JP5777502B2 - Visible light communication transmitting / receiving method, visible light communication transmitting apparatus, and program - Google Patents

Description

  The present invention relates to a technique for transmitting and receiving information in communication using visible light and electromagnetic waves in the surrounding band.

  In recent years, visible light sources have been used not only for illumination purposes for obtaining light but also for communication purposes. This contributes to the widespread use of light emitting diodes (LEDs) as visible light sources. Light emitting diodes are superior to conventional visible light sources in terms of life, size, and power consumption, although the amount of light emitted per element is less than that of conventional visible light sources such as incandescent bulbs and fluorescent lamps. In addition to the above characteristics, the light-emitting diode has a characteristic that the response speed is very fast. Moreover, it is easy to electrically control the light emission of the light emitting diode.

  Since light-emitting diodes have the characteristics described above, in recent years, research and development have been conducted not only for lighting applications for obtaining light but also for signal transmission applications using blinking of visible light. For example, Non-Patent Document 1 proposes to perform communication by superimposing a signal on a household lighting fixture using a light emitting diode. At present, visible light is not subject to the regulations of the Radio Law, so there are no restrictions on bandwidth and power, and it is possible to make these large, and we propose to use light emitting diodes exclusively for communication using this fact. There are also studies. (For example, refer nonpatent literature 2). Hereinafter, communication performed using a visible light source such as a light emitting diode is referred to as visible light communication.

  In the visible light communication, a photodetector such as a photodiode is used as an element on the receiving unit side. When the photodiode is used alone, a high sampling rate can be obtained, so that high-speed communication can be performed. On the other hand, Non-Patent Document 3 proposes using an image sensor as an element on the receiving unit side. The image sensor can capture the intensity distribution of each visible light obtained by a sensor in which photodiodes are arranged in a grid, and can observe the intensity distribution of the two-dimensional visible light by using a semiconductor element. Used for. When the image sensor is used for visible light communication, parallel communication can be performed because blinking of a plurality of light emitting elements can be observed simultaneously. Proposals for communication methods that take advantage of this feature are expected.

  It has also been proposed to use an image sensor not only for communication but also for visualization of sensor information. In the case of visible light communication using an image sensor, information is often turned on / off modulated or multi-valued in either single (serial communication) or parallel (parallel communication) (see, for example, Non-Patent Document 4). ).

Toshihiko Komine, Yuichi Tanaka, Masao Nakagawa, “Fusion System of White LED Lighting Signal Transmission and Power Line Signal Transmission”, IEICE Technical Report, The Institute of Electronics, Information and Communication Engineers, March 12, 2002, Vol.101, No.726, pp.99-104 Masanori Ishida, Shinichiro Haruyama, Masao Nakagawa, “Examination of Communication Speed Limit in Parallel Visible Light Wireless Communication System”, IEICE Technical Report CS Communication System, IEICE, January 4, 2007, Vol. .106, No.450, pp.37-41 Nobuo Iizuka, “Trends and Perspectives of Communication Technology for Visible Light Image Sensors (Research Report)”, Micromechatronics, The Japan Society of Clock Studies, June 10, 2010, Vol.54, No.202, pp.26-37 Toru Nagura, Takaya YAMAZATO, Masaaki KATAYAMA, Tomohiro YENDO, Toshiaki FUJII, Hiraku OKADA, “Improved Decoding Methods of Visible Light Communication System for ITS Using LED Array and High-Speed Camera”, Vehicular Technology Conference (VTC 2010-Spring), 2010 IEEE 71st, IEEE, 16-19 May 2010, pp.1-5

  In visible light communication, when an image sensor is used as a light receiving element of a receiving device, time resolution is more restricted than when a photodiode is used. For example, a meaningful minimum unit that encodes information to be transmitted is referred to as a “word”, and a signal of the minimum unit that constitutes a “word” is referred to as a “symbol”. One word is described by k symbols. It is assumed that the transmission apparatus can transmit r words per second, that is, a bit string of (k × r) bits per second. In the case of normal serial communication, if the condition that the receiving apparatus can receive a bit string of (k × r) bits per second is not satisfied, the transmitted bit string becomes completely meaningless. This is because the value of the word cannot be known unless k bits included in one word can be read in order.

  In the conventional visible light communication transmission / reception method, this problem is avoided by reducing the communication speed in accordance with the limitations of the receiving device. However, a method for realizing a high communication speed for a high-performance receiving apparatus and a low communication speed for a low-performance receiving apparatus using the same transmitting apparatus has not been proposed.

  The present invention has been made in view of such points, and even when a receiving device with sufficient processing speed and a receiving device with insufficient processing speed coexist, a transmission signal is transmitted using the same transmitting device. An object of the present invention is to provide a visible light communication transmitting / receiving method capable of transmitting / receiving.

  In order to solve the above-described problem, the visible light communication transmitting / receiving method of the present invention uses a transmission signal S (i, j) including N (1 ≦ n ≦ N) words composed of k symbols per second (k Xr) Transmission is performed using visible light from a transmitter capable of transmitting symbols to a receiver capable of receiving symbols per second (k × r). t represents time, i represents a word number in each signal, j represents a symbol number in each word, k and n are relatively prime, and n = p. The transmission device modulates the transmission signal S (i, j) to generate a transmission modulation signal M (i, j). The transmission apparatus rearranges the transmission modulation signal M (i, j) for every n words as i ′ = i, j ′ = p (j−1) +1, and transmits the transmission rearrangement signal Mm (i ′, j ′). The transmission device controls the light emitting element so that the transmission rearrangement signal Mm (i ′, j ′) is transmitted at time t = (i−1) / r + pj / kr, and transmits the visible light signal B (t ) Is output. The receiving device receives the received visible light signal B ′ (t) using the light receiving element, and generates a received rearranged signal Mm ′ (i ′, j ′). The reception rearranged signal Mm ′ (i ′, j ′) received by the receiving device at time t = (i−1) / r + pj / kr is converted into i = i ′, j = (j′−) for every n words. 1) Rearrangement is performed as / p + 1 to generate a reception modulation signal M ′ (i, j). The receiving device demodulates the received modulated signal M ′ (i, j) and outputs a received signal S ′ (i, j).

  According to the visible light communication transmitting / receiving method of the present invention, a signal received at a speed commensurate with the processing speed capability of each brightness intensity signal is performed by appropriately rearranging the transmission order of symbols modulated in the transmitting apparatus. Therefore, even if there are both receivers with sufficient brightness intensity processing speed and receivers with insufficient brightness intensity processing speed, the same transmitter is It is possible to transmit all of the information transmitted by the transmitting device to a receiving device with sufficient brightness intensity processing speed, and to a certain degree even for a receiving device with insufficient brightness intensity processing speed. Can send information.

