JP2011023822A - Radio communication system and control method of the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To allow a radio receiver to distinguish a position of a plurality of radio transmitters. <P>SOLUTION: The radio communication system includes a radio transmitter and a radio receiver, equipped with a directional antenna which can change the directive direction. The radio transmitter includes a first transmission means, a first reception means, a control means, and a determination means. The first transmission means transmits a radio signal to the radio receiver through the directional antenna. The first reception means receives strength information from the radio receiver, as a response to the radio signal. The control means executes transmitting by the first transmission means and receiving by the first reception means for each of a plurality of directive directions of the directional antenna. Based on the strength information corresponding to each of the plurality of directive directions of the directional antenna, the determination means determines a first direction and a second direction. In the first direction, the radio signal transmitted by the first transmission means goes to the radio receiver directly from the directional antenna. In the second direction, the radio signal transmitted by the first transmission means goes to a reflection point from the directional antenna. Wherein, the radio signal is reflected at the reflection point and goes to the radio receiver. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a wireless communication system and a control method thereof.

  As a technique for specifying a mutual position between wireless communication apparatuses that perform wireless communication using millimeter waves, a technique using a GPS receiver is known (Patent Document 1). In addition, in a wireless communication system using an array antenna having variable directivity, a technique for searching for a directivity characteristic that maximizes the received electric field strength of a carrier wave in a wireless reception device is also known (Patent Document 2).

JP 2001-136565 A Japanese Patent Laid-Open No. 11-68759

  Since the position resolution of GPS is not so high, the technology of Patent Document 1 is not very effective in an environment where a large number of wireless communication devices are concentrated in a narrow range. In addition, having a GPS receiver in every wireless communication device leads to an increase in cost.

  Further, in the technique of Patent Document 2, since the wireless receiver can know the direction of the wireless transmitter, but cannot know the distance, the positions of a plurality of wireless transmitters existing in the same direction are distinguished. I can't.

  The present invention has been made in view of such a situation, and an object of the present invention is to provide a technique that enables a wireless reception device to distinguish the positions of a plurality of wireless transmission devices.

  In order to solve the above-described problem, a first aspect of the present invention is a wireless communication system including a wireless transmission device including a directional antenna capable of changing a directivity direction, and a wireless reception device, wherein the wireless transmission device includes: A first transmission unit that transmits a radio signal to the radio reception device via the directional antenna, a first reception unit that receives intensity information from the radio reception device as a response to the radio signal, and the first transmission Control means for executing transmission by means and reception by the first receiving means for a plurality of directivity directions of the directional antenna, and intensity information corresponding to each of the plurality of directivity directions of the directional antenna. Based on the first direction in which the radio signal transmitted by the first transmission unit is directed directly from the directional antenna to the radio reception device, and transmitted by the first transmission unit. Determining means for determining a second direction in which a radio signal reflected from the reflection point and directed to the wireless reception device is directed from the directional antenna toward the reflection point; and a first direction and a second direction determined by the determination means Notification means for notifying the wireless reception device, wherein the wireless reception device is a second reception means for receiving a wireless signal from the wireless transmission device, and the strength of the wireless signal received by the second reception means. A wireless communication system is provided, comprising: second transmission means for transmitting the indicated intensity information to the wireless transmission device; and third reception means for receiving notification by the notification means.

  Other features of the present invention will become more apparent from the accompanying drawings and the following description of the preferred embodiments.

  With the above configuration, according to the present invention, the radio reception device can distinguish the positions of a plurality of radio transmission devices.

The block diagram which shows the structure of DTV100 (digital television) which is an example of the radio | wireless receiver of this invention. The block diagram which shows the structure of DVR200 (digital video recorder) which is an example of the wireless transmitter of this invention. 5 is a flowchart illustrating a flow of position confirmation processing according to the first embodiment. The figure which shows the example of a scan of a directivity direction. The conceptual diagram of direction intensity information. The conceptual diagram of angle information. The conceptual diagram of the method of calculating the distance of DTV100 and DVR200. The figure which shows the example of a scan of the directionality direction in a modification. 9 is a flowchart showing a flow of position confirmation processing according to the second embodiment.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. The technical scope of the present invention is determined by the scope of the claims, and is not limited by the following individual embodiments. In addition, all combinations of features described in the embodiments are not necessarily essential to the present invention.

