antenna. Thereby, the number of arriving waves W and the directions of arrival (orientation candidates) θa, θb,.

At S150, it is determined whether the number of incoming waves W obtained at S140 is larger than the value of the number of incoming wave counters C. If W> C, the process proceeds to S160, and if W ≦ C, the process proceeds to S180.
At S160, the value of the arrival wave number counter C is updated with the number W of arrival waves obtained at S140. At S170, the direction candidate obtained at S140 is stored in association with the designated frequency selected at S120 (updated if it is already stored), and the process proceeds to S180.

  In S180, it is determined whether the above-described processing has been performed for all designated frequencies. If there is an unprocessed designated frequency, the process returns to S120, and if the process is completed for all the designated frequencies, the process proceeds to S190.

In S190, the designated frequency finally stored in the process of S170 is selected as the target frequency.
In the subsequent S200, among the azimuth candidates stored for the target frequency, the arrival wave with the largest received intensity is selected as the direct wave, and the arrival direction of the direct wave is determined as the estimated azimuth DRk (k = 1 or 2). This is supplied to the estimation unit 35, and this processing ends. In addition, selection of a direct wave can use not only the method performed based on receiving strength but the known method of selecting a direct wave using the received signal in an object frequency.

[1.3. effect]
As described above, in the present embodiment, the number of arriving waves W is determined for each designated frequency, the designated frequency with the largest number of arriving waves W is selected as the target frequency, and the arrival is obtained using the reception signal at this target frequency The direction is a direction candidate, and a direct wave is selected from the direction candidate. That is, the interference state of the direct wave and the reflected wave changes every designated frequency even in the same communication environment. If there are incoming waves whose reception strength is greatly attenuated due to interference, the number W of incoming waves to be detected also decreases. In other words, it can be said that there is no cancellation by interference at the designated frequency where the number of incoming waves W is maximum, and there is a high possibility that a direct wave exists in the received signal.

  Therefore, according to this embodiment, the positioning result of the arrival direction of the direct wave can be stably obtained. Moreover, in the present embodiment, one designated frequency is determined as the target frequency, and the arrival direction is estimated using only the result of processing the received signal at the target frequency. Therefore, the influence of the reception signal at the designated frequency at which the direct wave is greatly attenuated can be eliminated, and the S / N of the direct wave is not deteriorated, so that the positioning result with high accuracy can be obtained. .

[2. Second embodiment]
The basic configuration of the second embodiment is the same as that of the first embodiment, and thus the description of the common configuration will be omitted, and differences will be mainly described.

  In the first embodiment described above, the target frequency is determined by the number of incoming waves W extracted for each designated frequency. On the other hand, the second embodiment is different from the first embodiment in that the target frequency is determined by the reception power P of the incoming wave.

[2.1. processing]
Below, the direct wave selection process which the direct wave selection part 332 performs instead of the process shown in FIG. 2 is demonstrated using the flowchart of FIG. As compared with the process shown in FIG. 2, the processes of S120 to S130 and S170 to S200 are the same, and only the processes of S110 and S140 to S160 related to the selection of the target frequency are different. Explain to.

  That is, in the present embodiment, as shown in FIG. 3, when the process is activated, the reception power register R storing the maximum value of the reception power of the arrival wave is initialized to 0 in S115, and the process proceeds to S120.

Then, when it is determined in S130 that the signal of the designated frequency selected in S120 is received, the process proceeds to S145.
In S145, high resolution azimuth estimation processing such as MUSIC is performed using the sampling value of the reception signal obtained from each antenna element constituting the array antenna. As a result, the arrival directions (orientation candidates) θa, θb,... Of each incoming wave are determined, and the largest received power of each incoming wave is extracted as the maximum received power P.

At S155, it is determined whether the maximum received power P obtained at S145 is larger than the value of the received power register R. If P> R, the process proceeds to S165, and if P ≦ R, the process proceeds to S180.
At S165, the value of the received power register R is updated with the maximum received power P obtained at S145, and the process proceeds to S170. The processes of S170 to S200 are the same as in the first embodiment.