The block diagram which shows the structure of the conventional visible light communication transmission / reception method. The schematic diagram explaining the principle of the conventional visible light communication transmission / reception method. The schematic diagram showing the process of the receiver with sufficient processing speed. The schematic diagram showing the process of the receiver with insufficient processing speed. 1 is a block diagram illustrating a configuration of a visible light communication transmission / reception method according to a first embodiment. FIG. 3 is a schematic diagram illustrating processing of the transmission device 11 according to the first embodiment. FIG. 3 is a schematic diagram illustrating processing of the reception device 21 according to the first embodiment. FIG. 3 is a schematic diagram illustrating processing of the reception device 22 according to the first embodiment. The block diagram which shows the structure of the visible light communication transmission / reception method of Example 2. FIG. The block diagram which shows the structure of the visible light communication transmission / reception method of Example 3. FIG. FIG. 9 is a schematic diagram illustrating processing of the transmission device 12 according to the third embodiment. FIG. 9 is a schematic diagram illustrating processing of the receiving device 24 according to the third embodiment. FIG. 10 is a schematic diagram illustrating processing of the reception device 22 according to the third embodiment. The block diagram which shows the structure of the visible light communication transmission / reception method of Example 4. FIG.

  Hereinafter, embodiments of the present invention will be described in detail. In addition, the same number is attached | subjected to the structure part which has the same function, and duplication description is abbreviate | omitted.

[Conventional Visible Light Transmission / Reception Method]
Prior to the description of the embodiment, the operation of the conventional visible light communication transmitting / receiving method will be described in detail with reference to FIGS. FIG. 1 is a block diagram showing a configuration of a conventional visible light communication transmitting / receiving method. FIG. 2 is a schematic diagram illustrating the principle of a conventional visible light communication transmitting / receiving method. The transmission device 10 includes a modulation unit 110, a visible light emission control unit 130, and a light emitting element 100. The receiving device 20 includes a light receiving element 200, a visible light reception control unit 210, and a demodulation unit 230. Assume that the transmitter 10 and the receiver 20 can communicate r words per second when there is no error. In the following description, it is assumed that one word is described by k symbols. As described above, a meaningful minimum unit obtained by encoding information to be transmitted is referred to as a “word”. Further, a minimum unit signal constituting a “word” is called a “symbol”. For example, when the signal (0010) has the meaning (b), (b) is a “word”, and 0 and 1 constituting (b) are “symbols”.

  The description of each signal will be described with reference to FIG. S (i) is a transmission signal that is a digital transmission signal output from the encoding device 8. M (i) is a transmission modulation signal output from the modulation unit 110. C (t) is an electrical signal output from the visible light emission control unit 130. B (t) is a transmission visible light signal that is a blinking pattern of the light emitting element 100. B ′ (t) is a received visible light signal which is a blinking pattern received by the light receiving element 200. C ′ (t) is an electrical signal output from the light receiving element 200. M ′ (i) is a reception modulation signal that is a digital signal before demodulation output from the visible light reception control unit 210. S ′ (i) is a received signal which is a demodulated digital signal output from the demodulator 230. However, i is an index about time.

  S (i, j) represents the value of the jth bit of the bit string S (i) transmitted at the time indicated by the index i. For example, when the transmission signal S (i) is (10110111), S (i, 5) is 0. Similarly, M (i, j) when on / off modulation is performed represents the j-th on / off value of the on / off sequence M (i) transmitted at the time indicated by the index i. For example, assuming that n is on and off is f, and M (i) is (nfnnfnnnn), M (i, 5) is off. A meaningful group of strings such as S (i) and M (i) corresponds to a “word”. Each element constituting a word such as S (i, j), M (i, j) corresponds to a “symbol”.

As described above, i is the index for the time, t _i is the time for transmitting the S (i). When transmitting r words per second, t _{i + 1} = t _i + 1 / r. S (i), M (i), C (t), B (t), B ′ (t), C ′ (t), M ′ (i), and S ′ (i) indicate the processing start time for each. It shall be adjusted. For example, when the process between the encoding unit 80 and the decoding unit 90 takes τ _{encoding unit and decoding unit} seconds, the time in the decoding unit 90 is denoted by t _i (decoding unit), and the time in the encoding unit 80 is determined. As t _i (encoding unit), it can be expressed as t _i (decoding unit) = t _i (encoding unit) + τ _{encoding unit and decoding unit} . In the following, “time (name of device or part)” is defined as the time in the device or part of that name.

  The encoding device 8 outputs a digital transmission signal S (i). The modulation unit 110 included in the transmission device 10 receives the transmission signal S (i) and outputs a modulation signal M (i). The visible light emission control unit 130 sends an electric signal C (t) corresponding to the blinking pattern to the light emitting element 100 based on M (i). The light emitting element blinks according to the electric signal C (t). Let this blinking pattern be B (t). The light receiving element 200 obtains a blinking pattern B ′ (t) that is a time series of brightness intensity. The blinking pattern B ′ (t) is obtained by superimposing noise on the blinking pattern B (t). The light receiving element 200 converts B ′ (t) into an electric signal C ′ (t) and passes it to the visible light reception control unit 210. The visible light reception control unit 210 samples the electric signal C ′ (t) and outputs M ′ (i) to the demodulation unit 230. The demodulator 230 demodulates M ′ (t) and outputs a digital signal S ′ (i). Ideally, S (i) = S ′ (i). In the case of the conventional transmission device 10 shown in FIG. 1, the time at which the transmission signal S (i, j) is transmitted is (i−1) / r + (j−1) / kr.

  FIG. 2 is a schematic diagram of serial communication using on / off modulation. The digital signal S (i) encoded by the encoding device 8 is expressed by a sequence (here, 10110111) composed of k symbols. The transmitting apparatus 10 converts this as a blinking pattern B (t). The receiving device 20 receives a time series B ′ (t) of brightness intensity in which noise is superimposed on B (t), converts it into a symbol sequence S ′ (i), and outputs it. Ideally, S (i) = S ′ (i). In this case, the blinking pattern B (t) output from the transmission apparatus 10 is as shown in FIG. 2, and the time required to transmit one symbol is 1 / (k × r). In order to realize a transmission path of (k × r) bits per second in serial communication of on / off modulation, it is necessary for the receiving device 20 to read a bit string (k × r) times per second.

[Problems of conventional visible light communication method]
The problems of the conventional visible light communication transmitting / receiving method will be described with reference to FIGS. FIG. 3 is a schematic diagram illustrating processing of a receiving apparatus having a sufficient processing speed, and FIG. 4 is a schematic diagram illustrating processing of a receiving apparatus having an insufficient processing speed. In FIG. 3, since the processing speed of the receiving device is sufficient, appropriate received signals S ′ (1), S ′ (2), and S ′ (3) are obtained. On the other hand, in FIG. 4, since the processing speed of the receiving apparatus is only 1/4 with respect to an appropriate speed, a meaningless value S ′ (1) is output.

