Transmitting method, receiving method, transmitting device, and receiving device

Abstract

A transmission method capable of securely acquiring information is provided. The transmission method causes a light source to be lit at a first brightness during a first period, and causes the light source to be lit alternately at a second brightness and a third brightness during a second period, thereby transmitting an optical signal from the light source, wherein the third brightness is lower than the second brightness.

Description

Technical Field

[0001] The present disclosure relates to a sending method, a receiving method, a sending device, and a receiving device. Background Art

[0002] One method for obtaining information such as a terminal's own location, such as for the purpose of utilizing location-based services, is to use GPS (Global Positioning System). In GPS-based methods, a terminal receives modulated signals transmitted from satellites and estimates its own location by performing positioning calculations. However, if a terminal has difficulty receiving radio waves transmitted from satellites (for example, indoors), it becomes difficult for the terminal to estimate its own location.

[0003] In this case, as a method for estimating the terminal's own position, as shown in the method disclosed in non-patent document 1, the terminal uses radio waves sent from a wireless access point (AP (access point)) of a wireless LAN (Local Area Network) to estimate its own position and other information.

[0004] (Prior art literature)

[0005] (Non-patent literature)

[0006] Non-patent literature 1Bayesian based location estimation system using wirelessLAN, Third IEEE Conference on Pervasive Computing and Commun.Workshops, pp.273-278, 2005.

[0007] Non-patent document 2: “High-Function Image Sensor”, Journal of the Society for Image Information and Media, vol. 66, no. 3, pp. 172-173, 2012.

[0008] Non-Patent Document 3: "Trends in High-Speed ​​Technology for CMOS Image Sensors," Journal of the Society for Image Media, vol. 66, no. 3, pp. 174-177, 2012.

[0009] Non-Patent Document 4: “New Organic CMOS Image Sensor Suitable for Pixel Size Miniaturization”, FUJIFILM RESEARCH & DEVELOPMENT, no. 55, pp. 14-17, 2010.

[0010] However, if a terminal does not store information such as the SSID (service set identifier) ​​of the access point it should connect to, it is not easy for the terminal to correctly determine which access point to connect to from among multiple nearby access points. Therefore, when a terminal connects to an access point to obtain information such as its location, it may connect to an access point with an insecure SSID, which may lead to risks such as information leakage. Summary of the Invention

[0011] One aspect of the present disclosure provides, for example, a transmission method that can securely acquire information for identifying an access point to which a terminal should connect.

[0012] A sending method according to one embodiment of the present disclosure lights a light source at a first brightness during a first period, and lights the light source alternately at a second brightness and a third brightness during a second period, thereby causing the light source to send an optical signal, wherein the third brightness is lower than the second brightness.

[0013] A receiving method according to one form of the present disclosure receives light of a first brightness from a light source during a first period, and receives a light signal sent from the light source by alternately receiving light of a second brightness and light of a third brightness during a second period, wherein the third brightness is lower than the second brightness, and outputs analysis information by analyzing data based on the light signal.

[0014] Furthermore, these general or specific aspects may be implemented by a system, method, integrated circuit, computer program, or recording medium, or by any combination of systems, devices, methods, integrated circuits, computer programs, and recording media.

[0015] According to one aspect of the present disclosure, a terminal can securely obtain information.

[0016] Advantages and effects of one embodiment of the present disclosure are apparent from the specification and drawings. The advantages and / or effects are provided by several embodiments and the features described in the specification and drawings, but not all of them need to be provided in order to obtain one or more of the same features. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1This is a diagram explaining the principle of line scan sampling.

[0018] Figure 2 An example of a captured image when the exposure time is long is shown.

[0019] Figure 3 An example of a captured image when the exposure time is short is shown.

[0020] Figure 4A This is a diagram explaining 4PPM.

[0021] Figure 4B This is a diagram explaining the Manchester encoding method.

[0022] Figure 5 An example of the configuration of a visible light communication system is shown.

[0023] Figure 6 A configuration example of a communication system according to the first embodiment is shown.

[0024] Figure 7 An example of a frame configuration according to the first embodiment is shown.

[0025] Figure 8 The positional relationship between the device and the terminal involved in Implementation 2 is shown.

[0026] Figure 9 A configuration example of a communication system according to Embodiment 3 is shown.

[0027] Figure 10 A display example of the display unit according to the third embodiment is shown.

[0028] Figure 11 An example of a frame structure of a modulated signal transmitted by the first device according to the third embodiment is shown.

[0029] Figure 12 An example of a frame structure of a modulated signal transmitted by a base station according to Embodiment 3 is shown.

[0030] Figure 13 This is a flowchart showing a processing example in the communication system involved in embodiment 3.

[0031] Figure 14 A display example of the display unit according to the third embodiment is shown.

[0032] Figure 15 A configuration example of a communication system according to the fourth embodiment is shown.

[0033] Figure 16 An example of a frame structure of a modulated signal transmitted by the first device according to the fourth embodiment is shown.

[0034] Figure 17 An example of a frame structure of a modulated signal transmitted by a wireless device of a terminal according to the fourth embodiment is shown.

[0035] Figure 18 This is a flowchart showing a processing example in the communication system involved in embodiment 4.

[0036] Figure 19 A configuration example of a communication system according to the fifth embodiment is shown.

[0037] Figure 20 An example of a frame structure of a modulated signal including an SSID transmitted by the third device according to the fifth embodiment is shown.

[0038] Figure 21 An example of the frame structure of a modulated signal including an encryption key transmitted by the third device according to the fifth embodiment is shown.

[0039] Figure 22 This is a flowchart showing a processing example in the communication system involved in embodiment 5.

[0040] Figure 23 This is a flowchart showing another processing example in the communication system involved in embodiment 5.

[0041] Figure 24 An example of a space in which the communication system according to the fifth embodiment is arranged is shown.

[0042] Figure 25 A configuration example of a communication system according to the sixth embodiment is shown.

[0043] Figure 26 This is a flowchart showing a processing example in the communication system involved in embodiment 6.

[0044] Figure 27 A configuration example of a communication system according to Embodiment 7 is shown.

[0045] Figure 28 An example of the frame structure of the modulated signal transmitted by the fifth device according to the seventh embodiment is shown.

[0046] Figure 29 An example of the frame structure of the modulated signal transmitted by the fifth device according to the seventh embodiment is shown.

[0047] Figure 30 An example of the frame structure of the modulated signal transmitted by the fifth device according to the seventh embodiment is shown.

[0048] Figure 31 An example of a frame transmission method performed by the fifth device according to the seventh embodiment is shown.

[0049] Figure 32 An example of a space in which the communication system according to the seventh embodiment is arranged is shown.

[0050] Figure 33 This is a flowchart showing a processing example in the communication system involved in embodiment 7.

[0051] Figure 34 A configuration example of a communication device according to the eighth embodiment is shown.

[0052] Figure 35 Another configuration example of the communication device according to the eighth embodiment is shown.

[0053] Figure 36 A first configuration example of the light receiving device according to the eighth embodiment is shown.

[0054] Figure 37 A first configuration example of the light reception signal processing unit according to the eighth embodiment is shown.

[0055] Figure 38 A second configuration example of the light reception signal processing unit according to the eighth embodiment is shown.

[0056] Figure 39 An example of controlling the image sensor in the eighth embodiment is shown.

[0057] Figure 40 A third configuration example of the light reception signal processing unit according to the eighth embodiment is shown.

[0058] Figure 41 A second configuration example of the light receiving device according to the eighth embodiment is shown.

[0059] Figure 42 An example of performing line scan sampling in parallel in multiple regions is shown.

[0060] Figure 43 A physical configuration example of a control unit according to the eighth embodiment is shown.

[0061] Figure 44 A configuration example of a control unit according to the eighth embodiment is shown.

[0062] Figure 45 Another configuration example of the control unit according to the eighth embodiment is shown.

[0063] Figure 46 This is the first figure for explaining the communication control of the acquired image according to the eighth embodiment.

[0064] Figure 47This is the second figure for explaining the communication control of the acquired image according to the eighth embodiment.

[0065] Figure 48 This is the third figure for explaining the communication control of the acquired image according to the eighth embodiment.

[0066] Figure 49 This is the fourth figure for explaining the communication control of the acquired image according to the eighth embodiment.

[0067] Figure 50 This is the fifth figure for explaining the communication control of the acquired image according to the eighth embodiment.

[0068] Figure 51 This is the sixth figure for explaining the communication control of the acquired image according to the eighth embodiment.

[0069] Figure 52 Another example of the configuration of a communication system that performs optical communication is shown.

[0070] Figure 53 A configuration example of a transmitting device and a receiving device according to Embodiment 10 is shown.

[0071] Figure 54 A configuration example of a transmitting device and a receiving device according to Embodiment 10 is shown.

[0072] Figure 55 An example of a frame structure of an optical modulation signal according to the tenth embodiment is shown.

[0073] Figure 56 An example of a reception state in the receiving device according to the tenth embodiment is shown.

[0074] Figure 57 An example of the structure of codewords involved in embodiment 10 is shown.

[0075] Figure 58 Another example of the structure of the codeword involved in Embodiment 10 is shown.

[0076] Figure 59 Another example of the reception state in the receiving device according to the tenth embodiment is shown.

[0077] Figure 60 Another example of the reception state in the receiving device according to the tenth embodiment is shown.

[0078] Figure 61 Another example of the structure of the codeword involved in Embodiment 10 is shown.

[0079] Figure 62 Another example of the structure of the codeword involved in Embodiment 10 is shown.

[0080] Figure 63 Another example of the structure of the codeword involved in embodiment 11 is shown.

[0081] Figure 64 An example of the configuration of a receiving device according to Embodiment 11 is shown.

[0082] Figure 65 Another example of the configuration of the receiving device according to the eleventh embodiment is shown.

[0083] Figure 66 Another example of the configuration of the receiving device according to the eleventh embodiment is shown.

[0084] Figure 67 Another example of the configuration of the receiving device according to the eleventh embodiment is shown.

[0085] Figure 68 An example of the configuration of a communication system according to Embodiment 12 is shown.

[0086] Figure 69 An example of the recognition result involved in embodiment 12 is shown.

[0087] Figure 70 Another example of the configuration of the communication system according to the twelfth embodiment is shown.

[0088] Figure 71A An example of the configuration of a transmitting device according to Embodiment 13 is shown.

[0089] Figure 71B An example of a liquid crystal screen according to Embodiment 13 is shown.

[0090] Figure 72 A usage example of the sending device involved in embodiment 13 is shown.

[0091] Figure 73 An example of the structure of a rearview mirror according to a fourteenth embodiment is shown.

[0092] Figure 74A An example of changes in the brightness of the lamp during the information transmission period and the lighting period according to the fifteenth embodiment is shown.

[0093] Figure 74B An example of the frame structure involved in embodiment 15 is shown.

[0094] Figure 74CA configuration example of a communication system according to a fifteenth embodiment is shown.

[0095] Figure 75 An example of a transmission device including a light source for illumination and a light source for communication according to a fifteenth embodiment is shown.

[0096] Figure 76 An example of a plurality of light sources provided in a vehicle is shown.

[0097] Figure 77 An example of a plurality of light receiving units provided in a vehicle is shown.

[0098] Figure 78 An example of the frame structure of the optical modulation signal is shown.

[0099] Figure 79 An example of visible light communication relay is shown.

[0100] Figure 80 An example of the frame structure of the optical modulation signal transmitted by the transmitting device of embodiment 13 is shown.

[0101] Figure 81 A sending device and a communication device according to embodiment 13 are shown.

[0102] Figure 82 The communication between the first communication device and the second communication device is shown.

[0103] Figure 83 A configuration example of a communication device is shown.

[0104] Figure 84 An example of the timing at which training symbols are transmitted from each of a plurality of light sources is shown.

[0105] Figure 85 An example of the reception timing of each of the plurality of light receiving units is shown.

[0106] Figure 86 Shown Figure 83 FIG. 1 shows a detailed configuration example of a transmission unit in a communication device that does not perform precoding.

[0107] Figure 87 Shown Figure 83 Detailed configuration example of a transmission unit that performs precoding in the communication device shown.

[0108] Figure 88 An example of the configuration of a light source is shown.

[0109] Figure 89 A configuration example of a communication system is shown.

[0110] Figure 90An example is shown in which the access point selects a light source and sets parameters, and the terminal selects a light receiving unit.

[0111] Figure 91 An example of an access point sending training symbols for light source parameters is shown.

[0112] Figure 92 An example is shown where an access point sends training symbols according to a light source.

[0113] Figure 93 A modified example of training for light source optimization is shown.

[0114] Figure 94 An example is shown in which the access point transmits "training symbols for light source / light receiving unit selection and light source parameters."

[0115] Figure 95 Three modes of communication or transmission are shown. DETAILED DESCRIPTION

[0116] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

[0117] [First Example of Modulation and Demodulation Method for Visible Light Communication]

[0118] In this embodiment, an optical communication method is adopted in which a modulated signal is transmitted and received as an optical signal.

[0119] First, a first example of visible light communication will be described. This first example is an example of an optical communication method that can be applied to each embodiment of the present application.

[0120] Line Scan Sampling

[0121] Smartphones and digital cameras are equipped with image sensors such as CMOS (Complementary Metal Oxide Semiconductor) sensors. Images captured by CMOS sensors do not entirely depict the same scene at the same moment. For example, as described in Non-Patent Documents 2 and 3, a rolling shutter method, in which the shutter is activated on a row-by-row basis, reads the amount of light received by the sensor on a row-by-row basis. Therefore, the time required for readout is estimated, and a time difference is created between each row to control the start and end of light reception. Consequently, images captured by CMOS sensors are composed of a large number of overlapping rows, each with a slight time lag.

[0122] In the first example of the visible light communication method, a method focusing on the properties of the CMOS sensor is considered to achieve faster reception of visible light signals. That is, in the first example of the visible light communication method, by using slightly different exposure times for each row, it is possible to Figure 1As shown, the brightness and color of the light source at multiple times are measured for each line from one image (image captured by the image sensor), thereby capturing a signal that is rapidly modulated faster than the frame rate.

[0123] Hereinafter, this sampling method is referred to as “line scan sampling,” and a column of pixels exposed at the same timing is referred to as an “exposure row.”

[0124] In addition, although "line scan sampling" can be achieved through the rolling shutter method of the CMOS sensor, the rolling shutter method can also be achieved through sensors other than CMOS sensors, such as CCD (Charge-Coupled Device) sensors, organic (CMOS) sensors as exemplified in non-patent document 4, etc., and "line scan sampling" can also be performed.

[0125] However, when shooting with the camera function (moving image or still image shooting function), even if you shoot a light source that flickers quickly, the flicker will not appear as streaks along the exposure line. This is because, in this setting, the exposure time is much longer than the light source's flickering period. Figure 2 As shown, the change in brightness due to the flickering (light emission pattern) of the light source is averaged, and the change in pixel value between exposure lines is small, resulting in a substantially uniform image.

[0126] In this regard, Figure 3 As shown in FIG, by setting the exposure time to approximately the flickering period of the light source, the flickering state (light emission pattern) of the light source can be observed as a brightness change of the exposure line. Figure 3 In the embodiment, although the length of the exposure period is set to be slightly longer than the length of the minimum period during which the same luminous state continues, and the difference in the start time of the exposure period between adjacent exposure lines is set to be shorter than the length of the minimum period during which the same luminous state continues, the setting of the exposure period in line scanning sampling is not limited to this. For example, the length of the exposure period can be set to be shorter than the length of the minimum period during which the same luminous state continues, or it can be set to a length of about twice the length of the minimum period during which the same luminous state continues. In addition, as an optical communication method, there are not only methods using optical signals such as Figure 4AIn some cases, the optical communication receiving device uses a combination of rectangular waves as shown, and in other cases, a method in which the optical signal continuously changes. In either case, the optical communication receiving device sets the difference between the start and end times of the exposure periods of temporally adjacent exposure lines to be equal to or less than the sampling interval corresponding to the sampling rate required for receiving and demodulating the optical signal. Furthermore, the optical communication receiving device sets the length of the exposure period to be equal to or less than the sampling interval. However, the optical communication receiving device may set the length of the exposure period to be less than 1.5 times the sampling interval, or less than 2 times the sampling interval.

[0127] For example, the exposure lines are designed to be parallel to the long side of the image sensor. In this case, as an example, if the frame rate is set to 30 fps (frames per second), at a resolution of 1920×1080, more than 32,400 samples per second can be obtained, and at a resolution of 3840×2160, more than 64,800 samples per second can be obtained.

[0128] Application examples of line scan sampling

[0129] In addition, although the above description describes line scan sampling for reading out a signal showing the amount of light received per row, the sampling method of the light signal using an image sensor such as a CMOS is not limited thereto. As a sampling method used in receiving the light signal, various methods can be applied, such as a method of obtaining the sampled signal at a sampling rate higher than the frame rate used when shooting a normal moving image. For example, by using a global shutter method having a shutter function for each pixel as shown in non-patent literature 2 and non-patent literature 3, a method of controlling the exposure period and reading out the signal for each pixel can be adopted, or a method of controlling the exposure period and reading out the signal in units of a group of multiple pixels that are not arranged in a row can be adopted. Furthermore, a method of reading out the signal from the same pixel multiple times within a period equivalent to one frame at the frame rate used when shooting a normal moving image can be adopted.

[0130] <Sampling by frame>

[0131] Furthermore, by using a frame rate method in which each pixel has a shutter function as disclosed in Non-Patent Documents 2 and 3, it is possible to sample an optical signal even in a method in which the frame rate is increased.

[0132] The embodiments to be described below can be implemented in any of the above-described “line scan sampling,” “application example of line scan sampling,” and “sampling by frame,” for example.

[0133] Light Source and Modulation Method

[0134] In visible light communication, for example, LEDs (Light Emitting Diodes) can be used as transmitters. LEDs are becoming increasingly popular as backlight sources for lighting and displays, and can flash rapidly.

[0135] However, for visible light communication (VLC) transmitters, it's sometimes undesirable to allow the light source to flicker freely. This is because if changes in brightness caused by VLC are perceptible to humans, they can impair the original function of the light source, such as illumination. Therefore, it's necessary to ensure that the transmitted signal does not dazzle the human eye while still providing the desired brightness.

[0136] As a modulation method that meets this requirement, there is a modulation method called 4PPM (4-Pulse Position Modulation). Figure 4A As shown in the figure, the brightness and darkness of the light source are combined 4 times and expressed in 2 bits. Figure 4A As shown, since 3 out of 4 times are bright and 1 out of 4 times is dark, the average brightness (average brightness) is 3 / 4=75% regardless of the content of the signal.

[0137] For comparison purposes, the same approach has Figure 4B The Manchester coding method shown. The Manchester coding method is a method of expressing 1 bit in two states, and the modulation efficiency is 50%, the same as 4PPM. One of the two times is a bright state, and the other is a dark state. The average brightness is 1 / 2 = 50%. That is, as a modulation method for visible light communication, 4PPM is more suitable than the Manchester coding method. However, even if the change in brightness is felt by people through visible light communication, since the communication performance is not reduced, there is no problem even if a method is adopted in which people can feel the change in brightness, depending on the application. Therefore, the transmitter (light source) can adopt modulation methods such as ASK (Amplitude Shift Keying), PSK (Phase Shift Keying), PAM (Pulse Amplitude Modulation), etc. to generate a modulation signal to light the light source and illuminate it.

[0138] <Overall configuration example of a communication system>

[0139] like Figure 5As shown, a communication system that performs visible light communication includes at least a transmitter that transmits (radiates) light signals and a receiver that receives (accepts) light signals. For example, there can be two types of transmitters: a variable optical transmitter that changes its transmission content according to the displayed image or content data, and a fixed optical transmitter that continuously transmits fixed content. However, a communication system utilizing light can be constructed even with only one of the variable and fixed optical transmitters.

[0140] The receiver receives the optical signal from the transmitter, and can obtain, for example, related information corresponding to the optical signal and provide it to the user.

[0141] Although the outline of the visible light communication method has been described above, the optical communication method applicable to the following embodiments is not limited to the above method. For example, the light-emitting portion of the transmitter may use multiple light sources to transmit data. In addition, the light-receiving portion of the receiving device may not be an image sensor such as a CMOS, and may be, for example, a communication method using a device that can convert an optical signal into an electrical signal using a photodiode or the like. In this case, since it is not necessary to use the above-mentioned line scan sampling to perform the sampling work, it can be applied even in a method that requires more than 32,400 samples per second. In addition, depending on the application, for example, a wireless communication method using a frequency other than visible light such as infrared and ultraviolet rays can be used.

[0142] (Implementation 1)

[0143] Figure 6 An example of the configuration of the device 100 and the terminal 150 in this embodiment is shown.

[0144] [Configuration of Device 100]

[0145] The device 100 (corresponding to a transmitter of visible light communication) includes a visible light source such as an LED (Light Emitting Diode), lighting, or a lamp (which may also be collectively referred to as a light source). Hereinafter, the device 100 will be referred to as a "first device."

[0146] exist Figure 6 In the first device 100, the transmitting unit 102 inputs, for example, information about a place or information about a position 101. Furthermore, the transmitting unit 102 may input information about a time 105. Furthermore, the transmitting unit 102 may input both the information about a place or information about a position 101 and the information about a time 105.

[0147] The transmitter 102 receives information about a place or position 101 and / or information about a time 105 as input, generates a (light) modulated signal 103 based on these input signals, and outputs the modulated signal 103. The modulated signal 103 is transmitted from a light source 104, for example.

[0148] Here, an example of the information 101 related to a place or a position will be described.

[0149] <Example 1>

[0150] The information 101 related to a place or position can be information on the latitude and / or longitude of the place and / or position. For example, information such as "45 degrees north latitude, 135 degrees east longitude" can be used as the information 101 related to a place or position.

[0151] <Example 2>

[0152] The information on a place or the information on a position 101 may be information on a residential address. For example, the information on a place or the information on a position 101 may be “1-1-1, ○○-cho, Chiyoda-ku, Tokyo”.

[0153] <Example 3>

[0154] The information on a place or the information on a position 101 may be information on a building, a facility, etc. For example, the information on "Tokyo Tower" may be used as the information on a place or the information on a position 101 .

[0155] <Example 4>

[0156] The information on a place or the information on a position 101 may be information on a specific place and / or position installed in a building, a facility, or the like.

[0157] For example, a parking lot has spaces for five cars. In this case, the first parking space is called A-1, the second parking space is called A-2, the third parking space is called A-3, the fourth parking space is called A-4, and the fifth parking space is called A-5. In this case, for example, the information "A-3" can be used as location information or position information 101.

[0158] Furthermore, this example is not limited to parking lots. For example, information related to "areas, seats, stores, facilities, etc.", such as concert facilities, baseball, soccer, and tennis stadiums, airplanes, airport lounges, railway stations, and stations, can be used as the place-related information or location-related information 101.

[0159] The above describes an example of the information on a place or the information on a position 101. However, the configuration method of the information on a place or the information on a position 101 is not limited to the above example.

[0160] [Configuration of Terminal 150]

[0161] Figure 6 The terminal 150 (corresponding to the receiver of visible light communication) receives the modulated signal 103 sent from the first device 100.

[0162] The light receiving unit (light receiver) 151 is, for example, a CMOS (Complementary Metal Oxide Semiconductor) or an organic CMOS image sensor. The light receiving unit 151 receives light including a modulated signal transmitted from the first device 100 and outputs a received signal 152 .

[0163] In addition, the received signal 152 output from the light receiving unit 151 can be a signal including information about an image or video obtained by an image sensor, or it can be an output signal of another element that performs optical-to-electrical conversion (converting light into an electrical signal). In the following description, when there is no special explanation of the processing performed by the light receiving unit 151 and it is recorded that the receiving device receives a modulated signal, it means that the receiving device is the light receiving unit 151, which performs optical-to-electrical conversion (converting light into an electrical signal) on light including the modulated signal to obtain a "modulated signal for transmitting information", or a "signal for an image or video" and a "modulated signal for transmitting information". However, the above method is an example of a method for a receiving device to receive a modulated signal, and the method for receiving a modulated signal is not limited to this.

[0164] Then, the receiving unit 153 receives the received signal 152 as input, performs processing such as demodulation and error correction decoding on the modulated signal included in the received signal 152 , and outputs received data 154 .

[0165] The data analyzer 155 receives the received data 154 as input, analyzes the received data 154 , and thereby estimates the location and / or position of the terminal 150 , for example, and outputs information 156 including at least the location and / or position information of the terminal 150 .

[0166] The display unit 157 receives the information 156 as input and displays information related to the location and / or position of the terminal 150 based on the location and / or position information of the terminal 150 included in the information 156 .

[0167] [Frame composition]

[0168] Figure 7An example of the frame structure of the modulated signal transmitted by the first device 100 is shown.

[0169] exist Figure 7 In FIG, the horizontal axis represents time. For example, the first device 100 transmits a preamble 201, and thereafter transmits a control information symbol 202, a symbol 203 related to location information or position information, and a symbol 204 related to time information.

[0170] The preamble 201 is a symbol used by the terminal 150 receiving the modulated signal transmitted by the first device 100 to perform, for example, signal detection, time synchronization, frame synchronization, and the like.

[0171] The control information symbol 202 is a symbol including data such as a modulation signal configuration method, an error correction coding method to be used, and a frame configuration method.

[0172] The code element 203 related to the location information or position information includes Figure 6 The code element of the information related to the place or the position 101 is shown.

[0173] In addition, the frame may also include symbols other than symbols 201, 202, and 203. For example Figure 7 As shown in FIG. 1 , the code element 204 related to the time information may also be included. The code element 204 related to the time information includes, for example, information 105 related to the time when the first device 100 transmits the modulated signal. In addition, the frame structure of the modulated signal transmitted by the first device 100 is not affected by Figure 7 Furthermore, the code elements contained in the modulated signal are not limited by Figure 7 The frame may also include symbols containing other data and / or information.

[0174] [Effect]

[0175] like Figure 6 、 Figure 7 As shown in the description of , the effect when the first device 100 sends a modulated signal and the terminal 150 receives the modulated signal is described.

[0176] Since the first device 100 transmits the modulated signal using visible light, the terminal 150 that can receive the modulated signal is not located far from the location of the first device 100. Therefore, the terminal 150 obtains the location and / or position information transmitted by the first device 100, thereby enabling the terminal 150 to easily obtain highly accurate position information (without performing complex signal processing).

[0177] Furthermore, assuming that the first device 100 is set in a place where it is difficult to receive satellite waves from the GPS, the terminal 150 can safely obtain highly accurate location information by receiving the modulated signal sent by the first device 100 even in a situation where it is difficult to receive satellite waves from the GPS.

[0178] (Implementation Method 2)

[0179] In this embodiment, a case where a plurality of first devices 100 described in Embodiment 1 exist will be described.

[0180] In this embodiment, for example Figure 8 As shown, with Figure 6 The first device 100 shown is a modulated signal sent by the 1-1 device 301-1 of the same structure. Figure 6 The terminal 150 shown is a terminal 302 having the same configuration as that of the terminal 302, which receives a modulated signal transmitted by the 1-1 device 301-1 and obtains, for example, information related to the 1-1 place and / or position and information related to the 1-1 time.

[0181] Similarly, with Figure 6 The first device 100 shown has a modulated signal transmitted by the first-second device 301-2 having the same configuration. The terminal 302 receives the modulated signal transmitted by the first-second device 301-2 and obtains information about the location and / or position of the first-second device and information about the time of the first-second device.

[0182] Then, the terminal 302 calculates the information about the 1-1 place and / or position and the information about the 1-2 place and / or position. Figure 8 The distance between the first device 301-1 and the second device 301-2 in FIG. Furthermore, the terminal 302 calculates the distance between the first device 301-1 and the second device 301-1 based on information related to the first time, for example, the time when the terminal 302 receives the modulated signal transmitted by the first device 301-1. Similarly, the terminal 302 can calculate the distance between the first device 301-2 and the second device 301-2 based on information related to the first time, for example, the time when the terminal 302 receives the modulated signal transmitted by the second device 301-2.

[0183] The terminal 302 can also know the location of the first device 301-1 from the information about the first place and / or position. The terminal 302 can also know the location of the second device 301-2 from the information about the first place and / or position.

[0184] Furthermore, the terminal 302 can know the "triangle formed by the 1-1 device 301-1, the 1-2 device 301-2, and the terminal 302" based on the "distance between the 1-1 device 301-1 and the 1-2 device 301-2", "the distance between the 1-1 device 301-1 and the terminal 302", and "the distance between the 1-2 device 301-2 and the terminal 302".