[2.2. effect]
As described above, in the present embodiment, the maximum received power P of the arriving wave is determined for each designated frequency, and the designated frequency at which the arriving wave having the largest maximum received power P is detected is selected as the target frequency. The arrival direction determined using the reception signal at the target frequency is taken as a direction candidate, and a direct wave is selected from the direction candidate. That is, the direct wave is likely to have a larger received power than the reflected wave, and the received power of the direct wave is the largest when no interference occurs. In other words, it can be said that a direct wave is likely to be present in the received signal at the designated frequency at which the maximum received power P is the largest. For this reason, according to this embodiment, the same effect as the effect of the first embodiment can be obtained.

[3. Third embodiment]
The basic configuration of the third embodiment is the same as that of the first embodiment, and thus the description of the common configuration will be omitted, and differences will be mainly described.

  In the first embodiment described above, the target frequency is determined by the number of incoming waves W extracted for each designated frequency. On the other hand, the third embodiment is different from the first embodiment in that the target frequency is determined by both the number of incoming waves W and the received power P of the incoming waves.

[3.1. processing]
Below, the direct wave selection process which the direct wave selection part 332 performs instead of the process shown in FIG. 2 is demonstrated using the flowchart of FIG.

  When this process is activated, the CPU functioning as the direct wave selection unit 332, in S210, whichever of the arrival wave number counter C that counts the arrival wave number and the reception power register R that stores the maximum value of the reception power of the arrival wave. Also initialize to 0.

  At S220, the designated frequency of the frequency switch 333 is selected. At S230, the process waits until the signal of the selected designated frequency is received, and when the signal of the designated frequency is received, the process proceeds to S240.

  In S240, high resolution azimuth estimation processing such as MUSIC is performed using the sampling value of the received signal obtained from each antenna element constituting the array antenna. As a result, the number of arriving waves W and the arriving directions (orientation candidates) θa, θb,... Of the arriving waves are determined, and the largest received power of each arriving wave is extracted as the maximum received power P.

In the subsequent S250, it is determined whether the number of incoming waves W obtained in S240 is larger than the value of the incoming wave number counter C. If W> C, the process proceeds to S260, and if W ≦ C, the process proceeds to S280.
In S260, the values of the arrival wave number counter C and the reception power register R are updated with the number W of arrival waves and the maximum reception power P obtained in S240. In S270, the calculation result in S240 is stored in association with the designated frequency selected in S220, and the process proceeds to S300.

In S280, it is determined whether the number of incoming waves W is equal to the value of the number of incoming wave counters C. If they are equal, the process proceeds to S290, and if they are not equal, the process proceeds to S300.
In S290, it is determined whether the maximum received power P obtained in S240 is larger than the value of the received power register R. If P> R, the process proceeds to S260, and if P ≦ R, the process proceeds to S300.

  In S300, it is determined whether or not the above-described process has been performed for all designated frequencies. If there is an unprocessed designated frequency, the process returns to S220, and if the process is completed for all the designated frequencies, the process proceeds to S310.

The processes of S310 and S320 are the same as the processes of S190 and S200.
[3.2. effect]
As described above, in this embodiment, the designated frequency at which the number of arriving waves W obtained for each designated frequency is maximum is selected as the target frequency. However, when there are a plurality of designated frequencies for which the number of incoming waves W is maximum, the designated frequency at which the incoming wave for which the maximum received power P is maximum is detected is selected as the target frequency. Then, the arrival direction obtained using the received signal at the selected target frequency is taken as a direction candidate, and a direct wave is selected from the direction candidate.

  For this reason, according to the present embodiment, it is possible to select a target frequency more suitable for selection of direct waves and estimation of the arrival direction of direct waves than in the first embodiment and the second embodiment. Accuracy and reliability can be further improved.

