JPS6220436A - Optical space propagation communication system - Google Patents

Abstract

PURPOSE:To perform the optical communication having less influence due to background optical noise by transmitting light with plural light emitting elements different in emitted light wavelength band and receiving light with plural photodetecting elements having the same wavelength bands as light emitting elements to detect coincidence among reproduced signals. CONSTITUTION:Transmission data 11 is converted to optical signals 8-9 having plural wavelength bands through plural driving circuits 12 by plural light emitting elements 17-18 different in emitted light wavelength band and is transmitted. In the reception side, signals 8-9 are received by plural photodetecting elements 19-20 having the same wavelength bands as light emitting elements 17-18 and are converted to electric signals, and they are reproduced to data at every wavelength band by signal reproducing circuits 15. Reproduced data are inputted to a coincidence detecting circuit 21 and are compared with one another, and reception data 16 is transmitted only when all output data of circuits 15 coincide with one another.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an optical space propagation system for performing information communication by propagating optical signals throughout the space.

[Conventional technology]

FIG. 3 is a diagram showing a conventional optical space propagation communication system disclosed in, for example, Japanese Unexamined Patent Publication No. 58-200646.

In the figure, (1) is a room, (2) and (5) are optical transceivers, (3) is an optical signal output from the optical transceiver (2), and (4) is a terminal. Also, Figure 4 shows the above (2) and (
5) is a diagram showing an example of the configuration of an optical transceiver, and in Figure 1, I is transmission data, (+3 is a drive circuit that drives a light emitting element according to this transmission data, Ul is a light emitting element that converts an electrical signal into an optical signal, α4 is a light receiving element that converts an optical signal into an electrical signal, (is is a signal reproducing circuit that reproduces a data signal from an input signal, and θe is received data output from this signal reproducing circuit.

The conventional optical space propagation communication system is configured as described above, and the optical transceiver (2) converts the transmitted data Oυ into an optical signal (3) by the light emitting element a via the drive circuit α. .

Radiation is emitted from the ceiling of the room (1) to each optical transceiver (5) of the terminal (4) installed on the floor. Optical transceiver (5
), the light receiving element 0 phase converts the optical signal (3) into an electrical signal, and the signal reproducing circuit 09 obtains received data αe. In this way, from the optical transceiver (2) to the optical transceiver (5).

Information communication is performed through spatial propagation of optical signals.

Similarly, information communication is also performed by spatial propagation of optical signals from the optical transceiver (5) provided on the floor to the optical transceiver (2) provided on the ceiling.

[Problem that the invention seeks to solve]

In the optical space propagation communication system as described above, the occurrence of communication errors due to background optical noise cannot be avoided during propagation of the optical signal (3). For this reason, in order to reduce the negative effects of particularly large amounts of sunlight as background light noise, communication is performed by selecting a wavelength band with a small spectral distribution of sunlight. However, there is a problem in that it is completely ineffective against background light noise caused by artificial light sources 9 other than sunlight, such as fluorescent lamps.

This invention has been made to solve these problems, and an object of the present invention is to provide an optical space propagation communication system that is less adversely affected by background optical noise and has high information reliability in information communication performed by space propagation of optical signals. .

[Means to solve the problem]

In the optical space propagation communication system according to the present invention, an optical transmitter is provided with a plurality of light emitting elements having different emission wavelength bands, and the same information is transmitted as optical signals in a plurality of wavelength bands. An optical receiver is equipped with a plurality of light-receiving elements in the same wavelength band as the light-emitting element, and detects the coincidence of the reproduced signals in each of the wavelength bands of reception 1-9 to reproduce the original information. It is.

[Effect]

In this invention, information is transmitted using optical signals in multiple wavelength bands, and the receiving side detects coincidence of reproduced signals in each wavelength band, and - determines the identity of the transmitted optical signal and the received optical signal. Therefore, information reliability is improved compared to the case where information is transmitted using the -wavelength band.

〔Example〕

FIG. 1 shows an embodiment of the present invention, and (1) and (4) are completely the same as the conventional device.

