WO2016129244A1

WO2016129244A1 - Arrival direction estimation apparatus

Info

Publication number: WO2016129244A1
Application number: PCT/JP2016/000526
Authority: WO
Inventors: 正義佐竹; 達人竹内; 健一郎三治
Original assignee: 株式会社デンソー
Priority date: 2015-02-12
Filing date: 2016-02-02
Publication date: 2016-08-18
Also published as: JP6538366B2; JP2016148591A

Abstract

In apparatuses (33, 34) that estimate an arrival direction of an arrival wave, a first azimuth candidate calculation unit (333: S210-S260) obtains arrival directions for all arrival waves received according to a reception signal from a partial array antenna, for each of a plurality of partial array antennas, where the array antennas are selected such that each comprises n (1<n<m) antenna elements and the center positions of the array direction of the antenna elements differ from each other. A direct wave selection unit (333: S270-S280) selects a direct wave arriving directly from a transmission source by comparing the arrival directions of the arrival waves obtained for each partial array antenna by the first azimuth candidate calculation unit.

Description

Direction of arrival estimation device

Cross-reference of related applications

This application is based on Japanese Patent Application No. 2015-25689 filed on February 12, 2015, the contents of which are incorporated herein by reference.

The present disclosure relates to an apparatus (Apparatus) that estimates a direction in which a transmitter exists using a wireless communication signal.

Conventionally, a radio communication signal in a high UHF band (several GHz) transmitted from a system to be measured is received by each element of an array antenna included in the measurement system, and the system to be measured is based on reception intensity and phase information of the received signal. There are known techniques for obtaining the direction of arrival of a radio communication signal from the radio and the relative position of the system under measurement and the measurement system. If there is a reflector that reflects radio waves around the system to be measured and the measurement system, the measurement system reflects not only the direct wave that directly arrives from the system to be measured but also the reflection that arrives after being reflected by the reflector. I also receive waves. Therefore, in order to correctly detect the direction in which the system to be measured is located, it is necessary to identify the direct wave and the reflected wave. As one of the technologies to achieve this, wireless communication signals are received at two different points by moving the measurement system, and direct waves and reflected waves are selected based on angle changes in the direction of arrival of wireless communication signals at both points. A technique is known (see Patent Document 1).

JP 2006-125993 A

However, the conventional technique needs to move the position of the measurement system (especially the array antenna), and may not be applied under conditions where the position of the measurement system is fixed.

This disclosure is intended to provide a technique for realizing selection of reflected waves and direct waves even when the position of the array antenna is fixed.

According to one example of the present disclosure, the arrival direction estimation device estimates an arrival direction of an incoming wave according to reception signals from m antenna elements (m is an integer of 3 or more) configuring an array antenna. Yes, the first direction candidate calculation unit, the direct wave selection unit, and the arrival direction determination unit are provided.

The first azimuth candidate calculation unit includes a plurality of partial arrays in which the array antennas are each composed of n (1 <n <m) antenna elements and the center positions of the antenna elements in the arrangement direction are different from each other. For each antenna, the arrival direction of the incoming wave is determined according to the received signal from the partial array antenna. The direct wave selection unit selects the direct wave that directly arrives from the transmission source by comparing the arrival directions of the incoming waves obtained for each partial array antenna by the first direction candidate calculation unit. The arrival direction determination unit determines the arrival direction estimation result using the arrival direction of the direct wave selected by the direct wave selection unit.

According to such a configuration, since a single array antenna is used as a plurality of partial antennas whose center positions are different from each other, received signals at a plurality of points having different positions can be obtained. Direct waves and reflected waves can be selected without moving the antenna.

The above and other objects, features, and advantages of the present disclosure will become more apparent from the following detailed description with reference to the accompanying drawings.
It is a block diagram which shows the structure of a position estimation system. It is explanatory drawing which shows the structure of an array antenna and the setting of a partial array antenna. It is a flowchart of a direct wave arrival direction estimation process. It is a flowchart of the direct wave selection process performed in the direct wave arrival direction estimation process. It is explanatory drawing which shows each parameter used for selection 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 the other setting method of a partial array antenna. It is explanatory drawing which shows the other setting method of a partial array antenna.

Embodiments to which the present disclosure is applied will be described below with reference to the drawings.

[Constitution]
As illustrated in FIG. 1, the position estimation system 1 includes a device under measurement (transmission side device) 2 and a measurement device (reception side device) 3. The device under measurement 2 includes, for example, a mobile phone or a smart key, and the measurement device 3 is configured as an on-vehicle device mounted on a vehicle, for example.