  In the conventional visible light communication transmission / reception method, this problem is avoided by reducing the communication speed in accordance with the limitations of the receiving device. However, a method for realizing a high communication speed for a high-performance receiving apparatus and a low communication speed for a low-performance receiving apparatus using the same transmitting apparatus has not been proposed. The present invention is capable of transmitting and receiving transmission signals using the same transmitter even when a receiver having sufficient brightness intensity processing speed and a receiver having insufficient brightness intensity processing speed coexist. An optical communication transmission / reception method is realized.

[Configuration of Example 1]
With reference to FIG. 5, the visible light communication transmission / reception method according to the first embodiment of the present invention will be described in detail. FIG. 5 is a block diagram showing a configuration of an apparatus for executing the visible light communication transmitting / receiving method of the present embodiment. An apparatus that executes the visible light communication transmitting / receiving method of the present embodiment includes a transmitting apparatus 11 and a receiving apparatus 21 or a receiving apparatus 22. As peripheral devices of this embodiment, there are an encoding device 8 and a decoding device 9. The encoding device 8 includes an encoding unit 80. The decoding device 9 includes a decoding unit 90.

  The transmission device 11 includes a modulation unit 110, a modulation result rearrangement unit 120, a visible light emission control unit 130, and a light emitting element 100. The modulation result rearrangement unit 120 includes a memory, a CPU, and the like. The transmission device 11 transmits r words every second. Therefore, the transmission device 11 transmits (k × r) symbols per second.

  The receiving device 21 includes a light receiving element 200, a visible light reception control unit 210, a light reception result rearrangement unit 220, and a demodulation unit 230. The light reception result rearrangement unit 220 includes a memory, a CPU, and the like. The receiving device 21 is a receiving device with sufficient processing speed of brightness intensity, and the processing speed of brightness intensity is (k × r) per second. That is, all the brightness intensity signals output from the transmission device 11 can be processed.

  The receiving device 22 includes a light receiving element 201, a visible light reception control unit 210, a light reception result rearranging unit 221, and a demodulation unit 230. The light reception result rearranging unit 221 includes a memory, a CPU, and the like. The receiving device 22 is a receiving device that does not have sufficient brightness intensity processing speed, and the brightness intensity processing speed is (k × r / p) per second. That is, 1 / p of the brightness intensity signals output from the transmission device 11 can be processed.

  It is assumed that the receiving device 21 and the receiving device 22 already know the parameters k, r, p, and n.

  In this embodiment, as compared with the conventional visible light communication transmission method, the transmission apparatus 11 includes the modulation result rearrangement unit 120, so that the order of the transmission signals S (i) is appropriately changed, and the processing capability is increased. Even if the receiving device 22 is not sufficient, it is possible to ensure a certain communication speed. The rearrangement algorithm for the transmission signal 11 in this embodiment is intended to transmit the transmission signal with low delay. Therefore, at the time when the transmission apparatus 11 of the present embodiment transmits the brightness intensity signal B (t) corresponding to the modulation signal M (i, 1), the conventional transmission apparatus 10 modulates the modulation signal M (i, 1). Is equal to the time at which the brightness intensity signal B (t) corresponding to is sent.

  In the following, description will be made in the order of procedures actually performed. First, the encoding unit 80 included in the encoding device 8 generates a transmission signal S (i) that is an encoded digital signal and outputs it to the transmission device 11.

[Processing of transmission device 11]
Modulation section 110 receives transmission signal S (i), modulates it, generates modulated signal M (i), and outputs it. S (i) is a word composed of k symbols. S (i, j) represents the jth symbol of S (i). M (i) is a modulation word corresponding to S (i). In the following, for simplicity, M (i, j) is a modulated symbol corresponding to S (i, j). For example, if k = 8 and the symbol is represented by bits, S (1) = (01000110), S (1,2) = 1. If the modulation symbol M (i, j) = f corresponding to S (i, j) = 0 and the modulation symbol M (i, j) = n corresponding to S (i, j) = 1, then M (1) = (fnfffnnf).

The modulation result rearrangement unit 120 assumes that m−1 modulation signals M (i) have already been transmitted, and n modulation signals M (m), M (m + 1),..., M (m + n−1). Are sequentially stored in the memory. Hereinafter, the signal written in the memory of the modulation result rearrangement unit 120 is referred to as Mem (i, j). Here, i and j are indexes representing memory addresses. N is equal to p. The modulation result rearrangement unit 120 rearranges the symbols of the input modulation signal M (i) according to the following procedure, generates the rearrangement signal Mm (i), and outputs the rearrangement signal Mm (i) to the visible light emission control unit 130. The rearrangement signal Mm (i) is the output of the modulation result rearrangement unit 120 at time t (modulation result rearrangement unit 120) = (i−1) / r + (j−1) / kr. Further, in order that the symbol rearrangement procedure of the modulation result rearrangement unit 120 does not cause collision of the output time of the rearrangement signal Mm (i, j), k and n must be relatively prime. is there.
Step 1: The index is reset to i = 1 and j = 1.
Step 2: Update the time. When 1 / kr time has elapsed since the previous update, t (modulation result rearrangement unit 120) = t (modulation result rearrangement unit 120) is updated to + 1 / kr. If not, wait.
Step 3: M (i, j) is substituted into Mem (i, p (j-1) +1).
Step 4: combination of integers satisfying t (modulation result rearranging unit 120) = (i′−1) / r + p (j′−1) / kr and 1 ≦ i ′ ≦ n and 1 ≦ j ′ ≦ k Check whether (i ′, j ′) exists. If yes, go to Step 5. If not, go to step 6.
Step 5: Output Mem (i ′, j ′) as Mm (i ′, j ′). Go to step 7.
Step 6: Check if j is equal to k. If equal, go to step 7. If not, go to step 8.
Step 7: Set i = i + 1 and j = 1. Go to step 2.
Step 8: Set j = j + 1. Go to step 2.
Here, Mem (i, j) in which the modulation signal M (i, j) output to the visible light emission control unit 130 is stored may be sequentially deleted and reused as an unused memory area.