(6) and (7) are optical transceivers that transmit and receive optical signals in a plurality of wavelength bands, and (8) to (9) are optical signals 1 to n in different wavelength bands, respectively. Also, Figure 2 shows the above (6) and (
7) is a diagram showing an example of the configuration of the optical transceiver. In FIG. 92, αυ, +12. (LS and αe are exactly the same as the conventional device. Uη~0& are light emitting elements 1~n that convert electrical signals into optical signals, and each has a different emission wavelength band. The light-receiving elements 1-n, 62+1 each having the same wavelength band as the light-emitting elements 1-n, respectively, and 62+1 are coincidence detection circuits serving as determination means for determining the identity of the transmitted optical signal and the received optical signal. signal regeneration circuit α9
By checking whether the outputs of are equal to each other,
This is to determine the identity of a transmitted optical signal and a received optical signal.

In the optical space propagation communication system configured as described above, the optical transceiver (6) transmits transmission data aO to a plurality of drive circuits (12
The light emitting elements 1 to n, each having a different emission wavelength band, are
Original signals 1 to n(8) to (8) of multiple wavelength bands at 0η to 0 ladder
9) K-convert the signal and radiate it to each optical transceiver (7) of the terminal (4) installed from the ceiling to the floor of one room (1).

In the optical transmitter/receiver (photodetector elements 1 to n11 to This data is compared in the coincidence detection circuit 01), and only when all the data output from each signal reproduction circuit (15) match, the received data e is outputted. At this time.

Even if an optical signal in a specific wavelength band is erroneously received due to background optical noise, it is compared with data in other wavelength bands in the coincidence detection circuit 01), so erroneous data will not be output as received data (IG). Similarly, information communication is also performed by spatial propagation of optical signals from the optical transceiver (7) provided on the floor to the optical transceiver (6) provided on the ceiling.

As described above, an optical transmitter is equipped with multiple light emitting elements with different emission wavelength bands, and one piece of information is transmitted as optical signals in multiple wavelength bands. , an optical receiver is equipped with multiple light-receiving elements in the same wavelength band as the light-emitting element, and by detecting coincidence of each reproduced signal and regenerating the original information, highly reliable information communication is possible. It becomes possible.

〔Effect of the invention〕

As explained above, this invention performs communication using optical signals in multiple wavelength bands, detects coincidence of reproduced signals in each wavelength band, and reproduces the original information. This has the effect that there is less influence from background optical noise and higher information reliability than when communication is performed using .

[Brief explanation of drawings]

Fig. 1 is a diagram showing an embodiment of the present invention, Fig. 2 is a diagram showing an optical transceiver of the invention, Fig. 3 is a diagram showing a conventional optical space propagation communication system, and Fig. 4 is a diagram showing a conventional optical space propagation communication system. FIG. 2 is a diagram showing an optical transceiver in a space propagation communication system. In the figure, (1) is a room, (2) is an optical transceiver, and (3) is a room.
) is an optical signal, (4) is a terminal, (5) to (7) are optical transceivers, (8) to (9) are optical signals, t1υ is transmitted data, α
1 is a drive circuit, (13 is a light emitting element, 041 is a light receiving element,
Alpha gu is a signal reproducing circuit, Sumi e is received data, 01 to α ladder are light emitting elements, sauce to ■ are light receiving elements, and 211 is a coincidence detection circuit. Note that the same reference numerals in each figure indicate the same or corresponding parts.

Claims (1)

[Claims] An optical transmitter having a plurality of light emitting elements with different emission wavelength bands, and an optical transmitter installed at a predetermined distance from the optical transmitter and corresponding to the wavelength band of the optical signal generated by the plurality of light emitting elements. It consists of an optical receiver having a plurality of light-receiving elements, and a determining means provided on the optical receiver side for determining the identity of a transmitted signal and a received signal. The light emitting element generates an optical signal which is converted into an optical signal having a different wavelength and sent out, the optical signal is received by a plurality of light receiving elements of the optical receiver, and further, by the action of the determining means, the optical signal is transmitted. An optical space propagation communication system characterized by determining the identity of an optical signal and a received optical signal.