  With reference to FIG.1 and FIG.2, the radio | wireless communications system of this invention is demonstrated. FIG. 1 is a block diagram showing a configuration of a DTV 100 (digital television) that is an example of a wireless reception apparatus of the present invention, and FIG. 2 is a configuration of a DVR 200 (digital video recorder) that is an example of a wireless transmission apparatus of the present invention. FIG. The wireless communication system of the present invention includes a DTV 100 and a DVR 200. Further, instead of or in addition to the DVR 200, one or more wireless transmission devices such as a DVC (digital video camera) and other DVRs may be included in the wireless communication system of the present invention.

  The DTV 100 and the DVR 200 correspond to the WiHD standard (WirelessHD). In the drawing, LRP is an abbreviation for Low-rate Physical layer, and HRP is an abbreviation for High-rate Physical layer.

  First, the DTV 100 will be described with reference to FIG. The antenna 101 is a directional antenna that performs millimeter-wave wireless communication with the DVR 200. The antenna 101 can change the direction of directivity according to control by the control unit 104. The low-speed communication unit 102 (second transmission unit / third reception unit) communicates a control signal such as a beacon with the DVR 200 via the antenna 101. The high-speed communication unit 103 (second receiving unit) performs AV data communication with the DVR 200 via the antenna 101.

  The control unit 104 controls each component of the DTV 100 according to a control program stored in a ROM (not shown). The user I / F 105 includes a remote controller and operation buttons for the user to input commands.

  The AV processing unit 106 performs broadcast reception processing, external input processing, image processing, and the like, and outputs AV data for display to the display unit 108. The memory 107 is used as a buffer memory for the AV processing unit 106. The display unit 108 displays video based on AV data input from the AV processing unit 106. Display unit 108 also includes a speaker that outputs audio based on AV data input from AV processing unit 106.

  Next, the DVR 200 will be described with reference to FIG. The antenna 201 is a directional antenna that performs millimeter-wave wireless communication with the DTV 100. The antenna 201 can change the direction of directivity according to control by the control unit 204. The low-speed communication unit 202 (first receiving unit / notifying unit) communicates a control signal such as a beacon with the DTV 100 via the antenna 201. The high-speed communication unit 203 (first transmission unit) performs AV data communication with the DTV 100 via the antenna 201.

  The control unit 204 controls each component of the DVR 200 according to a control program stored in a ROM (not shown). The user I / F 205 includes a remote controller and operation buttons for the user to input commands.

  The AV processing unit 206 performs broadcast reception processing, external input processing, decoding processing of content recorded in the storage unit 208 and the external recording / playback unit 209, image processing, and the like. AV data processed by the AV processing unit 206 is transmitted to the DTV 100 by the high-speed communication unit 203, recorded in the storage unit 208 through the control unit 204, or input to the external recording / playback unit 209 through the control unit 204. Or

  The memory 207 is used as a buffer memory for the AV processing unit 206. The storage unit 208 records AV data. The external recording / playback unit 209 outputs AV data to an external device or accepts input of AV data from the external device.

  FIG. 3 is a flowchart illustrating the flow of the position confirmation process according to the first embodiment. In S301, the low-speed communication unit 102 of the DTV 100 transmits a beacon signal via the antenna 101 in order to connect to a wireless transmission device existing in the vicinity.

  In S302, the low-speed communication unit 202 of the DVR 200 receives the beacon signal transmitted in S301 via the antenna 201. In response to receiving the beacon signal, in step S303, the control unit 204 transmits a beacon signal indicating a network connection request in order to perform authentication processing for connection with the control unit 104 of the DTV 100.

  In S304, the control unit 104 of the DTV 100 performs a network connection process with the DVR 200 according to the beacon signal transmitted in S303, and transmits a beacon signal indicating the completion of connection.