  FIG. 6 is a schematic diagram illustrating a situation in which the transmission device 11 rearranges the modulated signals M (i). Here, k = 8, n = 3, and p = 3 will be described. M (1,1) is transmitted as Mm (1,1) at time 0 from the modulation result rearrangement unit 120 to the visible light emission control unit 130 as in the conventional transmission apparatus 10. Subsequently, M (1,2) is sent out as Mm (1,4) at time 3 / 8r. Further, M (1,3) is transmitted as Mm (1,7) at time 6 / 8r. Hereinafter, M (1, j) is transmitted as Mm (1, 3 (j−1) +1) at time 3j / 8r. M (2,1) is sent from the modulation result rearrangement unit 120 to the visible light emission control unit 130 as Mm (2,1) at time 1 / r, as in the conventional transmission device 10. Subsequently, M (2, 2) is transmitted as Mm (2, 4) at time 1 / r + 3 / 8r. Further, M (2,3) is transmitted as Mm (2,7) at time 1 / r + 6 / 8r. Hereinafter, M (2, j) is transmitted as Mm (2,3 (j-1) +1) at time 1 / r + 3j / 8r. M (3, 1) is sent from the modulation result rearrangement unit 120 to the visible light emission control unit 130 at time 2 / r as Mm (3, 1), as in the conventional transmission device 10. Subsequently, M (3,2) is sent out as Mm (3,4) at time 2 / r + 3 / 8r. Further, M (3, 3) is transmitted as Mm (3, 7) at time 2 / r + 6 / 8r. Hereinafter, M (3, j) is transmitted as Mm (2,3 × (j−1) +1) at time 2 / r + 3j / 8r.

  The visible light emission control unit 130 includes an LED driver or the like. Based on the rearrangement signal Mm (i) output from the modulation result rearrangement unit 120, the electric signal C (t) is output to control the blinking pattern of the light emitting element 100.

  The light emitting element 100 is configured by an LED or the like. Based on the electric signal C (t) output from the visible light emission control unit 120, the light emission pattern B (t) blinks.

[Processing of receiving apparatus 21]
The light receiving element 200 is configured by a photodiode or the like. By detecting (k × r) brightness intensity signals per second, B ′ (t) is received and converted into an electrical signal C ′ (t) and output.

  The visible light reception control unit 210 receives the electric signal C ′ (t) as an input and outputs a reception rearrangement signal Mm ′ (i).

  The light reception result rearrangement unit 220 sequentially stores n reception rearrangement signals Mm ′ (i) output from the visible light reception control unit 210 in the memory. Hereinafter, a signal written in the memory of the light reception result rearrangement unit 220 is referred to as Mem ′ (i, j). Here, i and j are indexes representing memory addresses. The light reception result rearrangement unit 220 rearranges symbols of the received reception rearrangement signal Mm ′ (i) according to the following procedure, generates a reception modulation signal M ′ (i), and outputs the received modulation signal M ′ (i) to the demodulation unit 230. .

(Input procedure)
Step 1: The index is reset to i = 1 and j = 1.
Step 2: Update the time. When 1 / kr time has elapsed since the previous update, t (light reception result rearrangement unit 220) = t (light reception result rearrangement unit 220) + 1 / kr is updated. If not, wait.
Step 3: t (light reception result rearrangement unit 220) = (i′−1) / r + (j′−1) / kr and j ′ = p (j ″ −1) +1, 1 ≦ i ′ ≦ It is checked whether there is an integer combination (i ′, j ′, j ″) satisfying n, 1 ≦ j ″ ≦ k. If yes, go to Step 4. If not, go to Step 2.
Step 4: Substitute Mm ′ (i ′, j ′) into Mem ′ (i ′, j ″). Go to step 2.

(Output procedure)
Step 5: Reset the index to i ′ ″ = 1, j ′ ″ = 1.
Step 6: Check whether Mem ′ (i ′ ″, j ′ ″) has been written. If already written, go to Step 7. If not written, wait until it is written.
Step 7: Output Mem ′ (i ′ ″, j ′ ″) as M ′ (i ′ ″, j ′ ″).
Step 8: Check if j ′ ″ is equal to k. If equal, go to step 9. If not, go to step 10.
Step 9: Set i ′ ″ = i ′ ″ + 1, j ′ ″ = 1. Go to step 6.
Step 10: Set j ′ ″ = j ′ ″ + 1. Go to step 6.
Here, Mem ′ (i, j) in which the received modulation signal M ′ (i, j) output to the demodulator 230 is stored may be sequentially deleted and reused as an unused memory area.

  FIG. 7 is a schematic diagram showing a situation where the receiving device 21 rearranges the received rearrangement signal Mm ′ (i). Here, k = 8, n = 3, and p = 3 will be described. It is not necessary to rearrange Mm ′ (1,1) that the visible light reception control unit 210 outputs to the light reception result rearrangement unit 220 at time 0. Therefore, the light reception result rearrangement unit 220 outputs Mm ′ (1,1) as M ′ (1,1) to the demodulation unit 230. Mm ′ (1, 4) output from the visible light reception control unit 210 to the light reception result rearranging unit 220 at time 3 / 8r is sent to the demodulation unit 230 as M ′ (1, 2). Hereinafter, Mm ′ (1,3 (j−1) +1) sent from the visible light reception control unit 210 to the light reception result rearrangement unit 220 at time 3j / 8r is transferred to the demodulation unit 230 as M ′ (1, j). Sent out. It is not necessary to rearrange Mm ′ (2,1) that the visible light reception control unit 210 outputs to the light reception result rearrangement unit 220 at time 1 / r. Therefore, the light reception result rearrangement unit 220 outputs Mm ′ (2,1) as M ′ (2,1) to the demodulation unit 230. Mm ′ (2, 4) output from the visible light reception control unit 210 to the light reception result rearrangement unit 220 at time 1 / r + 3 / 8r is sent to the demodulation unit 230 as M ′ (2, 2). Hereinafter, at time 1 / r + 3j / 8r, Mm ′ (2,3 (j−1) +1) sent from the visible light reception control unit 210 to the light reception result rearrangement unit 220 is M ′ (2, j), and the demodulation unit 230. It is not necessary to rearrange Mm ′ (3, 1) that the visible light reception control unit 210 outputs to the light reception result rearrangement unit 220 at time 2 / r. Therefore, the light reception result rearrangement unit 220 outputs Mm ′ (3,1) as M ′ (3,1) to the demodulation unit 230. Mm ′ (3, 4) output from the visible light reception control unit 210 to the light reception result rearrangement unit 220 at time 2 / r + 3 / 8r is sent to the demodulation unit 230 as M ′ (3, 2). Hereinafter, at time 2 / r + 3j / 8r, Mm ′ (3,3 (j−1) +1) sent from the visible light reception control unit 210 to the light reception result rearrangement unit 220 is M ′ (3, j) as a demodulation unit. 230.

[Processing of Receiving Device 22]
The light receiving element 201 is configured by a photodiode or the like. By detecting (k × r / p) brightness intensity signals per second, B ′ (t) is received and converted into an electrical signal C ′ (t) and output.

