JPH04156119A - Optical space propagation communication equipment - Google Patents

Abstract

PURPOSE:To transmit data without adding a preamble signal to transmission data by transmitting and receiving data among all stations based on the same timing. CONSTITUTION:The clock signal generated by an oscillator (10) is converted to an optical signal (120 having a second wavelength band lambda2 by a second optical transmitter (11) and is outputted to the space. This optical signal (12) is reproduced to the original clock signal by each of second optical receivers (57) of optical transmitter-receivers (7) provided on the ceiling and optical transmitter-receivers (9) provided on the floor and is outputted to stations (4) and (5). Each of stations (4) and (5) uses the clock signal outputted from the second optical receiver (57) and uses the optical signal having a first wavelength band lambda3 to transmit and receive data. Consequently, all stations perform the operation based on the same timing. Thus, data can be transmitted without adding a preamble signal (54) just before a data signal (53).

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an optical system that performs information communication by spatially propagating optical signals.
This invention relates to an inter-propagation device.

[Conventional technology]

Fig. 3 is a diagram showing a conventional optical space propagation communication device disclosed in, for example, Japanese Patent Application Laid-Open No. 58-200646. In Fig. 9, (1) is a room, and (2) and (6) are optical transceivers. ,
(3) is an optical signal output from the optical transceiver (2);
(4) and (5) are stations.

FIG. 4 is a diagram showing an example of the configuration of the optical transceiver in (2) and (6) above. In FIG. 1, (51) is an optical transmitter that converts an electrical signal into an optical signal, and (52) is This is an optical receiver that regenerates electrical signals from optical signals. Furthermore, FIG. 5 is a diagram showing the format of transmission signals mutually transmitted between stations in a conventional optical space propagation device.
53) is a data signal exchanged between stations, (
s4)! d is a preamble signal containing a clock signal component for correctly reproducing the data signal (53) on the receiving side.

Next, the operation will be explained. When a data signal (53) to be transmitted to the station (51K) on the floor is generated, the station (4) transmits the signal to the receiving @CZ station (
In order to accurately reproduce this data signal (53) in 5),
The data signal (54) is converted into a Zria pull signal (54) that contains many components of the clock signal used by the own station on the transmitting side.
3) and outputs K to the optical transceiver (2). A transmission signal consisting of a preamble signal (54) and a data signal (53) is converted into an optical signal (3) by an optical transmitter (51).An optical transmitter/receiver is installed from the ceiling to the floor of the room (1). It is radiated towards each party receiver (52) K of the receiver (6). Of the optical signals (3) received by each party receiver (52),
Regenerate the clock signal from the preamble signal (54),
Based on this clock signal, a data signal (53) is reproduced and output to the station controller (5).

In this way, information communication is performed by spatial propagation of optical signals from the station (4) to the station (5) installed on the floor using the optical transceiver (2) installed on the ceiling. Information communication is also performed by spatial propagation of optical signals from station (5) provided in station (4) to station (4).

By the way, the preamble signal (54) is the data signal (54) on the receiving side because the operating clock signal of the station IIJ on the transmitting side and the operating clock signal of the station on the receiving side are independent and different.
3) A constant amount of Brian' pull signal (54) is always required, regardless of the amount of data 1 signal (53), which is used only to transmit the transmitter's clock signal for correctly reproducing L. be.

Therefore, in order to transmit, for example, a 1-bit data signal, a 64-bit preamble signal may be necessary.

Data transmission efficiency is determined by the ratio of the number of bits of the preamble signal to the number of bits of the data signal.

Transmission efficiency cannot be improved as much as the ratio between the number of bits of a preamble signal that can be transmitted in one transmission and the maximum number of bits of a data signal that can be transmitted in one transmission. In other words, in information transmission between stations, as long as a preamble signal is added to the data signal, the transmission efficiency will not be improved beyond a certain value.

[Problem to be solved by the invention]

Since conventional optical space propagation communication devices are configured as described above, a preamble signal must be added immediately before the transmitted data, and therefore the data transmission efficiency does not exceed a certain value. There was a problem.

This departure F! AFi was developed to solve the above-mentioned problems, and its purpose is to improve an optical space propagation communication device that can achieve data transmission without adding a preamble signal immediately before transmission data.

[Means to solve the problem]

The optical space propagation communication device according to the present invention provides a unique timing reference, and uses this timing reference for data transmission and /I/I.
The optical signal is converted into an optical signal of a different wavelength band, outputted into space, and supplied to each station controller, and each station regenerates this timing reference and transmits and receives data in accordance with it.