[0185] Therefore, the terminal 302 can calculate and obtain the position of the terminal 302 with high accuracy based on the "position of the 1-1 device 301-1", "position of the 1-2 device 301-2", and "the triangle formed by the 1-1 device 301-1, the 1-2 device 301-2, and the terminal 302".

[0186] However, the geodetic measurement method used by terminal 302 to obtain location and / or position information is not limited to the above description, and geodetic measurement can be performed using any method. For example, examples of geodetic measurement methods include triangulation, multi-angle measurement, trilateration, and leveling.

[0187] As described above, in this embodiment, the terminal 302 obtains the above information from the plurality of devices 301 including light sources that transmit location information, thereby enabling the terminal 302 to estimate the position of the terminal 302 with high accuracy.

[0188] Furthermore, in this embodiment, even if the device 301 having a light source for transmitting location information is set up in a place where it is difficult to receive radio waves from GPS satellites as described in Embodiment 1, the terminal 302 can safely obtain highly accurate location information by receiving the modulated signal sent by the device 301 even in such a situation where it is difficult to receive radio waves from GPS satellites.

[0189] In the above example, although the terminal 302 receives modulated signals transmitted by two devices 301, the same operation can be performed even when the terminal 302 receives modulated signals transmitted by more than two devices 301. Furthermore, the greater the number of devices 301, the more accurately the terminal 302 can calculate position information.

[0190] (Implementation 3)

[0191] Figure 9 An example of the configuration of the device 400 , the terminal 450 , and a base station 470 (or AP (access point)) that communicates with the terminal 450 in this embodiment is shown.

[0192] The device 400 includes, for example, a visible light source such as an LED, a lighting, a light source, or a lamp.

[0193] In addition, Figure 9 In the first device 400 shown, Figure 6 The same symbols are given to the components of the first device 100 that perform the same operations. Figure 9 The terminal 450 shown is for Figure 6 Components of the terminal 150 that perform the same operations are given the same symbols.

[0194] exist Figure 9 For example, in the first device 400, the transmitter 102 receives information 101 related to a location or position, information 401-1 related to the SSID (service set identifier) ​​of the base station 470, and information 401-2 related to the access destination. Furthermore, the transmitter 102 may receive information 105 related to the time.

[0195] Transmitter 102 receives as input information related to a location or position 101, information related to an SSID 401-1, information related to an access destination 401-2, and / or information related to a time 105, generates (optical) modulated signal 103 based on these input signals, and outputs modulated signal 103. Modulated signal 103 is then transmitted from, for example, light source 104.

[0196] Note that examples of the information on a place or the information on a position 101 have been described in the first embodiment and are therefore omitted here.

[0197] Next, the information 401 - 1 on the SSID and the information 401 - 2 on the access destination will be described.

[0198] First, the information 401 - 1 related to the SSID will be described.

[0199] The information 401-1 related to the SSID is shown Figure 9 Here, if it is determined that the SSID notified by the optical signal is the SSID of a secure base station, the first device 400 can provide the terminal 450 with access to the base station 470, which is a secure access destination. Figure 9 The terminal 450 can securely obtain information from the base station 470.

[0200] Furthermore, the first device 400 can limit the terminals that access the base station 470 to terminals that are located in a space where they can receive the optical signal transmitted (irradiated) by the first device 400 .

[0201] Furthermore, when terminal 450 receives an optical signal transmitted in a predetermined manner, it can determine that the notified SSID is the SSID of a secure base station. Furthermore, terminal 450 can also perform additional processing to determine whether the notified SSID is secure. For example, first device 400 can include a predetermined identifier in an optical signal and transmit it, and terminal 450 can determine whether the notified SSID is the SSID of a secure base station based on the received identifier. Furthermore, terminal 450 can also avoid performing the process of determining whether it is a secure base station and instead utilize the characteristics of visible light. A user can select a highly secure first device 400, and terminal 450 can receive the optical signal from the first device 400 to obtain the SSID of the highly secure base station.

[0202] In addition, Figure 9 Although only the base station 470 is shown, for example, when there are one or more base stations (or APs) other than the base station 470, the terminal 450 can also use the SSID obtained from the first device 400 to access the base station 470 and obtain information.

[0203] Next, the information 401 - 2 related to the access destination will be described.

[0204] The access destination information 401-2 is information related to the access destination used to obtain information after the terminal 450 accesses the base station 470. Specific operation examples of this embodiment will be described later.

[0205] The information 401 - 1 related to the SSID and the information 401 - 2 related to the access destination have been described above.

[0206] Terminal 450 receives modulated signal 103 transmitted from first device 400 .

[0207] The light receiving unit 151 is, for example, an image sensor such as a CMOS or an organic CMOS, and receives light including a modulated signal transmitted from the first device 400 , and outputs a received signal 152 .

[0208] Then, the receiving unit 153 receives the reception signal 152 received by the light receiving unit 151 as input, performs processing such as demodulation and error correction decoding on the modulated signal included in the reception signal 152 , and outputs reception data 154 .

[0209] Data analysis unit 155 receives received data 154 as input and estimates, for example, the location and / or position of terminal 450 based on received data 154. Data analysis unit 155 then outputs information 156 including at least the location and / or position information of terminal 450, information 451 regarding the SSID, and information 452 regarding the access destination.

[0210] The display unit 157 receives as input information 156 including the location and / or position information of the terminal 450, information 451 related to the SSID, and information 452 related to the access destination, and for example displays the location and / or position of the terminal 450, the SSID of the communication partner accessed by the wireless device 453 possessed by the terminal 450, and / or the access destination (hereinafter, this display is referred to as the "first display").

[0211] For example, after the first display, the wireless device 453 receives information 451 related to the SSID and information 452 related to the access destination as input. Then, the wireless device 453 connects to the other party to communicate using, for example, radio waves based on the information 451 related to the SSID. Figure 9 In this case, the wireless device 453 is connected to the base station 470.

[0212] Then, the wireless device 453 generates a modulated signal from the data including the information on the access destination based on the information 452 on the access destination, and transmits the modulated signal to the base station 470 using, for example, radio waves.

[0213] exist Figure 9 In the example, the base station 470 , which is the communication partner of the terminal 450 , receives the modulated signal transmitted by the wireless device 453 of the terminal 450 .

[0214] Base station 470 then performs processing such as demodulation and error correction decoding on the received modulated signal, and outputs received data 471 including the access destination information transmitted from terminal 450. Based on this access destination information, base station 470 accesses the desired access destination via the network and obtains, for example, desired information 472 from the access destination. Base station 470 then receives desired information 472 as input, generates a modulated signal based on desired information 472, and transmits this modulated signal to terminal 450 (wireless device 453) using, for example, radio waves.

[0215] The wireless device 453 of the terminal 450 receives the modulated signal transmitted from the base station 470 and performs processing such as demodulation and error correction decoding to obtain the desired information 472.

[0216] For example, the desired information 472 is a map, a building map / floor guide, a facility map / floor guide, a parking lot map / floor guide, information on "areas, seats, stores, facilities" in concert facilities, stadiums, airplane / airport lounges, railways, stations, etc.

[0217] The display unit 157 receives as input information 454 including desired information 472, information 156 including at least the location and / or position information of the terminal 450, and information 451 related to the SSID, and after the first display, maps the location of the terminal 450 to a map, a floor guide, facility information, seat information, and store information display based on the desired information 472 and the information 156 including at least the location and / or position information of the terminal 450, and then displays it.

[0218] Figure 10 A specific example of display on the display unit 157 is shown.

[0219] Figure 10 The display shows "3rd floor." Furthermore, A-1, A-2, A-3, A-4, A-21, A-22, A-23, and A-24 indicate the locations of parking spaces, respectively. Furthermore, a-1 and a-2 indicate the locations of elevators. The map information including the locations of parking spaces and elevators is an example of desired information 454 (472).

[0220] like Figure 10 As shown, the display unit 157 displays the current position of the terminal 450 by mapping it on a map. The current position is information obtained from the information 156 including at least the location and / or position information of the terminal 450.

[0221] Figure 11 Shown Figure 9 An example of the frame structure of the modulated signal transmitted by the first device 400 is shown. Figure 11 In , the horizontal axis is time. Figure 11 For transmission and Figure 7 The same symbols are assigned to code elements of the same information, and their descriptions are omitted.

[0222] In addition to the preamble 201 , the control information symbol 202 , the symbol 203 related to location information or position information, and the symbol 204 related to time information, the first device 400 also transmits a symbol 600 - 1 related to the SSID and a symbol 600 - 2 related to the access destination.

[0223] The code element 600-1 associated with the SSID is used to send Figure 9The code element 401-1 of the information related to the SSID and the code element 600-2 related to the access destination are used to send Figure 9 The code element of the information 401-2 related to the access destination. Figure 11 The frame can include Figure 11 Furthermore, not only the order in which the symbols are sent, but also the frame structure is not affected. Figure 11 Limited by the composition.

[0224] Figure 12 Shown Figure 9 The frame structure of the modulated signal transmitted by the base station 470 is shown as an example. Figure 12 , the horizontal axis is time.

[0225] like Figure 12 As shown, the base station 470 transmits a preamble 701 , for example, and then transmits a control information symbol 702 and an information symbol 703 .

[0226] The preamble 701 is a symbol used by the terminal 450 receiving the modulated signal transmitted by the base station 470 to perform signal detection, time synchronization, frame synchronization, frequency synchronization, frequency offset estimation, and the like.

[0227] Control information symbol 702 includes, for example, information regarding the error correction coding method, the modulation method, and frame structure used when generating the modulated signal. Wireless device 453 of terminal 450 performs demodulation of the modulated signal based on the information in control information symbol 702.

[0228] Information symbol 703 is a symbol for transmitting information. In the present embodiment, information symbol 703 is a symbol for transmitting desired information 472 described above.

[0229] in addition, Figure 9 The base station 470 shown may also transmit a signal including Figure 12 For example, the base station 470 may also transmit a frame including a pilot symbol (reference symbol) in the middle of the information symbol 703. In addition, the frame structure is not affected by the order in which the symbols are transmitted. Figure 12 And, in Figure 12 In , there can be multiple code elements in the frequency axis direction. Figure 12 In the , there are code elements in multiple frequencies (multiple carriers).

[0230] And, for example, regarding the first device 400 Figure 11The modulated signal having the frame structure shown above can be transmitted by repeating such a predetermined timing, for example. This allows multiple terminals 450 to perform the above-mentioned operations.

[0231] Figure 13 It shows the above Figure 9 This is a flowchart of an example of processing performed by "first device 400", "terminal 450" and "base station 470".

[0232] First, the first device 400 sends Figure 11 The modulated signal (ST801) is composed of the frames shown.

[0233] Then, terminal 450 receives the modulated signal transmitted by first device 400 and estimates the location and / or position of terminal 450 (ST802).

[0234] Then, terminal 450 receives the modulated signal transmitted by first device 400 and ascertains the SSID of base station 470 to which terminal 450 will access (ST803).

[0235] Then, the terminal 450 transmits a modulated signal including data including information 452 on an access destination for acquiring information such as a map to the base station 470 using, for example, radio waves (ST804).

[0236] Base station 470 receives the modulated signal transmitted by terminal 450, obtains information on the access destination, and accesses the desired access destination via the network, thereby obtaining desired information such as a map (information transmitted to terminal 450) (ST805).

[0237] Then, the base station 470 transmits a modulated signal including desired information such as the acquired map to the terminal 450 using, for example, radio waves (ST806).

[0238] The terminal 450 receives the modulated signal sent by the base station 470 and obtains information such as a map. Then, the terminal 450 performs a Figure 10 The display shown.

[0239] Then, Figure 10 An operation example in which a plurality of first devices 400 and base stations 470 are installed at the location shown will be described.

[0240] Figure 14 Recorded with Figure 10 Maps of the same places. Figure 14 yes Figure 10 The "3-layer" map described in . Figure 14As shown in the figure, A-1, A-2, A-3, A-4, A-21, A-22, A-23, and A-24 represent parking spaces, and a-1 and a-2 represent elevators.

[0241] And, in Figure 14 The position of "○" 901-1 is set with Figure 9 A first device having the same configuration as the first device 400 shown. Hereinafter, a first device having the same configuration as the first device 400 installed at position 901-1 will be referred to as "1-1 device 400." 1-1 device 400 has information "A-1" as location-related information or position-related information and transmits this information.

[0242] exist Figure 14 The position setting of "○" 901-2 has the same Figure 9 A first device having the same configuration as first device 400 installed at position 901-2 is hereinafter referred to as "1-2 device 400." 1-2 device 400 has information "A-2" as location-related information or position-related information and transmits this information.

[0243] exist Figure 14 The position setting of "○" 901-3 has the same Figure 9 A first device having the same configuration as first device 400 installed at position 901-3 is hereinafter referred to as "1-3 device 400." 1-3 device 400 has information "A-3" as location-related information or position-related information and transmits this information.

[0244] exist Figure 14 The position setting of "○" 901-4 has the same Figure 9 A first device having the same configuration as first device 400 installed at position 901-4 is hereinafter referred to as "first-fourth device 400." First-fourth device 400 has information "A-4" as location-related information or position-related information and transmits this information.

[0245] exist Figure 14 The "○" 901-21 position setting has the same Figure 9A first device having the same configuration as first device 400 installed at position 901-21 is hereinafter referred to as "1-21 device 400." 1-21 device 400 has information "A-21" as location-related information or position-related information and transmits this information.

[0246] exist Figure 14 The "○" 901-22 position setting has the same Figure 9 A first device having the same configuration as first device 400 installed at position 901-22 is hereinafter referred to as "1-22nd device 400." 1-22nd device 400 has information "A-22" as location-related information or position-related information and transmits this information.

[0247] exist Figure 14 The "○" 901-23 position setting has the same Figure 9 A first device having the same configuration as first device 400 installed at position 901-23 is hereinafter referred to as "1-23rd device 400." 1-23rd device 400 has information "A-23" as location-related information or position-related information and transmits this information.

[0248] exist Figure 14 The "○" 901-24 position setting has the same Figure 9 A first device having the same configuration as first device 400 installed at position 901-24 is hereinafter referred to as "1-24th device 400." 1-24th device 400 has information "A-24" as location-related information or position-related information and transmits this information.

[0249] And, in Figure 14 The "◎" 902 position setting has the same Figure 9 The following will have the same structure as the base station 470. Figure 9 A base station (or AP) having the same configuration as base station 470 is simply referred to as "base station 470." Here, the SSID of base station 470 installed at position 902 is set to "abcdef."

[0250] exists in Figure 14 When performing wireless communication, the terminals 450 around the location shown on the map can access the Figure 14The location of base station 470 is 902.

[0251] Therefore, it is set Figure 14 The "1-1 device 400" of 901-1 is the information related to the SSID (refer to Figure 9 401-1) and send "abcdef".

[0252] Likewise, it is set Figure 14 The "first-second device 400" of 901-2 is the information related to the SSID (refer to Figure 9 401-1) and send "abcdef".

[0253] Set in Figure 14 901-3 of the "1-3 device 400", as information related to the SSID (refer to Figure 9 401-1) and send "abcdef".

[0254] Set in Figure 14 901-4 of the "1-4 device 400", as information related to the SSID (refer to Figure 9 401-1) and send "abcdef".

[0255] Set in Figure 14 901-21 of the "1st-21st device 400", as information related to the SSID (refer to Figure 9 401-1) and send "abcdef".

[0256] Set in Figure 14 901-22 of the "1st-22nd device 400", as information related to the SSID (refer to Figure 9 401-1) and send "abcdef".

[0257] Set in Figure 14 901-23 of the "1st-23rd device 400", as information related to the SSID (refer to Figure 9 401-1) and send "abcdef".

[0258] Set in Figure 14 901-24 of the "1st-24th device 400", as information related to the SSID (refer to Figure 9 401-1) and send "abcdef".

[0259] A specific working example is described below.

[0260] Here, it is set to Figure 14 The 903-1 location exists with Figure 9 In this case, the terminal 450 receives the data from the terminal 450. Figure 14 The terminal 450 receives the modulated signal sent by the "1-4 device 400" at the position of 901-4 and obtains the position information of "A-4". Figure 14 The modulated signal sent by the "1st-4th device 400" at the position 901-4 is used to obtain the information of the SSID "abcdef". Figure 14 The terminal 450 is connected to the base station 470 of 902. Figure 14 The base station 470 of 902 obtains information such as a map. Then, the terminal 450 displays the map information and location information (for example, referring to Figure 10 .but, Figure 10 is an example for display only).

[0261] Likewise, in Figure 14 The 903-2 position exists with Figure 9 In this case, the terminal 450 receives the data from the terminal 450. Figure 14 The modulated signal sent by the "1st-22nd device 400" of 901-22 is used to obtain the location information "A-22". Figure 14 The modulated signal sent by the "1st-4th device 400" of 901-22 is obtained, and the information of the SSID called "abcdef" is obtained. Based on this, the terminal 450 sends a Figure 14 The terminal 450 is connected to the base station 470 of 902. Figure 14 The base station 470 of 902 obtains information such as a map. Then, the terminal 450 displays the map information and the location information (for example, referring to Figure 10 .but, Figure 10 is an example for display only).

[0262] In addition, the terminal 450 can Figure 14 The map (surrounding information) and location information shown are stored in a storage unit (not shown) included in terminal 450. When needed, the user of terminal 450 can retrieve the information stored in the storage unit. This allows the user to more conveniently use the map (surrounding information) and location information.

[0263] As described above, since the first device 400 transmits a modulated signal using visible light, the terminal 450 that can receive the modulated signal is limited to a range that can receive an optical signal from the location of the first device 400. Therefore, the location and / or position information transmitted by the first device 400 can be received by the terminal 450, and the terminal 450 can easily obtain highly accurate position information (without having to perform complex signal processing).

[0264] Furthermore, when the first device 400 is set in a place where it is difficult to receive radio waves from GPS satellites, even if the terminal 450 is in a situation where it is difficult to receive radio waves from GPS satellites, it can still receive the modulated signal sent by the first device 400, thereby being able to safely obtain highly accurate location information.

[0265] Furthermore, based on the SSID information sent from the first device 400, the terminal 450 connects to the base station (or AP) 470 to obtain information, thereby enabling the terminal 450 to securely obtain the information. This is because, when the terminal 450 obtains information from a modulated signal of visible light, since it is visible light, the user can easily visually identify the first device 400 that sent the modulated signal, thereby being able to determine whether the information source is secure. In contrast, when the SSID is obtained from a modulated signal of radio waves transmitted from a wireless LAN, for example, it is difficult for the user to identify the device that transmitted the radio waves. Therefore, in terms of ensuring the security of information, visible light communication is more suitable for obtaining the SSID than wireless LAN communication.

[0266] Alternatively, multiple signals can be input to Figure 9 For example, a control signal for controlling the wireless device 453 and information to be sent to the base station 470 may be input to the wireless device 453. In this case, it can be considered as an example of an operation in which the wireless device 453 starts communication according to the control signal. As described above, in this embodiment, the configuration of the first device is not affected by Figure 9 The configuration of the first device 400 is limited, and the configuration of the terminal is not limited to Figure 9 The configuration of the terminal 450 is not affected by the connection destination and configuration of the base station. Figure 9 The connection destination and configuration of the base station 470 shown are limited.

[0267] And, in Figure 9 Although the configuration of one base station 470 is described in the specification, there may be multiple (safe) base stations (or APs) that the terminal 450 can access. Figure 9The SSID-related symbol sent by the first device 400 may include information indicating the SSID of each of the multiple base stations (or APs). Figure 9 The display unit 157 of the terminal 450 displays a list of SSIDs of a plurality of base stations and / or a list of a plurality of access destinations as a display of access destinations (the aforementioned "first display"). Figure 9 The terminal 450 can select one or more base stations to which it is actually wirelessly connected based on the SSID information of multiple base stations (or APs) (ie, it can be connected to multiple base stations at the same time).

[0268] For example, three base stations 470 are configured. Here, the three base stations 470 are respectively referred to as base station #A, base station #B, and base station #C. Furthermore, the SSID of base station #A is set to "abcdef", the SSID of base station #B is set to "ghijk", and the SSID of base station #C is set to "pqrstu". In this case, the modulated signal transmitted by the first device 400 is Figure 11 The SSID-related symbol 600-1 in the frame structure shown includes information such as "set the SSID of base station #A to 'abcdef'", "set the SSID of base station #B to 'ghijk'", and "set the SSID of base station #C to 'pqrstu'". Figure 9 Terminal 450 receives symbol 600-1 related to the SSID and selects one or more base stations 470 to which it is actually connected wirelessly based on the information "set SSID of base station #A to 'abcdef'", "set SSID of base station #B to 'ghijk'", and "set SSID of base station #C to 'pqrstu'".

[0269] (Implementation 4)

[0270] Figure 15 An example of the configuration of the communication system in this embodiment is shown.

[0271] Figure 15 The communication system includes, for example, a device 1000 , a terminal 1050 , and a base station (or AP) 470 that communicates with the terminal 1050 .

[0272] The device 1000 includes, for example, a visible light source such as an LED, lighting, a light source, or a lamp (hereinafter referred to as a light source 104 ). In addition, the device 1000 is hereinafter also referred to as a “second device” in this embodiment.

[0273] In addition, Figure 15 In the second device 1000 shown, for Figure 6 The components of the first device 100 that perform the same operation are given the same reference numerals. Figure 15 The terminal 1050 shown is for Figure 6 The components of the terminal 150 that perform the same operations are given the same reference numerals. Figure 15 The communication between the wireless device 453 of the terminal 1050 and the base station 470 shown uses, for example, radio waves.

[0274] exist Figure 15 In the second device 1000, the transmitter 102 receives information 1001-1 related to the SSID, information 1001-2 related to the encryption key, and data 1002 as input, generates a (light) modulated signal 103 based on these input signals, and outputs the modulated signal 103. Then, the modulated signal 103 is transmitted from, for example, a light source 104.

[0275] Next, the information 1001 - 1 related to the SSID and the information 1001 - 2 related to the encryption key will be described.

[0276] First, the information 1001 - 1 related to the SSID will be described.

[0277] The information 1001-1 related to the SSID is shown Figure 15 In addition, as an example, the base station 470 transmits a modulated signal to the terminal 1050 via radio waves and receives a modulated signal from the terminal 1050 via radio waves. The second device 1000 provides the terminal 1050 with access to the base station 470, which is a secure access destination. Figure 15 The terminal 1050 can securely obtain information from the base station 470.

[0278] Furthermore, the second device 1000 can limit the terminals that access the base station 470 to terminals located in a space that can receive the optical signal transmitted (irradiated) by the second device 1000 .

[0279] Furthermore, when receiving an optical signal transmitted in a predetermined manner, terminal 1050 can determine that the notified SSID is the SSID of a secure base station. Furthermore, terminal 1050 can also perform separate processing to determine whether the notified SSID is secure. For example, second device 1000 can include a predetermined identifier in the optical signal and transmit it. Terminal 1050 can then determine whether the notified SSID is the SSID of a secure base station based on the received identifier.

[0280] In addition, Figure 15Although only base station 470 is shown, for example, when a base station (or AP) other than base station 470 exists, terminal 1050 can also access base station 470 using the SSID obtained from second device 1000 to obtain information.

[0281] Next, the information 1001-2 related to the encryption key will be described.

[0282] Information 1001-2 on the encryption key is information on the encryption key required for terminal 1050 to communicate with base station 470. Terminal 1050 can perform encrypted communication with base station 470 by obtaining information 1001-2 on the encryption key from second device 1000.

[0283] The information 1001 - 1 related to the SSID and the information 1001 - 2 related to the encryption key have been described above.

[0284] Figure 15 The terminal 1050 receives the modulated signal sent by the second device 1000. Figure 15 Terminal 1050, for Figure 6 Terminal 150, Figure 9 The components of terminal 450 that perform the same operation are given the same symbols.

[0285] The light receiving unit 151 included in the terminal 1050 is, for example, an image sensor such as a CMOS or an organic CMOS. The light receiving unit 151 receives light including a modulated signal transmitted from the second device 1000 and outputs a received signal 152 .

[0286] Then, the receiving unit 153 receives the reception signal 152 received by the light receiving unit 151 as input, performs processing such as demodulation and error correction decoding on the modulated signal included in the reception signal 152 , and outputs reception data 154 .

[0287] Data analyzer 155 receives received data 154 as input and, based on received data 154, outputs, for example, information 1051 about the SSID of the base station to be connected and information 1052 about the encryption key used for communicating with the base station to be connected. For example, in wireless LANs (Local Area Networks), encryption methods include WEP (Wired Equivalent Privacy), WPA (Wi-Fi Protected Access), and WPA2 (Wi-Fi Protected Access 2) (PSK (Pre-Shared Key) mode, EAP (Extended Authentication Protocol) mode). However, encryption methods are not limited to these.

[0288] The display unit 157 receives SSID information 1051 and encryption key information 1052 as input, and displays, for example, the SSID and encryption key of the communication partner to which the wireless device 453 of the terminal 1050 is to access (this display is referred to as the "first display" in this embodiment).

[0289] For example, after the first display is performed, wireless device 453 takes SSID information 1051 and encryption key information 1052 as input and establishes a connection with base station 470 (for example, the connection is achieved via radio waves). At this time, when base station 470 also communicates with wireless device 453 included in terminal 1050, it transmits a modulated signal using radio waves, for example.

[0290] Then, the wireless device 453 receives the data 1053 and the control signal 1054 as input, modulates the data 1053 according to the control indicated by the control signal 1054, and transmits the modulated signal via radio waves.

[0291] Then, for example, the base station 470 transmits data to the network (471) and receives data from the network (472). Thereafter, for example, the base station 470 transmits a modulated signal to the terminal 1050 via radio waves.

[0292] The wireless device 453 included in the terminal 1050 performs processing such as demodulation and error correction decoding on the modulated signal received via radio waves, and obtains the received data 1056. The display unit 157 displays the received data 1056.

[0293] Figure 16 Shown Figure 15 An example of the frame structure of the modulated signal transmitted by the second device 1000 is shown. Figure 16 In , the horizontal axis is time. Figure 16In the Figure 7 、 Figure 11 The same code elements are given the same numbers and their descriptions are omitted.

[0294] The code element 600-1 associated with the SSID is used to send Figure 15 The code element 1001-1 of the information related to the SSID and the code element 1101 related to the encryption key are used to send Figure 15 The data symbol 1102 is used to send the information 1001-2 related to the encryption key. Figure 15 The code element of data 1002.

[0295] The second device 1000 transmits a preamble 201, a control information symbol 202, a symbol 600-1 related to the SSID, a symbol 1101 related to the encryption key, and a data symbol 1102. In addition, the second device 1000 may also transmit a message including Figure 16 Furthermore, not only the order in which the symbols are sent, but also the frame structure is not affected. Figure 16 Limited by the composition.

[0296] Figure 17 Shown Figure 15 An example of a frame structure of a modulated signal transmitted by the wireless device 453 of the terminal 1050. Figure 17 , the horizontal axis is time.

[0297] like Figure 17 As shown, the wireless device 453 included in the terminal 1050 transmits, for example, a preamble 1201 , and thereafter transmits a control information symbol 1202 and an information symbol 1203 .

[0298] The preamble 1201 is a symbol used by the base station 470 receiving the modulated signal transmitted by the wireless device 453 of the terminal 1050 , for example, to perform signal detection, time synchronization, frame synchronization, frequency synchronization, frequency offset estimation, and the like.

[0299] Control information symbol 1202 includes, for example, information regarding the error correction coding method and modulation scheme used to generate the modulated signal, information regarding frame composition, and information regarding the transmission method. Base station 470 uses the information included in control information symbol 1202 to perform demodulation of the modulated signal.

[0300] The information symbol 1203 is a symbol used by the wireless device 453 of the terminal 1050 to transmit data.

[0301] In addition, the wireless device 453 of the terminal 1050 may also send a message including Figure 17For example, the wireless device 453 may transmit a frame including a pilot symbol (reference symbol) in the middle of the information symbol 1203. Moreover, not only the order in which the symbols are transmitted but also the frame structure is not affected. Figure 17 And, in Figure 17 In the frequency axis direction, there can also be multiple code elements. Figure 17 In the embodiment 3, the code element may also exist in multiple frequencies (multiple carriers). Figure 9 When the wireless device 453 of the terminal 450 sends a modulated signal, it can also be used Figure 17 Frame composition.