The light reception result rearrangement unit 221 sequentially stores n reception rearrangement signals Mm ′ (i) output from the visible light reception control unit 210 in the memory. The light reception result rearrangement unit 221 rearranges the symbols of the received reception rearrangement signal Mm ′ (i) according to the following procedure, generates the reception modulation signal M ′ (i), and outputs the received modulation signal M ′ (i) to the demodulation unit 230. . Note that Mm ′ (i, j) output by the visible light reception control unit 210 of the reception device 22 at time (i−1) / r + (j−1) / p is transmitted by the conventional transmission device 10. This corresponds to M ′ (i, j) output from the visible light reception control unit 210 of the receiving device 21 at time (i−1) / r + (j−1) / kr.
Step 1: The index is reset to i = 1 and j = 1.
Step 2: Update the time. When p / kr time has elapsed since the previous update, t (light reception result rearranging unit 221) = t (light reception result rearranging unit 221) + p / kr is updated. If not, wait.
Step 3: Substitute Mm ′ (i, j) for Mem ′ (i, j).
Step 4: Mem ′ (i, j) is output as M ′ (i, j).
Step 5: Check if j is equal to k. If equal, go to step 6. If not, go to step 7.
Step 6: Set i = i + 1 and j = 1. Go to step 2.
Step 7: Set j = j + 1. Go to step 2.
Here, Mem ′ (i, j) in which the received modulation signal M ′ (i, j) output to the demodulator 230 is stored may be sequentially deleted and reused as an unused memory area.

  FIG. 8 is a schematic diagram showing a situation where the receiving device 22 rearranges the received rearrangement signal Mm ′ (i). Here, k = 8, n = 3, and p = 3 will be described. It is not necessary to rearrange Mm ′ (1,1) that the visible light reception control unit 210 outputs to the light reception result rearrangement unit 221 at time 0. Therefore, the light reception result rearrangement unit 221 outputs Mm ′ (1,1) as M ′ (1,1) to the demodulation unit 230. Mm ′ (1,2) output from the visible light reception control unit 210 to the light reception result rearranging unit 221 at time 3 / 8r is sent to the demodulation unit 230 as M ′ (1,2). Thereafter, Mm ′ (1, j) sent from the visible light reception control unit 210 to the light reception result rearranging unit 221 at time 3j / 8r is sent to the demodulation unit 230 as M ′ (1, j).

  The reception device 22 may not include the light reception result rearranging unit 221 and may output Mm ′ (i, j) output from the visible light reception control unit 210 to the demodulation unit 230 as M ′ (i, j).

  The demodulator 230 demodulates the received rearranged signal M ′ (i, j) received from the received light result rearranger 221 and outputs a received signal S ′ (i).

  The decoding unit 90 included in the decoding device 9 decodes the reception signal S ′ (i) output from the demodulation unit 230.

[Configuration of Example 2]
With reference to FIG. 9, the visible light communication transmitting / receiving method according to the second embodiment of the present invention will be described in detail. FIG. 9 is a block diagram showing a configuration of an apparatus that executes the visible light communication transmitting / receiving method of the present embodiment. An apparatus that executes the visible light communication transmitting / receiving method of the present embodiment includes a transmitting apparatus 11 and a receiving apparatus 23. As peripheral devices of this embodiment, there are an encoding device 8 and a decoding device 9.

  The receiving device 23 includes a light receiving element 202, a visible light reception control unit 210, a light reception result rearranging unit 222, and a demodulation unit 230. The receiving device 23 is a receiving device whose processing speed of brightness intensity is q times that of the receiving device 22 of the first embodiment, and the processing speed of brightness intensity is (k × r × q / p) per second. is there. That is, q / p can be processed among the brightness intensity signals output from the transmission device 11 of the first embodiment. However, 1 ≦ p ≦ q, and s = p / q must be an integer. It is assumed that the receiving device 23 knows parameters k, r, p, n, q, and s in advance.

[Processing of receiving device 23]
The light receiving element 202 is configured by a photodiode or the like. By detecting (k × r × q / p) brightness intensity signals per second, B ′ (t) is received and converted into an electrical signal C ′ (t) and output.

  The light reception result rearrangement unit 222 sequentially stores n reception rearrangement signals Mm ′ (i) output from the visible light reception control unit 210 in the memory. The light reception result rearrangement unit 222 rearranges the symbols of the received reception rearrangement signal Mm ′ (i) according to the following procedure, generates the reception modulation signal M ′ (i), and outputs the received modulation signal M ′ (i) to the demodulation unit 230. . The light reception result rearrangement unit 222 is different from the light reception result rearrangement unit 220 included in the reception device 21 in that the step 2 of the symbol rearrangement procedure is different.

(Input procedure)
Step 1: The index is reset to i = 1 and j = 1.
Step 2: Update the time. When s / kr time has elapsed since the previous update, t (light reception result rearrangement unit 222) = t (light reception result rearrangement unit 222) + s / kr is updated. If not, wait.
Step 3: t (light reception result rearrangement unit 222) = (i′−1) / r + (j′−1) / kr and j ′ = p (j ″ −1) +1, 1 ≦ i ′ ≦ It is checked whether there is an integer combination (i ′, j ′, j ″) satisfying n, 1 ≦ j ″ ≦ k. If yes, go to Step 4. If not, go to Step 2.
Step 4: Substitute Mm ′ (i ′, j ′) into Mem ′ (i ′, j ″). Go to step 2.

(Output procedure)
Step 5: Reset the index to i ′ ″ = 1, j ′ ″ = 1.
Step 6: Check whether Mem ′ (i ′ ″, j ′ ″) has been written. If already written, go to Step 7. If not written, wait until it is written.
Step 7: Output Mem ′ (i ′ ″, j ′ ″) as M ′ (i ′ ″, j ′ ″).
Step 8: Check if j ′ ″ is equal to k. If equal, go to step 9. If not, go to step 10.
Step 9: Set i ′ ″ = i ′ ″ + 1, j ′ ″ = 1. Go to step 6.
Step 10: Set j ′ ″ = j ′ ″ + 1. Go to step 6.

  The second embodiment of the present invention has such a configuration, in addition to the receiving device 21 having sufficient brightness intensity signal processing capability and the receiving device 22 having 1 / p brightness intensity signal processing capability. Even in an environment where reception devices 23 having a processing capability of brightness intensity signals of q / p are mixed, transmission signals can be transmitted and received using the same transmission device 11.

[Configuration of Example 3]
With reference to FIG. 10, the visible light communication transmitting / receiving method according to the third embodiment of the present invention will be described in detail. FIG. 10 is a block diagram showing a configuration of an apparatus that executes the visible light communication transmitting / receiving method of the present embodiment. The apparatus that executes the visible light communication transmitting / receiving method of the present embodiment is configured by the transmitting apparatus 12 and the receiving apparatus 24 or the receiving apparatus 22 of the first embodiment. As peripheral devices of this embodiment, there are an encoding device 8 and a decoding device 9.

