JP2007129637A - Optical communication equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide optical communication equipment capable of realizing a high transmission speed, and dealing with large-capacity information communication, in information communication conforming to IrDA communication standards. <P>SOLUTION: In the optical communication equipment which performs information communication by an infrared communication system conforming to the IrDA communication standards, a small-capacity information signal to be transmitted at a low transmission speed and a large-capacity information signal to be transmitted at a high transmission speed are multiplexed, and the maximum value of the packet size of the large-capacity information signal is found from the bit time of the low transmission speed and the pulse width. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an optical communication apparatus that transmits and receives an information signal using an optical signal.

  In an optical communication device mounted on a portable information terminal such as a cellular phone or PDA (Personal Digital Assistance), a wireless communication method is used as an information communication means. Among the wireless communication systems, the infrared communication system is widely adopted because it is strong in security and can be implemented at a low price.

  A problem in this infrared communication system is the transmission speed.

  Conventionally, personal digital assistants have been used for small-capacity information communication, mainly text, but in recent years, the demand has rapidly increased as a familiar tool for large-capacity information communication such as high-quality still images, video, and music. ing. For this reason, there is great expectation for an optical communication apparatus that realizes large-capacity information communication at a high transmission rate.

  However, the response speed of an LED (Light Emitting Diode) serving as a light source for an infrared communication system is slow, which is one of the factors that limit the increase in transmission speed. Therefore, an LED having a faster response speed has been developed, but there are problems such as a short transmission distance, low luminous efficiency, and relatively high cost.

  Therefore, a proposal has been made that an encoding technique performed in a wired communication system is applied to a wireless communication system, and a high transmission speed can be realized even with an LED having a slow response speed (for example, see Patent Document 1).

  By the way, in the infrared communication system, a standard based on IrDA (InfraRed Data Association) is standard.

  According to the IrDA infrared communication standard, the communication packet structure is as shown in FIG.

  Here, by setting the address field (Address) to 0xFF, the DLSAP (Destination Link Service Access Point) field, and the SLSAP (Source Link Service Access Point) field to 0x70, a one-to-many, that is, broadcast-type optical communication apparatus is constructed. Is possible.

In this case, there is no need for a connection process between portable information terminals performed by one-to-one communication, and data can be easily transmitted.
JP 11-41301 A

  The reception function of an optical communication apparatus that employs an IrDA-compliant infrared communication system mounted on a cellular phone, a PDA, or the like is limited to a transmission rate of 9600 bps and a maximum number of data within 382 bytes. For this reason, even if a higher transmission rate can be realized on the transmission side, only information communication in accordance with the transmission rate on the reception side, that is, 9600 bps can be performed.

  The present invention has been made in view of the above points, and an optical communication apparatus capable of realizing a higher transmission speed even in information communication conforming to the IrDA communication standard and capable of accommodating large-capacity information communication. The purpose is to provide.

  The present invention can solve the above problems by providing the following configuration.

  (1) a first parallel / serial conversion means for converting an information signal from a parallel signal to a serial signal; an encoding means for encoding the information signal converted into a serial signal by the parallel / serial conversion means; In an optical communication apparatus having a light emitting element for transmitting as an optical signal and a driving means for driving the light emitting element, a second parallel / serial conversion means for converting an information signal from a parallel signal to a serial signal, and the encoding means An optical communication apparatus comprising: multiplexing means for multiplexing the information signal encoded by the information signal and the information signal converted into a serial signal by the second parallel / serial conversion means.

  (2) In the optical communication apparatus according to (1), the transmission speed of the second parallel / serial conversion means is higher than the transmission speed of the first parallel / serial conversion means. An optical communication device.

  (3) In the optical communication apparatus according to (1), the packet size of the information signal from the second parallel / serial conversion unit is a bit time obtained from a transmission rate of the first parallel / serial conversion unit. An optical communication device characterized in that the amount of information obtained from the difference between the pulse width of the information signal from the first parallel / serial conversion means is maximized and multiplexed by the multiplexing means.

  (4) A light receiving element that receives an information signal as an optical signal, a decoding unit that decodes the received information signal, and a first serial / parallel conversion that converts the decoded information signal from a serial signal to a parallel signal. Means for demultiplexing the information signal received by the light receiving element into information signals having different transmission rates, and a high transmission rate among the information signals divided by the demultiplexing unit. And a second serial / parallel converter for converting an information signal having a serial signal into a parallel signal.