[0302] The frame structure of the modulated signal transmitted by the base station 470 in this embodiment is the same as that described in the third embodiment. Figure 12 The frame structure is the same as Figure 12 As shown, the base station 470 transmits a preamble 701 , for example, and then transmits a control information symbol 702 and an information symbol 703 .

[0303] The preamble 701 is a symbol used by the wireless device 453 of the terminal 1050 to receive the modulated signal transmitted by the base station 470 , for example, to perform signal detection, time synchronization, frame synchronization, frequency synchronization, frequency offset estimation, and the like.

[0304] Control information symbol 702 is a symbol containing data such as information regarding the error correction coding method and modulation scheme used to generate the modulated signal, information regarding frame composition, and information regarding the transmission method. Wireless device 453 of terminal 1050 demodulates the modulated signal based on the information in control information symbol 702.

[0305] Information symbol 703 is a symbol used by base station 470 to transmit data.

[0306] in addition, Figure 15 The base station 470 shown may also transmit a signal including Figure 12 For example, the base station 470 may transmit a frame including a pilot symbol (reference symbol) in the middle of the information symbol 703. Furthermore, not only the order in which the symbols are transmitted but also the frame structure is not affected. Figure 12 And, in Figure 12 In the frequency axis direction, there can be multiple code elements. Figure 12 In addition, code elements may also exist in multiple frequencies (multiple carriers).

[0307] Furthermore, for example, it is possible to consider that the second device 1000 sends Figure 16A method of transmitting a modulated signal composed of frames at a predetermined timing, for example, a method of repeatedly transmitting. In this way, multiple terminals 1050 can perform the above-mentioned operations.

[0308] Figure 18 yes Figure 15 This is a flowchart of an example of processing performed by the "second device 1000", "terminal 1050" and "base station 470" shown.

[0309] First, the second device 1000 sends Figure 16 The modulated signal (ST1301) is composed of the frames shown.

[0310] Then, terminal 1050 receives the modulated signal transmitted by second device 1000 and obtains the SSID of base station 470 to which terminal 1050 is to access (ST1302).

[0311] At the same time, terminal 1050 obtains an encryption key used when terminal 1050 communicates with base station 470 to be accessed (ST1303).

[0312] Then, terminal 1050 establishes a connection with base station 470 via radio waves (ST1304). Terminal 1050 receives a response from base station 470 and terminates the connection with base station 470 (ST1305).

[0313] Then, terminal 1050 transmits information on a connection destination to base station 470 using radio waves (ST1306).

[0314] Base station 470 obtains information to be transmitted to terminal 1050 from the network (ST1307).

[0315] Then, base station 470 transmits the acquired information to terminal 1050 using radio waves, and terminal 1050 obtains the information (ST1308). Terminal 1050 obtains necessary information from the network via base station 470, for example, when necessary.

[0316] As described above, based on the SSID information and encryption key information transmitted from the second device 1000, the terminal 1050 connects to the base station 470 and obtains information. This allows the terminal 1050 to securely obtain information via the secure base station 470. This is because, when the terminal 1050 obtains information from a modulated signal of visible light, the user can easily determine whether the information source is secure due to the visible light. In contrast, if the SSID is obtained from a modulated signal of radio waves transmitted by a wireless LAN, for example, it is difficult for the user to identify the device that transmitted the radio waves. Therefore, from the perspective of ensuring information security, visible light communication is more suitable for obtaining SSIDs than wireless LAN communication.

[0317] In this embodiment, the case where second device 1000 transmits encryption key information is described. However, if, for example, base station 470 does not perform encrypted communications using an encryption key, second device 1000 may transmit only information related to the SSID, rather than encryption key information. In this case, the same operation can be performed by simply removing the encryption key-related configuration from the above configuration.

[0318] Furthermore, the configuration of the second device is not affected by Figure 15 The configuration of the second device 1000 shown is not limited by the configuration of the terminal. Figure 15 The connection destination and configuration of the base station are not limited by the configuration of the terminal 1050 shown. Figure 15 The connection destination and configuration of the base station 470 shown are limited.

[0319] And, in Figure 15 Although only one base station 470 is described, there may be multiple (safe) base stations (or APs) that the terminal 1050 can access. In addition, these multiple base stations and the terminal 1050 use radio waves to send and receive modulated signals. Figure 15 The SSID-related codeword sent by the second device 1000 may include information about the SSID of each of these multiple base stations (or APs). Figure 15 The display unit 157 of the terminal 1050 displays a list of SSIDs of multiple base stations and / or a list of multiple access destinations as the display of the access destination. Figure 15 The codeword related to the encryption key sent by the second device 1000 may include information on the encryption keys used to connect to each of these multiple base stations (or APs). Figure 15 The terminal 1050 can select one or more base stations to which it is actually wirelessly connected (i.e., it can be connected to multiple base stations at the same time) based on the SSID information and encryption key information of multiple base stations (for example, through radio waves).

[0320] For example, three base stations 470 are deployed. These three base stations 470 are referred to herein as base station #A, base station #B, and base station #C. Furthermore, the SSID of base station #A is "abcdef," the SSID of base station #B is "ghijk," and the SSID of base station #C is "pqrstu." Furthermore, the encryption key used to connect to base station #A is "123," the encryption key used to connect to base station #B is "456," and the encryption key used to connect to base station #C is "789."

[0321] In this case, the modulated signal sent by the second device 1000 is Figure 16 The SSID-related symbol 600-1 in the frame structure includes information such as "set the SSID of base station #A to 'abcdef'", "set the SSID of base station #B to 'ghijk'", and "set the SSID of base station #C to 'pqrstu'". Figure 16 The code element 1101 related to the encryption key in the frame structure includes information such as "set the encryption key for connecting to base station #A to '123'", "set the encryption key for connecting to base station #B to '456'", and "set the encryption key for connecting to base station #C to '789'".

[0322] then, Figure 15 Terminal 1050 receives symbol 600-1 related to the SSID and obtains information such as "Set the SSID of base station #A to 'abcdef'," "Set the SSID of base station #B to 'ghijk'," and "Set the SSID of base station #C to 'pqrstu'." Furthermore, terminal 1050 receives symbol 1101 related to the encryption key and obtains information such as "Set the encryption key for connecting to base station #A to '123'," "Set the encryption key for connecting to base station #B to '456'," and "Set the encryption key for connecting to base station #C to '789'." Based on this information, terminal 1050 selects one or more base stations to connect to wirelessly (e.g., via radio waves) and establishes a connection.

[0323] Furthermore, as shown in this embodiment, a light source such as an LED is used, and base station 470 to which terminal 1050 is to connect is set. Therefore, since the modulated signal transmitted by terminal 1050 is wireless, there is no need for a mode for performing special settings, such as procedures for wirelessly connecting terminal 1050 to base station 470. Furthermore, the modulated signal transmitted by base station 470 does not require a mode for performing special settings, such as procedures for wirelessly connecting terminal 1050 to base station 470. Therefore, this embodiment can improve the data transmission efficiency of wireless communication.

[0324] Furthermore, as mentioned above, the encryption key can be an encryption key for the wireless LAN SSID, or an encryption key that limits the connection mode, service mode, network connection range, etc. In other words, an encryption key can be introduced when certain restrictions are desired.

[0325] (Implementation 5)

[0326] Figure 19 An example of the configuration of the communication system in this embodiment is shown.

[0327] Figure 19 The communication system includes, for example, devices 1400A and 1400B, a terminal 1050 , and a base station (or AP) 470 that communicates with the terminal 1050 .

[0328] Devices 1400A and 1400B include, for example, visible light sources such as LEDs, lighting, light sources, and lamps (hereinafter referred to as light sources 1406-1 and 1406-2). Device 1400A is hereinafter referred to as the "third device" and device 1400B is hereinafter referred to as the "fourth device" in this embodiment.

[0329] In addition, Figure 19 The terminal 1050 shown is for Figure 1 The terminal 150 shown or Figure 15 The components of the terminal 1050 shown in the figure that perform the same operation are given the same reference numerals. Figure 19 The same is true for the base station (or AP) 470 shown. Figure 9 The base station 470 shown in FIG. 1 is provided with components that perform the same operation as Figure 9 Same symbols. And, Figure 19 The communication between the wireless device 453 of the terminal 1050 and the base station 470 shown uses, for example, radio waves.

[0330] exist Figure 19 In the third device 1400A, a transmitter 1404-1 receives information 1401-1 related to the SSID and data 1402-1 as input, generates a (light) modulated signal 1405-1 based on these input signals, and outputs the modulated signal 1405-1. The modulated signal 1405-1 is then transmitted from, for example, a light source 1406-1.

[0331] exist Figure 19 In the fourth device 1400B, the transmitter 1404-2 receives the information 1403-2 related to the encryption key and the data 1402-2 as input, generates a (light) modulated signal 1405-2 based on these input signals, and outputs the modulated signal 1405-2. Then, the modulated signal 1405-2 is transmitted from, for example, a light source 1406-2.

[0332] Next, the information 1401 - 1 related to the SSID and the information 1403 - 2 related to the encryption key will be described.

[0333] First, the information 1401 - 1 related to the SSID will be described.

[0334] The information 1401-1 related to the SSID is shown Figure 19That is, the third device 1400A provides the terminal 1050 with access to the base station 470, which is a safe access destination, via radio waves. Figure 19 The terminal 1050 securely obtains information from the base station 470.

[0335] Furthermore, when terminal 1050 receives an optical signal transmitted in a predetermined manner, it may also determine that the notified SSID is the SSID of a secure base station. Furthermore, terminal 1050 may also perform a separate process to determine whether the notified SSID is secure. For example, third device 1400A may include a predetermined identifier in the optical signal and transmit it. Terminal 1050 may then determine whether the notified SSID is the SSID of a secure base station based on the received identifier.

[0336] In addition, Figure 19 Although only the base station 470 is shown, for example, when a base station (or AP) other than the base station 470 exists, the terminal 1050 can also access the base station 470 and obtain information by using the SSID obtained from the third device 1400A and the encryption key obtained from the fourth device 1400B.

[0337] Next, the information 1403-2 related to the encryption key will be described.

[0338] The encryption key information 1403-2 is necessary for the terminal 1050 to communicate with the base station 470 via radio waves. The terminal 1050 obtains the encryption key information 1403-2 from the fourth device 1400B, thereby enabling encrypted communication with the base station 470.

[0339] The information 1401 - 1 related to the SSID and the information 1403 - 2 related to the encryption key have been described above.

[0340] Figure 19 The terminal 1050 receives the modulated signal sent by the third device 1400A.

[0341] The light receiving unit 151 included in the terminal 1050 is, for example, an image sensor such as a CMOS or an organic CMOS. The light receiving unit 151 receives light including a modulated signal transmitted from the third device 1400A and outputs a received signal 152 .

[0342] Then, the receiving unit 153 receives the reception signal 152 received by the light receiving unit 151 as input, performs processing such as demodulation and error correction decoding on the modulated signal included in the reception signal 152 , and outputs reception data 154 .

[0343] Data analyzer 155 receives received data 154 as input and outputs, based on the received data, SSID information 1051 of a base station to be connected. Wireless device 453 obtains SSID information of base station 470 to which it is connected via radio waves from SSID information 1051.

[0344] Figure 19 The terminal 1050 receives the modulated signal sent by the fourth device 1400B.

[0345] The light receiving unit 151 included in the terminal 1050 is, for example, an image sensor such as a CMOS or an organic CMOS. The light receiving unit 151 receives light including a modulated signal transmitted from the fourth device 1400B and outputs a received signal 152 .

[0346] Then, the receiving unit 153 receives the reception signal 152 received by the light receiving unit 151 as input, performs processing such as demodulation and error correction decoding on the modulated signal included in the reception signal 152 , and outputs reception data 154 .

[0347] Data analyzer 155 receives received data 154 as input and, based on the received data, outputs, for example, encryption key information 1052 used for communicating with the base station serving as the connection destination. For example, encryption methods used in wireless LANs (Local Area Networks) include WEP (Wired Equivalent Privacy), WPA (Wi-Fi Protected Access), and WPA2 (Wi-Fi Protected Access 2) (PSK (Pre-Shared Key) mode and EAP (Extended Authentication Protocol) mode). However, encryption methods are not limited to these.

[0348] The wireless device 453 included in the terminal 1050 obtains the encryption key information of the base station 470 to which the wireless device 453 is to connect from the encryption key information 1052 used for communicating with the base station to be connected (eg, via radio waves).

[0349] The display unit 157 receives SSID information 1051 and encryption key information 1052 as input, and displays, for example, the SSID and encryption key of the communication partner to which the wireless device 453 of the terminal 1050 is to access (this display is referred to as the "first display" in this embodiment).

[0350] For example, after the first display, wireless device 453 takes SSID information 1051 and encryption key information 1052 as input and establishes a radio wave connection with base station 470. At this time, when base station 470 also communicates with wireless device 453 included in terminal 1050, for example, a modulated signal is transmitted using radio waves.

[0351] After that, the wireless device 453 receives the data 1053 and the control signal 1054 as input, modulates the data 1053 according to the control indicated by the control signal 1054 , and transmits the modulated signal via radio waves.

[0352] Then, for example, the base station 470 transmits data to the network (471) and receives data from the network (472). After that, for example, the base station 470 transmits a modulated signal to the terminal 1050 via radio waves.

[0353] The wireless device 453 included in the terminal 1050 performs processing such as demodulation and error correction decoding on the modulated signal received via radio waves, and obtains the received data 1056. The display unit 157 displays the received data 1056.

[0354] Figure 20 Shown Figure 19 An example of the frame structure of the modulated signal transmitted by the third device 1400A is shown. Figure 20 In , the horizontal axis is time. Figure 20 , for Figure 2 、 Figure 11 、 Figure 16 The same symbols are assigned to the same code elements, and their descriptions are omitted.

[0355] The code element 600-1 associated with the SSID is used to Figure 19 The data symbol 1102 is a symbol for transmitting the information 1401-1 related to the SSID. The data symbol 1102 is a symbol for transmitting the data 1402-1.

[0356] The third device 1400A transmits the preamble 201, the control information symbol 202, the symbol 600-1 related to the SSID, and the data symbol 1102. In addition, the third device 1400A may also transmit the Figure 20 Furthermore, not only the order of sending symbols but also the frame structure is not affected. Figure 20 restrictions on the composition of.

[0357] Figure 21 Shown Figure 19 An example of a frame structure of a modulated signal transmitted by the fourth device 1400B. Figure 21 In , the horizontal axis is time. Figure 21 In the Figure 7 、 Figure 16 The same symbols are assigned to the same code elements, and their descriptions are omitted.

[0358] The code element 1101 related to the encryption key is used to Figure 19 Data symbol 1102 is a symbol for transmitting data 1402-2.

[0359] The fourth device 1400B transmits a preamble 201, a control information symbol 202, a symbol 1101 related to an encryption key, and a data symbol 1102. Figure 19 The 4th device 1400B may also send a message including Figure 21 Furthermore, not only the order in which the symbols are sent, but also the frame structure is not affected. Figure 21 restrictions.

[0360] The frame structure of the modulated signal transmitted by the wireless device 453 in this embodiment is the same as that described in the fourth embodiment. Figure 17 The frame structure is the same. Figure 17 As shown, the wireless device 453 included in the terminal 1050 transmits, for example, a preamble 1201 , and thereafter transmits a control information symbol 1202 and an information symbol 1203 .

[0361] Preamble 1201 is used to receive Figure 19 The base station (or AP) 470 of the modulated signal sent by the wireless device 453 of the terminal 1050, for example, performs code elements for signal detection, time synchronization, frame synchronization, frequency synchronization, frequency offset estimation, etc.

[0362] Control information symbol 1202 includes, for example, data used when generating a modulated signal, including information regarding the error correction coding method, the modulation method, frame configuration, and transmission method. Base station 470 performs demodulation and other operations based on the information included in control information symbol 1202.

[0363] The information symbol 1203 is a symbol used by the wireless device 453 of the terminal 1050 to transmit data.

[0364] in addition, Figure 19 The wireless device 453 of the terminal 1050 shown may also send a message including Figure 17 For example, the wireless device 453 may transmit a frame including a pilot symbol (reference symbol) in the middle of the information symbol 1203. Furthermore, not only the order in which the symbols are transmitted but also the frame structure is not affected. Figure 17And, in Figure 17 In the frequency axis direction, there can also be multiple code elements. Figure 17 , code elements can exist in multiple frequencies (multiple carriers).

[0365] The frame structure of the modulated signal transmitted by the base station 470 in this embodiment is the same as that described in the third embodiment. Figure 12 The frame structure is the same as Figure 12 As shown, the base station 470 transmits a preamble 701 , for example, and then transmits a control information symbol 702 and an information symbol 703 .

[0366] The preamble 701 is used to receive the modulated signal sent by the base station 470. Figure 19 The wireless device 453 of the terminal 1050, for example, performs code elements such as signal detection, time synchronization, frame synchronization, frequency synchronization, and frequency offset estimation.

[0367] The control information symbol 702 is a symbol including data such as the error correction coding method, information on the modulation method, information on the frame configuration, and information on the transmission method used when generating a modulated signal. Figure 19 The wireless device 453 of the terminal 1050 performs demodulation of the modulated signal according to the information of the control information codeword 702.

[0368] Information symbol 703 is used to Figure 19 The base station 470 transmits the codeword for data.

[0369] in addition, Figure 19 The base station 470 shown may also transmit a signal including Figure 12 For example, the base station 470 may transmit a frame including a pilot symbol (reference symbol) in the middle of the information symbol 703. Furthermore, not only the order in which the symbols are transmitted but also the frame structure is not affected. Figure 12 And, in Figure 12 In the frequency axis direction, there can be multiple code elements. Figure 12 In , code elements can also exist in multiple frequencies (multiple carriers).

[0370] Furthermore, for example, it is possible to consider the third device 1400A sending Figure 20 The modulated signal composed of frames is sent repeatedly at regular timings. In this way, multiple terminals 1050 can perform the above operations. Similarly, it can be considered that the fourth device 1400B sends Figure 21 The modulated signal composed of frames is repeatedly transmitted at regular timing, for example. In this way, multiple terminals 1050 can perform the above-mentioned operations.

[0371] Figure 22 It shows Figure 19 Flowchart of the first example of the process performed by the "third device 1400A", "fourth device 1400B", "terminal 1050" and "base station 470". Figure 22 In the Figure 18 The same work is assigned the same symbol.

[0372] First, the third device 1400A sends Figure 20 The modulated signal (ST1701) is composed of the frames shown.

[0373] Then, terminal 1050 receives the modulated signal transmitted by third device 1400A, and obtains the SSID of base station 470 to which terminal 1050 is to access (ST1702).

[0374] Next, the fourth device 1400B sends Figure 21 The modulated signal (ST1703) is composed of the frames shown.

[0375] Then, terminal 1050 receives the modulated signal transmitted by fourth device 1400B, and obtains an encryption key used when communicating with base station 470 to which terminal 1050 is about to access (ST1704).

[0376] Then, terminal 1050 establishes a radio wave connection with base station 470 (ST1304). Terminal 1050 terminates the radio wave connection with base station 470 by receiving a response from base station 470 (ST1305).

[0377] Then, terminal 1050 transmits information on a connection destination to base station 470 using radio waves (ST1306).

[0378] Base station 470 obtains information to be transmitted to terminal 1050 from the network (ST1307).

[0379] Then, base station 470 transmits the acquired information to terminal 1050 using radio waves, and terminal 1050 obtains the information (ST1308). Terminal 1050 obtains necessary information from the network via base station 470, for example, when necessary.

[0380] Figure 23 It shows Figure 19 Flowchart of the second example of the processing performed by the "third device 1400A", "fourth device 1400B", "terminal 1050" and "base station 470". Figure 23 In the Figure 18 The same work is assigned the same symbol.

[0381] First, the fourth device 1400B sends Figure 21 The modulated signal (ST1801) is composed of the frames shown.

[0382] Then, terminal 1050 receives the modulated signal transmitted by fourth device 1400B, and obtains an encryption key used when communicating with base station 470 to which terminal 1050 is about to access (ST1802).

[0383] Next, the third device 1400A sends Figure 20 The modulated signal (ST1803) is composed of the frames shown.

[0384] Then, terminal 1050 receives the modulated signal transmitted by third device 1400A, and obtains the SSID of base station 470 to which terminal 1050 is to access (ST1804).

[0385] Then, terminal 1050 establishes a radio wave connection with base station 470 (ST1304). Terminal 1050 terminates the radio wave connection with base station 470 by receiving a response from base station 470 (ST1305).

[0386] Then, terminal 1050 transmits information on the connection destination to base station 470 using radio waves (ST1306).

[0387] Base station 470 obtains information to be transmitted to terminal 1050 from the network (ST1307).

[0388] Then, base station 470 transmits the acquired information to terminal 1050 using radio waves, and terminal 1050 obtains the information (ST1308). For example, terminal 1050 obtains necessary information from the network via base station 470 when necessary.

[0389] As described above, based on the SSID sent from the third device 1400A and the encryption key information sent from the fourth device 1400B, the terminal 1050 connects to the base station 470 and obtains information. That is, since the device from which the terminal 1050 obtains the SSID information is different from the device from which the encryption key information is obtained, the information can be securely obtained via the base station 470, which has guaranteed security. This is because, when the terminal 1050 obtains information from a modulated signal of visible light, since it is visible light, the user can easily determine whether the information source is safe. In contrast, for example, when the SSID is obtained from a modulated signal of radio waves transmitted by a wireless LAN, it is difficult for the user to distinguish the device that transmitted the radio waves. Therefore, from the perspective of ensuring the security of information, visible light communication is more suitable for obtaining the SSID than wireless LAN communication.

[0390] In this embodiment, fourth device 1400B transmits encryption key information. However, if, for example, base station 470 does not perform encrypted communications using an encryption key, fourth device 1400B may not transmit encryption key information, and third device 1400A may transmit only information related to the SSID. In this case, the same operation can be performed by omitting the encryption key-related configuration from the above configuration.

[0391] Furthermore, as shown in this embodiment, by separately setting up a device that sends information related to the SSID (the third device 1400A) and a device that sends information related to the encryption key (the fourth device 1400B), more secure communication between the terminal 1050 and the base station 470 can be achieved.

[0392] For example, consider Figure 24 The space shown. Figure 24 There are area #1 and area #2, and there are entrances and exits as well as walls between area #1 and area #2. Figure 24 In the space, movement from area #1 to area #2, and from area #2 to area #1, can only be achieved through entrances and exits.

[0393] exist Figure 24 In area #1, a base station 470, a third device 1400A, and a fourth device 1400B are installed. In area #2, only the third device 1400A is installed. Figure 24 In the example, both area #1 and area #2 can receive the radio waves sent by base station 470.

[0394] At this time, terminal 1050 located in area #1, where fourth device 1400B is installed, obtains the encryption key of base station 470 from fourth device 1400B, thereby enabling communication with base station 470. Furthermore, even if terminal 1050, which is connected to base station 470 in area #1, moves to area #2, it can still communicate with base station 470 using the encryption key obtained from fourth device 1400B in area #1. Furthermore, even if terminal 1050, which is connected to base station 470 in area #1, moves to an area outside of area #1 and area #2 and then returns to either area #1 or area #2, it can still communicate with base station 470 using the encryption key obtained from fourth device 1400B in area #1.

[0395] Furthermore, terminal 1050, which cannot enter area #1, cannot obtain the encryption key from fourth device 1400B. In this case, terminal 1050 only knows the SSID of base station (or AP) 470. Therefore, for example, terminal 1050 can communicate with base station 470 using services that can be enjoyed by simply knowing the SSID of base station 470. Compared to services that can be enjoyed by knowing both the SSID and the encryption key, the services that can be enjoyed by simply knowing the SSID of base station 470 are limited.

[0396] Therefore, only terminals 1050 that can enter area #1 can communicate with base station 470. This ensures communication security and enables the construction of a system that provides different services for each area.

[0397] Furthermore, by changing the encryption key used for communication between terminal 1050 and base station 470 (for example, at a certain time interval), communication between terminal 1050 and base station 470 that holds the encryption key before the change is no longer possible. This operation enables more secure communication.

[0398] Furthermore, the configuration of the third device and the configuration of the fourth device may not be affected by Figure 19 The configuration of the terminal is not limited by the configuration of the third device 1400A and the fourth device 1400B shown. Figure 19 The connection destination and configuration of the base station are not limited by the configuration of the terminal 1050 shown. Figure 19 The connection destination and configuration of the base station 470 shown are limited.

[0399] And, in Figure 19 Although only one base station 470 is configured, there may be multiple (secure) base stations (or APs) that the terminal 1050 can access. Figure 19 The SSID-related codeword sent by the third device 1400A may include information about the SSID of each of the multiple base stations 470. Figure 19 The codeword related to the encryption key sent by the fourth device 1400B may include information about the encryption key used to connect to each of the multiple base stations. Figure 19 The display unit 157 of the terminal 1050 displays a list of SSIDs of a plurality of base stations and / or a list of a plurality of access destinations as a display of access destinations (the aforementioned "first display"). Figure 19 The terminal 1050 can select one or more base stations to which it is actually wirelessly connected based on the SSID information and encryption key information of multiple base stations (that is, it can be connected to multiple base stations at the same time).

[0400] For example, three base stations 470 are deployed. Here, these three base stations 470 are referred to as base station #A, base station #B, and base station #C. Furthermore, the SSID of base station #A is "abcdef," the SSID of base station #B is "ghijk," and the SSID of base station #C is "pqrstu." Furthermore, the encryption key used to connect to base station #A is "123," the encryption key used to connect to base station #B is "456," and the encryption key used to connect to base station #C is "789."

[0401] In this case, the modulated signal sent by the third device 1400A is Figure 20 The SSID-related symbol 600-1 in the frame structure includes information such as "set the SSID of base station #A to 'abcdef'", "set the SSID of base station #B to 'ghijk'", and "set the SSID of base station #C to 'pqrstu'". Figure 21 The code element 1101 related to the encryption key in the frame structure includes information such as "set the encryption key for connecting to base station #A to '123'", "set the encryption key for connecting to base station #B to '456'", and "set the encryption key for connecting to base station #C to '789'".

[0402] then, Figure 19 Terminal 1050 receives symbol 600-1 related to the SSID and obtains information such as "Set the SSID of base station #A to 'abcdef'," "Set the SSID of base station #B to 'ghijk'," and "Set the SSID of base station #C to 'pqrstu'." Furthermore, terminal 1050 receives symbol 1101 related to the encryption key and obtains information such as "Set the encryption key for connecting to base station #A to '123'," "Set the encryption key for connecting to base station #B to '456'," and "Set the encryption key for connecting to base station #C to '789'." Based on this information, terminal 1050 selects a base station for wireless connection (e.g., via radio waves) and connects to it.

[0403] Furthermore, as shown in this embodiment, by utilizing a light source such as an LED and by setting the base station 470 to which terminal 1050 will connect, the modulated signal transmitted by terminal 1050 is wireless, eliminating the need for special mode settings, such as those required for establishing a wireless communication connection between terminal 1050 and base station 470. Furthermore, the modulated signal transmitted by base station 470 does not require special mode settings, such as those required for establishing a wireless communication connection between terminal 1050 and base station 470. Therefore, this embodiment can improve data transmission efficiency in wireless communication.

[0404] Furthermore, as described above, the encryption key may be an SSID encryption key for a wireless LAN, or an encryption key for limiting connection types, service types, network connection range, etc. In other words, an encryption key may be introduced when certain restrictions are desired.

[0405] (Implementation 6)

[0406] Figure 25 An example of the configuration of the communication system in this embodiment is shown.

[0407] Figure 25 The communication system includes, for example, a base station 2000 and a terminal 1050. The base station 2000 includes a transmitting device 2001 and a wireless device 2002. Figure 25 In the Figure 6 、 Figure 15 The same work is assigned the same symbol. And, Figure 25 The wireless device 2002 communicates with the wireless device 453 using, for example, radio waves.

[0408] Figure 25 The transmitting device 2001 of the base station (or AP) 2000 includes, for example, a visible light source such as an LED, an illumination, a light source, or a lamp (hereinafter referred to as light source 104). First, the operation of the transmitting device 2001 (i.e., the portion related to the visible light source such as an LED, an illumination, a light source, or a lamp) will be described.