The device under measurement 2 includes an antenna 21, a transmitter 22, and a communication controller 23. 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) via the antenna 21. The communication controller 23 controls communication using a wireless communication signal. Hereinafter, the radio wave transmitted by the device under test 2 is also referred to as “designated wave”.

The measuring apparatus 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. As shown in FIG. 2, each of the first and

second array antennas

31 and 32 includes m antenna elements E1 to Em (m is a positive number of 3 or more, m = 8 in the figure) arranged in the horizontal direction. It consists of Further, the two

array antennas

31 and 32 are arranged at different positions at least in the horizontal direction. Note that the array antenna device can also be referred to as including a first array antenna 31 and a second array antenna 32. Furthermore, the arrival direction estimation device can be referred to as including a first reception unit 33 and a second reception unit 34.

Returning to FIG. 1, the first receiving unit 33 estimates the arrival direction of the received designated wave according to the received signal from the first array antenna 31, and the first estimation direction DR <b> 1 that is the estimation result is sent to the position estimating unit 35. Supply. The second receiving unit 34 estimates the arrival direction of the received designated wave according to the received signal from the second array antenna 32, and supplies the second estimation direction DR2 that is the estimation result to the position estimating unit 35.

Since the first receiving unit 33 and the second receiving unit 34 have the same configuration, only the configuration of the first receiving unit 33 will be described here. The first reception unit 33 includes an element switch 331, a receiver 332, and a direct wave arrival direction estimation unit 333. The element switch 331 receives reception signals from the antenna elements E1 to Em constituting the first array antenna 31, and receives reception signals from the antenna elements selected in accordance with instructions from the direct wave arrival direction estimation unit 333. To machine 332. As shown in FIG. 2, the setting for selecting all antenna elements is Y0, the setting for selecting n (n = 4 in the figure) antenna elements from one end (left end in the figure) of the array antenna is Y1, and the array is selected. A setting for selecting n antenna elements from the other end (right end in the figure) of the antenna is denoted as Y2. The array antenna configured by the antenna elements selected by the setting Y1 or Y2 is hereinafter referred to as a partial array antenna. The number of antenna elements constituting the partial array antenna (hereinafter referred to as “number of elements (also referred to as element count)”) n is the maximum number of incoming waves (total number of direct waves and reflected waves) that may be received simultaneously. The number is set to n = p + 1 where p is the number. Here, n is also referred to as the first specific number. On the other hand, the second specific number is referred to as being greater than the first specific number. It can be said that m is an example of the second specific number.

Returning to FIG. 1, the receiver 332 samples the received signal supplied via the element switch 331 and supplies it to the direct wave arrival direction estimation unit 333. The direct wave arrival direction estimation unit 333 is also referred to as a direct wave arrival direction estimation circuit 333. As an electronic control unit, in the present embodiment, the direct wave arrival direction estimation unit 333 includes, as an example, a known microcomputer including a CPU, a ROM, and a RAM. A direct wave arrival direction estimation process for estimating the arrival direction of the direct wave by processing the sampled reception signal (hereinafter referred to as reception data) supplied from 332 is executed.

The position estimator 35 is also referred to as a position estimator circuit 35. In the present embodiment, the position estimator 35 is a known microcomputer including a CPU, a ROM, and a RAM, and is estimated by the first receiver 33. In accordance with the first estimated azimuth DR1, the second estimated azimuth DR2 estimated by the second receiver 34, the installation interval of the first array antenna 31 and the second array antenna 32, etc., the designated wave is used using a known triangulation technique. The position of the device under measurement 2 that is the transmission source of is estimated.

[Direct wave arrival direction estimation processing]
Here, the details of the direct wave arrival direction estimation processing executed by the direct wave arrival direction estimation unit 333 will be described with reference to the flowchart shown in FIG. This process is repeatedly started as long as power is supplied from the battery of the vehicle on which the measuring device 3 is mounted.

The described flowchart includes a plurality of sections (or referred to as steps), and each section is expressed as, for example, S110. Further, each section can be divided into a plurality of subsections, while a plurality of sections can be combined into one section. Each section can be referred to as a device, module, or proper name, for example, a calculation section can be referred to as a calculation device, a calculation module, or a calculator. In addition, the section includes (i) not only a section of software combined with a hardware unit (eg, a computer) but also (ii) a section of hardware (eg, an integrated circuit, a wiring logic circuit) and related devices. It can be realized with or without the function. Furthermore, the hardware section can be included inside the microcomputer.