  In step S305, the control unit 204 of the DVR 200 secures a high-speed signal transmission path for transmitting AV data. Specifically, the control unit 204 transmits a high-speed signal via the antenna 201 using the high-speed communication unit 203. At this time, in order to confirm the directivity, the control unit 204 enhances the degree of directivity of the antenna 201.

  In step S <b> 306, the control unit 204 changes the directionality of the antenna 201. Specifically, the control unit 204 sets the directivity direction so as to sequentially scan all directions represented by (vertical direction v, horizontal direction h) = (0, 0) to (V, H). . For example, when (V, H) is (5, 5), a total of 36 directions are set. Further, the order of scanning is not particularly limited. For example, the scanning is performed in a zigzag manner as shown in FIG. In S307, the high-speed communication unit 203 transmits the adjustment high-speed wireless signal via the antenna 201 having the directivity in the direction set in S306.

  In step S308, the high-speed communication unit 103 of the DTV 100 receives the wireless signal transmitted in step S307 via the antenna 101. The control unit 104 measures the strength of the received radio signal. In the position confirmation process, the directionality of the antenna 101 remains fixed, but after the position confirmation process is completed, the directionality of the antenna 101 is detected in order to detect the direction in which the AV data reception strength increases. Scanning similar to that of the antenna 201 is performed in the direction. In step S309, the low-speed communication unit 102 transmits strength information indicating the strength of the wireless signal received in step S308 via the antenna 101.

  In S310, the low speed communication unit 202 of the DVR 200 receives the strength information transmitted in S309 as a response to the radio signal transmitted in S307. In S311, the control unit 204 associates and stores the parameter (v, h) indicating the directivity set in S306 and the intensity information (i) received in S310. In step S312, the control unit 204 determines whether or not scanning in all directions has been completed (whether (v, h) = (V, H)). If the determination result is “No”, the process returns to S306, and the same processing is repeated for the next directivity direction. If the determination result is “Yes”, the process proceeds to S313. When scanning in all directions is completed, direction intensity information 501 is obtained as shown in FIG.

  In S313, the control unit 204 determines (calculates) the direction of the direct wave (first direction) and the direction of the indirect wave (second direction) based on the direction intensity information 501. Here, the direct wave means a radio signal that goes directly from the antenna 201 to the antenna 101 (without being reflected). The indirect wave means a radio signal transmitted from the antenna 201 and reflected from a reflection point (for example, a ceiling) and heading toward the antenna 101, and the direction of the indirect wave means a direction from the antenna 201 toward the reflection point. To do. The calculated direction is represented, for example, by an angle in the vertical direction (direct wave angle, indirect wave angle) with the horizontal direction as a reference (0 degree). Details of the direction determination processing in S313 will be described later.

  In step S <b> 314, the low speed communication unit 202 transmits the direction (angle information) calculated in step S <b> 313 via the antenna 201. Here, the low-speed communication unit 202 may transmit the intensity information together with the angle information in order to indicate whether the transmitted angle information is for a direct wave or an indirect wave.

In S315, the low-speed communication unit 102 of the DTV 100 receives the angle information transmitted in S314. For example, when the DTV 100 communicates with three DVRs (DVR 200a, DVR 200b, DVR 200c), the DTV 100, as shown in FIG. 6, (θ _a0 , θ _a1 ), (θ _b0 , θ _b1 ), and (θ _c0 ). , Θ _c1 ) are received. If the DVR 200a and the DVR 200b exist on the same straight line when viewed from the antenna 101, θ _a0 = θ _b0 , but θ _a1 is different from θ _b1 , so the DTV 100 distinguishes the position of the DVR 200a from the position of the DVR 200b. be able to.