[0409] In transmitting device 2001, transmitting section 102 receives SSID information 1001-1, encryption key information 1001-2, and data 1002 as input, generates (optical) modulated signal 103 based on these input signals, and outputs modulated signal 103. Modulated signal 103 is then transmitted from, for example, light source 104.

[0410] Next, the information 1001 - 1 regarding the SSID and the information 1001 - 2 regarding the encryption key will be described.

[0411] First, the information 1001 - 1 related to the SSID will be described.

[0412] The information 1001-1 related to the SSID is shown Figure 25 In other words, the transmitting device 2001 can provide the terminal 1050 with access to the wireless device 2002, which is the access destination, via secure wireless. Figure 25 The terminal 1050 can securely obtain information from the wireless device 2002.

[0413] Furthermore, the transmitting device 2001 limits the terminals that access the wireless device 2002 to terminals located in a space where they can receive the optical signal transmitted (irradiated) from the transmitting device 2001 .

[0414] Furthermore, when terminal 1050 receives an optical signal transmitted in a predetermined manner, it can determine that the notified SSID is the SSID of a secure base station. Furthermore, terminal 1050 can also perform additional processing to determine whether the notified SSID is secure. For example, transmitting device 2001 can include a predetermined identifier in the optical signal and transmit it. Terminal 1050 can then determine whether the notified SSID is the SSID of a secure base station based on the received identifier.

[0415] In addition, Figure 25 Although only the base station 2000 is shown, even if there is a base station (or AP) other than the base station 2000, the terminal 1050 uses the SSID and encryption key obtained from the transmitting device 2001 to access the wireless device 2002 of the base station 2000 and obtain information.

[0416] Next, the information 1001-2 related to the encryption key will be described.

[0417] The information 1001-2 on the encryption key is necessary for the terminal 1050 to communicate with the wireless device 2002. The terminal 1050 obtains the information 1001-2 on the encryption key from the transmitting device 2001, thereby enabling encrypted communication between the wireless device 2002 and the terminal 1050.

[0418] The information 1001 - 1 related to the SSID and the information 1001 - 2 related to the encryption key have been described above.

[0419] Figure 25 The terminal 1050 receives the modulated signal sent by the transmitting device 2001. Figure 25 Terminal 1050, for Figure 6 Terminal 150, Figure 15 Components of the terminal 1050 that perform the same operations are given the same symbols.

[0420] The light receiving unit 151 included in the terminal 1050 is, for example, an image sensor such as a CMOS or an organic CMOS. The light receiving unit 151 receives light including a modulated signal transmitted from the transmitting device 2001 and outputs a received signal 152 .

[0421] Then, the receiving unit 153 receives the reception signal 152 received by the light receiving unit 151 as input, performs processing such as demodulation and error correction decoding on the modulated signal included in the reception signal 152 , and outputs reception data 154 .

[0422] Data analyzer 155 receives received data 154 as input and, based on the received data, outputs, for example, information 1051 about the SSID of wireless device 2002 of base station 2000, the destination of connection, and information 1052 about an encryption key used for communicating with wireless device 2002 of base station 2000, the destination of connection. For example, encryption methods used in wireless LANs (Local Area Networks) include WEP (Wired Equivalent Privacy), WPA (Wi-Fi Protected Access), and WPA2 (Wi-Fi Protected Access 2) (PSK (Pre-Shared Key) mode and EAP (Extended Authentication Protocol) mode). However, the encryption method is not limited to these.

[0423] The display unit 157 receives SSID information 1051 and encryption key information 1052 as input, and displays, for example, the SSID and encryption key of the communication partner to which the wireless device 453 of the terminal 1050 is to access (this display is referred to as the "first display" in this embodiment).

[0424] For example, after the first display, wireless device 453 takes SSID information 1051 and encryption key information 1052 as input and establishes a connection with wireless device 2002 of base station 2000 (for example, this connection is achieved via radio waves). At this time, when wireless device 2002 of base station 2000 also communicates with wireless device 453 included in terminal 1050, a modulated signal is transmitted using radio waves, for example.

[0425] After that, the wireless device 453 receives the data 1053 and the control signal 1054 as input, modulates the data 1053 according to the control indicated by the control signal 1054, and transmits the modulated signal via radio waves.

[0426] Then, for example, the wireless device 2002 of the base station 2000 transmits data to the network (471) and receives data from the network (472). Thereafter, for example, the wireless device 2002 of the base station 2000 transmits a modulated signal to the terminal 1050 via radio waves.

[0427] The wireless device 453 included in the terminal 1050 performs processing such as demodulation and error correction decoding on the modulated signal received via radio waves, and obtains the received data 1056. The display unit 157 displays the received data 1056.

[0428] The frame structure of the modulated signal transmitted by the transmitting device 2001 of the base station 2000 in this embodiment is the same as that described in the fourth embodiment. Figure 16 The frame structure is the same. That is, Figure 16 In the example, the code element 600-1 related to the SSID is used to send Figure 25 The code element 1001-1 of the information related to the SSID and the code element 1101 related to the encryption key are used to send Figure 25 The data symbol 1102 is used to send the information 1001-2 related to the encryption key. Figure 25 The code element of data 1002.

[0429] like Figure 16 As shown, the transmitting device 2001 of the base station 2000 transmits a preamble 201, a control information symbol 202, a symbol 600-1 related to the SSID, a symbol 1101 related to the encryption key, and a data symbol 1102. In addition, the transmitting device 2001 of the base station 2000 may also transmit a message including Figure 16 Furthermore, not only the order in which the symbols are sent, but also the frame structure is not affected. Figure 16 Limited by the composition.

[0430] The frame structure of the modulated signal transmitted by the wireless device 453 of the terminal 1050 in this embodiment is the same as that described in the fourth embodiment. Figure 17 The frame structure is the same. Figure 17 As shown, Figure 25 The wireless device 453 of the terminal 1050 sends, for example, a preamble 1201, and then sends a control information code element 1202 and an information code element 1203.

[0431] At this time, the preamble 1201 is a symbol used by the wireless device 2002 of the base station 2000 to receive the modulated signal transmitted by the wireless device 453 , for example, to perform signal detection, time synchronization, frame synchronization, frequency synchronization, frequency offset estimation, and the like.

[0432] Control information symbol 1202 includes, for example, data such as the error correction coding method used when terminal 1050 generates a modulated signal, information related to the modulation method, information related to frame structure, and information related to the transmission method. Wireless device 2002 of base station 2000 performs demodulation of the modulated signal based on the information included in control information symbol 1202.

[0433] The information symbol 1203 is a symbol used by the wireless device 453 of the terminal 1050 to transmit data.

[0434] In addition, the wireless device 453 of the terminal 1050 can send a message including Figure 17 For example, the wireless device 453 may transmit a frame including a pilot symbol (reference symbol) in the middle of the information symbol 1203. Furthermore, not only the order in which the symbols are transmitted but also the frame structure is not affected. Figure 17 And, in Figure 17 In the frequency axis direction, there can be multiple code elements. Figure 17 In the , codeword can exist in multiple frequencies (multiple carriers).

[0435] The frame structure of the modulated signal transmitted by the wireless device 2002 in this embodiment is different from that described in the third embodiment. Figure 12 The frame structure is the same. Figure 12 As shown, the wireless device 2002 transmits, for example, a preamble 701 , and thereafter transmits a control information symbol 702 and an information symbol 703 .

[0436] The preamble 701 is a symbol used by the wireless device 453 of the terminal 1050 receiving the modulated signal transmitted by the wireless device 2002 to perform, for example, signal detection, time synchronization, frame synchronization, frequency synchronization, and frequency offset estimation.

[0437] Control information symbol 702 includes, for example, data used when generating a modulated signal, including information regarding the error correction coding method, modulation scheme, frame structure, and transmission method. Wireless device 453 of terminal 1050 performs demodulation of the modulated signal based on the information in control information symbol 702.

[0438] The information symbol 703 is a symbol used by the wireless device 2002 to transmit data.

[0439] in addition, Figure 25 The wireless device 2002 of the base station 2000 shown can also send a signal including Figure 12For example, the wireless device 2002 may transmit a frame including a pilot symbol (reference symbol) in the middle of the information symbol 703. Furthermore, not only the order in which the symbols are transmitted but also the frame structure is not affected. Figure 12 And, in Figure 12 In the frequency axis direction, there can be multiple code elements. Figure 12 In , symbols may exist on multiple frequencies (multiple bins).

[0440] And, for example, it can be considered that the sending device 2001 sends Figure 16 The modulated signal composed of frames is sent at regular timing, for example, repeatedly. In this way, multiple terminals 1050 can perform the above-mentioned operations.

[0441] Figure 26 It shows Figure 25 1 is a flowchart of an example of processing executed by the "transmitting device 2001 of the base station 2000", the "terminal 1050", and the "wireless device 2002 of the base station 2000".

[0442] First, the sending device 2001 Figure 16 The modulated signal consisting of a frame is sent (ST1301).

[0443] Then, terminal 1050 receives the modulated signal transmitted by transmitting device 2001 and obtains the SSID of base station 2000 (wireless device 2002) to which terminal 1050 is to access (ST1302).

[0444] Then, the terminal 1050 obtains an encryption key used when communicating with the base station 2000 (wireless device 2002) to which the terminal 1050 is about to access (ST1303).

[0445] Terminal 1050 then establishes a radio wave connection with wireless device 2002 of base station 2000 (ST1304). Terminal 1050 receives a response from wireless device 2002 of base station 2000, and the connection between terminal 1050 and wireless device 2002 of base station 2000 is terminated (ST1305).

[0446] Then, the terminal 1050 transmits the connection destination information to the wireless device 2002 of the base station 2000 using radio waves (ST1306).

[0447] The wireless device 2002 of the base station 2000 obtains information to be transmitted to the terminal 1050 from the network (ST1307).

[0448] Then, wireless device 2002 of base station 2000 transmits the acquired information to terminal 1050 using radio waves, and terminal 1050 obtains the information (ST1308). For example, terminal 1050 obtains necessary information from the network via wireless device 2002 of base station 2000 when necessary.

[0449] As described above, terminal 1050 connects to wireless device 2002 of base station 2000 and obtains information based on the SSID information and encryption key information transmitted from transmitting device 2001 of base station 2000. This allows secure information acquisition via base station 2000, which ensures security. This is because when terminal 1050 obtains information from a modulated signal of visible light, the user can easily determine whether the information source is secure due to the visible light. In contrast, if the SSID is obtained from a modulated signal of radio waves transmitted by a wireless LAN, for example, it is difficult for the user to identify the device that transmitted the radio waves. Therefore, from the perspective of ensuring information security, visible light communication is more suitable for obtaining SSIDs than wireless LAN communication.

[0450] In this embodiment, the case where transmitting device 2001 transmits encryption key information has been described. However, if, for example, wireless device 2002 of base station 2000 is not performing encrypted communications using an encryption key, transmitting device 2001 may transmit only information related to the SSID, rather than encryption key information. In this case, the same operation can be achieved by simply removing the encryption key-related configuration from transmitting device 2001.

[0451] And, as Figure 25 As shown in FIG, the SSID and encryption key of the wireless device 2002 of the base station 2000 may be rewritten. Figure 25 In the example, the information 1001-1 related to the SSID and the information 1001-2 related to the encryption key are input to the wireless device 2002. The wireless device 2002 of the base station 2000 rewrites the SSID and the encryption key based on the input information 1001-1 related to the SSID and the information 1001-2 related to the encryption key. In this way, the security of the communication between the terminal 1050 and the wireless device 2002 of the base station 2000 can be further ensured. Figure 25 In the embodiment, the wireless device 2002 of the base station 2000 has the function of rewriting the SSID and the encryption key. However, a configuration may be adopted in which both or either the SSID and the encryption key do not have the function of rewriting.

[0452] Furthermore, the configuration of the sending device is not limited to Figure 25 The configuration of the transmitting device 2001 shown in FIG. 2 is not limited to the configuration of the terminal. Figure 25 The configuration of the terminal 1050 shown, the connection destination of the wireless device, and the configuration are not limited to Figure 25 The connection destination and configuration of the wireless device 2002 are shown.

[0453] And, in Figure 25 Although the configuration of one base station 2000 is described, there may be multiple wireless devices 2002 of (secure) base stations (or APs) 2000 that the terminal 1050 can access. In addition, the wireless devices 2002 of these multiple base stations 2000 and the terminal 1050 use radio waves to transmit and receive modulated signals. In this case, Figure 25 The SSID-related codewords sent by the transmitting device 2001 may include the SSID information of each of the wireless devices 2002 of the multiple base stations 2000. Figure 25 The codeword related to the encryption key sent by the transmitting device 2001 may include information on the encryption key used to connect to each of the wireless devices 2002 of the multiple base stations 2000. Figure 25 The terminal 1050 selects the wireless device 2002 of the base station 2000 to be wirelessly connected (or connects to the wireless devices of multiple base stations) based on the SSID information and encryption key information of the wireless devices 2002 of multiple base stations 2000 (for example, through radio waves).

[0454] For example, there are three base stations 2000 equipped with wireless devices 2002. Here, the wireless devices 2002 of the three base stations 2000 are referred to as wireless device #A, wireless device #B, and wireless device #C. The SSID of wireless device #A is "abcdef," the SSID of wireless device #B is "ghijk," and the SSID of wireless device #C is "pqrstu." The encryption key used to connect to wireless device #A is "123," the encryption key used to connect to wireless device #B is "456," and the encryption key used to connect to wireless device #C is "789."

[0455] In this case, the modulated signal transmitted by the transmitting device 2001 is Figure 16 The SSID-related symbol 600-1 in the frame structure of includes information such as "set the SSID of wireless device #A to 'abcdef'", "set the SSID of wireless device #B to 'ghijk'", and "set the SSID of wireless device #C to 'pqrstu'". Figure 16The code element 1101 related to the encryption key in the frame structure includes information such as "set the encryption key for connecting to wireless device #A to '123'", "set the encryption key for connecting to wireless device #B to '456'", and "set the encryption key for connecting to wireless device #C to '789'".

[0456] then, Figure 25 Terminal 1050 receives symbol 600-1 related to the SSID and obtains information such as "Set the SSID of wireless device #A to 'abcdef'," "Set the SSID of wireless device #B to 'ghijk'," and "Set the SSID of wireless device #C to 'pqrstu'." Furthermore, terminal 1050 receives symbol 1101 related to the encryption key and obtains information such as "Set the encryption key for connecting with wireless device #A to '123'," "Set the encryption key for connecting with wireless device #B to '456'," and "Set the encryption key for connecting with wireless device #C to '789'." Based on this information, terminal 1050 selects a base station for wireless connection (e.g., via radio waves) and establishes a connection.

[0457] Furthermore, as shown in this embodiment, by using a light source such as an LED and setting the wireless device 2002 of the base station 2000 that the terminal 1050 is to access, the modulated signal transmitted by the terminal 1050 is wireless, eliminating the need for special mode settings, such as those required for establishing a wireless communication connection between the terminal 1050 and the base station 2000. Furthermore, the modulated signal transmitted by the base station 2000 does not require special mode settings, such as those required for establishing a wireless communication connection between the terminal 1050 and the base station 2000. Therefore, this embodiment can improve the data transmission efficiency of wireless communication.

[0458] Furthermore, as described above, the encryption key may be an encryption key for the wireless LAN SSID, or an encryption key for limiting the connection form, service form, network connection range, etc. In other words, an encryption key can be introduced when certain restrictions are required.

[0459] (Implementation 7)

[0460] Figure 27 An example of the configuration of the communication system in this embodiment is shown.

[0461] Figure 27 The communication system includes device 1000, terminal 1050, base station (or AP) 470-1 (base station #1), base station (or AP) 470-2 (base station #2), and base station (or AP) 470-3 (base station #3) that communicate with terminal 1050. Figure 27 In the Figure 6 、 Figure 9 、 Figure 15 The same work is assigned the same symbol.

[0462] The device 1000 includes, for example, a visible light source such as an LED, a lighting source, a lamp (light source 104). In addition, the device 1000 is hereinafter referred to as the "fifth device" in this embodiment. Figure 27 The communication between the wireless device 453 and the base station 470-1 (base station #1), the communication between the wireless device 453 and the base station 470-2 (base station #2), and the communication between the wireless device 453 and the base station 470-3 (base station #3) are carried out, for example, via radio waves.

[0463] exist Figure 27 In the fifth device 1000, a transmitter 102 receives information 1001-1 related to an SSID, information 1001-2 related to an encryption key, and data 1002 as input, generates a (light) modulated signal 103 based on these input signals, and outputs the modulated signal 103. The modulated signal 103 is then transmitted from, for example, a light source 104.

[0464] Next, the information 1001 - 1 related to the SSID and the information 1001 - 2 related to the encryption key will be described.

[0465] First, the information 1001 - 1 related to the SSID will be described.

[0466] The information 1001-1 related to the SSID includes, for example, Figure 27 The information of the SSID of base station 470-1 (base station #1), the information of the SSID of base station 470-2 (base station #2), and the information of the SSID of base station 470-3 (base station #3). In addition, as an example, base stations 470-1, 470-2, and 470-3 transmit modulated signals via radio waves and receive modulated signals of radio waves. That is, the fifth device 1000 provides access to the secure access destination, namely base stations 470-1, 470-2, and 470-3, for the terminal 1050. Accordingly, Figure 27 Terminal 1050 can securely obtain information from base stations 470-1, 470-2, and 470-3.

[0467] Furthermore, the fifth device 1000 can limit the terminals that access the base stations 470 - 1 , 470 - 2 , and 470 - 3 to terminals located in a space that can receive the optical signal transmitted (irradiated) by the fifth device 1000 .

[0468] Furthermore, when receiving an optical signal transmitted in a predetermined manner, terminal 1050 may determine that the notified SSID is the SSID of a secure base station. Furthermore, terminal 1050 may also perform additional processing to determine whether the notified SSID is secure. For example, fifth device 1000 may include a predetermined identifier in the optical signal and transmit it. Terminal 1050 may then determine whether the notified SSID is the SSID of a secure base station based on the received identifier.

[0469] In addition, Figure 27 Although base stations 470-1, 470-2, and 470-3 are shown in the figure, for example, base stations (or APs) other than base stations 470-1, 470-2, and 470-3 may also exist.

[0470] Next, the information 1001-2 related to the encryption key will be described.

[0471] Information 1001-2 related to encryption keys is information related to encryption keys required for terminal 1050 to communicate with base stations 470-1, 470-2, and 470-3. By obtaining information 1001-2 related to encryption keys from fifth device 1000, terminal 1050 can perform encrypted communications between "terminal 1050 and base station 470-1," "terminal 1050 and base station 470-2," and "terminal 1050 and base station 470-3."

[0472] The information 1001 - 1 related to the SSID and the information 1001 - 2 related to the encryption key have been described above.

[0473] Figure 27 The terminal 1050 receives the modulated signal sent by the fifth device 1000. Figure 27 Terminal 1050, for Figure 6 Terminal 150, Figure 9 The components of terminal 450 that perform the same operation are given the same symbols.

[0474] The light receiving unit 151 included in the terminal 1050 is, for example, an image sensor such as a CMOS or an organic CMOS. The light receiving unit 151 receives light including a modulated signal transmitted from the fifth device 1000 and outputs a received signal 152 .

[0475] Then, the receiving unit 153 receives the reception signal 152 received by the light receiving unit 151 as input, performs processing such as demodulation and error correction decoding on the modulated signal included in the reception signal 152 , and outputs reception data 154 .

[0476] Data analyzer 155 receives received data 154 as input and, based on received data 154, outputs, for example, information 1051 about the SSIDs of base stations 470-1, 470-2, and 470-3 to be connected, and information 1052 about encryption keys used for communicating with base stations 470-1, 470-2, and 470-3 to be connected. For example, encryption methods used in wireless LANs (Local Area Networks) include WEP (Wired Equivalent Privacy), WPA (Wi-Fi Protected Access), and WPA2 (Wi-Fi Protected Access 2) (PSK (Pre-Shared Key) mode and EAP (Extended Authentication Protocol) mode). However, the encryption method is not limited to these.

[0477] The display unit 157 receives SSID information 1051 and encryption key information 1052 as input, and displays, for example, the SSID and encryption key of the communication partner to which the wireless device 453 of the terminal 1050 is to access (this display is referred to as the "first display" in this embodiment).

[0478] For example, after the first display, wireless device 453 establishes a connection with one of base stations 470-1, 470-2, or 470-3 (e.g., the connection is established using radio waves) using SSID information 1051 and encryption key information 1052 as input. At this time, if the connected base station 470 also communicates with wireless device 453 included in terminal 1050, a modulated signal is transmitted using radio waves, for example.

[0479] After that, the wireless device 453 receives the data 1053 and the control signal 1054 as input, modulates the data 1053 according to the control indicated by the control signal 1054, and transmits the modulated signal as a radio wave.

[0480] Then, for example, the connected base station 470 transmits data to the network (any one of 471-1, 471-2, or 471-3) and receives data from the network (any one of 472-1, 472-2, or 472-3). After that, for example, the connected base station 470 transmits a modulated signal to the terminal 1050 via radio waves.

[0481] The wireless device 453 included in the terminal 1050 performs processing such as demodulation and error correction decoding on the modulated signal received via radio waves, and obtains the received data 1056. The display unit 157 displays the received data 1056.

[0482] As the modulated signal sent by the 5th device 1000, Figure 27 In this case, there are three types of frame structures. Figure 28 Frame 2300-1 (frame #1) is one of the three frame configurations. Figure 29 Frame 2300-2 (frame configuration #2), one of the three frame configurations, is shown. Figure 30 Frame 2300 - 3 (frame configuration # 3 ), which is one of the three frame configurations, is shown.

[0483] Figure 28 FIG. 2 shows an example of the structure of the frame 2300-1 (frame #1) of the modulated signal transmitted by the fifth device 1000. Figure 28 In , the horizontal axis is time. Figure 28 In the Figure 2 、 Figure 16 The same symbols are assigned to the same code elements, and their descriptions are omitted. Figure 28 Frame 2300-1 (frame #1) is used to send Figure 27 A frame containing information on the SSID of base station 470 - 1 (base station # 1 ) and information on the encryption key of base station 470 - 1 (base station # 1 ) (an encryption key for access to base station 470 - 1 ).

[0484] The code element 2301-1 associated with the SSID is used to send Figure 27 The code element 1001-1 of the information related to the SSID is used. And the code element 2301-1 related to the SSID is used Figure 27 The fifth device 1000 sends a codeword for the SSID of the base station 470-1 (base station #1).

[0485] The code element 2302-1 related to the encryption key is used to send Figure 27 The code element 1001-2 of the information related to the encryption key is used. Figure 27 The fifth device 1000 sends a codeword for the encryption key (encryption key used for access to the base station 470-1) of the base station 470-1 (base station #1).

[0486] The fifth device 1000 transmits the preamble 201, the control information symbol 202, the symbol 2301-1 related to the SSID, the symbol 2302-1 related to the encryption key, and the data symbol 1102. Figure 28 Frame 2300-1 (frame #1) of symbols other than the ones described above. Furthermore, not only the order of sending symbols but also the structure of frame 2300-1 (frame #1) are not affected. Figure 28 Limited by the composition.

[0487] Figure 29 FIG. 2 shows an example of the structure of the frame 2300-2 (frame #2) of the modulated signal transmitted by the fifth device 1000. Figure 29 In , the horizontal axis is time. Figure 29 In the Figure 2 、 Figure 16 The same symbols are assigned to the same code elements, and their descriptions are omitted. Figure 29 Frame 2300-2 (frame #2) is used to send Figure 27 A frame containing information on the SSID of base station 470 - 2 (base station # 2 ) and information on the encryption key of base station 470 - 2 (base station # 2 ) (an encryption key for access to base station 470 - 2 ).

[0488] The code element 2301-2 associated with the SSID is used to send Figure 27 The code element 1001-1 of the information related to the SSID is used. And the code element 2301-2 related to the SSID is used Figure 27 The fifth device 1000 sends a codeword for the SSID of the base station 470-2 (base station #2).

[0489] The code element 2302-2 related to the encryption key is used to send Figure 27 The code element 1001-2 of the information related to the encryption key is used. Figure 27 The codeword used by the fifth device 1000 to send the encryption key of the base station 470-2 (base station #2) (the encryption key used for access to the base station 470-2).

[0490] The fifth device 1000 transmits the preamble 201, the control information symbol 202, the symbol 2301-2 related to the SSID, the symbol 2302-2 related to the encryption key, and the data symbol 1102. Figure 29 Frame 2300-2 (frame #2) of symbols other than the ones described above. Furthermore, not only the order of sending the symbols but also the structure of frame 2300-2 (frame #2) are not affected. Figure 29 Limited by the composition.

[0491] Figure 30 FIG. 2 shows an example of the structure of the frame 2300-3 (frame #3) of the modulated signal transmitted by the fifth device 1000. Figure 30 In , the horizontal axis is time. Figure 30 In the Figure 2 、 Figure 16 The same symbols are assigned to the same code elements, and their descriptions are omitted. Figure 30 Frame 2300-3 (frame #3) is used to send Figure 27A frame containing information on the SSID of base station 470-3 (base station #3) and information on the encryption key of base station 470-3 (base station #3) (encryption key for access to base station 470-3).

[0492] The code element 2301-3 related to the SSID is used to send Figure 27 The code element 1001-1 of the information related to the SSID is used. And the code element 2301-3 related to the SSID is used Figure 27 The fifth device 1000 sends a codeword for the SSID of the base station 470-3 (base station #3).

[0493] The code element 2302-3 related to the encryption key is used to send Figure 27 Furthermore, symbol 2302-3 related to the encryption key is a symbol used by fifth device 1000 to transmit the encryption key (encryption key for accessing base station 470-3) to base station 470-3 (base station #3).

[0494] The fifth device 1000 transmits the preamble 201, the control information symbol 202, the symbol 2301-3 related to the SSID, the symbol 2302-3 related to the encryption key, and the data symbol 1102. Figure 30 Frame 2300-3 (frame #3) of symbols other than the ones described above. Furthermore, not only the order of sending the symbols but also the structure of frame 2300-3 (frame #3) are not affected. Figure 30 Limited by the composition.

[0495] Figure 31 As shown, the 5th device 1000 sends " Figure 28 Frame 2300-1 (frame #1)", " Figure 29 Frame 2300-2 (frame #2)", " Figure 30 An example of a transmission method when the frame 2300-3 (frame #3) is used. Figure 31 , the horizontal axis is time.

[0496] exist Figure 31 In "Frame #1 Group Transmission" 2601-1, 2601-2, one or more Figure 28 Frame 2300-1 (frame #1) is sent. And, in "frame #2 group transmission" 2602-1, 2602-2, one or more Figure 29 Frame 2300-2 (frame #2) is sent. And, in "frame #3 group transmission" 2603-1, 2603-2, one or more Figure 30 Frame 2300-3 (frame #3) is sent.

[0497] The following describes this in detail.

[0498] First, in "Frame #1 Group Transmission" 2601-1, 2601-2, Figure 28 The following describes the case where frame 2300-1 (frame #1) is sent more than one time.

[0499] For example, when using an image sensor such as a CMOS or organic CMOS sensor, light receiving unit 151 may process received signals in units of frames in moving or still images. Furthermore, for example, the term "4K 30p" for moving images means that the number of pixels per frame is 3840 x 2160, and the number of frames per second is 30.

[0500] Therefore, if the 5th device 1000 sends a message that contains " Figure 28 Frame 2300-1 (frame #1)", " Figure 29 Frame 2300-2 (frame #2)", " Figure 30 The modulated signal of the frame 2300-3 (frame #3) is Figure 27 It becomes difficult for the terminal 1050 to select the base station 470 to access from multiple base stations 470-1, 470-2, and 470-3.

[0501] Therefore, in this embodiment, it is proposed Figure 31 The frame structure shown.

[0502] <Method 1-1>

[0503] As the 1-1 method, since each of the "Frame #1 Group Transmission" 2601-1 and 2601-2 includes multiple Figure 28 Therefore, the time interval occupied by each of the "frame #1 group transmission" 2601-1 and 2601-2 becomes longer than the frame in the video or still image.

[0504] According to this, the terminal 1050 can receive a video or a still image from the fifth device 1000, including a frame of " Figure 28 Frame 2300-1 (frame #1)", " Figure 29 Frame 2300-2 (frame #2)", " Figure 30 The modulated signal of frame 2300-3 (frame #3) can be prevented from receiving a modulated signal including a different SSID and encryption key. Figure 27 The terminal 1050 can easily select a base station 470 to access from multiple base stations 470-1, 470-2, and 470-3.