  The transmission device 12 includes a modulation unit 110, a modulation result rearrangement unit 121, a visible light emission control unit 130, and a light emitting element 100. The modulation result rearrangement unit 121 includes a memory, a CPU, and the like. The transmission device 12 transmits r words every second. Therefore, the transmission device 11 transmits (k × r) symbols per second.

  The receiving device 24 includes a light receiving element 200, a visible light reception control unit 210, a light reception result rearranging unit 223, and a demodulation unit 230. The light reception result rearrangement unit 223 includes a memory, a CPU, and the like. The receiving device 24 is a receiving device with sufficient processing speed of brightness intensity, and the processing speed of brightness intensity is (k × r) per second. That is, all brightness intensity signals output from the transmission device 12 can be processed. It is assumed that the receiving device 24 knows parameters k, r, p, and n in advance.

  According to the present embodiment, the modulation result rearrangement unit 121 included in the transmission device 12 outputs the rearrangement signal Mm (i) to the visible light emission control unit 130 after rearranging all n modulation signals M (i). Therefore, the transmission / reception delay becomes larger than that in the first embodiment. On the other hand, p needs to be relatively prime to k in the first embodiment. However, in this embodiment, since it is only necessary to be a natural number, the degree of freedom of the value of p is increased, and a more flexible design is possible.

[Processing of transmitting device 12]
The modulation result rearrangement unit 121 rearranges the symbols of the input modulation signal M (i) according to the following procedure.

(Input procedure)
Step 1: The index is reset to i = 1 and j = 1.
Step 2: Update the time. When 1 / kr time has passed since the previous update, t (modulation result rearrangement unit 121) = t (modulation result rearrangement unit 121) + 1 / kr is updated. If not, wait.
Step 3: M (i, j) is substituted into Mem (i, p (j-1) +1).
Step 4: Check if j is equal to k. If equal, go to step 5. If not, go to step 6.
Step 5: Set i = i + 1 and j = 1. Go to step 2.
Step 6: Set j = j + 1. Go to step 2.

(Output procedure)
Step 7: Update the time. Share the time of step 2.
Step 8: t (modulation result rearrangement unit 121) = n / r + (i′−1) / kr + (j′−1) / kr and j ′ = p (j ″ −1) +1, 1 ≦ It is confirmed whether there exists an integer combination (i ′, j ′, j ″) satisfying i ′ ≦ n, 1 ≦ j ″ ≦ k. If yes, go to Step 9. If not, go to step 7.
Step 9: Output Mem (i ′, j ′) as Mm (i ′, j ′). Go to step 7.
Here, Mem (i, j) in which the modulation signal M (i, j) output to the visible light emission control unit 130 is stored may be sequentially deleted and reused as an unused memory area.

  FIG. 11 is a schematic diagram illustrating a situation in which the transmission device 12 rearranges the modulated signals M (i). Here, k = 8, n = 3, and p = 3 will be described. M (1,1) is sent as Mm (1,1) at time 3 / r from the modulation result rearrangement unit 121 to the visible light emission control unit 130 as in the conventional transmission apparatus 10. Subsequently, M (2,1) is transmitted as Mm (2,1) at time 3 / r + 1 / 8r. Further, M (3,1) is sent out as Mm (3,1) at time 3 / r + 2 / 8r. Hereinafter, M (i, j) is visible light from the modulation result rearrangement unit 121 as Mm (i, 3 (j−1) +1) at time 3 / r + (i−1) / 8r + 3 (j−1) / 8r. It is sent to the light emission control unit 130.

[Processing of receiving device 24]
The light reception result rearrangement unit 223 sequentially stores the n reception rearrangement signals Mm ′ (i) output from the visible light reception control unit 210 in the memory. The light reception result rearrangement unit 223 rearranges the symbols of the received reception rearrangement signal Mm ′ (i) according to the following procedure, generates the reception modulation signal M ′ (i), and outputs the received modulation signal M ′ (i) to the demodulation unit 230. .

(Input procedure)
Step 1: The index is reset to i = 1 and j = 1.
Step 2: Update the time. When p / kr time has elapsed since the previous update, t (light reception result rearranging unit 223) = t (light reception result rearranging unit 223) + p / kr is updated. If not, wait.
Step 3: t (light reception result rearrangement unit 223) = (i′−1) / kr + (j′−1) / kr and j ′ = p (j ″ −1) +1, 1 ≦ i ′ ≦ It is checked whether there is an integer combination (i ′, j ′, j ″) satisfying n, 1 ≦ j ″ ≦ k. If yes, go to Step 4. If not, go to Step 2.
Step 4: Substitute Mm ′ (i ′, j ′) into Mem ′ (i ′, j ″). Go to step 2.

(Output procedure)
Step 5: Reset the index to i ′ ″ = 1, j ′ ″ = 1.
Step 6: Check whether Mem ′ (i ′ ″, j ′ ″) has been written. If already written, go to Step 7. If not written, wait until it is written.
Step 7: Output Mem ′ (i ′ ″, j ′ ″) as M ′ (i ′ ″, j ′ ″).
Step 8: Check if j ′ ″ is equal to k. If equal, go to step 9. If not, go to step 10.
Step 9: Set i ′ ″ = i ′ ″ + 1, j ′ ″ = 1. Go to step 6.
Step 10: Set j ′ ″ = j ′ ″ + 1. Go to step 6.
Here, Mem ′ (i, j) in which the received modulation signal M ′ (i, j) output to the demodulator 230 is stored may be sequentially deleted and reused as an unused memory area.