In S316, the control unit 104 calculates the distance L to the DVR 200 based on the angle information and the distance A from the antenna 101 to the reflection point. FIG. 7 is a conceptual diagram showing this calculation method (assuming that DTV 100 and DVR 200b exist in the same plane). FIG. 7 shows a DVR 200b as an example. As is clear from FIG. 7, the distance L is
_{L = 2A (cosθ b0 × tan} (θ b1 -θ b0) + sinθ b0) / tanθ b1 × tan (θ b1 -θ b0)
Is calculated by

  Next, details of the direction determination processing in S313 will be described. Taking the directional intensity information 501 in FIG. 5 as an example, the angle in the vertical direction with respect to v = (0, 1, 2, 3, 4, 5) as the reference (0 degree) in the horizontal direction is, for example, ( 70 degrees, 40 degrees, 10 degrees, -10 degrees, -40 degrees, -70 degrees). Here, the direction of v = 2 where the intensity information has the maximum value “d” corresponds to the direct wave. Therefore, the direction of the direct wave is represented by angle information of “10 degrees”. However, since the directivity direction of the antenna 201 changes only at a predetermined interval, the direct wave direction is actually between v = 1 and v = 2 or between v = 2 and v = 3. There is a possibility. Therefore, the angle may be calculated in consideration of intensity information at v = 1,3. The direction of the indirect wave is determined in the same manner as in the case of the direct wave. However, v = 1 where the intensity information is the second largest value “a” is used in the determination. The direction determined in this way is conceptually indicated by reference numeral 502.

  As described above, according to the present embodiment, since the DTV 100 can know the directions of both the direct wave and the indirect wave from the DVR 200, the positions of a plurality of wireless transmission devices can be distinguished.

<Modification>
In the processing from S306 to S312 in FIG. 3, the control unit 204 of the DVR 200 may perform scanning in the order shown in FIG. Then, when the control unit 204 detects a reception intensity that is equal to or greater than a threshold (for example, “9”) and then detects a stronger reception intensity, the first detection is performed as an indirect wave, and the next detection is performed as a direct wave. The scanning may be terminated when a direct wave is detected. Thereby, the time required for scanning can be shortened.

  In the first embodiment, the DVR 200 executes the direction determination process, but in the second embodiment, the DTV 100 executes the direction determination process. Thereby, the processing load of the DVR 200 is reduced. In the second embodiment, the configurations of the DTV 100 and the DVR 200 are the same as those in the first embodiment, and thus the description thereof is omitted.

  FIG. 9 is a flowchart illustrating the flow of the position confirmation process according to the second embodiment. In FIG. 9, steps in which processing similar to that in Embodiment 1 is performed are denoted by the same reference numerals, and description thereof is omitted (see FIG. 3).

  In S901, the high-speed communication unit 203 of the DVR 200 transmits a parameter (v, h) (direction information) indicating the direction of directivity set in S306 as a high-speed signal for adjustment.

  In step S902, the DTV 100 high-speed communication unit 303 receives the wireless signal including the parameter transmitted in step S901 via the antenna 101. In step S903, the control unit 104 measures the strength of the received radio signal. In the position confirmation process, the directionality of the antenna 101 remains fixed, but after the position confirmation process is completed, the directionality of the antenna 101 is detected in order to detect the direction in which the AV data reception strength increases. Scanning similar to that of the antenna 201 is performed in the direction.

  In step S904, the control unit 104 stores the parameter (v, h) received in step S902 and the intensity information (i) measured in step S903 in association with each other. In step S <b> 905, the low-speed communication unit 202 of the DVR 200 transmits a measurement end notification via the antenna 201. In step S906, the control unit 104 of the DTV 100 performs direction determination processing in the same manner as in step S313 in the first embodiment.

[Other Examples]
The components and processes described in the above embodiments may be implemented by hardware, software, or a combination thereof. Software (program) that implements some or all of these components and processes, and a storage medium storing the software are also included in the scope of the present invention.