[0505] <Method 2-1>

[0506] As the 2-1 method, Figure 28 The time interval occupied by the frame 2300-1 (frame #1) becomes longer than the time of the frames in the video or still image.

[0507] For example, it can be constructed as follows: Figure 28 The code element 2301-1 related to the SSID includes multiple "information of the SSID of base station #1" (that is, "information of the SSID of base station #1" is repeatedly included), and the code element 2302-1 related to the encryption key includes multiple "information of the encryption key of base station #1 (information of the encryption key used for connecting to base station #1)" (that is, "information of the encryption key of base station #1 (information of the encryption key used for connecting to base station #1)" is repeatedly included).

[0508] According to this, the terminal 1050 can receive a video or a still image from the fifth device 1000, including a frame of " Figure 28 Frame #1 of 2300-1"," Figure 29 Frame #2 of 2300-2"," Figure 30 The modulated signal of frame #3 of 2300-3 can be prevented from being received, that is, the modulated signal including different SSIDs and encryption keys can be prevented from being received. Therefore, the terminal 1050 can easily select the base station 470 to be accessed from multiple base stations 470-1, 470-2, and 470-3.

[0509] With the same way of thinking, "Frame #2 group transmission" 2602-1 and 2602-2 can be constructed as follows.

[0510] <Method 1-2>

[0511] As the 1-2 method, since each of the "Frame #2 Group Transmission" 2602-1 and 2602-2 includes multiple Figure 29 Therefore, the time interval occupied by the "frame #2 group transmission" is made longer than the frame in the video or still image.

[0512] <Method 2-2>

[0513] As the 2-2 method, Figure 29 The time interval occupied by frame 2300-2 (frame #2) becomes longer than the time of the frames in the video or still image.

[0514] For example, it can be constructed as follows: Figure 29The code element 2301-2 related to the SSID includes multiple "information of the SSID of base station #2" (that is, the "information of the SSID of base station #2" is repeatedly included), and the code element 2302-2 related to the encryption key includes "information of the encryption key of base station #2 (information of the encryption key used for connecting to base station #2)" (that is, "information of the encryption key of base station #2 (information of the encryption key used for connecting to base station #2)" is repeatedly included).

[0515] With the same way of thinking, "Frame #3 Group Transmission" 2603-1 and 2603-2 can be constructed as follows.

[0516] Methods 1-3

[0517] As the 1-3 method, since each of the "frame #3 group transmission" 2603-1 and 2603-2 includes multiple Figure 30 Therefore, the time interval occupied by the "frame #3 group transmission" is made longer than the frame in the video or still image.

[0518] <Method 2-3>

[0519] As the 2nd-3rd method, Figure 30 The time interval occupied by frame 2300-3 (frame #3) becomes longer than the time of the frames in the video or still image.

[0520] For example, it can be constructed as follows: Figure 30 The code element 2301-3 related to the SSID includes multiple "information of the SSID of base station #3" (that is, "information of the SSID of base station #3" is repeatedly included), and the code element 2302-3 related to the encryption key includes multiple "information of the encryption key of base station #3 (information of the encryption key used for connecting to base station #3)" (that is, "information of the encryption key of base station #3 (information of the encryption key used for connecting to base station #3)" is repeatedly included).

[0521] Then, if Figures 28 to 31 As shown, the effect when the fifth device 1000 sends a frame is explained.

[0522] As an example, consider Figure 32 In the area of ​​2700. Figure 32In the diagram, fifth device 1000 is arranged at positions marked with "○" 2701-1, 2701-2, 2701-3, 2701-4, 2701-5, 2701-6, 2701-7, 2701-8, 2701-8, 2701-9, and 2701-10. Furthermore, base station 470-1 (base station #1) is arranged at position marked with "◎" 2702-1, base station 470-2 (base station #2) is arranged at position marked with "◎" 2702-2, and base station 470-3 (base station #3) is arranged at position marked with "◎" 2702-3.

[0523] For example, inside the area 2703, there are 99 terminals (hereinafter simply referred to as terminals 1050) having the same configuration as the terminal 1050.

[0524] At this time, for example, the fifth device 1000, located at positions "○" 2701-5 and 2701-10, transmits not only the SSID information of base station 470-3 (base station #3) but also the encryption key information for accessing base station 470-3 (base station #3). This is because the base station closest to the positions "○" 2701-5 and 2701-10 is base station 470-3 (base station #3).

[0525] In this case, all 99 terminals 1050 access base station 470-3 (base station #3). This concentration of access increases the possibility that terminals 1050 may have difficulty accessing base station 470-3 (base station #3).

[0526] Taking this into consideration, by controlling 99 terminals 1050 to access base station 470-1 (base station #1) (“◎” position 2702-1), base station 470-2 (base station #2) (“◎” position 2702-2), and base station 470-3 (base station #3) (“◎” position 2702-3) as evenly as possible, the number of terminals 1050 that have difficulty accessing base station 470 can be reduced.

[0527] For example, since the timings at which 99 terminals 1050 access the fifth device 1000 are generally different, as shown in this embodiment, when the fifth device 1000 is connected to the terminal 1050, Figures 28 to 31 When frames are transmitted in this manner, each of the 99 terminals 1050 obtains the SSID and encryption key of one of base stations 470-1, 470-2, and 470-3, according to the timing of access to fifth device 1000. This allows "control to ensure that all 99 terminals 1050 have access to base stations 470-1, 470-2, and 470-3 as evenly as possible." Therefore, as described above, the number of terminals 1050 that have difficulty accessing base station 470 can be reduced.

[0528] In addition, Figure 31 The example of the sending method shown in the figure is that the fifth device 1000 sends " Figure 28 Frame 2300-1 (frame #1)", " Figure 29 Frame 2300-2 (frame #2)", " Figure 30 Frame 2300-3 (Frame #3)". However, the 5th device 100 sends " Figure 28 Frame 2300-1 (frame #1)", " Figure 29 Frame 2300-2 (frame #2)", " Figure 30 The sending method of the frame 2300-3 (frame #3) is not limited to this.

[0529] For example, in Figure 31 Although it is shown that the fifth device 1000 repeatedly performs "frame #1 group transmission", "frame #2 group transmission", and "frame #3 group transmission" in sequence, it is not necessary for "frame #1 group transmission", "frame #2 group transmission", and "frame #3 group transmission" to be repeated in sequence. Figure 31 Alternatively, for example, the fifth device 1000 may randomly perform "frame group 1 transmission", "frame group #2 transmission", "frame group #3 transmission" in time, and the order of "frame group 1 transmission", "frame group #2 transmission", and "frame group #3 transmission" may be the same as Figure 31 The fifth device 1000 only needs to perform "frame #1 group transmission", "frame #2 group transmission", and "frame #3 group transmission".

[0530] And it can be, in Figure 31 In the example, although the fifth device 1000 continuously performs "frame #1 group transmission", "frame #2 group transmission", and "frame #3 group transmission", it is not necessary to perform continuous transmission. For example, Figure 31 In the example, there is a time interval between the frame #1 group 2601-1 and the frame #2 group 2602-2.

[0531] And, in Figure 31 Although the structure of is only "frame #1 group transmission", "frame #2 group transmission", "frame #3 group transmission", other code elements and other frames may also exist. Figure 31 as well as Figure 27 In the example, although the number of base stations 470 is 3, the number of base stations 470 is not limited thereto. Even when there are 2 or more base stations 470, the same operation as when there are 3 base stations 470 can be performed. Therefore, for example, when there are N base stations 470 (N is an integer greater than 2), if the fifth device 1000 performs Figure 31As shown in the transmission, there is "Group Transmission Frame #k". Here, k is an integer from 1 to N. Therefore, "Group Transmission Frame #k" includes symbols related to the SSID (information about the SSID of base station #k) and symbols related to the encryption key (information about the encryption key used to access base station #k).

[0532] Figure 27 The frame structure of the modulated signal transmitted by the wireless device 453 of the terminal 1050 is the same as that described in the fourth embodiment. Figure 17 The frame structure is the same. Figure 17 As shown, Figure 27 The wireless device 453 of the terminal 1050 sends, for example, a preamble 1201, and then sends a control information code element 1202 and an information code element 1203.

[0533] The preamble 1201 is a symbol used by base stations 470 - 1 , 470 - 2 , and 470 - 3 receiving the modulated signal transmitted by the wireless device 453 of the terminal 1050 to perform signal detection, time synchronization, frame synchronization, frequency synchronization, frequency offset estimation, and the like.

[0534] Control information symbol 1202 includes, for example, data such as the error correction coding method used to generate the modulated signal, information regarding the modulation method, information regarding the frame structure, and information regarding the transmission method. Base stations 470-1, 470-2, and 470-3 perform demodulation of the modulated signal based on the information included in control information symbol 1202.

[0535] The information symbol 1203 is a symbol used by the wireless device 453 of the terminal 1050 to transmit data.

[0536] in addition, Figure 27 The wireless device 453 of the terminal 1050 may also send a message including Figure 17 Frames containing symbols other than the ones described (e.g., frames containing pilot symbols (reference symbols) in the middle of information symbols 1203). Furthermore, not only the order in which the symbols are transmitted but also the frame structure is not affected. Figure 17 And, in Figure 17 In the case of a multi-code signal, there can be multiple code elements in the frequency axis direction, that is, there can be code elements on multiple frequencies (multiple carriers).

[0537] Figure 27 The frame structure of the modulated signal transmitted by base stations 470-1, 470-2, and 470-3 is the same as that described in Embodiment 3. Figure 12 The frame structure is the same. Figure 12As shown, base stations 470 - 1 , 470 - 2 , and 470 - 3 , for example, send a preamble 701 , and thereafter send a control information symbol 702 and an information symbol 703 .

[0538] Preamble 701 is a symbol used by wireless device 453 of terminal 1050 receiving modulated signals transmitted from base stations 470-1, 470-2, and 470-3 to perform signal detection, time synchronization, frame synchronization, frequency synchronization, frequency offset estimation, and the like.

[0539] Control information symbol 702 includes, for example, data used when generating a modulated signal, including information regarding the error correction coding method, modulation scheme, frame structure, and transmission method. Wireless device 453 of terminal 1050 performs demodulation of the modulated signal based on the information in control information symbol 702.

[0540] The information symbol 703 is a symbol used by base stations 470-1, 470-2, and 470-3 to transmit data.

[0541] Alternatively, base stations 470-1, 470-2, and 470-3 may send a message including Figure 12 For example, base stations 470-1, 470-2, and 470-3 transmit frames including pilot symbols (reference symbols) in the middle of information symbol 703. Furthermore, not only the order in which symbols are transmitted but also the frame structure is not affected. Figure 12 Therefore, in Figure 12 In the frequency axis direction, there can be multiple code elements. Figure 12 In , symbols may exist on multiple frequencies (multiple bins).

[0542] Figure 33 This is a flowchart showing an example of processing performed by the "fifth device 1000", "terminal 1050", and "base station #X".

[0543] First, the 5th device 1000 sends Figure 31 The modulated signal (ST2801) is composed of frames.

[0544] Then, the terminal 1050 receives the modulated signal sent by the fifth device 1000, Figure 27 The base station that the terminal 1050 is to access is selected from base stations 470-1 (base station #1), 470-2 (base station #2), and 470-3 (base station #3) (ST2802).

[0545] This point will be described below. The terminal 1050 receives the modulated signal sent by the fifth device 1000 in order to access one of the base stations 470. At this time, the terminal 1050 obtains the modulated signal in a certain frame of a video or a still image. Figure 31 In the frame #1 group transmission, the terminal 1050 selects one of the following: "Frame #2 group transmission," "Frame #3 group transmission," or "Frame #1 group transmission." Then, based on the obtained base station information (e.g., SSID), the terminal 1050 determines which base station 470 to access: base station 470-1 (base station #1), base station 470-2 (base station #2), or base station 470-3 (base station #3).

[0546] Next, the terminal 1050 receives the modulated signal transmitted by the fifth device 1000 and obtains the SSID of the base station #X to which the terminal 1050 is to access (ST2803).

[0547] Furthermore, the terminal 1050 obtains an encryption key for communicating with the base station #X to which the terminal 1050 is about to access (ST2804).

[0548] Then, the terminal 1050 establishes a connection with the base station #X via radio waves (ST2805). The terminal 1050 receives a response from the base station #X, thereby terminating the connection between the terminal 1050 and the base station #X (ST2806).

[0549] Then, the terminal 1050 transmits the connection destination information to the base station #X using radio waves (ST2807).

[0550] Base station #X obtains information from the network for transmission to terminal 1050 (ST2808).

[0551] Then, the base station #X transmits the acquired information to the terminal 1050 using radio waves, and the terminal 1050 obtains the information (ST2809). For example, the terminal 1050 obtains necessary information from the network via the base station #X when necessary.

[0552] As described above, based on the SSID information and encryption key information transmitted from the fifth device 1000, the terminal 1050 connects to the base station 470 and obtains information, thereby enabling secure acquisition of information via the base station 470, whose security is guaranteed. This is because, when information is obtained from a modulated signal of visible light, the user can easily determine whether the information source is secure due to the visible light. In contrast, for example, when the SSID is obtained from a modulated signal of radio waves transmitted by a wireless LAN, it is difficult for the user to identify the device that transmitted the radio waves. Therefore, from the perspective of ensuring information security, visible light communication is more suitable for obtaining SSIDs than wireless LAN communication.

[0553] In this embodiment, the fifth device 1000 is described as transmitting encryption key information. However, if, for example, base station 470 does not perform encrypted communication using an encryption key, fifth device 1000 may transmit only information related to the SSID, rather than encryption key information. In this case, the same operation can be performed simply by removing the encryption key-related configuration from the above configuration.

[0554] Furthermore, the composition of the fifth device is not affected by Figure 27 The structure of the terminal is not limited by the structure of the fifth device 1000 shown. Figure 27 The configuration of the terminal 1050 shown is limited, and the connection destination and configuration of base stations #1, #2, and #3 are not limited. Figure 27 The base stations 470-1, 470-2, and 470-3 shown are limited by their connection destinations and configurations.

[0555] Furthermore, according to this embodiment, even when a plurality of terminals 1050 exist in a certain area, the number of terminals 1050 that have difficulty accessing the base station 470 can be reduced.

[0556] In addition, Figure 32 In the embodiment, the frame structure of the modulated signal sent by the fifth device 1000 at the position of "○" 2701-1, 2701-2, 2701-3, 2701-4, 2701-5, 2701-6, 2701-7, 2701-8, 2701-8, 2701-9, and 2701-10 can all be the same as Figure 31 The structure of the fifth device 1000 is the same, and the modulated signals sent by the fifth device 1000 can also have different frame structures. There can also be multiple fifth devices 1000 that send modulated signals with the same frame structure.

[0557] (Implementation 8)

[0558] In this embodiment, as an example of an application of the aforementioned communication method using optical signals, a case where the communication method using optical signals is combined with image processing is described. The communication system involved in the embodiments of the present application can be applied, for example, to vehicle-to-vehicle communication, and to communication between a communication device installed on or near a road and a vehicle (road-to-vehicle communication).

[0559] First, the basic structure of this embodiment will be briefly described. However, this basic structure is not limited to vehicles and can also be applied to mobile terminals such as smartphones and notebook computers, as well as other electronic devices.

[0560] Figure 341 is a block diagram showing the configuration of a communication device A1000 as an example of a communication device in this embodiment. The communication device A1000 includes a light receiving device A1002, a control unit A1004, and a wireless device A1006.

[0561] Light receiving device A1002 receives light signal A1001 and / or captures still or moving images, outputting light receiving data A1003. Light signal A1001 is emitted by a transmitter (not shown). Control unit A1004 controls other devices included in communication device A1000 and processes light receiving data A1003 input from light receiving device A1002 or wirelessly received data input from wireless device A1006. Wireless device A1006 wirelessly connects to another communication device A1100 based on control signal A1005 from control unit A1004, wirelessly communicating with the device to transmit or receive wireless data. The wireless transmission and reception data are exchanged between wireless device A1006 and control unit A1004 as wireless communication data A1008. The control unit A1004 outputs a control signal A1007 for controlling the operation of the light receiving device A1002, and the light receiving device A1002 controls its operation based on the control signal A1007.

[0562] The control unit A1004 may also perform image processing using the still image data or video data when the light receiving data A1003 generated by the light receiving device A1002 includes still image data or video data. Detailed examples of the image processing performed by the control unit A1004 will be described later.

[0563] Figure 35 2 is a block diagram showing the structure of a communication device A2000 which is another example of the communication device in this embodiment. Figure 35 For Figure 34 The components of the communication device A1000 shown in FIG. Figure 34 The communication device A2000 is different from the communication device A1000 in that it includes a presentation unit A2003 and an input unit A2004.

[0564] The control unit A1004 generates an image based on the received light data A1003 and / or wirelessly received data, other input information, information read from a memory, and the like, and outputs the generated image as prompt information A2002 to the prompt unit A2003. The prompt information A2002 may include, for example, image information or text information generated based on the received light data A1003 or other data. The prompt unit A2003 may be, for example, a liquid crystal display, a plasma display, an organic EL display, etc., and may display an image signal generated from the image information or text information received as prompt information A2002, but is not limited to such. For example, the prompt information A2002 may be audio information, and the prompt unit A2003 may be a speaker that outputs audio in accordance with the audio information. In response to user operations, the input unit A2004 outputs input information A2005, such as information indicating the user's operation or input text information, to the control unit A1004. The input unit A2004 may be, for example, a touch screen, physical keys, a floating touch display, a motion sensor, etc., but is not limited thereto. For example, the input unit A2004 may be a microphone, and the input information A2005 may be sound information.

[0565] Next, the detailed structure of the light receiving device A1002 is described.

[0566] Figure 36 This is a block diagram showing the configuration of the light receiving device A3000 which is a first example of the detailed configuration of the light receiving device A1002 in this embodiment.

[0567] The light receiving device A3000 includes a light receiving unit A3001 and a light receiving signal processing unit A3003. Figure 6 The light receiving unit 151 has the same structure, receives light incident from the outside, and outputs a reception signal A3002. The light reception signal processing unit A3003 performs a predetermined process on the reception signal A3002, and sends the signal obtained as the light reception data A1003.

[0568] An example of the prescribed processing performed by the light-receiving signal processing unit A3003 on the received signal A3002 includes demodulating and performing error correction decoding on the modulated signal components contained in the received signal A3002, and outputting the demodulated data A4002 obtained as the light-receiving data A1003. Furthermore, in another example, the light-receiving signal processing unit A3003, as a prescribed processing, generates still image data or moving image data from the received signal A3002 obtained by the light-receiving unit A3001, i.e., an image sensor such as a CMOS or organic CMOS, and outputs the generated still image data or moving image data as the light-receiving data A1003. Here, the still image data or moving image data may be encoded data obtained by encoding using an image compression method or a moving image compression method, or it may be uncompressed data. The following describes a detailed example of the configuration of the light-receiving signal processing unit A3003.

[0569] Figure 37 The following shows an example of the structure of the light receiving signal processing unit A3003, that is, the structure of the light receiving signal processing unit A4000. The light receiving signal processing unit A4000 includes a receiving processing unit A4001. The receiving processing unit A4001 performs demodulation, error correction, and other processing on the received signal A3002, and outputs the obtained demodulated data A4002 as the light receiving data A1003. The received signal A3002 input to the light receiving signal processing unit A4000 can be, for example, a signal obtained by an image sensor such as a CMOS sensor using a sampling method for light signal reception such as the above-mentioned line scan sampling, an application example of line scan sampling, or sampling by frame. It can also be a signal obtained by sampling at a sampling rate that meets the requirements for light signal reception using an element different from an image sensor that can convert an optical signal such as a photodiode into an electrical signal.

[0570] Figure 38 Another example of the configuration of the received light signal processing unit A3003 is shown, which illustrates the configuration of the received light signal processing unit A5000. The received light signal processing unit A5000 includes an image data generating unit A5001, which outputs image data A5002 containing information about the optical signal as received light data A1003. Specifically, the image data generating unit A5001 generates still image data or video data from the received signal A3002, and outputs the generated still image data or video data, i.e., image data A5002, as received light data A1003.

[0571] In the following description, for simplicity, image data A5002 is described as video data unless otherwise specified. However, the video data described below can be replaced with still image data, or with a combination of video data and still image data.

[0572] When the light receiving device A1002 includes the light receiving signal processing unit A5000, the light receiving unit A3001 is an image sensor such as a CMOS sensor. The light receiving device A1002 controls the operation of the light receiving unit A3001. Figure 39 During the first period, the sampling method for receiving the optical signal is used to obtain the received signal A3002. Figure 39 During the second period, the receiving signal A3002 is obtained using the shooting method for video shooting.

[0573] Hereinafter, a signal obtained using the sampling method for receiving an optical signal will be referred to as an optical communication imaging signal, and a signal obtained using the imaging method for video imaging will be referred to as a video imaging signal. Furthermore, data generated by the image data generation unit A5001 based on the optical communication imaging signal will be referred to as optical communication imaging data, and data generated based on the video imaging signal will be referred to as video imaging data.

[0574] Figure 39 An example of a method for controlling an image sensor is shown in which a single image sensor is used to obtain both an optical communication imaging signal and a video imaging signal by time division. Figure 39 During the first period, the light receiving unit A3001 adopts a sampling method for receiving light signals to obtain a shooting signal for optical communication. During the second period, the light receiving unit A3001 adopts a shooting method for video shooting to obtain a shooting signal for video.

[0575] Here, the first period and the second period each correspond to, for example, one or more frames in a video. However, the light receiving device A1002 can switch between a sampling mode for receiving light signals and a capture mode for capturing video using timing that is not synchronized with the frames in the video. The light receiving device A1002 can configure the first period periodically or aperiodically. Furthermore, the rules for configuring the first period, such as the period for configuring the first period, can be dynamically changed.

[0576] Furthermore, the light receiving device A1002 can determine the timing for starting and / or ending the first period based on a signal input from the outside. For example, the light receiving device A1002 controls the operation of the light receiving unit A3001 based on a control signal A1007 input from the control unit A1004. In this case, the control unit A1004 can output a control signal for controlling the operation of the light receiving unit A3001 based on a signal received from a transmitting device external to the communication devices A1000 and A2000 using a communication method such as wireless communication, wired communication, or optical communication, as well as data obtained from a sensor such as an image sensor included in the communication devices A1000 and A2000.

[0577] The control information for controlling the operation of the light receiving unit A3001 may be, for example, a signal specifying the rules for configuring the first and second periods described above. Generally, it may be a signal instructing the light receiving unit A3001 to obtain a video signal using a video capture method. This instruction is an instruction to obtain a video signal for optical communication using a sampling method used when temporarily or intermittently receiving an optical signal. Specific examples will be described later.

[0578] Furthermore, while the above description illustrates an example in which the first and second periods are alternately configured, the image sensor control method is not limited thereto. For example, a third period in which the CMOS sensor operates using a different imaging or sampling method may be configured between the first and second periods, and a transition time for switching the operation of the image sensor may be included between the first and second periods.

[0579] According to the image sensor control method, a single image sensor can be used to obtain both an optical communication imaging signal and a video imaging signal in a time-division manner, thereby reducing the number of image sensors required for a communication device.

[0580] In addition, the light receiving device A1002 can also make the light receiving part A3001 always operate in a sampling mode for receiving optical signals to obtain the received signal A3002.

[0581] When generating the video data A5002, the image data generating unit A5001 may perform encoding processing using a moving image compression method on a video signal composed of a plurality of frames generated from the received signal A3002.

[0582] For example, when the received signal A3002 includes a shooting signal for optical communication and a shooting signal for video, the image data generation unit A5001 performs motion image compression processing on the frames generated from the shooting signal for video, excluding the images (or frames) generated from the shooting signal for optical communication. In this case, the light receiving device A1002 outputs the encoded video data and the image data generated from the shooting signal for optical communication as received light data A1003.

[0583] In the above description, the imaging signal for optical communication is output from the light receiving device A1002 as image data. However, the imaging signal for optical communication may be output from the light receiving device A1002 in any format as long as the optical signal can be demodulated. For example, the imaging signal may be data in which the grayscale values ​​of pixels included in each exposure line are averaged or added together, or data in which the grayscale values ​​of pixels included in each region after each exposure line is divided into multiple regions are sequentially arranged.

[0584] Furthermore, when the received signal A3002 includes both the optical communication imaging signal and the video imaging signal, the motion image encoding process to be performed by the image data generation unit A5001 is not limited to the motion image encoding process described above. For example, the image data generation unit A5001 performs a common motion image compression process on a video including frames composed of both the optical communication imaging signal and the video imaging signal, and the light receiving device A1002 outputs the encoded video data generated from the optical communication imaging signal and the video imaging signal as received light data A1003.

[0585] Next, the operation of the control unit A1004 in the case where the light receiving device A1002 includes the light receiving signal processing unit A5000 will be described.

[0586] When the light receiving device A1002 includes the light receiving signal processing unit A5000, the light receiving device A1002 does not perform processing such as demodulation and error correction on the captured data for optical communication. Therefore, the control unit A1004 uses the captured data for optical communication included in the light receiving data A1003 to perform processing such as demodulation and error correction on the optical signal to obtain data transmitted via the optical signal.

[0587] In addition, when the light receiving data A1003 includes not only shooting data for optical communication but also shooting data for video, the control unit A1004 can demodulate and correct errors in the optical signal included in the shooting data for optical communication, and can perform image processing such as pattern recognition on the shooting data for video. Furthermore, the light receiving device A1002 or the wireless device A1006 can be controlled based on the results of image processing such as pattern recognition.

[0588] As an example of signal processing using video shooting data, for example, there can be listed: processing for detecting a person or a part of the body such as a person's face, processing for identifying a person, processing for detecting an object such as a vehicle or a drone, processing for identifying an object such as a vehicle or a drone, processing for detecting the work or movement of a detected person or object, processing for tracking a detected person or object, etc. These processes can be performed as follows: extracting feature quantities determined according to the purpose of the signal processing from the video shooting data and using the extracted feature quantities, or they can be performed using a multi-layer neural network and a model produced by machine learning. In addition, when using a model produced by machine learning using a multi-layer neural network, the pre-processed data can be input into the model produced by machine learning using the multi-layer neural network based on pre-processing of the video shooting data.

[0589] In addition, in the above description, although the shooting data for video is used in the signal processing performed by the control unit A1004, in addition to the shooting data for video, sound data or data obtained by other sensors, etc. can also be used, and sound data or data obtained by other sensors, etc. can be used instead of the shooting data for video.

[0590] Furthermore, when the light receiving device A1002 has the structure of a light receiving signal processing unit A5000, and the light receiving device A1002 outputs the encoded video data as the light receiving data A1003, the control unit A1004 can perform motion image decoding processing corresponding to the motion image encoding processing on the encoded video data included in the light receiving data A1003 as the above-mentioned signal processing or part of the signal processing.

[0591] Next, an example of the configuration of the light receiving signal processing unit A3003 is described.

[0592] Figure 40 The third example of the structure of the light receiving signal processing unit A3003 is shown, that is, the structure of the light receiving signal processing unit A7000. The light receiving signal processing unit A7000 includes a reception processing unit A7001 and an image data generating unit A7003.

[0593] The receiving processing unit A7001 of the light receiving signal processing unit A7000 has the same Figure 37 The light receiving signal processing unit A4000 described above has the same functions as the reception processing unit A4001.

[0594] The image data generating unit A7003 of the light receiving signal processing unit A7000 has the same Figure 38 The image data generating unit A5001 has the same function as the light receiving signal processing unit A5000 described above.

[0595] If the light receiving device A1002 includes a light receiving signal processing unit A7000, the light receiving device A1002 controls the light receiving unit A3001 to obtain the video capture signal and the optical communication capture signal as the received signal A3002. The light receiving signal processing unit A7000 inputs the video capture signal to the image data generation unit A7003 and the optical communication capture signal to the receiving processing unit A7001. Of course, the light receiving signal processing unit A7000 may also input the optical communication capture signal to the image data generation unit A5001.

[0596] The light reception signal processing unit A7000 outputs the demodulated data A7002 and the video data A7004 as light reception data A1003.