  FIG. 12 is a schematic diagram showing a situation where the receiving device 24 rearranges the received rearrangement signal Mm ′ (i). Here, k = 8, n = 3, and p = 3 will be described. There is no need to rearrange Mm ′ (1, 1) output from the visible light reception control unit 210 to the light reception result rearrangement unit 223 at time 3 / r. Therefore, the light reception result rearrangement unit 223 outputs Mm ′ (1,1) as M ′ (1,1) to the demodulation unit 230. Mm ′ (1,4) output from the visible light reception control unit 210 to the light reception result rearrangement unit 223 at time 3 / r + 3 / 8r is sent to the demodulation unit 230 as M ′ (1,2). Hereinafter, at time 3 / r + 3j / 8r, Mm ′ (1,3 (j−1) +1) sent from the visible light reception control unit 210 to the light reception result rearrangement unit 223 is M ′ (1, j) and a demodulation unit 230. It is not necessary to rearrange Mm ′ (2,1) that the visible light reception control unit 210 outputs to the light reception result rearrangement unit 223 at time 4 / r. Therefore, the light reception result rearrangement unit 223 outputs Mm ′ (2,1) as M ′ (2,1) to the demodulation unit 230. Mm ′ (2, 4) output from the visible light reception control unit 210 to the light reception result rearrangement unit 223 at time 4 / r + 3 / 8r is sent to the demodulation unit 230 as M ′ (2, 2). Hereinafter, at time 4 / r + 3j / 8r, Mm ′ (2,3 (j−1) +1) sent from the visible light reception control unit 210 to the light reception result rearrangement unit 223 is M ′ (2, j) and a demodulation unit 230. It is not necessary to rearrange Mm ′ (3, 1) that the visible light reception control unit 210 outputs to the light reception result rearrangement unit 223 at time 5 / r. Therefore, the light reception result rearrangement unit 223 outputs Mm ′ (3,1) as M ′ (3,1) to the demodulation unit 230. Mm ′ (3,4) output from the visible light reception control unit 210 to the light reception result rearranging unit 223 at time 5 / r + 3 / 8r is sent to the demodulation unit 230 as M ′ (3, 2). Hereinafter, at time 5 / r + 3j / 8r, Mm ′ (3,3 (j−1) +1) sent from the visible light reception control unit 210 to the light reception result rearrangement unit 223 is M ′ (3, j) as a demodulator. 230.

[Processing of receiving device 22]
The receiving apparatus 22 according to the third embodiment performs the same operation except that the reception start time of the reception rearranged signal Mm ′ (i) is delayed by n / r seconds compared to the first embodiment. .

  FIG. 13 is a schematic diagram illustrating a situation where the receiving device 22 rearranges the received rearranged signal Mm ′ (i) when the receiving device 22 receives a signal transmitted by the transmitting device 12 of the present embodiment. Here, k = 8, n = 3, and p = 3 will be described. There is no need to rearrange Mm ′ (1, 1) output from the visible light reception control unit 210 to the light reception result rearranging unit 221 at time 3 / r. Therefore, the light reception result rearrangement unit 221 outputs Mm ′ (1,1) as M ′ (1,1) to the demodulation unit 230. Mm ′ (1,2) output from the visible light reception control unit 210 to the light reception result rearranging unit 221 at time 3 / r + 3 / 8r is sent to the demodulation unit 230 as M ′ (1,2). Hereinafter, Mm ′ (1, j) sent from the visible light receiving control unit 210 to the received light result rearranging unit 221 at time 3 / r + 3j / 8r is sent to the demodulating unit 230 as M ′ (1, j).

[Configuration of Example 4]
With reference to FIG. 14, the visible light communication transmission / reception method according to the fourth embodiment of the present invention will be described in detail. FIG. 14 is a block diagram showing a configuration of an apparatus that executes the visible light communication transmitting / receiving method of the present embodiment. An apparatus that executes the visible light communication transmission / reception method of the present embodiment includes a transmission apparatus 12 and a reception apparatus 25. As peripheral devices of this embodiment, there are an encoding device 8 and a decoding device 9.

  The receiving device 25 includes a light receiving element 202, a visible light reception control unit 210, a light reception result rearranging unit 224, and a demodulation unit 230. The receiving device 25 is a receiving device whose brightness intensity processing speed is q times that of the receiving device 22 of the third embodiment, and the processing speed of brightness intensity is (k × r × q / p) per second. is there. That is, q / p can be processed among the brightness intensity signals output from the transmission device 12 according to the third embodiment. However, 1 ≦ p ≦ q, and s = p / q must be an integer. It is assumed that the receiving device 25 knows parameters k, r, p, n, q, and s in advance.

[Processing of receiving device 25]
The light reception result rearrangement unit 224 sequentially stores n reception rearrangement signals Mm ′ (i) output from the visible light reception control unit 210 in the memory. The light reception result rearrangement unit 224 rearranges the symbols of the received reception rearrangement signal Mm ′ (i) according to the following procedure, generates the reception modulation signal M ′ (i), and outputs the received modulation signal M ′ (i) to the demodulation unit 230. . The light receiving result rearranging unit 224 is different from the light receiving result rearranging unit 223 included in the receiving device 24 of the third embodiment in the step 2 of the symbol rearranging procedure.

(Input procedure)
Step 1: The index is reset to i = 1 and j = 1.
Step 2: Update the time. When s / kr time has passed since the previous update, t (light reception result rearrangement unit 224) = t (light reception result rearrangement unit 224) + s / kr is updated. If not, wait.
Step 3: t (light reception result rearranging unit 224) = (i′−1) / kr + (j′−1) / kr and j ′ = p (j ″ −1) +1, 1 ≦ i ′ ≦ It is checked whether there is an integer combination (i ′, j ′, j ″) satisfying n, 1 ≦ j ″ ≦ k. If yes, go to Step 4. If not, go to Step 2.
Step 4: Substitute Mm ′ (i ′, j ′) into Mem ′ (i ′, j ″). Go to step 2.

(Output procedure)
Step 5: Reset the index to i ′ ″ = 1, j ′ ″ = 1.
Step 6: Check whether Mem ′ (i ′ ″, j ′ ″) has been written. If already written, go to Step 7. If not written, wait until it is written.
Step 7: Output Mem ′ (i ′ ″, j ′ ″) as M ′ (i ′ ″, j ′ ″).
Step 8: Check if j ′ ″ is equal to k. If equal, go to step 9. If not, go to step 10.
Step 9: Set i ′ ″ = i ′ ″ + 1, j ′ ″ = 1. Go to step 6.
Step 10: Set j ′ ″ = j ′ ″ + 1. Go to step 6.

  The fourth embodiment of the present invention has such a configuration, in addition to the receiving device 24 having sufficient processing capability of the brightness intensity signal and the receiving device 22 having processing capability of the brightness intensity signal of 1 / p. Even in an environment where reception devices 25 having a brightness intensity signal processing capability of q / p coexist, transmission signals can be transmitted and received using the same transmission device 12.

[Position of modulation result rearrangement section]
In all the embodiments described above, the transmission apparatus includes the modulation result rearrangement unit. However, the transmission apparatus may include an encoding apparatus or another apparatus not shown. Further, it may be in another place in the transmission apparatus.

[Application to communication methods other than visible light communication]
In all the embodiments described above, the description is limited to the case of visible light communication, but can be easily applied to infrared light communication, other wireless communication, and wired communication. In that case, what is necessary is just to change the part after the modulation | alteration part of a transmitter according to each communication method. As for the receiving apparatus, the part before the demodulator may be changed in accordance with each communication method.

[Other modulation methods]
In all the embodiments described above, the case of using on / off modulation that takes a value of 0 to 1 has been described, but multi-value conversion can be easily performed. In this case, the encoding device and / or the modulation unit may be changed.