[4. Fourth embodiment]
The basic configuration of the fourth embodiment is the same as that of the first embodiment, so the same reference numerals are given to the common components, and the descriptions thereof will be omitted, and differences will be mainly described.

[4.1. Constitution]
As shown in FIG. 5, the position estimation system 1a includes a device to be measured (transmission side device) 2 and a measurement device (reception side device) 3a. The device under test 2 is the same as that of the first embodiment.

  The measuring apparatus 3a includes a first array antenna 31, a second array antenna 32, a first receiving unit 33a, a second receiving unit 34a, and a position estimating unit 35. The first array antenna 31, the second array antenna 32, and the position estimation unit 35 are the same as those in the first embodiment.

  However, as shown in FIG. 6, each of the first and second array antennas 31, 32 has m (m is a positive number of 3 or more, m = 8 in the figure) antenna elements E1 arranged in the horizontal direction. It shall be comprised by-Em.

  Since the first receiving unit 33a and the second receiving unit 34a have the same configuration, only the configuration of the first receiving unit 33a will be described here. The first receiver 33 a includes an element switch 334, a receiver 331 a, a direct wave selector 332 a, and a frequency switch 333.

  The element switch 334 receives the reception signal from each of the antenna elements E1 to Em constituting the first array antenna 31, and receives the reception signal from the antenna element selected according to the instruction from the direct wave selection unit 332a. Supply to As shown in FIG. 6, the setting to select all antenna elements is Y0, and the setting to select n (n = 4 in the drawing) antenna elements from one end (the left end in the drawing) of the array antenna is Y1, the array A setting for selecting n antenna elements from the other end (right end in the drawing) of the antenna is denoted as Y2. An array antenna configured by antenna elements selected by the setting Y1 or Y2 is hereinafter referred to as a partial array antenna. The number n of antenna elements constituting the partial array antenna (hereinafter referred to as “the number of elements”) is n = p + 1 where p is the maximum number of incoming waves (total number of direct waves and reflected waves) that can be received simultaneously. Set to

  Returning to FIG. 5, the receiver 331a samples the reception signal supplied via the element switching unit 334 and supplies it to the direct wave selection unit 332a. The direct wave selection unit 332a includes a known microcomputer including a CPU, a ROM, and a RAM, and selects a direct wave by processing a sampled received signal (hereinafter referred to as received data) supplied from the receiver 331a. And perform a direct selection process to estimate the direction of arrival of the selected direct wave.

[4.2. processing]
Here, the details of the direct wave selection process performed by the direct wave selection unit 332a will be described using the flowchart shown in FIG. The present process is repeatedly activated as long as power is supplied from the battery of the vehicle on which the measuring device 3 is mounted.

  When this process is activated, the CPU functioning as the direct wave selection unit 332a selects a designated frequency of the frequency switch 333 in S410, and initializes the setting of the element switch 334 to Y0 in S420.

At S430, the process waits until the signal of the selected designated frequency is received, and when the signal of the designated frequency is received, the process proceeds to S440.
In S440, high resolution azimuth estimation processing such as MUSIC is performed using the sampling value (reception data) of the reception signal supplied from each antenna element constituting the array antenna. Thereby, the arrival directions (orientation candidates) of all the arrival waves are determined.

In the subsequent S450, the orientation candidate obtained by the processing in S440 is stored in the memory.
In the subsequent S460, an angle difference calculation process (described later) for obtaining an angle difference in the direction of arrival detected by each partial array antenna is executed for the same incoming wave.

  At S470, it is determined whether the processing of S410 to S460 has been performed for all the frequencies that can be switched by the frequency switch 333. If there is an unprocessed frequency, the process returns to S410, and if all frequencies have been processed, the process proceeds to S480.