[0597] In this case, additional information or metadata such as time information may be added to the demodulated data A7002. The time information is information indicating the time when the modulated signal corresponding to the demodulated data was received. The time information added to the demodulated data A7002 may also be in a format that allows identification of the relationship with the time information added to the video data A7004. For example, the light-receiving signal processing unit A7000 may assign the time information of the demodulated data A7002 and the time information of the video data A7004 based on a shared clock signal or time axis. The time information of the demodulated data A7002, such as information indicating an offset of the time information of the video data A7004 relative to the time information of the demodulated data A7002, and information indicating the relationship between the time information of the video data A7004 may also be included in the time information of the demodulated data A4002 or the time information of the video data A5002.

[0598] Furthermore, the demodulated data A7002 may include position information as additional information or metadata, where the position information indicates the position within the image of a transmitting device or light source that transmits a modulated signal corresponding to the demodulated data.

[0599] The additional information of the demodulated data A7002 may include both time information and location information, or only one of them. Furthermore, the additional information of the demodulated data A7002 may also include related information related to the demodulated data in addition to the time information or location information.

[0600] In addition, although the position information is information showing the position of the transmitting device or light source in the image, it can also be other information. For example, it can be information showing the area within the image used for the detection of the light signal, or it can be information showing the position in the three-dimensional space. The position information in the three-dimensional space can be, for example, information showing the direction in which the light receiving device A1002 shoots, and the position of the shooting data for the video in the image, or it can be information showing the value or area of ​​the coordinates in the coordinate system centered on the light receiving device or communication device estimated by this information. Furthermore, it can be information showing the value or area of ​​the coordinates in any coordinate system used in GPS or three-dimensional maps, etc., estimated using the position information of the communication device or light receiving device. Furthermore, the light receiving device A1002 uses not only the shooting data for the video, but also the distance image data in addition to the shooting data for the video to estimate the position in the three-dimensional space when obtaining the distance image data showing the depth of the object being shot.

[0601] The range image can be obtained by, for example, a TOF (Time-Of-Flight) method, a distance measurement method using stereoscopic parallax, a LIDER (Laser Imaging Detection and Ranging) method, or the like.

[0602] The demodulated data A7002 and the video data A7004 can be sent to the control unit A1004 of the communication device A1000 or the control unit A1004 of the communication device A2000 as multiple separated data streams or data packet strings, and the data stream multiplexed into a format capable of storing both the demodulated data A7002 and the video data A7004 can be sent to the control unit A1004 of the communication device A1000 or the control unit A1004 of the communication device A2000 via one data stream or data packet string.

[0603] Figure 41 The second example of the configuration of the light receiving device A1002 is shown, that is, the configuration of the light receiving device A8000. The light receiving device A8000 includes a first light receiving unit A8001-1, a second light receiving unit A8001-2, a first light receiving signal processing unit A8003-1, and a second light receiving signal processing unit A8003-2.

[0604] First light receiving unit A8001-1 is an image sensor such as a CCD, CMOS, or organic CMOS. Second light receiving unit A8001-2 is an image sensor such as a CCD, CMOS, or organic CMOS, or a device capable of converting optical signals such as a photodiode into electrical signals. Light receiving device A8000 operates first light receiving unit A8001-1 in a video capture mode, obtaining a video capture signal as received signal A8002-1.

[0605] When the second light receiving unit A8001-2 is an image sensor, the light receiving device A8000 operates the second light receiving unit A8001-2 in a sampling mode for receiving optical signals, and obtains an imaging signal for optical communication as a received signal A8002-2. Furthermore, when the second light receiving unit A8001-2 is a device such as a photodiode that can convert an optical signal into an electrical signal, the light receiving device A8000 uses the second light receiving unit A8001-2 to obtain a received signal A8002-2 sampled at the sampling rate required for receiving optical signals.

[0606] The first light receiving signal processing unit A8003-1 has, for example, Figure 38 The light receiving signal processing unit A5000 shown in the figure has the same function as that of outputting image data A8004-1, which is shooting data for video, as light receiving data A1003.

[0607] The second light receiving signal processing unit A8003-2 has, for example, Figure 37 The same function as the light receiving signal processing unit A4000 shown in FIG. 1 is used to output the demodulated data A8004-2 as the light receiving data A1003. Figure 38 The light receiving signal processing unit A5000 shown in the figure has the same function as that of outputting image data A8004-2, which is imaging data for optical communication, as light receiving data A1003.

[0608] Through this structure, since the light receiving device A8000 can simultaneously obtain the shooting data for video, namely the image data A8004-1, and the image data A8004-2 as demodulation data or shooting data for optical communication, there will be no period when the shooting data for video is not obtained, so that both optical communication and video shooting can be carried out.

[0609] In addition, although the light receiving device A8000 is described as including a combination of two systems of a light receiving unit and a light receiving signal processing unit, it may also include N (N is an integer greater than or equal to 3) systems of light receiving units and light receiving signal processing units.

[0610] Furthermore, the first light receiving part A8001-1 and the second light receiving part A8001-2 do not have to be other components. For example, a part of the pixels of the image sensor can be used as the first light receiving part A8001-1, so that it works in a shooting mode for video shooting and is used for video shooting. Alternatively, another part of the pixels of the same image sensor can be used as the second light receiving part A8001-2, so that it works in a sampling mode for receiving optical signals and is used for optical communication.

[0611] Similarly, when the light receiving device A8000 includes N or more light receiving units and light receiving signal processing units, the pixels in the first area of ​​the image sensor can be operated in a shooting mode for video shooting and used for video shooting, while the pixels included in each area from the second area to the Nth area of ​​the image sensor can be operated in a sampling mode for receiving light signals and used for optical communication. In addition, when it is not necessary to perform video shooting and optical communication simultaneously, any pixel of the image sensor does not need to be operated in the shooting mode for video shooting. The pixels of the image sensor can be divided into multiple areas, and the pixels in each area can be operated in a sampling mode for receiving light signals, so that multiple optical communications can be performed in parallel.

[0612] In addition, when using an image sensor for video capture or optical communication, it is not necessary to keep all pixels operating all the time, and pixels that do not operate temporarily or intermittently may be included, that is, elements that do not read out the charge accumulated by receiving light may be included.

[0613] Next, use Figure 42 An example of control of an image sensor when the image sensor is used to simultaneously receive a plurality of optical signals is shown.

[0614] Figure 42 (A) shows a state in which four light sources AD, each transmitting a different light signal, are included in the capture range that can be captured using the capture mode for video capture. Figure 42 Each quadrilateral within the shooting range of (A) corresponds to one pixel.

[0615] At this time, the light receiving device A8000 is Figure 42 The regions A to D shown in (B) including the light sources AD are judged, and according to each of the regions A to D, the pixels included in the region are operated in a sampling manner for receiving light signals, thereby obtaining light signals.

[0616] As an example of a configuration in which sampling for receiving an optical signal is performed for each region, a sampling method in an image sensor having a shutter function for each pixel will be described.

[0617] (Example of line scan sampling for each area)

[0618] exist Figure 42In the area A shown in (C), line scanning sampling is performed with 4 pixels arranged in the vertical direction (column direction) forming one row. The following describes this case. In this case, area A is composed of 5 rows. The light receiving device exposes the 5 rows of area A by staggering the exposure period in units of rows, thereby obtaining a change in the grayscale or color of the modulated light signal. However, the size of each area, that is, the number of pixels in the row direction and the number of pixels in the column direction included in each area, is not affected by the size of each area. Figure 42 Furthermore, the size of the sampling area for optical communication can be changed according to the size, position, and mutual positional relationship of each light source in the screen. Figure 42 In the example (C), although one row is formed by four pixels arranged in the column direction, one row may be formed by five pixels arranged in the row direction. Figure 42 In the case of (C), it can also be considered as 4 rows with a row direction.

[0619] The light receiving device Figure 42 In area A of (C), after reading the signal of Line 1, the leftmost row in area A, the signal of the row adjacent to the right of the row just read is sequentially read. When reading the signal of Line 5, the rightmost row in area A, is completed, the signal returns to Line 1, the leftmost row, and the signal reading for each row is repeated.

[0620] The light receiving device can also be Figure 42 Line scan sampling is performed in each of regions B through D of (B) by obtaining signals using the same processing as for region A. Here, the light receiving device exposes the leftmost rows of all regions for the same duration, or at different times. Furthermore, the rows of region A and region C located in the same column on the image sensor can be exposed for the same duration, and the rows of region B and region D located in the same column on the image sensor can be exposed for the same duration. However, regions A through D include rows exposed during the same exposure period.

[0621] Here, although the case where multiple pixels arranged in the vertical direction (column direction) are treated as one row, exposed for the same period, and signals are read out in units of rows is described, line scanning sampling can also be performed even if multiple pixels arranged in the horizontal direction (row direction) are treated as one row.

[0622] While the above description describes a case where at least one pixel included in an image sensor is used for both video capture and optical communication, and the pixel is switched between acquiring signals using the capture method for video capture and acquiring signals using the sampling method for optical communication, the configuration of a light-receiving device including an image sensor is not limited thereto. For example, an image sensor may include pixels for optical communication separate from pixels for video capture.

[0623] In the case where the image sensor includes pixels for optical communication that are different from pixels for video capture, the shape or size of the pixels for optical communication may be different from the shape or size of the pixels for video capture.

[0624] Furthermore, it is possible to independently control the shooting of video using pixels for video shooting and the sampling of optical communication using pixels for optical communication. When the processing of one party is not needed, the processing of one party can be stopped, and the power supply to the circuit used to obtain the signal required in the processing can be partially or completely stopped to suppress power consumption.

[0625] As mentioned above, by performing line scan sampling, Figure 42 As shown in (A), different modulation signals from multiple light sources can be received in parallel, which can improve the data transmission speed.

[0626] Next, an example of the configuration of the control unit A1004 included in the communication device A1000 or the communication device A2000 will be described.

[0627] Figure 43 An example of the physical configuration of the control unit A1004 is shown, namely, the control unit A10000. The control unit A10000 includes a CPU (Central Processing Unit) A10001 and a memory A10002. The memory A10002 stores data required by the control unit A1004 when executing programs or performing processing. The CPU A10001, for example, processes data read from the memory A10002, thereby fulfilling the functions of the control unit A1004. Furthermore, the memory A10002 stores data such as image data obtained by the receiving device, and reads stored data.

[0628] In addition, although the CPU and memory are described as the components constituting the control unit A10000, other components may also be included. For example, a GPU (Graphics Processing Unit) may be included in addition to the CPU, or circuits for performing image processing such as motion image encoding and decoding, and pattern recognition for video data. Furthermore, the control unit A10000 may also include I / O (Input / Output) for controlling the transmission of data between devices connected to the control unit A10000, such as the wireless device A1006.

[0629] Figure 44 The first example of the configuration of the control unit A1004 is shown, that is, the configuration of the control unit A11000. The control unit A11000 includes a signal processing unit A11002, a wireless control unit A11004, and a light receiving device control unit A11006.

[0630] The signal processing unit A11002 obtains image data including captured data for optical communication from the light receiving device A1002 as received light data A1003, or obtains demodulated data on which demodulation and error correction have been performed as an optical signal. If the received light data A1003 is image data including captured data for optical communication, the signal processing unit A11002 obtains a received signal corresponding to the modulated signal from the captured data for optical communication, and obtains demodulated data by demodulating and correcting errors on the received signal.

[0631] Wireless control unit A11004 outputs control signal A1005 to wireless device A1006 for controlling the operation of wireless device A1006. Wireless control unit A11004 transmits wireless reception data received via wireless device A1006 to signal processing unit A11002, and transmits wireless transmission data to be transmitted to other communication devices via wireless device A1006 from signal processing unit A11002 to wireless device A1006.

[0632] The signal processing unit A11002 performs signal processing using any data such as demodulated data of optical communication, video capture data, and wireless reception data obtained via the light receiving device A1002 and the wireless device A1006. Based on the results of the signal processing, the signal processing unit A11002 issues control instructions to the wireless device A1006 from the wireless control unit A11004, or issues control instructions to the light receiving device from the light receiving device control unit A11006 (A11005).

[0633] The light receiving device control unit A11006 controls the light receiving device A1002 based on instructions from the signal processing unit A11002. As an example of controlling the light receiving device A1002, the light receiving units A3001, A8001-1, and A8001-2 can be used to control whether to acquire signals using a capture mode for video capture or a sampling mode for receiving light signals. When acquiring signals using a sampling mode for receiving light signals using a portion of pixels in an image sensor, the pixel area to be operated using the sampling mode for receiving light signals can be set. However, the control of the light receiving device A1002 is not limited to this. For example, the control of switching the power of the light receiving device A1002 on and off can be controlled, or the switching of signal processing for the received light signals performed within the light receiving device A1002 can be controlled. Furthermore, some of the controls described here can be automatically executed based on the results of the signal processing for the received light signals performed within the light receiving device A1002.

[0634] Figure 45 The second example of the configuration of the control unit A1004 is shown, that is, the configuration of the control unit A12000. The control unit A12000 is different from the control unit A11000 in that it includes a device control unit A12002.

[0635] The device control unit A12002 receives the video data obtained by the signal processing unit A11002 or the processing results of the signal processing unit A11002 as input (A12001), generates an image to be displayed by the presentation unit A2003, and outputs the generated image signal as presentation information A2002 to the presentation unit A2003. The device control unit A12002 obtains input information A2005 from the input unit A2004 in response to user operations on the input unit A2004, and transmits the information to the signal processing unit A11002.

[0636] With this configuration, the signal processing unit A11002 can perform signal processing based on input information A2005 obtained in response to user operations, in addition to demodulated optical communication data, video capture data, and wireless reception data obtained via the light receiving device A1002 and the wireless device A1006. For example, based on the results of the aforementioned signal processing, the signal processing unit A11002 issues control instructions to the wireless device A1006 to the wireless control unit A11004, issues control instructions (A11005) to the light receiving device control unit A11006, and issues instructions to change the image to be displayed on the display unit A2003.

[0637] Below, as an example of the processing performed by the control unit A1004, a communication control method for controlling the wireless device A1006 based on the results of image processing such as demodulated data obtained from the received light signal and pattern recognition performed on the captured data for video will be described.

[0638] Signal processing unit A11002 obtains video data from light receiving device A1002 as received light data A1003 and performs image processing such as pattern recognition on the video data. Wireless control unit A11004 controls wireless device A1006 based on the image processing results of signal processing unit A11002.

[0639] The communication control method described in this embodiment uses demodulated data to which additional information is added. This additional information is information that associates the demodulated data obtained by receiving an optical signal with additional information such as positional information indicating the position of the light source used to transmit the optical signal or the transmitter that transmitted the optical signal on an image. In this embodiment, the information transmitted using optical communication can be arbitrary and is not limited to the transmission of specific information. The following description of this communication control method uses optical signals as an example to describe the transmission of connection information. This connection information includes information necessary for connection or communication with other wireless communication devices, such as the SSID of the base station described in Embodiments 3 to 7.

[0640] Signal processing unit A11002 performs processing using demodulated data to which additional information obtained by light receiving device A1002 or within signal processing unit A11002 is added. Here, the demodulated data is connection information corresponding to other wireless communication devices. If signal processing unit A11002 receives multiple pieces of connection information, it uses the additional information corresponding to each piece of connection information and the results of image processing such as pattern recognition to control the communication processing performed by wireless device A1006.

[0641] Next, a first example of communication control based on the result of image processing will be described.

[0642] In the first example of communication control based on the result of image processing, the communication devices A1000 and A2000 are vehicles or devices mounted on vehicles, and a camera mounted on the vehicle is used as the light receiving device A1002. Figure 46 An example of an image captured by a camera that captures the front of the vehicle is schematically shown. Figure 46 3 other vehicles A13001, A13002, and A13003 are shown traveling in front of the vehicles corresponding to the communication devices A1000 and A2000.

[0643] In addition, in this embodiment, although the camera that captures images in front of the vehicle is used as an example for description, the present invention is also applicable to a camera that captures images in the rear or lateral direction of the vehicle.

[0644] Here, other vehicles A13001, A13002, and A13003 each have a light source such as an LED, and a transmitter 102 that uses the light source to transmit an optical signal. As the light source for optical communication, any light source that a vehicle has, such as a headlight or taillight, can be used. The specific light source used to transmit the optical signal among the multiple light sources on the vehicle can be arbitrarily designed according to the form of optical communication used. Furthermore, when multiple light sources on a vehicle are used to transmit optical signals, the vehicle can have a transmitter for optical communication for each of the multiple light sources, or a single transmitter can transmit optical signals using multiple light sources. Furthermore, a vehicle can also have a light source for optical communication that is unrelated to the headlights or taillights.

[0645] Other vehicles A13001, A13002, and A13003 may also have, in addition to the transmitting unit and light source for optical communication, Figure 34 or Figure 35 1000 and A2000. Furthermore, if the vehicle itself and the other vehicles A13001, A13002, and A13003 have the functions of transmitting and receiving optical signals and wireless communication, each vehicle is equipped with a transmitter 102 and a light source 104 for optical communication with the communication devices A1000 and A2000. In this case, the control unit A1004 can control the data transmitted by the transmitter 102.

[0646] In the first example of communication control based on image processing results, other vehicles A13001, A13002, and A13003 transmit connection information via optical communication. This connection information is information that can be used to connect to the communication devices installed in each vehicle. The following describes a case where the connection information includes information indicating the channel used for communication with the SSID when the communication devices installed in each vehicle operate as base stations.

[0647] In the above description, the SSID is used as an example of an identifier included in the connection information for identifying the communication partner. However, the identifier information included in the connection information is not limited to the SSID. For example, it can be a physical address such as the MAC (Media Access Control) address of another communication device, or a logical address such as the IP (Internet Protocol) address of another communication device. Furthermore, when the identifier information is not used to select another communication device for direct communication with the communication device, but is used to select a resource to be accessed via a network such as the Internet, it can be the address of a server communicating via the Internet, or a URL (Uniform Resource Locator), URN (Uniform Resource Name), or URI (Uniform Resource Identifier) ​​used to identify resources on the Internet. The identifier information included in the connection information can be any information as long as it can identify another communication terminal or Internet resource to be accessed.

[0648] In addition, although the above description describes a case where information about the channel used by the connection information is notified, the connection information may not only include information about the channel used, but may also include other information. Examples of other information that can be used as connection information include information related to encryption keys, the type of specifications of the corresponding physical layer transmission method, and the corresponding data format or communication protocol.

[0649] Figure 47 The diagram schematically shows the connection information obtained by demodulating the optical signals transmitted by the respective transmitting units of other vehicles A13001, A13002, and A13003 using light sources, at the light receiving device A1002 or control unit A1004 of communication devices A1000 and A2000. Communication devices A1000 and A2000 obtain connection information indicating that the SSID is "XXX" and the channel used is "1" from the optical signal transmitted by other vehicle A13001, that the SSID is "YYY" and the channel used is "3" from the optical signal transmitted by other vehicle A13002, and that the SSID is "ZZZ" and the channel used is "3" from the optical signal transmitted by other vehicle A13003.

[0650] This connection information can be replaced by information obtained by wireless device A1006 of communication devices A1000 and A2000 performing carrier sensing over a certain period of time and receiving signals transmitted from each of multiple other communication devices. However, it is difficult for communication devices A1000 and A2000 to identify which of the multiple other communication devices in the vicinity these signals are from, and thus there is a possibility that the communication device A1000 and A2000 may connect to and communicate with a communication device other than the one with which they actually intend to communicate.

[0651] Therefore, in the first example of communication control based on the result of image processing, the control unit A1004 of the communication device A1000, A2000 performs image processing on the shooting data for the video shot by the light receiving device A1002, for example, Figure 46 In the image, each of the other vehicles A13001, A13002, and A13003 is detected. At this time, the control unit A1004 associates each of the other vehicles A13001, A13002, and A13003 detected from the image with the three pieces of connection information received via optical communication, based on the positions of the light sources of the three received optical signals. This allows the control unit A1004 to determine the connection information used when wirelessly communicating with each of the three vehicles detected from the image.

[0652] Next, control unit A1004 determines the relative positional relationships of other vehicles A13001, A13002, and A13003, as well as the relative positional relationships of each vehicle with respect to the vehicle itself, from the image, and selects a wireless communication partner. For example, control unit A1004 may select the vehicle A13003 closest to the vehicle itself as the communication partner. Furthermore, control unit A1004 may determine the lane in which each vehicle is traveling and, from among the vehicles traveling in the vehicle's lane, select the vehicle A13001 that is located forward in the image as the communication partner.

[0653] This configuration enables the association of information such as identifiers like SSIDs and addresses used in wireless communications, which are difficult to associate with devices in real space using wireless communications alone, with objects detected through signal processing such as pattern recognition based on sensor data obtained from sensors, such as images captured by image sensors. This facilitates connections to appropriate communication partners when acquiring information about the surrounding environment or the movement of surrounding vehicles, for example, for purposes of controlling autonomous driving, including driving assistance.

[0654] Next, a second example of communication control based on the result of image processing will be described.

[0655] In the second example of communication control based on image processing results, the configuration of the communication devices A1000 and A2000, or the vehicle equipped with the communication devices A1000 and A2000, and the configuration of the other vehicles A13001 and A13002 are the same as in the first example of communication control based on image processing results. The second example of communication control based on image processing results differs from the first example in that another vehicle A15003, which does not have the function of transmitting optical signals, is used instead of the other vehicle A13003.

[0656] Figure 48 In the second example of communication control based on the result of image processing, an example of an image captured by a camera that captures the front of the vehicle is schematically shown. Figure 48 , three other vehicles A13001, A13002, and A15003 corresponding to the communication devices A1000 and A2000 traveling in front of the vehicle are shown.

[0657] Figure 49 The schematic diagram shows connection information obtained by demodulating optical signals transmitted by the respective transmitting units of other vehicles A13001 and A13002 using light sources at the light receiving devices A1002 or control units A1004 of communication devices A1000 and A2000. Communication devices A1000 and A2000 obtain connection information from the optical signal transmitted by other vehicle A13001, indicating that the SSID is "XXX" and the channel used is "1." They also obtain connection information from the optical signal transmitted by other vehicle A13002, indicating that the SSID is "YYY" and the channel used is "3." However, since other vehicle A15003 does not have the function of transmitting optical signals, communication devices A1000 and A2000 cannot obtain connection information related to other vehicle A15003.

[0658] In the second example of communication control based on the result of image processing, the control unit A1004 of the communication device A1000, A2000 performs image processing on the captured data for the video captured by the light receiving device A1002, for example, Figure 48The other vehicles A13001, A13002, and A15003 are detected in the image. At this time, the control unit A1004 associates the two pieces of connection information received in optical communication with the other vehicles A13001, A13002, and A15003 detected in the image, based on the positions of the light sources of the two received optical signals. This allows the control unit A1004 to identify the connection information used for wireless communication with the other vehicles A13001 and A13002 detected in the image, and also to identify the SSID used by the base station or communication device other than "XXX" or "YYY" when communicating with the other vehicle A15003.

[0659] First, a case will be described in which another vehicle A15003 does not have a function of transmitting an optical signal but has a function of performing wireless communication using an SSID such as "PPP".

[0660] At this time, the wireless device A1006 detects the three SSIDs "XXX", "YYY" and "PPP" as the SSIDs of other communication devices installed in vehicles within the communication distance by performing carrier sensing. The control unit A1004 judges "PPP", which is different from the SSIDs "XXX" and "YYY" included in the connection information received as an optical signal, as the SSID used when communicating with other vehicles A15003, and establishes a correspondence between the other vehicles A15003 and the SSID "PPP".

[0661] The control unit A1004 determines the relative positional relationships between other vehicles A13001, A13002, and A15003, as well as the relative positional relationships between each vehicle and the vehicle itself, from the image, and selects a wireless communication partner. For example, the control unit A1004 may select the vehicle A15003 closest to the vehicle itself as the communication partner. Alternatively, the control unit A1004 may determine the lane of each vehicle and select the vehicle A13001, which is traveling in the vehicle's lane and is located furthest ahead in the image, as the communication partner.

[0662] This configuration enables the association of identifiers such as SSIDs and addresses in wireless communications, which are difficult to associate with devices in real space using only wireless communications, with images captured by image sensors, or with objects detected through signal processing such as pattern recognition of sensor data. This facilitates connections to appropriate communication partners when acquiring information about the surrounding environment or the movement of surrounding vehicles, for example, for purposes of autonomous driving control, including driving assistance.

[0663] Next, a case will be described where another vehicle A15003 has neither the function of transmitting optical signals nor the function of wireless communication.

[0664] At this point, wireless device A1006 performs carrier sensing and detects the two SSIDs "XXX" and "YYY" as the SSIDs of other communication devices installed in vehicles within a communicable range. Since control unit A1004 cannot detect an SSID different from the SSIDs "XXX" and "YYY" included in the connection information received as an optical signal as the SSIDs of other communication devices installed in the vehicle, it determines that the other vehicle A15003 does not have wireless communication capabilities or is not in a wireless communication relationship.

[0665] The control unit A1004 determines the relative position of other vehicles A13001, A13002, and A15003, as well as their relative position relative to the vehicle itself, from the image, and selects either vehicle A13001 or vehicle A13002 as the target for wireless communication. For example, the control unit A1004 may select the closest vehicle A13002 to the vehicle itself, which is capable of communication, as the target for communication. Alternatively, the control unit A1004 may determine the lane in which each vehicle is traveling and select the vehicle A13001 that is traveling in the vehicle's lane and is located furthest ahead in the image as the target for communication.

[0666] This configuration allows information such as identifiers such as SSIDs and addresses in wireless communications, which are difficult to associate with devices in real space using only wireless communications, to be associated with images obtained by image sensors, or with objects detected through signal processing such as pattern recognition of sensor data obtained by sensors. This makes it possible to determine, for example, that information cannot be obtained through communication with another vehicle A15003 traveling immediately ahead. This prevents misidentification of another vehicle A13001 or another vehicle A13002, which is capable of communication, as another vehicle A15003 when autonomous driving control including driving assistance is being performed, thereby facilitating appropriate autonomous driving control.

[0667] Next, a third example of communication control based on the result of image processing will be described.

[0668] In the third example of communication control based on image processing results, the configuration of the communication devices A1000 and A2000, or the vehicle equipped with the communication devices A1000 and A2000, and the configuration of the other vehicles A13002 and A13003 are the same as in the first example of communication control based on image processing results. The third example of communication control based on image processing results differs from the first example in that police car A17001 is used instead of other vehicle A13001. Police car A17001 differs from other vehicles A13001 in that it is a police vehicle, but it has the same configuration as other vehicles A13001, with the functions of transmitting optical signals and wireless communication.

[0669] Figure 50 In the third example of communication control based on the result of image processing, an example of an image captured by a camera that captures the front of the vehicle is schematically shown. Figure 50 , other vehicles A13002 and A13003 and a police car A17001 traveling in front of the vehicles corresponding to the communication devices A1000 and A2000 are shown.

[0670] Figure 51 The diagram schematically shows the connection information obtained by demodulating optical signals transmitted by the light sources of the respective transmitting units of other vehicles A17001, A13002, and A13003 at the light receiving device A1002 or control unit A1004 of communication devices A1000 and A2000. Communication devices A1000 and A2000 obtain connection information from the optical signal transmitted by police car A17001, indicating that the SSID is "QQQ" and the channel used is "1." They obtain connection information from the optical signal transmitted by other vehicle A13002, indicating that the SSID is "YYY" and the channel used is "3." And they obtain connection information from the optical signal transmitted by other vehicle A13003, indicating that the SSID is "ZZZ" and the channel used is "3."

[0671] In the third example of communication control based on the result of image processing, the control unit A1004 of the communication device A1000, A2000 performs image processing on the captured data for the video captured by the light receiving device A1002, for example, Figure 50The police car A17001 and the other vehicles A13002 and A13003 are detected in the image. At this time, the control unit A1004 associates the police car A17001 and the other vehicles A13002 and A13003 detected in the image with the three pieces of connection information received via optical communication, based on the positions of the light sources of the three received optical signals. This allows the connection information used for wireless communication to be determined for each of the police car A17001 and the other vehicles A13002 and A13003 detected in the image.

[0672] Control unit A1004 uses information such as the vehicle's appearance to classify the three vehicles identified during image processing into specific categories, such as police vehicles. It then identifies vehicle A17001 as a police vehicle. Control unit A1004 selects police vehicle A17001, which has a higher priority for obtaining information, as the wireless communication target, from among police vehicle A17001 and other vehicles A13002 and A13003.

[0673] According to this configuration, when an object is recognized by signal processing such as pattern recognition from sensor data obtained by a sensor, such as an image acquired by an image sensor, the recognized object can be further classified in detail, and communication control can be performed based on the classification.