[Application to parallel communication]
In all the embodiments described above, the description is limited to the case of serial communication, but can be easily extended to parallel communication. In that case, a plurality of pairs of transmission devices and reception devices may be prepared.

[Program, recording medium]
The various processes described above are not only executed in time series according to the description, but may also be executed in parallel or individually as required by the processing capability of the apparatus that executes the processes. Needless to say, other modifications are possible without departing from the spirit of the present invention.

  Further, when the above-described configuration is realized by a computer, processing contents of functions that each device should have are described by a program. The processing functions are realized on the computer by executing the program on the computer.

  The program describing the processing contents can be recorded on a computer-readable recording medium. As the computer-readable recording medium, for example, any recording medium such as a magnetic recording device, an optical disk, a magneto-optical recording medium, and a semiconductor memory may be used.

  The program is distributed by selling, transferring, or lending a portable recording medium such as a DVD or CD-ROM in which the program is recorded. Furthermore, the program may be distributed by storing the program in a storage device of the server computer and transferring the program from the server computer to another computer via a network.

  A computer that executes such a program first stores, for example, a program recorded on a portable recording medium or a program transferred from a server computer in its own storage device. When executing the process, the computer reads a program stored in its own recording medium and executes a process according to the read program. As another execution form of the program, the computer may directly read the program from a portable recording medium and execute processing according to the program, and the program is transferred from the server computer to the computer. Each time, the processing according to the received program may be executed sequentially. Also, the program is not transferred from the server computer to the computer, and the above-described processing is executed by a so-called ASP (Application Service Provider) type service that realizes the processing function only by the execution instruction and result acquisition. It is good. Note that the program in this embodiment includes information that is used for processing by an electronic computer and that conforms to the program (data that is not a direct command to the computer but has a property that defines the processing of the computer).

  In this embodiment, the present apparatus is configured by executing a predetermined program on a computer. However, at least a part of these processing contents may be realized by hardware.

  The present invention can be used for visible light communication in which a transmission signal is transmitted and received by detecting visible light emitted from a light emitting element such as a light emitting diode and electromagnetic waves in a peripheral band thereof with an image sensor or a photodiode.

10 to 12 Transmitting device 100 Light emitting element 110 Modulating unit 120 to 121 Modulation result rearrangement unit 130 Visible light emission control unit 20 to 25 Receiving device 200 to 202 Light receiving element 210 Visible light reception control unit 220 to 224 Light reception result rearranging unit 230 Demodulator 8 Encoder 80 Encoder 9 Decoder 90 Decoder

Claims (4)

Receives (k × r) symbols per second from a transmitter capable of transmitting a transmission signal S (i, j) containing N (1 ≦ n ≦ N) words composed of k symbols per second (k × r) symbols. A visible light communication transmitting / receiving method of transmitting using visible light to a possible receiving device,
t represents time, i represents the word number in each signal, j represents the symbol number in each word, k and n are relatively prime, and n = p.
A modulation step in which the transmission device modulates the transmission signal S (i, j) to generate a transmission modulation signal M (i, j);
The transmission apparatus rearranges the transmission modulation signal M (i, j) for every n words as i ′ = i, j ′ = p (j−1) +1, and transmits the transmission rearrangement signal Mm (i Modulation result rearranging step to generate ', j');
The transmission device controls the light emitting element so that the transmission rearrangement signal Mm (i ′, j ′) is transmitted at time t = (i−1) / r + p (j−1) / kr, A visible light emission control step of outputting a transmission visible light signal B (t);
A visible light receiving control step in which the receiving device receives a received visible light signal B ′ (t) using a light receiving element and generates a received rearranged signal Mm ′ (i ′, j ′);
The received rearranged signal Mm ′ (i ′, j ′) received at the time t = (i−1) / r + p (j−1) / kr by the receiving device is converted into i = i ′ for every n words. , J = (j′−1) / p + 1, and a reception result rearranging step for generating a reception modulation signal M ′ (i, j),
A demodulation step in which the receiving apparatus demodulates the received modulated signal M ′ (i, j) and outputs a received signal S ′ (i, j);
The visible light communication transmission / reception method characterized by including. Every second (k × r ÷ p) from a transmitter capable of transmitting a transmission signal S (i, j) including N (1 ≦ n ≦ N) words composed of k symbols per second (k × r) symbols. A visible light communication transmitting / receiving method of transmitting using visible light to a receiver capable of receiving symbols,
t represents time, i represents the word number in each signal, j represents the symbol number in each word, k and n are relatively prime, and n = p.
A modulation step in which the transmission device modulates the transmission signal S (i, j) to generate a transmission modulation signal M (i, j);
The transmission apparatus rearranges the transmission modulation signal M (i, j) for every n words as i ′ = i, j ′ = p (j−1) +1, and transmits the transmission rearrangement signal Mm (i Modulation result rearranging step to generate ', j');
The transmission device controls the light emitting element so that the transmission rearrangement signal Mm (i ′, j ′) is transmitted at time t = (i−1) / r + p (j−1) / kr, A visible light emission control step of outputting a transmission visible light signal B (t);
A visible light receiving control step in which the receiving device receives a received visible light signal B ′ (t) using a light receiving element and generates a received rearranged signal Mm ′ (i ′, j ′);
From the received rearranged signal Mm ′ (i ′, j ′) received by the receiving device at time t = (i−1) / r + p (j−1) / kr, a received modulated signal M ′ (i, j ) To generate a reception result sorting step;
A demodulation step in which the receiving apparatus demodulates the received modulated signal M ′ (i, j) and outputs a received signal S ′ (i, j);
The visible light communication transmission / reception method characterized by including. Visible light communication transmitter for transmitting visible light transmission signal S (i, j) containing N (1 ≦ n ≦ N) words composed of k symbols using a light emitting element every second (k × r) symbols Because
t represents time, i represents the word number in each signal, j represents the symbol number in each word, k and n are relatively prime, and n = p.
A modulation unit that modulates the transmission signal S (i, j) to generate a transmission modulation signal M (i, j);
The transmission modulation signal M (i, j) is rearranged every n words as i ′ = i, j ′ = p (j−1) +1, and the transmission rearrangement signal Mm (i ′, j ′) A modulation result rearrangement unit for generating
The visible light signal is transmitted by controlling the light emitting element so that the transmission rearrangement signal Mm (i ′, j ′) is transmitted at time t = (i−1) / r + p (j−1) / kr. A visible light emission control unit that outputs B (t);
A visible light communication transmitting apparatus comprising: The program for functioning a computer as a modulation part with which the visible light communication transmitter of Claim 3 is equipped, a modulation result rearrangement part, and a visible light emission control part .

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