  According to the present invention, it is possible to realize a higher transmission speed and perform large-capacity information communication even in information communication complying with the IrDA communication standard.

  Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to examples.

  A transmission process in the optical communication apparatus of the present invention will be described with reference to FIG.

  The optical communication apparatus according to the present embodiment described below is connected to various information processing terminals such as a mobile phone or a PDA (Personal Data Assistance) in a state where it is built or communicable. The optical communication device is used in these terminals for so-called broadcast-type communication from a base station such as a server device to each terminal, or for large-capacity communication between the terminals. Note that the optical communication apparatus according to the present embodiment is built in the terminal and is connected in a communicable state with other components via a control bus in the terminal.

  FIG. 1 is a block diagram showing a system configuration on the transmission side of this embodiment.

  In FIG. 1, reference numeral 101 denotes a control bus such as a CPU, and reference numeral 102 denotes a UART (Universal Asynchronous Receiver Transmitter) connected to the control bus 101. The UART 102 converts a parallel signal into a serial signal at a transmission speed of 9600 bps.

  Reference numeral 103 denotes an encoder that encodes an information signal that has become a serial signal in the UART 102. There are various methods for encoding, and an optimal method is selected according to the type of information source and the characteristics of the transmission path.

  Reference numeral 104 denotes a controller for parallel / serial conversion of information signals as in the case of the UART 102, but the transmission speed is as high as 100 Mbps.

  A multiplexing circuit 105 multiplexes the 9600 bps information signal encoded by the encoder 103 and the information signal from the 100 Mbps controller 104.

  Here, the multiplexing process in the multiplexing circuit 105 will be described with reference to FIG.

  The information signal (hereinafter referred to as 9600 bps information signal) which is a serial signal in the UART 102 and is encoded by the encoder 103 is not generated when the data type is “1” and is not generated when the data type is “0”. A pulse is generated. The pulse width of the generated pulse is 1.41 μs to 22.1 μs.

  In the multiplexing circuit 105 of the present invention, after transmitting the pulse of the 9600 bps information signal having the pulse width of 1.41 μs to 22.1 μs, the information signal from the 100 Mbps controller (hereinafter referred to as the 100 Mbps information signal) is 9600 bps. A so-called time-division control is performed in which the pulses are continuously transmitted within one bit time in the information signal, and information signals having different transmission rates are multiplexed and transmitted.

  At this time, the 100 Mbps information signal is transmitted by being divided into packet sizes that fall within the above-mentioned length of time in order to enable transmission within the time of 1 bit in the 9600 bps information signal.

  Here, when a 1-bit information signal is transmitted at a transmission rate of 9600 bps by the above method, the packet size of a 100 Mbps information signal that can be continuously transmitted is obtained.

  First, in the 9600 bps information signal, the bit time is 1 / 9600≈104 μs (201). Since the information signal of 100 Mbps is transmitted continuously to the information signal of 9600 bps within this bit time, the difference between the bit time of 104 μs of 9600 bps and the pulse width (1.41 μs to 22.1 μs) (202) is calculated as 100 Mbps. It becomes the bit time of the information signal (203).

  At this time, the smaller the pulse width, the longer the required bit time, so the maximum capacity that can be obtained is as follows.

104 μs-1.41 μs = 102.59 μs Maximum bit time 102.59 μs x 100 Mbps = 10259 bits Maximum capacity required

  The signal multiplexed by the multiplexing circuit 105 as described above is transmitted as an optical signal 108 by driving the LED 107 by the LED driving circuit 106.

  Next, the reception process in the optical communication apparatus of the present invention will be described with reference to FIG.

  FIG. 3 is a block diagram showing a system configuration on the receiving side of this embodiment.

  The information signal transmitted as the optical signal 108 from the light emitting element 107 is received by the light receiving element 107a. Here, for example, a PD (Photo Diode) or the like is used as the light receiving element. The information signal received by the light receiving element 107a is amplified by the preamplifier 106a.

  Reference numeral 105a denotes a demultiplexing circuit which controls the reverse process of the multiplexing circuit 105 in FIG. That is, the demultiplexing circuit 105a decomposes the multiplexed information signal according to the transmission speed, and transmits the 9600 bps information signal to the decoder 103a and the 100 Mbps information signal to the 100 Mbps controller 104a.

  Reference numeral 103 a denotes a decoder that decodes the information signal encoded by the encoder 103. The decoded information signal is converted from a serial signal to a parallel signal by the UART 102a. At this time, the UART 102a may have a parallel / serial conversion function, and may be the same as the UART 102 in FIG.