[0674] The aforementioned control for selecting the police car as the communication partner with the highest priority for obtaining information is merely an example. Different control can be performed when the police car is identified. For example, police car A17001 may transmit an identifier identifying the police car in an optical signal. Control unit A1004 may not directly connect to the police car wirelessly, but may instead specify the identifier received from police car A17001 in the optical signal to other vehicles A13002 or A13003, thereby obtaining information about police car A17001.

[0675] Furthermore, when a police car is detected through image processing, the following communication control may be performed, that is, instead of always performing the same communication control, when the police car lights of the identified police car are lit, priority is given to the collection of information related to the police car, or when the communication devices A1000 and A2000 are equipped with a microphone used as a sensor other than the image sensor, the alarm sound may be detected by performing pattern recognition signal processing on the sound data obtained by the control unit A1004 with the microphone, thereby giving priority to the collection of information related to the police car.

[0676] Furthermore, when detecting sound emitted by another device using sound data obtained by a microphone, a modulated signal generated based on transmission data such as an identifier of the other device may be simultaneously transmitted.

[0677] This configuration allows the device emitting a sound identified through signal processing such as pattern recognition to be associated with the transmitted data, such as an identifier, transmitted as the sound signal. This makes it possible to easily identify the device emitting the detected sound, for example, in an environment where there are multiple devices with known identifiers.

[0678] Alternatively, a sound signal may be used instead of an optical signal. In this case, the light receiving device A1002 in the communication devices A1000 and A2000 is replaced with a sound detection device such as a microphone. Furthermore, by employing a device such as an array microphone that can determine the direction of arrival of sound as the sound detection device, the device emitting the sound to be detected can be more accurately associated with the sound signal.

[0679] Furthermore, the communication devices A1000 and A2000 according to this embodiment may include multiple wireless devices. For example, the communication devices A1000 and A2000 may include multiple wireless devices corresponding to communication methods defined by different standards, or may include multiple wireless devices corresponding to the same communication method.

[0680] Furthermore, when the communication devices A1000 and A2000 involved in this embodiment are vehicles or communication devices installed in vehicles, the light receiving device A1002 can be, for example, a camera in a driving recorder, a camera for a rearview monitor, a camera for checking the surroundings of the vehicle body, a camera used to project images onto a monitor instead of a side mirror, or the like. Thus, by using a camera installed for purposes other than optical communication to receive optical signals, the communication control disclosed in this embodiment can be implemented without adding additional cameras, which can contribute to cost reduction and the widespread use of optical signal receiving functions. Furthermore, since such cameras are installed in areas necessary for the driver, that is, in areas where they can capture important information from the perspective of vehicle operation, more information can be collected by combining signal processing such as image recognition with wireless communication, thereby facilitating the provision of appropriate autonomous driving control and information to the driver.

[0681] The embodiment described in this application is a method and apparatus for demodulating a transmission signal transmitted using a communication method that can be received by a sensor such as an image sensor or a microphone using sensing data that can be obtained by the sensor.

[0682] In the above-described embodiment, signal processing such as pattern recognition such as image recognition is further performed on the sensing data obtained by the sensor, thereby determining the correspondence between the object in the real space detected or recognized from the sensing data and the transmission source of the transmission signal.

[0683] In the above-described embodiment, by further utilizing transmission signals to transmit information such as SSIDs, addresses, and identifiers used only in network-based processing, including communications, it is possible to easily associate information used in network-based processing with objects in real space. Specifically, information used in network-based processing, which has been difficult to associate with objects in real space, can now be utilized based on sensor data obtained from real space.

[0684] In the above-mentioned embodiment, by further using an image sensor as a sensor to transmit information used in processing including communication via a network using an optical signal, the reliability of establishing correspondence between visible objects and information used in processing including communication via a network can be improved.

[0685] In the above-described embodiment, identifiers used for communication, such as SSIDs and addresses, are further transmitted via optical signals. The identifier of the target to be connected via communication is selected based on the results of signal processing using image recognition. This allows communication control based on the positional relationship or attributes of objects in real space. This allows communication to be initiated by specifying the target to be connected, thereby obtaining information and providing control instructions. This provides a means for communicating with the appropriate target in an environment where, for example, multiple devices exist within an unspecified range of communication, and promotes the creation and widespread use of new services via communication.

[0686] The above describes the eighth embodiment of the present application.

[0687] In addition, as an example of a communication system that performs visible light communication, although Figure 5 The structure of the communication system for visible light communication is described, but the structure of the communication system for visible light communication is not limited to Figure 5 For example, it can be Figure 52 The structure shown in (for example, refer to "IEEE 802.11-16 / 1499r1"). Figure 52 In this embodiment, the transmission signal is not up-converted but is transmitted as an optical signal in baseband. That is, the device for transmitting optical signals (i.e., the device having a light source) of this embodiment has Figure 52 The transmission side configuration shown in FIG. 1 is a terminal for receiving optical signals in this embodiment. Figure 52 The configuration of the receiving side is shown.

[0688] (Implementation 9)

[0689] In this embodiment, Figure 52 Provide additional explanation.

[0690] conduct Figure 52 The symbol mapping unit inputs the transmission data, performs mapping based on the modulation method, and outputs the symbol sequence (ci).

[0691] The equalization pre-processing unit receives a symbol sequence as input, performs equalization pre-processing on the symbol sequence to reduce equalization processing on the receiving side, and outputs the symbol sequence after the equalization pre-processing.

[0692] The Hermitian symmetry processing unit receives the symbol sequence after pre-equalization processing as input, allocates subcarriers to the symbol sequence after pre-equalization processing so as to ensure Hermitian symmetry, and outputs a parallel signal.

[0693] The (fast) inverse Fourier transform unit receives the parallel signal as input, performs (fast) inverse Fourier transform on the parallel signal, and outputs the (fast) inverse Fourier transformed signal.

[0694] The parallel-serial and cyclic prefix adding unit receives the (fast) inverse Fourier transformed signal as input, adds parallel-serial conversion and a cyclic prefix, and outputs the signal as a signal processed.

[0695] The digital-to-analog converter receives the processed signal as input, performs digital-to-analog conversion, and outputs an analog signal. The analog signal is output as light from one or more LEDs, for example.

[0696] Furthermore, the equalization pre-processing unit and the Hermitian symmetry processing unit may not be provided. In other words, the signal processing in the equalization pre-processing unit and the Hermitian symmetry processing unit may not be performed.

[0697] The photodiode receives light as input and obtains a received signal through a TIA (Transimpedance Amplifier).

[0698] The analog-to-digital conversion unit performs analog-to-digital conversion on the received signal and outputs a digital signal.

[0699] The cyclic prefix removal and serial-to-parallel conversion unit receives a digital signal as input, removes the cyclic prefix, and then performs serial-to-parallel conversion to input a parallel signal.

[0700] The (fast) Fourier transform takes the parallel signal as input, performs a (fast) Fourier transform, and outputs the (fast) Fourier transformed signal.

[0701] The detection unit receives the Fourier-transformed signal as input, performs detection, and outputs a received symbol sequence.

[0702] The symbol demapping unit takes the received symbol sequence as input, performs demapping, and obtains a received data sequence.

[0703] As described above, even if a transmitting device that transmits an optical modulated signal and a receiving device that receives an optical modulated signal are applied to each embodiment in this specification, each embodiment can be implemented in the same manner.

[0704] (Implementation 10)

[0705] In embodiment 8, use Figure 42 The example described is a case where a transmitting device transmits a plurality of optical modulated signals and a receiving device receives a plurality of optical modulated signals. In this embodiment, an example of this case will be described.

[0706] Figure 53 FIG1 shows an example of the configuration of the transmitting device and the receiving device in this embodiment. Figure 53 In the embodiment, the transmitting device 100 transmits a plurality of optical modulated signals, and the receiving device 150 receives the plurality of optical modulated signals to obtain received data. Figure 53 In the Figure 6 The same work is assigned the same symbol.

[0707] Figure 53 The transmitting device in transmits M optical modulation signals. In addition, M is an integer greater than 2.

[0708] Transmitter A2002_i receives data A2001_i and control signal A2005 as input, performs signal processing based on the error correction coding method and the transmission method included in control signal A2005, and generates and outputs optical modulated signal A2003_i. Here, i is an integer from 1 to M.

[0709] Then, the optical modulated signal A2003_i is transmitted from the light source A2004_i.

[0710] The light receiving unit A2051 of the image sensor or the like receives light corresponding to the light modulation signal A2003_i. In this case, the light receiving unit A2051 receives light corresponding to M light modulation signals. The method for receiving multiple light signals at the light receiving unit A2051 is as described in the eighth embodiment, for example.

[0711] The light receiving unit A2051 outputs a light receiving signal A2052_i corresponding to the light modulated signal 2003_i. Here, i is an integer from 1 to M.

[0712] The receiving unit A2053_i receives the optical reception signal A2052_i corresponding to the optical modulation signal A2003_i, performs processing such as demodulation and error correction decoding, and outputs reception data A2054_i corresponding to the data A2001_i.

[0713] The data acquisition unit A2055 receives data A2054_1, data A2054_2, ..., data A2054_M as input, generates and outputs data A2056.

[0714] Figure 54 Shown with Figure 53 Different examples of the configuration of the transmitting device and the receiving device in this embodiment. Figure 54 In relation to Figure 53 The same work is assigned the same symbol.

[0715] Distributor A2102 receives information A2101 and control signal A2005 as input. Based on information regarding the error correction coding method included in control signal A2005, it performs error correction coding on information A2101, generating error-correction-coded data. Distributor A2102 then distributes the error-correction-coded data and outputs error-correction-coded data A2001_i.

[0716] Furthermore, the allocation of the M error-correction coded data A2001_i can be performed arbitrarily. For example, the error-correction coded data can be divided into M data series, and each of the M data series can be allocated to the error-correction coded data A2001_i. Furthermore, M data series consisting of the same data can be generated from the error-correction coded data, and each data series can be allocated to the error-correction coded data A2001_i. The allocation method to the error-correction coded data A2001_i is not limited to this method; M data series can be generated from the error-correction coded data, and each data series can be allocated to the error-correction coded data A2001_i.

[0717] The transmitter A2002_i receives data A2001_i and control signal A2005 as input, performs signal processing based on the transmission method according to information on the transmission method contained in the control signal A2005, generates and outputs an optical modulated signal A2003_i. Note that i is an integer from 1 to M.

[0718] Then, the optical modulated signal A2003_i is transmitted from the light source A2004_i.

[0719] The light receiving unit A2051 of the image sensor or the like receives light corresponding to the light modulation signal A2003_i. At this time, the light receiving unit A2051 receives light corresponding to M light modulation signals. The method for receiving multiple light signals at the light receiving unit A2051 is similar to that described in Embodiment 8, for example.

[0720] The light receiving unit A2051 outputs a light receiving signal A2052_i corresponding to the light modulated signal 2003_i. Here, i is an integer from 1 to M.

[0721] The receiving unit A2053_i receives the optical reception signal A2052_i corresponding to the optical modulation signal A2003_i, performs processing such as demodulation, and outputs (the log-likelihood ratio of) reception data 2054_i corresponding to the data A2001_i.

[0722] The error correction decoding unit A2151 receives (the log-likelihood ratio of) received data 2054_1, received data 2054_2, ..., received data 2054_M as input, performs error correction decoding, and outputs received data A2152.

[0723] Figure 55 Shown Figure 53 、 Figure 54 An example of the frame structure of the optical modulated signal transmitted by the transmitting device 100 in .

[0724] Figure 55 The frame structure A2201_1 shows Figure 53 、 Figure 54 An example of the frame structure of the optical modulation signal A2003_1 in FIG. In the frame structure A2201_1, the horizontal axis represents time.

[0725] therefore, Figure 55 The frame structure A2201_i shows Figure 53 、 Figure 54 An example of the frame structure of the optical modulation signal A2003_i in FIG. In addition, in the frame structure A2201_i, the horizontal axis is time. Therefore, i is an integer greater than 1 and less than M. (i.e., in Figure 55 The M frame structure is shown in FIG.

[0726] As shown in the frame structure A2201_i, Figure 53 、 Figure 54 The transmitting device 100 in the optical modulation signal A2003_i transmits a preamble code A2210_i, a control information code element A2211_i, and a data code element A2212_i.

[0727] Figure 56An example of the reception state in the receiving device 150 is shown. In the following example, Figure 53 、 Figure 54 The transmitting device 100 in FIG. 1 includes 16 (M=16) light sources.

[0728] exist Figure 56 In FIG. 1 , A2300 represents an image sensor as an example of a light receiving unit, and A2301_1 represents light emitted by a first light source, which includes a first light modulation signal. In addition, the first light modulation signal corresponds to Figure 55 A2201_1.

[0729] Therefore, in Figure 56 In the example, A2301_i is the light irradiated by the i-th light source, and the light includes the i-th optical modulation signal. In addition, the i-th optical modulation signal is equivalent to Figure 55 A2201_i. In addition, i is an integer greater than or equal to 1 and less than or equal to 16.

[0730] exist Figure 56 In the example of the receiving state in the receiving device 150, the light receiving part of the receiving device 150 receives light from the 4th light source including the 4th optical modulation signal, light from the 8th light source including the 8th optical modulation signal, and light from the 12th light source including the 12th optical modulation signal.

[0731] For example, if Figure 53 、 Figure 54 The transmitting device 100 transmits 16 optical modulation signals from 16 light sources. Figure 56 In the case of the state, due to Figure 53 、 Figure 54 The receiving device 150 in FIG. 1 cannot receive all 16 optical modulation signals, and thus cannot obtain correct received data. The following describes a method for overcoming this problem.

[0732] Figure 57 Shown Figure 55 This is an example of the configuration of the preamble A2210_i, the information included in the control information symbol A2211_i, and the symbol of the frame configuration A2201_i of the optical modulated signal A2003_i. Note that i is an integer from 1 to M (=16).

[0733] The preamble A2210_i and control information code element A2211_i in the frame structure A2201_i are as follows: Figure 57 As shown, it includes code element A2401 for signal detection, code element A2402 for synchronization, code element A2403 including information related to the number of optical modulation signals transmitted, and code element A2404 including information related to the error correction coding method, transmission method, and modulation method.

[0734] The code element A2401 used for signal detection is a code element used by the receiving device 150 to know the existence of the optical modulation signal. By detecting this code element, the receiving device 150 knows the existence of the optical modulation signal.

[0735] Symbol A2402 for synchronization is a symbol used for time synchronization (including frequency synchronization in some cases) of the receiving device 150. By using this symbol, the receiving device 150 can perform time synchronization, thereby enabling highly accurate demodulation of each symbol.

[0736] Symbol A2403 including information on the number of optical modulation signals to be transmitted is a symbol for notifying the transmitting device 100 of the number of optical modulation signals to be transmitted. Figure 56 When in the state, code element A2403 including information related to the number of optical modulation signals transmitted sends the information "16".

[0737] The receiving device 150 Figure 56 In the receiving state, by receiving the code element A2403 including the information about the number of optical modulation signals transmitted, it can be known that "16" optical modulation signals are transmitted by the transmitting device 100. Figure 56 In the receiving state, the receiving device 150 knows that only 3 optical modulated signals are received among the 16 optical modulated signals.

[0738] The code element A2404 includes information related to the error correction coding method, the transmission method, and the modulation method. For example, it is a code element that includes information related to the error correction coding method, the transmission method, and the modulation method used in the data code element (the code element used to transmit data) in the optical modulation signal A2003_i. By receiving the code element, the receiving device 150 can know the error correction coding method, the transmission method, and the modulation method used in the optical modulation signal A2003_i.

[0739] exist Figure 55 In the case of a frame structure of optical modulation signal A2003_1 to optical modulation signal A2003_16, the transmitting device 100 transmits Figure 57 Thus, Figure 56 As shown, even when receiving device 150 fails to receive all optical modulated signals, it is still possible to determine the number of optical modulated signals transmitted by transmitting device 100. This allows receiving device 150 to determine whether all optical modulated signals have been received or not. By suspending signal processing midway when not all optical modulated signals are received, unnecessary power consumption can be suppressed.

[0740] Figure 58 Shown with Figure 57 Different, Figure 55The frame structure of the optical modulation signal A2003_i in FIG is an example of the preamble A2210_i, the information included in the control information code element A2211_i, and the code element structure. In addition, i is an integer greater than 1 and less than M (=16), and Figure 58 In the Figure 57 The same operations are assigned the same symbols, and since they have already been explained, their explanation is omitted.

[0741] exist Figure 58 Relative to Figure 57 , as the codeword transmitted by the transmitting device 100, codeword A2501 including information related to the number of the optical modulation signal is added.

[0742] Figure 58 yes Figure 55 The frame configuration A2201_i of the optical modulation signal A2003_i is the frame configuration of the i-th optical modulation signal, so the codeword A2501 including the information related to the number of the optical modulation signal includes the information "i".

[0743] For example, symbol A2501 including information on the number of the optical modulation signal transmitted by the transmitting device 100 as the first optical modulation signal includes information "1".

[0744] The receiving device 150 Figure 56 In the receiving state, by receiving symbol A2403, which includes information about the number of transmitted optical modulated signals, it is possible to determine that "16" optical modulated signals were transmitted by transmitting device 100. Consequently, since receiving device 150 receives "symbol A2501," which includes information about the number of optical modulated signals, "symbol A2501A," which includes information about the number of optical modulated signals, and "symbol A2501A," which includes information about the number of optical modulated signals, both included in the fourth optical modulated signal, and in the eighth optical modulated signal, and in the twelfth optical modulated signal, it is possible to determine that the fourth, eighth, and twelfth optical modulated signals have been received. By knowing this, receiving device 150 performs operations to improve the reception conditions, thereby improving the data reception quality. The details of these operations will be described later.

[0745] Another example of the reception state in the receiving device 150 is Figure 59 、 Figure 60 In addition, Figure 59 、 Figure 60 In the Figure 56 The same operations are assigned the same numbers, and since they have already been described, their description is omitted.

[0746] exist Figure 59 In the example of the receiving state of the receiving device 150, the light receiving unit A2300 of the receiving device 150 receives light from the first light source including the first light modulation signal to light from the 16th light source including the 16th light modulation signal, that is, receives 16 light modulation signals. Figure 59 In the case of, for example, the first optical modulation signal is received at the upper left of the light receiving part A2300.

[0747] exist Figure 60 In the example of the receiving state of the receiving device 150, the light receiving unit A2300 of the receiving device 150 receives light from the first light source including the first light modulation signal to light from the 16th light source including the 16th light modulation signal, that is, receives 16 light modulation signals. Figure 60 In the case of, for example, the first light modulation signal is received at the lower right of the light receiving part A2300, which is the same as Figure 59 different.

[0748] Figure 59 、 Figure 60 The receiving state of is only an example, and the conditions under which the receiving device 150 receives the first to sixteenth optical modulated signals may vary depending on the environment. Figure 58 As shown, since each optical modulated signal includes "symbol A2501 including information related to the optical modulated signal number," receiving device 150 can determine "which optical modulated signal was received at which portion of the light receiving unit." Consequently, receiving device 150 obtains the i-th received data from the i-th optical modulated signal. When replacement of the first through sixteenth received data is required, receiving device 150 can identify "which optical modulated signal" the received data represents based on "symbol A2501 including information related to the optical modulated signal number." This allows accurate replacement of the received data, thereby improving data reception quality.

[0749] Next, a method of constructing a frame that is different from the above-described method will be described.

[0750] Figure 55 Shown Figure 53 、 Figure 54 An example of the frame structure of the optical modulation signal transmitted by the transmitting device 100 in FIG. 1 has been described, so the description is omitted.

[0751] For example, Figure 55 The optical modulation signal A2003_1 in the frame composition A2201_1 in the preamble and control information code element composition is as follows: Figure 57As shown, the preamble and control information code elements from "frame configuration A2201_2 in optical modulation signal A2003_2" to "frame configuration A2201_16 in optical modulation signal A2003_16" are composed as follows: Figure 61 In addition, Figure 61 In the Figure 57 The same job is assigned the same number. Figure 61 The characteristic feature of is that it includes "symbol A2403 including information about the number of optical modulation signals to be transmitted." That is, the transmitting device 100 transmits "symbol A2403 including information about the number of optical modulation signals to be transmitted" only as optical modulation signal A2003_1.

[0752] At this time, for Figure 56 If the receiving state of receiving device 150 is not correct, since receiving device 150 does not receive "symbol A2403 related to the transmitted optical modulated signal," it cannot determine the number of optical modulated signals transmitted by transmitting device 100. In this case, receiving device 150 determines that it is difficult to correctly receive data and stops signal processing for reception, thereby reducing unnecessary power consumption.

[0753] In addition, although the description of this example states that "the transmitting device 100 transmits "the code element A2403 related to the transmitted optical modulation signal" only with the optical modulation signal A2003_1", it is not limited to this. As long as "the transmitting device 100 transmits "the code element A2403 related to the transmitted optical modulation signal" in a part of the optical modulation signal A2003_1 to A2003_16", the same effect as described above can be obtained.

[0754] Other examples will be further described.

[0755] Figure 55 Shown Figure 53 、 Figure 54 This is an example of the frame structure of the optical modulation signal transmitted by the transmitting device 100 in FIG. 1 , which has already been described and therefore will be omitted.

[0756] For example, Figure 55 The optical modulation signal A2003_1 in the frame composition A2201_1 in the preamble and control information code element composition is as follows: Figure 58 As shown, the preamble and control information code elements of "frame configuration A2201_2 in optical modulation signal A2003_2" to "frame configuration A2201_16 in optical modulation signal A2003_16" are composed as follows: Figure 62 As shown. In addition Figure 62 In the Figure 57 、 Figure 58The same job is assigned the same number. Figure 62 The characteristic of the optical modulation signal A2003_1 is that it does not include "the code element A2403 related to the transmitted optical modulation signal". In other words, the transmitting device 100 transmits "the code element A2403 related to the transmitted optical modulation signal" only as the optical modulation signal A2003_1.

[0757] At this time, Figure 56 If the receiving state of receiving device 150 is not correct, since receiving device 150 does not obtain "symbol A2403 related to the transmitted optical modulated signal," it cannot grasp the number of optical modulated signals transmitted by transmitting device 100. In this way, receiving device 150 determines that it is difficult to correctly receive data and stops signal processing for reception, thereby reducing unnecessary power consumption.

[0758] In addition, although the description of this example states that "the transmitting device 100 transmits "the code element A2403 related to the transmitted optical modulation signal" only with the optical modulation signal A2003_1", the present invention is not limited to this example. As long as "the transmitting device 100 transmits "the code element A2403 related to the transmitted optical modulation signal" in the optical modulation signal of a part of the optical modulation signals A2003_1 to A2003_16", the same effect as described above can be obtained.

[0759] As an example only, "the transmitting device 100 may also be configured to transmit a preamble and a control information symbol in a portion of the optical modulated signals A2003_1 to A2003_16."

[0760] As described above, when the transmitting device transmits multiple optical modulated signals, as described in this embodiment, the effect that can be obtained is that by transmitting the optical modulated signals, the receiving device can obtain high data reception quality or reduce power consumption.

[0761] In addition, although the number of optical modulation signals sent by the transmitting device is described as 16 in this embodiment, it is not limited to this. Figure 53In a configuration such as 100, the number of optical modulated signals to be transmitted can be changed according to the transmission time. For example, 16 optical modulated signals may be transmitted during the first time, 8 optical modulated signals may be transmitted during the second time, and 1 optical modulated signal may be transmitted during the third time. Furthermore, in this example, during the first time, "16" is transmitted in "symbol A2404 related to the transmitted optical modulated signal," during the second time, "8" is transmitted in "symbol A2404 related to the transmitted optical modulated signal," and during the third time, "1" is transmitted in "symbol A2404 related to the transmitted optical modulated signal."

[0762] Therefore, in this embodiment, although Figure 55 However, the frame structure is not limited to this, and other code elements may also exist in the frame. In addition, the order in which the code elements are sent is not limited. Figure 55 Limited by the order.

[0763] Furthermore, as the composition of the preamble and control information symbols, although Figure 57 、 Figure 58 、 Figure 61 、 Figure 62 Although the above description is given, the same operation can be performed even if some symbols do not exist in each figure or other symbols exist in each figure. That is, the composition of the preamble and control information symbols is not affected by Figure 57 、 Figure 58 、 Figure 61 、 Figure 62 Furthermore, the order in which the symbols constituting the preamble and control information symbols are sent is not limited by Figure 57 、 Figure 58 、 Figure 61 、 Figure 62 Limited by examples.

[0764] (Implementation 11)

[0765] In this embodiment, it will be explained that, for example, the receiving state of the receiving device 150 is Figure 56 In the illustrated situation, a method is implemented for improving the reception quality of data at the receiving device 150 .

[0766] As described in the tenth embodiment, the receiving device 150 becomes Figure 56 In the case of the situation shown in FIG, it is difficult for the receiving device 150 to correctly obtain the received data. Figure 63 The situation shown. Figure 63 In the Figure 56 The same job is assigned the same number.

[0767] exist Figure 63 In this case, the area illuminated by each light source in the light receiving unit such as the image sensor is small, which may cause a problem of reduced data reception quality in the receiving device 150. In addition, when a line scan method or line scan sampling is performed by area, there is a possibility that the data reception quality of the receiving device 150 will be significantly reduced.

[0768] In this embodiment, a configuration example of the receiving device 150 that overcomes such a problem will be described.

[0769] As an example of the configuration of a transmission device for transmitting data, there is Figure 53 The sending device 100. In addition, due to Figure 53 The explanation has already been given, so the explanation is omitted.

[0770] right Figure 53 The receiving device 150 for receiving the optical modulated signal transmitted by the transmitting device 100 is configured as follows: Figure 64 shown.

[0771] And, as a sending device for sending data Figure 53 Different configuration examples include Figure 54 The sending device 100. In addition, due to Figure 54 The explanation has already been given, so the explanation is omitted.

[0772] right Figure 54 The receiving device 150 for receiving the optical modulated signal transmitted by the transmitting device 100 is configured as follows: Figure 65 shown.

[0773] The following Figure 64 、 Figure 65 The receiving device 150 is described below.

[0774] Figure 64 Yes Figure 53 An example of a configuration of a receiving device 150 for receiving an optical modulated signal transmitted by a transmitting device 100, Figure 53 The same job is assigned the same number.

[0775] Lens (group) A3101 takes lens control signal A3109 as input to control focal length, aperture, focus, etc.

[0776] The image sensor (light receiving unit) A3103 receives light A3102 transmitted through the lens and outputs light reception signals A2052_1 to A2502_M and an image signal A3104. The image signal A3104 undergoes signal processing and can be displayed as an image on an internal display unit or on an external display unit via an interface.

[0777] The data acquisition unit A2055 receives the received data A2054_1 to A2054_M as input, and outputs data A2056 and reception status information A3107.

[0778] Reception status information A3107 may be, for example, the "information regarding the transmitted optical modulated signal" obtained from "symbol A2403 including information regarding the transmitted optical modulated signal" transmitted by transmitting device 100, and the "information regarding the optical modulated signal number" obtained from "symbol A2501 including information regarding the optical modulated signal number" transmitted by transmitting device 100 in Embodiment 10. Furthermore, reception status information A3107 may be reception status information generated from the "information regarding the transmitted optical modulated signal" and the "information regarding the optical modulated signal number." However, the present invention is not limited to this example.

[0779] The object recognition unit A3105 receives the image signal A3104, reception status information A3107, and instruction signal A3150 as input and performs object recognition based on instruction signal A3150. For example, if instruction signal A3150 indicates "communication in progress," the object recognition unit A3105 begins recognizing the optical modulation signal. At this point, the object recognition unit A3105 receives the image signal A3104 and reception status information A3107 as input and outputs an object recognition signal A3106. The specific operation will be described later.

[0780] The lens control unit A3108 takes the object recognition signal A3106 as input, such as the recognition Figure 56 、 Figure 63 The receiving state is "whether to perform lens control, if the lens control is performed, determine the setting value of the focal length, the setting value of the aperture, and the setting of the focus", and outputs the lens control signal A3109 corresponding to these controls. Figure 64 Although the lens control unit A3108 receives the object recognition signal A3106 as input, there may also be input signals other than this.

[0781] Figure 65 Shows the reception Figure 54 An example of the configuration of a receiving device 150 for receiving an optical modulated signal transmitted by a transmitting device 100, Figure 53 、 Figure 54The same operations are assigned the same numbers. In addition, since the operations of the lens (group) A3101, the image sensor A3103, the object recognition unit A3105, and the lens control unit A3108 have already been described, their description will be omitted.