  In S480, among the angle differences calculated for each frequency and each incoming wave in S480 above, the largest one is extracted. An incoming wave corresponding to the maximum angular difference is called a selected incoming wave, and a frequency at which the maximum angular difference is detected is called a target frequency.

  At S490, of the orientation candidates stored at S450 for the target frequency, the one closest to the arrival direction of the selected arrival wave is determined as the arrival direction of the direct wave, and this is determined as the estimated orientation DRk (k = 1 or 2). This is supplied to the position estimation unit 35, and the present process is ended.

Here, the details of the angle difference calculation process executed in S <b> 460 described above will be described with reference to FIGS. 8 and 9.
In this process, as shown in FIG. 8, first, at S510, the parameter i used for the switching setting of the element switching device 334 is initialized to one.

In the subsequent S520, the setting of the element switching unit 334 is set to Yi.
In the following S530, the process waits until the designated wave is received. When the designated wave is received, the arrival directions θia, θib,... Of the designated wave are estimated by using the reception signals from the respective antenna elements constituting the partial array antenna corresponding to the setting Yi in S540. In addition, the difference of an arrival wave shall be represented by a, b, c, ... (refer FIG. 9).

In the subsequent S550, the parameter i is incremented.
At S560, it is determined whether the parameter i is equal to or greater than the number of switching settings of the element switch 334, that is, Imax (Imax = 2 here) which is the number of types of partial array antennas.

  If i <Imax, there is an unprocessed switch setting, the process returns to S520, and if i ≧ Imax, the process proceeds to S570, assuming that the process is completed for all the switch settings.

  In S570, angle differences Δθa, Δθb,... Of the directions of arrival detected by the partial array antennas are calculated for each of the detected arrival waves a, b,. Note that whether or not the two incoming directions detected with different switching settings are due to the same incoming wave is determined depending on whether or not the angle difference between the two incoming directions is within a predetermined range.

  In the case of Imax ≧ 3, it is assumed that i, j = 1 to Imax, i ≠ j, x = a, b, c,... And angle difference Δθ ijx = | for all combinations (i, j) of switching setting. θix−θjx | is calculated, and an average value of a plurality of angular differences Δθ ijx obtained for each incoming wave x or a value determined by a majority decision is taken as an angular difference Δθx of the incoming wave x.

The fact that direct waves and reflected waves can be sorted by comparing the difference in angle is described in detail in, for example, Japanese Patent Application Laid-Open No. 2006-125993, and thus the description thereof is omitted here.
[4.3. effect]
As described above, in the present embodiment, the angle difference Δθx of the arrival direction detected by each partial array antenna for the same arrival wave is determined for each designated frequency, and the arrival wave with the largest angle difference Δθx is a direct wave, The designated frequency at which the incoming wave is detected is selected as the target frequency. Furthermore, the direction of arrival obtained using the received signal at this target frequency is taken as a direction candidate, and a direct wave is selected from the direction candidate. That is, since the direct wave is larger than the reflected wave in the angular difference Δθx, the incoming wave with the largest angular difference Δθx is the direct wave, and the designated frequency at which the incoming wave is detected is the direct wave It can be said that there is a high possibility of being well received. For this reason, according to this embodiment, the same effect as the effect of the first embodiment can be obtained.

  Further, in the present embodiment, by using a single array antenna 31 as a plurality of partial antennas set so as to have different central positions, reception signals at a plurality of points having different positions can be obtained. Therefore, the separation of the direct wave and the reflected wave can be realized without moving the measuring device 3.

  Furthermore, in the present embodiment, the direct wave is selected according to the low resolution arrival direction estimated using the reception signal from the partial array antenna, and the reception signals from all array antennas are used as the arrival direction of the direct wave. It uses the high-resolution arrival direction estimated by This makes it possible to obtain highly accurate estimation results of the direction of arrival.

[5. Other embodiments]
As mentioned above, although embodiment of this invention was described, this invention can take various forms, without being limited to the said embodiment.