When this processing is started, the CPU functioning as the direct wave arrival direction estimation unit 333 initializes the setting of the element switch 331 to Y0 which is a setting for selecting all antenna elements in S110. In S120, the process waits until a designated wave that is a radio wave transmitted by the device under test 2 is received. When the designated wave is received, the process proceeds to S130.

In S130, the arrival directions of all incoming waves are estimated by executing high-resolution azimuth estimation processing such as MUSIC (Multiple Signal Classification) using received signals from all antenna elements. In S140, all arrival directions detected by the process in S120 are stored in the memory as orientation candidates.

In S150, a direct wave selection process (described later) for selecting a direct wave is executed using a partial array antenna. In S150, a direct wave is selected in S280 described later. In S160, among the azimuth candidates stored in S140, the one closest to the arrival direction (selected azimuth) of the incoming wave selected as the direct wave in S150 is determined as the estimation result of the direct wave arrival direction, This process ends.

[Direct wave selection processing]
Details of the direct wave selection processing executed in the previous S150 will be described with reference to FIGS.

In this process, as shown in FIG. 4, first, in S210, a parameter i used for switching setting of the element switch 331 is initialized to 1.

In S220, the element switch 331 is set to Yi. In S230, the process waits until a designated wave is received. When the designated wave is received, the arrival directions θia, θib,... Of the designated wave are estimated using received signals from the respective antenna elements constituting the partial array antenna corresponding to the setting Yi in S240. In addition, the difference of an incoming wave shall be represented by a, b, c, ... (refer FIG. 5).

In step S250, the parameter i is incremented. In S260, it is determined whether or not the parameter i is equal to or greater than the number of switching settings of the element switch 331, that is, Imax (here, Imax = 2), which is the number of types of partial array antennas.

If i <Imax, the process returns to S220 assuming that there is an unprocessed switch setting, and if i ≧ Imax, the process proceeds to S270, assuming that all the switch settings have been processed.

S270 calculates, for each detected incoming wave a, b,..., Angle differences Δθa, Δθb,... Of arrival directions detected by the partial array antennas (see FIG. 5). Whether or not two arrival directions detected by different switching settings are due to the same arrival wave is determined based on whether or not the angle difference between the two arrival directions is within a predetermined range.

If Imax ≧ 3, i, j = 1 to Imax, i ≠ j, x = a, b, c,..., And the angle difference Δθijx = | θix−θjx | is calculated, and an average value of a plurality of angular differences Δθijx obtained for each incoming wave x or a value determined by majority decision is defined as an angular difference Δθx of the incoming wave x.

In S280, in S270, the incoming wave having the maximum angle difference Δθx obtained for each incoming wave is selected as the direct wave, and this process is terminated. Note that the fact that direct waves and reflected waves can be selected by comparing the angle difference is described in detail in, for example, Patent Document 1, and thus the description thereof is omitted here.

Note that the direct wave arrival direction estimation unit 333 executes S210 to S260 as a first direction candidate calculation unit, S270 to S280 as a direct wave selection unit, and S110 to S140 and S160 as an arrival direction determination unit. Further, among the arrival direction determination units, S110 to S140 are also referred to as second orientation candidate calculation units, and S160 is also referred to as a selection unit.

[effect]
As described above, the measuring device 3 constituting the position estimation system 1 uses a single array antenna 31 as a plurality of partial antennas set so that the center positions are different from each other, thereby allowing a plurality of different positions. Since the reception signal at the point is obtained, the direct wave and the reflected wave can be selected without moving the measuring device 3.

The measuring apparatus 3 selects a direct wave according to the arrival direction of the low resolution estimated using the reception signal from the partial array antenna, and uses the reception signals from all the array antennas as the arrival direction of the direct wave. The direction of arrival with high resolution estimated in this way is used. Thereby, a highly accurate estimation result of the direction of arrival can be obtained.

[Other Embodiments]
As mentioned above, although embodiment of this indication was described, this indication can take various forms, without being limited to the above-mentioned embodiment.

(1) In the above embodiment, as an example, the functions of the direct wave arrival direction estimation unit 333 and the position estimation unit 35 are realized by processing executed by a microcomputer. However, the realization of each of these units by software is merely an example, and as described above in the description of the flowchart, the whole or a part thereof may be realized by hardware such as a logic circuit. .