[0782] The error correction decoding unit A2155 takes the received data A2054_1 to A2054_M as input and outputs data A2056 and reception status information A3107.

[0783] Then, Figure 64 、 Figure 65 The control method of lens (group) A3101 in FIG. 1 is described with a specific example.

[0784] As described in the embodiment 10, for example, when the receiving state of the receiving device 150 is Figure 56 In the case of the situation shown in FIG, since the light irradiated from several light sources is not received by the light receiving unit, it is difficult for the receiving device 150 to correctly receive the data. Figure 63 In the case shown, there is a problem that the reception quality of data in the receiving device 150 deteriorates.

[0785] In addition, the receiving device 150 is Figure 59 、 Figure 60 In the case of the reception state shown, the data reception quality is high.

[0786] As described above, the receiving device 150 is Figure 59 、 Figure 60 The receiving state shown can improve the data reception quality when controlling the lens (group) A3101. Figure 64 、 Figure 65 The receiving device 150 is an example of a configuration for achieving the above-mentioned reception quality.

[0787] right Figure 64 、 Figure 65 A specific example of controlling the receiving device 150 is described below.

[0788] For example, the receiving state of the receiving device 150 is considered to be Figure 56 The state shown. At this time, Figure 64 、 Figure 65 As already explained, the reception status information A3107 in the Receive State Received is generated based on the "information about the transmitted optical modulated signal" and the "information about the number of the optical modulated signal". Therefore, the situation that 3 optical modulated signals out of 16 optical modulated signals are already receivable is determined by Figure 64 、 Figure 65 The object recognition unit A3105 recognizes it.

[0789] Furthermore, the object recognition unit A3105 recognizes the "reception status of the light modulation signal, for example, at which position of the image sensor the three light modulation signals are received" from the image signal A3104. That is, the object recognition unit A3105 performs Figure 56 . Object recognition in the image. Object recognition unit A3105 then identifies the "reception status of the optical modulation signal" and the "failure to receive 16 optical modulation signals." Furthermore, in this example, object recognition unit A3105 determines, based on these recognition results, whether to perform lens control and "determine the optimal focal length setting value, optimal aperture setting value, and optimal focus setting" for optimal communication, and outputs object recognition signal A3106 including this information. Object recognition signal A3106 only needs to include the "optimal focal length setting value" and does not necessarily need to include information on the optimal aperture setting value and the optimal focus setting.

[0790] The lens control unit A3108 takes the object recognition signal A3106 as input, and outputs the lens control signal A3109 for controlling the lens (group) A3101 based on the information such as "optimal focal length setting value, optimal aperture setting value, optimal focus setting" included in the object recognition signal A3106.

[0791] By carrying out such a series of work, Figure 64 、 Figure 65 The receiving device 150 becomes, for example, Figure 59 、 Figure 60 The reception state shown hereby provides an effect that high data reception quality can be obtained.

[0792] In the above example, although the receiving state of the receiving device 150 is changed from Figure 56 Control into Figure 59 、 Figure 60 The example of the case of " is described, but it is not limited to this example. The receiving state of the receiving device 150 can also be changed from Figure 63 Control into Figure 59 、 Figure 60 However, it is not limited to this.

[0793] Then, for Figure 64 、 Figure 65 Different Figure 66 、 Figure 67 An example of control of the receiving device 150 is described.

[0794] Figure 66 Shows the reception Figure 53An example of the configuration of a receiving device 150 for receiving an optical modulated signal transmitted by a transmitting device 100, Figure 64 The same operations are assigned the same numbers, and description of the parts already described will be omitted.

[0795] Figure 66 The receiving device 150 and Figure 64 The difference between the receiving device 150 and the image sensor A3103 is that there is a signal processing unit A3302 after the image sensor A3103.

[0796] The signal processing unit A3302 has at least a zoom (zooming in (or reducing) an image) processing function.

[0797] Therefore, the signal processing unit A3302 takes the image signal A3301, the zoom signal A3300, the object recognition signal A3106, and the indication signal A3150 as input. When the indication signal A3150 indicates "shooting mode (shooting)", the signal processing unit A3302 performs signal processing for zoom on the image signal A3301 based on the zoom (image magnification (or reduction)) information of the zoom signal A3300, and outputs the image signal A3104 after signal processing.

[0798] When instruction signal A3150 indicates "communication mode (communication is in progress)," signal processing unit A3302 performs zoom signal processing on image signal A3301 based on information such as the "optimal focal length setting value, optimal aperture setting value, and optimal focus setting" included in object recognition signal A3106, and outputs processed image signal A3104 and processed received light signals 2052_1 to A2052_M. As described above, this improves the reception state, thereby improving the quality of data reception.

[0799] In addition, since the method of improving the reception state in the lens control unit A3108 has been described, the description is omitted.

[0800] As described above, the receiving device 150 can improve the quality of data reception due to the improved reception state. Figure 66 In the case where the lens (group) A3101 does not have a focal length changing function, the focal length change for improving reception cannot be performed.

[0801] Figure 67 Yes Receive Figure 54 An example of the structure of the receiving device 150 for the optical modulated signal transmitted by the transmitting device 100 is provided. Figure 65The same operations are assigned the same numbers, and the description of the parts that have already been described is omitted.

[0802] Figure 67 The receiving device 150 and Figure 65 The difference between the receiving device 150 and Figure 66 Likewise, there is a signal processing unit A3302 following the image sensor A3103.

[0803] In addition, the details of the operation of the signal processing unit A3302 have been explained, so the explanation is omitted here. And, as already explained, since the reception state is improved, the effect of improving the reception quality of data can be obtained.

[0804] In addition, since the method of improving the reception state in the lens control unit A3108 has been described, the description is omitted.

[0805] As described above, the receiving device 150 can improve the quality of data reception due to the improved reception state. Figure 67 In the case where the lens (group) A3101 does not have a focal length changing function, the focal length change for improving reception is not performed.

[0806] However, in Figure 64 、 Figure 65 、 Figure 66 、 Figure 67 In receiving device 150, lens (group) A3101 can have multiple focal length settings. For example, a method is conceivable where the focal length can be set to between 12 mm and 35 mm, or where the focal length can be set to 12 mm and 25 mm. The following description will be based on this example.

[0807] As a first example, we can consider the case where multiple discrete values ​​are supported as focal length.

[0808] Figure 64 、 Figure 65 、 Figure 66 、 Figure 67 When the receiving device 150 is set to "communication mode" according to the instruction signal A3150, although communication starts, the focal length of the lens (group) A3101 at this time can be set to 12mm, which is the widest angle. Figure 56 As shown, it is more likely that the reception state where some optical modulation is difficult to receive can be avoided. This can improve the reception quality of data. However, in order to achieve only the improvement of the reception quality of data, the focal length and other parameters can also be controlled to the optimal value.

[0809] In addition, in this example, although the examples of supporting 12mm and 25mm focal lengths are explained, even if more than two focal lengths are supported, setting the focal length to the widest angle, for example, when starting communication is also an effective method for improving the data reception quality.

[0810] As a second example, a case where the focal length can be set continuously (or finely) can be considered.

[0811] Figure 64 、 Figure 65 、 Figure 66 、 Figure 67 When the receiving device 150 is set to "communication mode" by the instruction signal A3150, although communication starts, the focal length of the lens (group) A3101 at this time can be set to 12mm for the widest angle. Figure 56 As shown, it is highly likely that the reception condition where some optical modulation is difficult to receive can be avoided. This can improve data reception quality. However, in this example, since the focal length can be finely adjusted, even a setting of 14mm, for example, is likely to achieve the same effect. However, to further improve data reception quality, the focal length and other parameters can also be controlled to optimal values.

[0812] exist Figure 66 、 Figure 67 Consider a case where the signal processing unit A3302 of the receiving device 150 has a zoom (image magnification (or reduction)) processing function. Here, examples are described corresponding to 1x image magnification (or non-magnification), 2x image magnification, and 4x image magnification.

[0813] Figure 66 、 Figure 67 When the receiving device 150 is set to "communication mode" by the instruction signal A3150, although communication starts, the zoom (zoom in (or out) of the signal processing unit A3302 at this time can be set to "1x image zoom (no zoom)" of the widest angle. The case of setting to the widest angle is as shown in FIG. Figure 56 As shown, it is more likely that the reception state where some optical modulation is difficult to receive can be avoided. This can improve the data reception quality. However, to further improve the data reception quality, the zoom value can be controlled to an optimal value.

[0814] (Implementation 12)

[0815] In this embodiment, the configuration and processing operations of a communication system including a transmitter and a receiver mounted on a vehicle are described. Furthermore, each of the transmitter and receiver in this embodiment may include all or part of the functions of the transmitter and receiver in the above-described embodiments.

[0816] Figure 68 An example of the configuration of a communication system mounted on a vehicle is shown.

[0817] The communication system includes a transmitting device 810 and a receiving device 820 .

[0818] The transmitting device 810 transmits (performs illumination) N optical modulated signals, for example. N is an integer greater than or equal to 2. (However, N may also be an integer greater than or equal to 1.) Such a transmitting device 810 includes N transmitting groups for generating N optical modulated signals, each of which is a light signal. These transmitting groups are composed of light sources 811_i and transmission signal processing units 813_i. i is an integer greater than or equal to 2 and less than or equal to N. (However, i may also be an integer greater than or equal to 1.)

[0819] The transmission signal processing unit 813_i generates and outputs a modulated signal 812_1 based on the information 814_i. Furthermore, the transmitting device 810 does not necessarily need to transmit N optical modulated signals. In other words, the transmitting device 810 may not transmit an optical modulated signal, or the transmitting device 810 may transmit more than one and less than N optical modulated signals (or may perform illumination).

[0820] The light source 811_i is composed of, for example, at least one LED or other lighting device, and can be used as a left headlight, a right headlight, a left taillight, a right taillight, a fog light (or a right fog light, a left fog light), a brake light (or a right brake light, a left brake light), or a position light (or a right position light, a left position light), etc. Furthermore, the light source 811_i is not limited to these lighting devices or lamps and can also be used as lighting devices or lamps for other purposes.

[0821] The light source 811_i changes its brightness according to the modulation signal 812_i from the transmission signal processing unit 813_i, and transmits the light signal corresponding to the modulation signal 812_i as the light modulation signal. However, although the example of this embodiment uses brightness changes as an example, data can also be transmitted by changing the color in the color space or chromaticity diagram generated by changes in the tristimulus values ​​X, Y, and Z.

[0822] For example, information 814_i includes information for identifying the vehicle model (or vehicle model information) of the vehicle on which the communication system is mounted, namely, vehicle model identification information (or vehicle model information), the vehicle's speed, and information about the position of light source 811_i within the vehicle body. Information about the position of light source 811_i within the vehicle body includes, for example, information about the position within the vehicle body on which the communication system is mounted, specifically, information about whether the light source 811_i is positioned on the vehicle body, such as the left front or right front, left rear or right rear, front center, or rear center.

[0823] The receiving device 820 includes M receiving groups that each receive optically modulated signals, and a display information generator 830. M is an integer greater than or equal to 1. Each receiving group includes an (electronic) rearview mirror 821_j, a recognition unit 823_j, a demodulation unit 826_j, and a sensor control unit 827_j. j is an integer greater than or equal to 1 and less than or equal to M.

[0824] Rearview mirror 821_j is, for example, an electronic rearview mirror that functions as a light-receiving unit. Specifically, rearview mirror 821_j electronically implements the vehicle's left rearview mirror, right rearview mirror, interior rearview mirror, or bumper-mounted rearview mirror. Furthermore, rearview mirror 821_j is not limited to these rearview mirrors and can also be used as a rearview mirror for other purposes or installed in other locations.

[0825] Specifically, rearview mirror 821_j includes an image sensor, such as a CMOS, organic CMOS, or CCD. This rearview mirror 821_j receives ambient light and outputs image data 822_j. Here, rearview mirror 821_j changes the image sensor's scanning method, specifically, the method for reading light intensity, in response to a control signal 829_j from a sensor control unit 827_j.

[0826] Specifically, when the control signal 829_j indicates control for moving images, the rearview mirror 821_j reads the light intensity using a line scan sampling method with a long exposure time, thereby outputting imaging data 822_j for moving images as described in the eighth embodiment.

[0827] Furthermore, when the control signal 829_j indicates control for optical communication, the rearview mirror 821_j reads the light intensity by a line scan sampling method with a short exposure time, thereby outputting imaging data 822_j for optical communication as shown in Embodiment 8. The imaging data 822_j for optical communication is data based on the light modulation signal transmitted by the transmitting device 810 of the communication system mounted on another vehicle. More specifically, the rearview mirror 821_j is as follows. Figure 42 As shown, line scan sampling is performed according to the areas included in the image sensor. That is, the rearview mirror 821_j performs line scan sampling for each of one or more areas indicated by the control signal 829_j.

[0828] Thus, rearview mirror 821_j can simultaneously receive multiple optical modulation signals. Furthermore, since receiving device 820 includes multiple rearview mirrors 821_j, it can simultaneously receive even more optical modulation signals. Furthermore, while line sampling is used in the above example, it is also possible to omit line sampling and instead read the light intensity for each pixel.

[0829] The recognition unit 823_j performs pattern recognition, object recognition, etc. on the camera data 822_j for the moving image output from the rearview mirror 821_j. Based on this, the recognition unit 823_j recognizes the object that transmits the light modulation signal from the multiple objects reflected in the image of the camera data for the moving image. Hereinafter, this object is referred to as the "transmitting object". The recognition unit 823_j outputs an object recognition signal 824_j indicating the recognition result of the transmitting object. In addition, in the case where the transmitting object is a vehicle, for example, a vehicle carrying Figure 68 In the communication system shown, the (illuminated) light modulated signal sent by the transmitting object includes vehicle type identification information (or vehicle type information), the vehicle's driving speed, and information on the configuration position of the light source on the vehicle body.

[0830] The sensor control unit 827_j outputs a control signal 829_j corresponding to the object recognition signal 824_j to the demodulator 826_j and the rearview mirror 821_j. For example, when the object recognition signal 824_j indicates that the transmitting object is not recognized, the sensor control unit 827_j outputs a control signal 829_j indicating control for moving images. In addition, when the object recognition signal 824_j indicates that the transmitting object is recognized, the sensor control unit 827_j outputs a control signal 829_j indicating control for moving images, for example, in Embodiment 8. Figure 39 As shown, control signal 829_j for controlling moving images and control signal 829_j for controlling optical communication are periodically alternately output. In this case, control signal 829_j for controlling optical communication indicates the area of ​​the image sensor reflecting the transmitting object identified by recognition unit 823_j. If multiple transmitting objects are identified, control signal 829_j for controlling optical communication indicates the area of ​​the image sensor reflecting each of the multiple identified transmitting objects. In this way, rearview mirror 821_j performs line scanning sampling on these areas, simultaneously receiving multiple optical modulation signals.

[0831] Upon receiving moving image data (received light signal) 822_j from the rearview mirror 821_j, the demodulator 826_j outputs received data 828_j included in the moving image data (received light signal) 822_j. Furthermore, upon receiving optical communication data (received light signal) 822_j from the rearview mirror 821_j, the demodulator 826_j performs demodulation and error correction decoding on the optical communication data (received light signal) 822_j. Specifically, the demodulator 826_j receives a control signal 829_j from the sensor control unit 827_j and uses the image sensor to identify the area of ​​the transmitting object indicated by the control signal 829_j. The demodulator 826_j then demodulates and performs error correction decoding on the data in the identified area within the optical communication data (received light signal) 822_j, and outputs received data 828_j.

[0832] Therefore, received data 828_j is estimated reception data of the data transmitted by the transmitting object. Therefore, received data 828_i includes information sent by the transmitting object, including vehicle type identification information, driving speed, and the location of the light source on the vehicle body. The transmitting object can be, for example, an oncoming vehicle, a preceding vehicle, or a following vehicle.

[0833] The display information generating unit 830 receives reception data 828_j and object recognition signals 824_j from each of the M receiving groups. Based on these reception data 828_j and object recognition signals 824_j, the display information generating unit 830 generates and outputs display information 831. The display included in the vehicle displays an image based on this display information 831.

[0834] This system allows the display to show images of the area surrounding a vehicle equipped with a communication system. Furthermore, when there are vehicles transmitting light-modulated signals nearby, information related to the vehicle can be associated with the vehicle being displayed. This vehicle information includes information identifying the vehicle's model, its speed, and the location of its light sources on the vehicle's body.

[0835] The effect achieved by the transmission and reception method in such a communication system is that a transmission distance of 100 m or more can be ensured, and optical modulated signals can be transmitted and received even when the vehicle speed is 200 km / h or less.

[0836] Furthermore, the rearview mirror 821_j may also have a function of instantly switching the focal length of the lens used to project the image onto the image sensor. This has the advantage of being able to instantly receive light modulation signals from each of multiple transmitting objects (e.g., vehicles) at different distances from the vehicle equipped with the communication system.

[0837] In addition, in the communication system of this embodiment, in addition to the light sources 811_1 to 811_N and the rearview mirrors 821_1 to 821_M, at least one component may be configured as a CPU or LSI 850.

[0838] In the above description, it is stated that "when the sending object is a vehicle, for example, Figure 68 In the communication system shown, the light modulation signal transmitted (illuminated) by the transmitting object includes: vehicle type identification information, vehicle speed, and information about the configuration position of the light source on the vehicle body. The following describes the effect when the light modulation signal includes information about the vehicle type identification information, vehicle speed, and information about the configuration position of the light source on the vehicle body.

[0839] As described above, the receiving device 820 receives the light modulated signal sent by the sending object and performs demodulation and other processing to obtain the vehicle model identification information (or vehicle model information) of the sending object, the vehicle's driving speed information, and "information on the configuration position of the light source on the vehicle body."

[0840] At this time, when the receiving device 820 obtains the vehicle type confirmation information (or vehicle type information) of the sending object, although Figure 68 Although not shown, for example, the receiving device 820 includes a storage unit having a database related to the “relationship between vehicle model and size”. For example, the database is as follows.

[0841] When the vehicle type confirmation information is "0000000000" (binary), it means "the vehicle type is #0, the total length is 3395mm, the vehicle width is 1475mm, and the vehicle height is 1780mm."

[0842] When the vehicle type confirmation information is "0000000001" (binary), it means "the vehicle type is #1, the total length is 4840mm, the vehicle width is 1820mm, and the vehicle height is 1695mm."

[0843] When the vehicle model confirmation information is "1111111111" (binary), it means "the vehicle model is #1023, the total length is 4270mm, the vehicle width is 1785mm, and the vehicle height is 1445mm."

[0844] Therefore, the receiving device 820 obtains the vehicle model identification information by receiving the optical modulated signal sent by the sending object and demodulating it. Then, the storage unit of the receiving device 820 takes the vehicle model identification information as input, obtains the "vehicle model, total length, vehicle width, and vehicle height" information from the above-mentioned database and outputs it.

[0845] Therefore, the receiving device 820 can estimate the distance to the transmitting object based on the information of “vehicle type, overall length, width, and height.” Furthermore, the display information generating unit 830 included in the receiving device can more accurately grasp the transmitting object.

[0846] In this way, the effect that can be achieved is that the sending object sends a light modulated signal including vehicle model information, so that the receiving device that receives the light modulated signal can more accurately grasp the state of the sending object.

[0847] Alternatively, it can be Figure 70 In the structure shown, when the communication system has a wireless communication system 842, the wireless communication system 842 is used to send a modulated signal including vehicle type identification information. The communication partner of the wireless communication system 842 obtains the vehicle type identification information and sends a modulated signal including data such as "vehicle type, total length, vehicle width, and vehicle height". The communication system receives the modulated signal and obtains information such as "vehicle type, total length, vehicle width, and vehicle height". In addition, regarding Figure 70 The work will be explained later.

[0848] Furthermore, the receiving device obtains “information on the arrangement position of the light source on the vehicle body.” The effect of this will be described using an example.

[0849] For example, a vehicle equipped with a communication system only receives the light modulation signal from the light source of the "right headlight," which is the transmitting object. Therefore, the receiving device 820 in the communication system demodulates only the received signal corresponding to the light modulation signal of the light source of the "right headlight," and recognizes that the "right headlight" information has been obtained based on the "light source's position information on the vehicle body" contained in the received signal.

[0850] In this way, the light source of the right headlight of the vehicle equipped with the communication system can recognize the presence of a vehicle and recognize that part of the vehicle is blocked by the obstruction. In addition, it can be recognized that the left side of the transmitting object is blocked by the obstruction.

[0851] This has the effect that, by having the transmitting object transmit "information on the configuration position of the light source on the vehicle body" to each light source, the communication system that obtains this information can estimate the condition of the transmitting object more specifically.

[0852] Next, the recognition result in the recognition unit 823_i is described. Figure 69 An example of the recognition result is shown.

[0853] For example, the recognition unit 823_j obtains the object recognition signal 824_j from the rearview mirror 821_j used as the center rearview mirror. Figure 69As shown in (a), the headlights of multiple following vehicles are recognized as transmitting objects by performing pattern recognition on the object recognition signal 824_j. Then, the recognition unit 823_j identifies the positions of the multiple transmitting objects in the object recognition signal 824_j.

[0854] The demodulation unit 826_1 performs demodulation or error correction on each area of ​​the camera data 822_j for optical communication. The above-mentioned areas are areas including the location of the transmitting object determined by the recognition unit 823_j. Based on this, the demodulation unit 826_i obtains information about the transmitting object from the area. The information about the transmitting object includes information on the vehicle type, information on the vehicle's speed, and "information on the configuration position of the light source on the vehicle body." For example Figure 69 As shown in (a), the vehicle type identification information is, for example, "Company α, vehicle type C", the driving speed information is, for example, "48 km / h", and the "light source configuration position information on the vehicle body" is, for example, "right front".

[0855] The display information 831 output from the display information generating unit 830 includes the information of each transmitting object obtained by the demodulating unit 826_i. Therefore, if the control unit such as the ECU (Electronic Control Unit) mounted on the vehicle obtains the display information 831, as shown in FIG. Figure 69 As shown in (b), the control unit can identify the size, shape, and position of other vehicles surrounding the vehicle. Specifically, the control unit determines the size and shape of the vehicle based on the vehicle model indicated by the vehicle model identification information by referencing a database, etc. The control unit then identifies the size and position of the vehicle indicated in object identification signal 824_j based on the "light source configuration position on the vehicle body" information included in the transmitted object information and the "light source configuration position and size on the vehicle body" indicated in object identification signal 824_j. The control unit also identifies surrounding information, such as obstructions and overlapping vehicles.

[0856] That is, the control unit does not recognize the size, shape, and position of other vehicles from the image as the object recognition signal 824_j, but can quickly recognize them based on the information of the transmitted object. In other words, the burden of image processing can be reduced, and the recognition speed of other vehicles in the surrounding area can be improved. Figure 68It is not recorded in the text, and sensors for identifying objects may also be installed. When these sensors are used to identify the "size, shape and position of other vehicles", the effect that can be obtained is that the receiving device 820 can obtain the vehicle type identification information, the vehicle's driving speed information, and "the configuration position of the light source on the vehicle body" contained in the light modulation signal sent by the light source of the sending object, and can use this information to more accurately grasp the "state of the sending object and the state of the surroundings of the sending object".

[0857] Furthermore, the transmitted object information includes information about the location of the light source on the vehicle body. This allows the control unit to quickly identify whether the left and right headlights of another vehicle are present in the image, or whether one of the left or right headlights is obstructed. Furthermore, the control unit can tailor this information to the vehicle type, enabling it to identify motorcycles and bicycles, which are difficult for conventional object recognition sensors to detect. Furthermore, because the transmitted object information includes driving speed information, the control unit can accurately identify the speed of other vehicles. These advantages are achieved.

[0858] The display information 831 output from the display information generating unit 830 includes not only the information of the transmitting object but also the object recognition signal 824_j. In this case, the object recognition signal 824_j includes the data of a moving image or a still image.

[0859] Therefore, if the control unit such as ECU (Electronic Control Unit) mounted on the vehicle obtains the display information 831, Figure 69 As shown in (c), an image of other vehicles surrounding the vehicle can be displayed on the vehicle's display. Furthermore, the control unit can overlay information about the transmitting object onto the image displayed on the display. In other words, information obtained from the light source can be displayed in correspondence with the light source of the transmitting object reflected in the image. This can achieve such an effect.

[0860] Figure 70 The structure of the communication system mounted on the vehicle is shown. Figure 68 Different examples. In addition, for Figure 70 The components included in the communication system shown are Figure 68 The same components included in the communication system shown are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0861] exist Figure 68 In the communication system shown, the information transmitted and received via the optical modulated signal is vehicle type identification information, driving speed information, and "information on the position of the light source on the vehicle body." Figure 70In the communication system shown, the information transmitted and received by the optical modulated signal is Figure 68 The communication system shown is different and has information related to wireless access of the vehicle. Figure 70 The communication system shown transmits information related to wireless access of a vehicle equipped with the communication system (i.e., the own vehicle) to other vehicles using optical modulation signals.

[0862] The information related to wireless access is, for example, information on SSID (Service Set Identifier) ​​when the communication method of the wireless communication system 842 is wireless LAN (Local Area Network). Figure 70 Transmitter 810 transmits (illuminates) the SSID information of wireless communication system 842 included in the communication system using an optically modulated signal. Furthermore, the communication method of wireless communication system 842 is not limited to wireless LAN. If wireless communication system 842 uses another wireless communication method utilizing radio waves, identification information distinguishing wireless communication system 842 can be used as information related to wireless access. This point has been described in detail in other embodiments of this specification.

[0863] Furthermore, the optical modulation signal including the information related to the wireless access of the wireless communication system 842 possessed by the communication system of the other vehicle (herein referred to as the second vehicle) is transmitted by the communication system of the second vehicle, and the optical modulation signal including the information related to the wireless access of the wireless communication system 842 possessed by the communication system of the second vehicle is transmitted by the communication system of the second vehicle. Figure 70 The communication system of the first vehicle receives the signal. The communication system of the first vehicle searches for the modulated signal transmitted by the wireless communication system 842 of the communication system of the second vehicle from the wireless access-related information of the wireless communication system 842 of the communication system of the second vehicle, and communicates with the communication system of the second vehicle via wireless (i.e., radio waves).

[0864] Specifically, Figure 70 The comm...

Claims

1. A sending method, During the first period, the light source is turned on at a first brightness. During the second period, the light source is alternately turned on with a second brightness and a third brightness, so that the light source sends a light signal, wherein the second brightness is lower than the first brightness and the third brightness is lower than the second brightness. The first period is set between two consecutive second periods. In the transmission method, the light source is controlled so that a guard interval is provided between the first period and the second period that follows it, and a fourth brightness in the guard interval is lower than the first brightness in the first period.

2. A receiving method, During the first period, light of the first brightness is received from the light source. During the second period, the optical signal transmitted from the light source is received by alternately receiving light of a second brightness and light of a third brightness, wherein the second brightness is lower than the first brightness and the third brightness is lower than the second brightness. By analyzing the data based on the optical signal, analysis information is outputted. The first period is set between two consecutive second periods. In the receiving method, light is further received in a protection interval provided between the first period and the second period following the first period, and a fourth brightness in the protection interval is lower than the first brightness in the first period.

3. A transmitting device comprising a light source and a transmitting unit, The sending unit causes the light source to send an optical signal by lighting the light source at a first brightness during a first period and lighting the light source alternately at a second brightness and a third brightness during a second period, wherein the second brightness is lower than the first brightness and the third brightness is lower than the second brightness. The first period is set between two consecutive second periods. In the transmitting device, the light source is controlled so that a guard interval is provided between the first period and the second period that follows it, and a fourth brightness in the guard interval is lower than the first brightness in the first period.

4. A receiving device comprising a light receiving unit and a data analyzing unit, The light receiving unit receives a light signal sent from the light source by receiving light of a first brightness from the light source during a first period and alternately receiving light of a second brightness and light of a third brightness during a second period, wherein the second brightness is lower than the first brightness and the third brightness is lower than the second brightness. The data analysis unit analyzes the data based on the optical signal to output analysis information. The first period is set between two consecutive second periods. The light receiving unit further receives light in a protection interval provided between the first period and the second period following the first period, and a fourth brightness in the protection interval is lower than the first brightness in the first period.

Images