  (1) In the above embodiment, the functions of the direct wave selection units 332 and 332a are realized by processing executed by a microcomputer. However, implementing this function by software is merely an example, and all or part of it may be implemented by hardware such as a logic circuit.

  (2) In the fourth embodiment, as a partial array antenna, one selecting n antenna elements from one end of m array antennas and one selecting n antenna elements from the other end are used. There is. In FIG. 6, although it is set to have a relation of n = m / 2, it is not limited to this, and as shown in FIGS. 10 (a) and 10 (b), 2 ≦ n ≦ m− It can be set arbitrarily within the range of 1. However, as n increases, the positional difference between both partial array antennas decreases, so the resolution of the angle difference degrades, but the number of elements increases, and the number of detectable arrival waves increases. The smaller the difference is, the lower the resolution of the angular difference but the smaller the number of detectable arrival waves.

  Further, the partial array antennas do not necessarily have to be set at both ends, as long as the central positions along the arrangement direction of the antenna elements are different from each other. As shown in FIG. 10C, if the total number of elements of the array antenna is m and the number of elements of the partial array antenna is n, (m-n + 1) types of partial array antennas can be set, and Any two or more can be used.

  (3) In the fourth embodiment, the arrival direction determined using the entire array antenna is the arrival direction of the direct wave, but the arrival direction determined using the partial array antenna is the same as the arrival direction of the direct wave. It may be

  (4) In the fourth embodiment, the element switch 334 is switched according to the setting of the partial array antenna to be used, and the reception signal is acquired again for each setting. However, all the antenna elements constituting the array antenna The received signals may be acquired at one time and stored in the memory, and the stored value of the received signal from the corresponding antenna element may be read out and processed when the processing related to the partial array antenna is executed. In this case, since the element switching device 334 can be omitted, the device configuration can be simplified.

  (5) The function possessed by one component in the above embodiment may be distributed to a plurality of components, or the function possessed by a plurality of components may be integrated into one component. Further, at least a part of the configuration of the above embodiment may be replaced with a known configuration having the same function. In addition, part of the configuration of the above embodiment may be omitted. Further, at least a part of the configuration of the above-described embodiment may be added to or replaced with the configuration of the other above-described embodiment. In addition, all the aspects contained in the technical thought specified only by the words described in the claim are an embodiment of the present invention.

  1, 1a Position estimation system 2. Measured device 3, 3a Measurement device 21 Antenna 22 Transmitter 23 Communication controller 24 Frequency switch 31 First array antenna 32 Second array antenna 33 33a First receiver 34, 34a Second receiver 35 Position estimation unit 331, 331a Receiver 332, 332a Direct wave selection unit 333 Frequency switch 334 Element switch E1 to Em Antenna element

Claims (3)