(2) In the above embodiment, as the partial array antenna, one that selects n antenna elements from one end of m array antennas and one that selects n antenna elements from the other end are used. In FIG. 2, it is set so as to have a relationship of n = m / 2, but is not limited to this, and as shown in FIGS. 6A and 6B, in the range of 2 ≦ n ≦ m−1. It can be set arbitrarily. However, as n is increased, the position difference between the two partial array antennas is reduced, so the resolution of the angle difference is degraded. However, the number of incoming waves is increased because the number of elements is increased. The smaller the resolution, the lower the resolution of the angle difference, but the number of detectable incoming waves decreases.

Also, the partial array antennas do not necessarily need to be set at both ends, and the center positions of the partial antennas may be different. As shown in FIG. 6C, if the total number of elements of the array antenna is m and the number of elements of the partial array antenna is n, (mn + 1) types of partial array antennas can be set. More than one can be used.

(3) In the above embodiment, the arrival direction obtained using the entire array antenna is set as the direct wave arrival direction. However, the arrival direction obtained using the partial array antenna may be directly used as the direct wave arrival direction. Good.

(4) In the above embodiment, the element switch 331 is switched according to the setting of the partial array antenna to be used, and the received signal is reacquired for each setting. However, reception of all antenna elements constituting the array antenna is performed. When signals are acquired in a lump and stored in a memory and a process related to a partial array antenna is executed, a stored value of a received signal from a corresponding antenna element may be read and processed. In this case, since the element switch 331 can be omitted, the apparatus configuration can be simplified.

(5) In the present disclosure, in addition to the arrival direction estimation devices (the first reception unit 33 and the second reception unit 34), a device (measurement device 3) or a system (position estimation system 1) including the arrival direction estimation device as a constituent element It can also be realized in various forms.

(6) Although the present disclosure has been described with reference to the embodiments, it is understood that the present disclosure is not limited to the embodiments and structures. The present disclosure includes various modifications and modifications within the equivalent range. In addition, various combinations and forms, as well as other combinations and forms including only one element, more or less, are within the scope and spirit of the present disclosure.

Claims

An arrival direction estimation device (33, 34) for estimating an arrival direction of an incoming wave according to received signals from m (m is an integer of 3 or more) antenna elements constituting an array antenna (31, 32),
The array antenna is composed of n (1 <n <m) antenna elements, and each of the partial array antennas selected so that the center positions of the antenna elements in the arrangement direction are different from each other. A first azimuth candidate calculation unit (333: S210 to S260) for obtaining the arrival directions of all the incoming waves received according to the reception signals from the partial array antenna;
A direct wave selection unit (333: S270˜) that selects a direct wave directly coming from the transmission source by comparing the arrival directions of the incoming waves obtained for each of the partial array antennas by the first direction candidate calculation unit. S280),
An arrival direction determination unit (333: S110 to S140, S160) for determining an estimation result of the arrival direction using the direct wave arrival direction selected by the direct wave selection unit;
An arrival direction estimation device comprising:
The direct wave selection unit obtains an angle difference of arrival directions based on the same arrival wave for each arrival direction detected by any two partial array antennas by the first direction candidate calculation unit, and the angle difference is the maximum The arrival direction estimation apparatus according to claim 1, wherein the arrival wave is selected as the direct wave.
Three or more partial array antennas are set,
The direct wave selection unit calculates the angular difference for all combinations of the partial array antennas, and selects the direct wave using a result obtained by averaging or majority deciding the angular difference for each incoming wave. The direction-of-arrival estimation apparatus according to 1.
The arrival direction determining unit
A second azimuth candidate calculation unit (333: S110 to S140) for estimating the arrival direction of the incoming wave according to received signals from more antenna elements than the antenna elements constituting the partial array antenna;
Of the arrival directions calculated by the two-azimuth candidate calculation unit, a selection unit (333: S160) that selects the one closest to the arrival direction of the direct wave selected by the direct wave selection unit and makes the estimation result )When,
The direction-of-arrival estimation apparatus according to any one of claims 1 to 3.
5. The number m of the antenna elements is set to satisfy m ≧ 2 × (p + 1), where p is a maximum number of assumed reflected waves. Direction of arrival estimation device.
2. The partial array antenna that uses n antenna elements continuous from one end of the array antenna and one that uses n antenna elements continuous from the other end of the array antenna are used. The arrival direction estimation apparatus according to claim 5.