JPH07250041A - Signal transmitting device - Google Patents

Abstract

PURPOSE:To provide a signal transmitting device which can deal with the change of transmission mode in the future. CONSTITUTION:Each of component blocks 11-17 of a transmitting device 1 and each of component blocks 21-27 of a receiving device 2 has a module constitution. A digital multiplexing part 15 multiplexes various signals sent from the digital signal transmitting parts 11-13. An analog multiplexing part 16 synthesizes the signals multiplexed by the part 15 with the signals of an analog signal transmitting part 14. An optical transmitting part 17 converts the synthesized signals into the optical signals and outputs them to an optical fiber 3. A light receiving part 21 of the device 2 converts the received optical signal into an electric signal. Then an analog multiplexing/demultiplexing part 22 separates the analog signal from the electric signal and sends this analog signal to an analog signal receiving part 27. A digital multiplexing/demultiplexing part 23 separates other signals from the electric signal and sends them to the digital signal receiving parts 24-26.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a signal transmission device for transmitting various signals through a transmission line such as an optical fiber or a metal cable.

[0002]

2. Description of the Related Art Signals transmitted from a transmission side to a reception side include, for example, various signals for data transmission, voice transmission, image transmission, etc. Also, for example, the same image transmission signal has a pulse frequency. There are analog signals such as modulation (PFM) and digital signals such as pulse code modulation (PCM). Further, for example, a light emitting / receiving element used for optical transmission also has a short wavelength (0.8 μm) light emitting diode (LED) and a photodiode (PD) for short distance transmission, and a long wavelength (1.3 μm) for long distance. Laser diode (LD) and avalanche photodiode (APD). When configuring a signal transmission device, a transmission-side transmission device (transmission device) and a reception-side transmission device (reception device) are designed in accordance with the type of signal, the purpose of transmission, the transmission distance, etc.
It was manufactured.

[0003]

By the way, as for the optical fiber used as the transmission line, since the price of the single mode (SM) type fiber has been reduced in recent years, this tends to be adopted as a standard. Since the SM type fiber has an extremely high bandwidth, it does not need to be laid again even if the amount of information increases, and it can be used in the future. In this way, although the transmission line is standardized, the transmitter and receiver are designed and manufactured individually according to the type of signal as described above. When the purpose of use and the environment change with the passage of time, the transmitter and the receiver must be redesigned and manufactured, resulting in enormous labor, time, and cost.

The following examples can be given as examples of the above changes. (A) Initially, only data transmission was performed by a manned transmission station, but PFM image information is added when the transmission station is unmanned. (B) Initially 1 Mbit / in a pair of transceivers
Second data transmission was used, but with the increase in the number of stations, network support and 100 megabits / second digitized multimedia. (C) Initially, PFM analog image transmission was used.
Image processing is performed on the side of the central control room, so when using full digital transmission of 150 megabits / second. (D) At the beginning, the telephone voice transmission was 1.5 megabits / second, but when converting to 6 megabits / second transmission due to an increase in staff and the introduction of videophones. (E) Initially, a signal transmission system using a metal cable was constructed, but since the problem due to lightning surges frequently occurs, the transmission system is changed to an optical transmission system.

An object of the present invention is to solve the above problems in the prior art and to provide a signal transmission device capable of coping with a change in the transmission mode in the future.

[0006]

In order to achieve the above object, the present invention is a signal transmission device for transmitting an arbitrary signal from a transmission side to a reception side, wherein a transmission side transmission device installed at the transmission side is provided. A signal transmitting section for transmitting the arbitrary signal, a signal multiplexing section for multiplexing signals from these signal transmitting sections,
And each module of the optical transmission unit that converts the signal from this signal multiplexing unit into an optical signal and transmits it,
A receiving-side transmission device installed on the receiving side, an optical receiving unit that receives an optical signal and converts the optical signal into an electric signal, a signal demultiplexing unit that separates the signal from the optical receiving unit into individual signals, and Each module separated by the signal demultiplexing unit is composed of each module of the signal receiving unit, and the specifications of the corresponding modules of the transmission side transmission device and the reception side transmission device are matched with each other. It is characterized by

[0007]

The digital signal from the signal transmitting section of the transmitting side transmission device is multiplexed by the signal multiplexing section when there are plural signals, and when the analog signal is also output from the signal transmitting section. The converted signal is also multiplexed with the analog signal. The signal from the signal multiplexer is converted into an optical signal by the optical transmitter. The optical receiver of the receiving-side transmission device receives the transmitted optical signal and converts it into an electrical signal. The signal from the optical receiving unit is separated into original digital signals and analog signals by the signal demultiplexing unit, and the separated signals are transmitted to the signal receiving unit. Signal transmitter,
Signal multiplexer, optical transmitter, optical receiver, signal demultiplexer,
The signal receiving unit and the signal receiving unit have a modular configuration, and the specifications of the corresponding modules of the transmission side transmission device and the reception side transmission device are made to coincide with each other.