  The 100 Mbps controller 104a is a controller for serial / parallel conversion of information signals. However, it may have a parallel / serial conversion function like the UART 102a, and may be the same as the 100 Mbps controller 104 in FIG.

  In the optical communication apparatus of the present invention, at the start of connection, the information on the transmitting side is transmitted by inserting information indicating that a large-capacity information signal is continuously transmitted into the 9600 bps information signal, and when the receiving side receives the signal, A large-capacity information signal can be obtained in the process described with reference to FIG.

  In this embodiment, a 9600 bps information signal with a limit on the amount of information that can be transmitted includes large-capacity information (for example, image information, music data, or commercial film) transmitted by a 100 Mbps information signal transmitted continuously. Information related to (video information) (for example, identification information capable of specifying the data content) can also be stored.

  Furthermore, in this embodiment, when an optical communication apparatus is used for communication between information processing terminals, a terminal on the transmission side asks for information as to whether or not the terminal on the reception side can handle a large capacity transmission of 100 Mbps. It can also be included in an information signal of 9600 bps.

  In this way, the receiving terminal can always switch the reception capability in accordance with the transmitted transmission of 100 Mbps without waiting to cope with large-capacity transmission.

  In addition, by setting the address field (Address) to 0xFF, the DLSAP (Destination Link Service Access Point) field, and the SLSAP (Source Link Service Access Point) field to 0x70 according to the IrDA communication standard, the broadcast type optical communication device is set to 0x70. Can be built.

  At this time, in the present embodiment, for example, a 9600 bps information signal indicates a small capacity information such as a URL (Uniform Resource Locator) of a website, and a 100 Mbps information signal indicates a large capacity information not related to the small capacity information. It is also possible to transmit information independent of the 9600 bps information signal and the 100 Mbps information signal.

  In this case, it is possible to provide a service for distributing a large amount of information such as a part of new music data or a commercial film together with a small amount of information such as a URL at a transmission speed of 9600 bps.

  In the present embodiment, the transmission rate of the first information signal converted by the UART 102 is 9600 bps and the transmission rate of the second information signal converted by the controller 104 is 100 Mbps. Needless to say, the apparatus is not limited to this, and can be implemented at various transmission rates.

  By using the optical communication device of the present invention, large-capacity information communication that requires a high transmission speed, such as an electronic advertisement board or an information distribution device using illumination light, can be realized.

The block diagram which shows the system configuration | structure of the transmission side of a present Example Packet timing chart explaining multiplexing of information signals The block diagram which shows the system configuration | structure of the receiving side of a present Example The figure which shows the packet structure of the conventional example

Explanation of symbols

101 CPU bus 102 UART
103 Encoder 104 100 Mbps Controller 105 Multiplexing Circuit 106 LED Drive Circuit 107 LED
108 Optical signal

Claims (4)

First parallel-serial conversion means for converting an information signal from a parallel signal into a serial signal, encoding means for encoding the information signal converted into a serial signal by the parallel-serial conversion means, and the information signal as an optical signal In an optical communication device having a light emitting element for transmitting and a driving means for driving the light emitting element,
Second parallel-serial conversion means for converting an information signal from a parallel signal to a serial signal;
Multiplexing means for multiplexing the information signal encoded by the encoding means and the information signal converted into a serial signal by the second parallel-serial conversion means;
An optical communication device comprising: The optical communication device according to claim 1,
An optical communication apparatus characterized in that the transmission speed of the second parallel / serial conversion means is higher than the transmission speed of the first parallel / serial conversion means. The optical communication device according to claim 1,
The packet size of the information signal from the second parallel / serial conversion means is the bit time determined from the transmission speed of the first parallel / serial conversion means and the information signal from the first parallel / serial conversion means. An optical communication apparatus characterized in that the amount of information obtained from the difference from the pulse width is maximized and multiplexed by the multiplexing means. A light receiving element that receives an information signal as an optical signal, a decoding unit that decodes the received information signal, and a first serial / parallel conversion unit that converts the decoded information signal from a serial signal to a parallel signal. In an optical communication device having
Demultiplexing means for dividing the information signal received by the light receiving element into information signals of different transmission rates;
A second serial / parallel conversion means for converting an information signal having a high transmission rate among the information signals divided by the demultiplexing means, from a serial signal to a parallel signal;
An optical communication device comprising:

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