A measuring device (3) for receiving the designated wave and estimating an arrival direction of the designated wave from a device under test that sequentially switches a plurality of frequencies and repeatedly transmits a designated wave that is set in advance,
An array antenna (31, 32) composed of a plurality of antenna elements,
A signal extraction unit (331) for extracting a signal of a designated frequency specified from the reception signals output from each antenna element constituting the array antenna;
A frequency switching unit (333) that switches the specified frequency in synchronization with the switching of the frequency in the device under test;
An arrival wave information extraction unit (332: S110 to S180, S210 to S310 to extract arrival wave information that is information on each arrival wave detected at the designated frequency from the signal extracted by the signal extraction unit. S300, 332a: S410 to S470),
Selection of a direct wave that is the designated wave that directly comes from the device under test according to the incoming wave information extracted by the incoming wave information extraction unit, and an object that has a frequency suitable for estimating the direction of arrival of the direct wave An estimation unit (332: S190 to S200, S310 to S320, 332a: S480 to S490) for selecting the frequency and estimating the arrival direction of the direct wave using the received signal at the target frequency;
Equipped with
The incoming wave information extraction unit (332: S110 to S180) uses the number of incoming waves as the incoming wave information,
The estimation unit (332: S190 to S200, S310 to S320) selects a designated frequency at which the number of incoming waves is maximum as the target frequency, selects the direct wave from the reception signal of the target frequency, and selects the direct wave. you and performing DOA estimation measurement device. A measuring device (3) for receiving the designated wave and estimating an arrival direction of the designated wave from a device under test that sequentially switches a plurality of frequencies and repeatedly transmits a designated wave that is set in advance,
An array antenna (31, 32) composed of a plurality of antenna elements,
A signal extraction unit (331) for extracting a signal of a designated frequency specified from the reception signals output from each antenna element constituting the array antenna;
A frequency switching unit (333) that switches the specified frequency in synchronization with the switching of the frequency in the device under test;
An arrival wave information extraction unit (332: S110 to S180, S210 to S310 to extract arrival wave information that is information on each arrival wave detected at the designated frequency from the signal extracted by the signal extraction unit. S300, 332a: S410 to S470),
Selection of a direct wave that is the designated wave that directly comes from the device under test according to the incoming wave information extracted by the incoming wave information extraction unit, and an object that has a frequency suitable for estimating the direction of arrival of the direct wave An estimation unit (332: S190 to S200, S310 to S320, 332a: S480 to S490) for selecting the frequency and estimating the arrival direction of the direct wave using the received signal at the target frequency;
Equipped with
The arrival wave information extraction unit (332: S210 to S300) uses the number of arrival waves and the reception intensity of each arrival wave as the arrival wave information,
The estimation unit (332: S190 to S200, S310 to S320) selects, as the target frequency, the designated frequency at which the arriving wave having the largest received intensity is detected among the designated frequencies having the largest number of arriving waves. the direct wave of selection and the direct wave measurement apparatus you and performs DOA estimation from the received signal of the target frequency. A measuring device (3) for receiving the designated wave and estimating an arrival direction of the designated wave from a device under test that sequentially switches a plurality of frequencies and repeatedly transmits a designated wave that is set in advance,
an array antenna (31, 32) composed of m antenna elements , where m is an integer of 3 or more ,
A signal extraction unit (331) for extracting a signal of a designated frequency specified from the reception signals output from each antenna element constituting the array antenna;
A frequency switching unit (333) that switches the specified frequency in synchronization with the switching of the frequency in the device under test;
An arrival wave information extraction unit (332: S110 to S180, S210 to S310 to extract arrival wave information that is information on each arrival wave detected at the designated frequency from the signal extracted by the signal extraction unit. S300, 332a: S410 to S470),
Selection of a direct wave that is the designated wave that directly comes from the device under test according to the incoming wave information extracted by the incoming wave information extraction unit, and an object that has a frequency suitable for estimating the direction of arrival of the direct wave An estimation unit (332: S190 to S200, S310 to S320, 332a: S480 to S490) for selecting the frequency and estimating the arrival direction of the direct wave using the received signal at the target frequency;
Equipped with
The incoming wave information extraction unit (332a: S410 to S470) comprises the array antenna, each of which includes n (1 <n <m) of the antenna elements, and the central positions of the antenna elements in the arrangement direction are mutually different. The arrival direction of an incoming wave is determined for each of a plurality of subarray antennas selected to be different, and the angular difference in the arrival direction between any two partial array antennas based on the same incoming wave is extracted as the incoming wave information. ,
The estimation unit (332a: S480 to S490) selects an incoming wave with the largest angle difference as a direct wave, selects a designated frequency at which the incoming wave is detected as the target frequency, and selects the partial array antenna. The arrival direction of the incoming wave estimated from the reception signal at the target frequency by more antenna elements than the constituent antenna elements is taken as a direction candidate, and among the direction candidates, it is obtained from the reception signal from the partial array antenna A measuring apparatus characterized in that one closest to the arrival direction of the direct wave is an estimation result of the arrival direction of the direct wave.

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