Claims (4)

A wireless communication system including a wireless transmission device and a wireless reception device including a directional antenna capable of changing the direction of directivity,
The wireless transmission device
First transmission means for transmitting a wireless signal to the wireless reception device via the directional antenna;
First receiving means for receiving intensity information from the wireless receiver as a response to the wireless signal;
Control means for executing transmission by the first transmission means and reception by the first reception means for a plurality of directivity directions of the directional antenna;
Based on intensity information corresponding to each of the plurality of directivity directions of the directional antenna, a first direction in which a radio signal transmitted by the first transmission means is directed directly from the directional antenna to the radio reception device; Determining means for determining a second direction in which a radio signal transmitted from the first transmission means, reflected by a reflection point and directed to the wireless reception device is directed from the directional antenna toward the reflection point;
Notification means for notifying the wireless reception device of the first direction and the second direction determined by the determination means;
With
The wireless receiver is
Second receiving means for receiving a radio signal from the radio transmitting device;
Second transmission means for transmitting strength information indicating the strength of the radio signal received by the second reception means to the radio transmission device;
Third receiving means for receiving notification by the notifying means;
A wireless communication system comprising: A wireless communication system including a wireless transmission device and a wireless reception device including a directional antenna capable of changing the direction of directivity,
The wireless transmission device
Transmitting means for transmitting a wireless signal including direction information indicating the direction of the directivity of the directional antenna to the wireless reception device via the directional antenna;
Control means for executing transmission by the transmission means for a plurality of directivity directions of the directional antenna;
With
The wireless receiver is
Receiving means for receiving a radio signal including the direction information from the radio transmitting device;
Storage means for associating and storing intensity information indicating the intensity of the radio signal received by the receiving means and direction information included in the radio signal;
Based on the intensity information and the direction information stored by the storage unit for each of the plurality of directivity directions of the directional antenna, the radio signal transmitted by the transmission unit is directly transmitted from the directional antenna to the radio reception device. A determining unit that determines a first direction toward the first direction and a second direction in which a radio signal transmitted from the transmission unit, reflected by a reflection point, and directed to the radio reception device is directed from the directional antenna toward the reflection point;
A wireless communication system comprising: A control method of a wireless communication system including a wireless transmission device and a wireless reception device having a directional antenna capable of changing the direction of directivity,
A first transmission step in which the wireless transmission device transmits a wireless signal to the wireless reception device via the directional antenna;
A first reception step in which the wireless transmission device receives strength information from the wireless reception device as a response to the wireless signal;
A control step in which the wireless transmission device executes transmission in the first transmission step and reception in the first reception step in a plurality of directivity directions of the directional antenna;
The wireless transmission device transmits the wireless signal transmitted in the first transmission step from the directional antenna to the wireless reception device based on intensity information corresponding to each of the plurality of directivity directions of the directional antenna. A determining step of determining a first direction directly directed and a second direction in which a radio signal transmitted in the first transmission step, reflected by a reflection point and directed to the wireless reception device is directed from the directional antenna toward the reflection point; ,
A notification step in which the wireless transmission device notifies the wireless reception device of the first direction and the second direction determined in the determination step;
A second reception step in which the wireless reception device receives a wireless signal from the wireless transmission device;
A second transmission step in which the wireless reception device transmits strength information indicating the strength of the wireless signal received in the second reception step to the wireless transmission device;
A third reception step in which the wireless reception device receives the notification in the notification step;
A control method comprising: A control method of a wireless communication system including a wireless transmission device and a wireless reception device having a directional antenna capable of changing the direction of directivity,
A transmitting step in which the wireless transmission device transmits a wireless signal including direction information indicating a directionality of the directional antenna to the wireless reception device via the directional antenna;
A control step in which the wireless transmission device performs transmission in the transmission step for a plurality of directivity directions of the directional antenna; and
The wireless reception device receives a wireless signal including the direction information from the wireless transmission device; and
A storage step in which the wireless reception device associates and stores strength information indicating the strength of the wireless signal received in the reception step and direction information included in the wireless signal;
Based on the strength information and the direction information stored in the storage step for each of the plurality of directivity directions of the directional antenna, the wireless reception device transmits the wireless signal transmitted in the transmission step from the directional antenna. A first direction directly toward the wireless reception device and a second direction transmitted in the transmission step and reflected by a reflection point and directed to the wireless reception device are determined from a second direction toward the reflection point from the directional antenna. A decision process;
A control method comprising:

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