[Effect]

In the optical space propagation communication device according to the present invention, since all stations transmit and receive data according to a unique timing standard, the operation timing of the station controller on the data transmission side and the operation timing of the station on the data reception side are not the same. Data transmission is achieved without adding a preamble signal immediately before the transmission data for transmitting the operation timing signal of the station on the data transmission side.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. 1st
In the figure, (13, +4. +51 is exactly the same as the above conventional device, (7) and (9) are optical transceivers, (8) optical signal in Vi first wavelength band λ□, (IQ is an oscillator that oscillates at a predetermined frequency, Q1+ is a second optical transmitter that converts the clock signal input from this oscillator αQ into the original signal of the second wavelength band λ, and a2 is the second tHL long band) , with the optical signal of
Figure 2 is a diagram showing the broadcasting of the optical transceivers in (7) and (9) above. In Figure 1, (55) H station (
4) into an optical signal (8) of the first wavelength band λ1! a first optical transmitter that converts and outputs (56
) #'i A first optical receiver that regenerates the original electrical signal from the optical signal (8) in the first wavelength band and outputs it to the stage 3 (4), (57) is in the second wavelength band. This is a second optical receiver that reproduces the original clock signal from the optical signal of λ2 and outputs it to the stage (4).

Next, the operation will be explained. The clock signal generated by the oscillator αC is converted into an optical signal (2)K in the second wavelength band λ by the second optical transmitter (2) and outputted during the period (9). The second optical receiver (57) of the optical transmitter/receiver (7) installed on the ceiling and all the optical transmitters/receivers (9) installed on the floor The original clock signal is regenerated and output to stations (4) and (5).

Each station (4) and (5) Fi uses a second optical receiver (
57) using the clock signal outputted by the first wavelength band λ.
Data is exchanged using optical signals from . Therefore, since all stations operate according to the same timing standard, the preamble signal (53) is immediately preceded by the data signal (53).
Data transmission can be achieved without adding 54).

In the above embodiment, the clock signal is output from one Fi second optical receiver to one station, but the clock signal is output from one second optical receiver to multiple stations. A signal may also be output, and the same effects as in the above embodiment can be achieved.

〔Effect of the invention〕

As described above, according to the present invention, all stations are configured to be able to exchange data with each other based on the same timing standard, so data transmission can be achieved without adding a preamble signal to the transmitted data.

[Brief explanation of drawings]

FIG. 1 is a diagram showing an optical space propagation communication device according to an embodiment of the present invention, FIG. 2 is a diagram showing the configuration of an optical transceiver in the optical space propagation communication device of the present invention, and FIG. 3 is a diagram showing a conventional optical space propagation communication device. A diagram showing a propagation communication device, FIG. 4 is a diagram showing the m configuration of an optical handset in a conventional optical space propagation communication device, and FIG. 5 is a diagram showing mutual transmission between stations in a conventional optical space propagation communication device. FIG. 3 is a diagram showing a signal format. In the figure, fl) #'i room, l2) Fi party transmitter/receiver, (3) is an optical signal, (4) is a station, f51 Fi
station, (6) is an optical transceiver, (7) is an optical transceiver, (8) is an optical signal of the first wavelength band λ, (9) is an optical transceiver, 4 is an oscillator, oFiF2O3 transmitter, a5 ! J
is an optical signal in the second wavelength band λ, (51) #i optical transmitter, (52) is an optical receiver, (53) is a data signal, (54) #'i preamble signal, (55
) Fi is the first optical transmitter, (56) is the first optical receiver, and (57) is the second optical receiver. In addition, in Figure 1, the numeral 4 indicates the same or equivalent part.

Claims (1)

[Claims] a plurality of stations that exchange data with each other; a first optical transmitter that converts an electrical signal output from the station into an optical signal of a first wavelength band λ_1; and a first optical transmitter that outputs the optical signal of a first wavelength band λ_1; A first optical receiver that regenerates the original electrical signal from the optical signal of λ_1 and outputs it to the station, an oscillator that oscillates at a predetermined frequency, and a clock signal output of this oscillator that is in the first wavelength band λ_1. Different second wavelength band λ_
a second optical transmitter that converts and outputs the optical signal in the second wavelength band λ_2, and a second optical receiver that regenerates the original clock signal from the optical signal in the second wavelength band λ_2 and outputs it to the station. Optical space propagation communication device.