[0008]

The present invention will be described below with reference to the illustrated embodiments. FIG. 1 is a block diagram of a signal transmission device according to an embodiment of the present invention. In this figure, 1 is a transmitter, 2 is a receiver, and 3 is a transmission path. The transmitting device 1 includes a signal transmitting section 10 including digital signal transmitting sections 11, 12, 13 and an analog signal transmitting section 14, a digital multiplexing section 15 and an analog multiplexing section 16 (the details of which are shown in FIGS. 2 and 3). Signal multiplexing section 101 and optical transmission section 17
It is composed of each module.

The digital signal transmitters 11 to 13 receive digital signals and analog signals from the outside, digitize them internally, and digital multiplex unit 15
The analog signal transmission unit 14 is an interface module for inputting an analog signal from the outside, such as an image signal, and outputting the analog signal to the analog multiplexing unit 16.

The receiver 2 includes a signal demultiplexer 2 including an optical receiver 21, an analog demultiplexer 22, and a digital demultiplexer 23 (the details of which are shown in FIGS. 4 and 5).
01, and the signal receiving unit 20 including the digital signal receiving units 24, 25 and 26 and the analog signal receiving unit 27.

FIG. 2 shows the digital multiplexing unit 15 shown in FIG.
It is a block diagram of. In this figure, 151 to 153 are shown in FIG.
The transmission buffers (buffer memories) corresponding to the digital signal transmission units 11 to 13 shown in FIG. 1, 154 is a memory transfer switching unit, and 155 is a transmission control unit.

FIG. 3 is a block diagram of the analog multiplexer 16 shown in FIG. In this figure, 161 is a bi-phase conversion unit, 162 is a modulator, 163 is a band pass filter (B
PF), 164 is a low-pass filter (LPF), 165
Is a multiplexer and 166 is a pulse frequency modulator (PFM).

FIG. 4 shows the analog demultiplexer 22 shown in FIG.
It is a block diagram of. In this figure, 221 is a demodulation circuit, 2
Reference numeral 22 is a bandpass filter (BPF), 223 is a detector, 224 is a digital modulator, and 225 is a lowpass filter (LPF).

FIG. 5 shows the digital demultiplexing unit 2 shown in FIG.
3 is a block diagram of FIG. In this figure, 231 is a reception control unit, 232 is a memory transfer switching unit, and 233 to 235 are shown in FIG.
Is a receiving buffer (buffer memory) corresponding to the digital signal receiving units 24 to 26 shown in FIG.

Next, the operation (function of each module) of this embodiment will be described. The signal transmission device of this embodiment can transmit a total of four types of signals, namely, three digital signals and one analog signal. The case of transmitting the four types of signals will be described below. Signal (data) to be transmitted
Is input to the digital signal transmitters 11 to 13 and the analog signal transmitter 14, the digital signals 11s to 13s and the analog signal 14s corresponding to the input signals.
Are output respectively. In this case, each digital signal 1
1s to 13s is NRZ (Non Return to
Zero-type pulses are used. This is because the clock component of the transmission signal is added in the next-stage digital multiplexing unit 15.

A CMI (Coded Mark I)
If a coded signal including a clock component such as the N.version) is used, the clock component is further doubled in the digital multiplexing unit 15, and the transmission efficiency deteriorates. The data is not demodulated because it is properly demodulated by.

The digital signals 11s to 13s are transmitted to the corresponding transmission buffers 15 of the digital multiplexing unit 15, respectively.
1 to 153 are stored. The memory transfer switching unit 154 sequentially switches the connection with each of the transmission buffers 151 to 153 to sequentially take out each pulse of each digital signal accumulated therein and transfer it to the transmission control unit 155.

The transmission controller 155 adds a frame pulse to the transferred pulse to form a transmission frame, and adds a clock component in NRZ type for each transmission frame (CMI conversion) for multiplexing. The converted signal 15s is output. In this way, the transmission buffers 151 to 153, the memory switching unit 154, and the transmission control unit 155 multiplex three digital signals by time division to create the multiplexed signal 15s.

Since a clock component is added to the multiplexed signal 15s, demodulation and demultiplexing can be appropriately performed on the receiving side even if there is a difference in transmission rate among the digital signals 11s to 13s. . Further, the total transmission rate of the input signals can be transmitted up to the transmission rate of the transmission control unit 155. For example, the signal transmission rate of the transmission control unit 155 is 1
If it is megabit / sec (in this case, the transmission rate of the signal including the CMI-converted clock component needs to be 2 megabit / sec), theoretically, it is possible to process an input of 64 kbit / sec for 15 channels. Yes (actually, a gap between time-divided transmission frames is required, and the number of channels that can be transmitted is smaller than this).

The multiplexed signal 15s created by the digital multiplexer 15 is transmitted to the analog multiplexer 16. The transmitted multiplexed signal 15s is converted into an analog multiplexing unit 15s.
In the biphasing unit 161, the sine wave is converted into an analog waveform signal (biphase). The converted waveform signal is modulated by being superimposed on an appropriate carrier wave in the modulator 162. The side signal of this modulated signal is cut by the band pass filter 163 and is input to the multiplexer 165, where it is combined with the analog signal 14s (the signal that has passed through the low pass filter 164) from the analog signal transmission section 14. It The signals thus multiplexed are subjected to pulse frequency modulation (PMF conversion) in the pulse frequency modulator 166 and input to the optical transmitter 17 as the analog frequency multiplexed signal 16s.

Here, the modulation in the modulator 162 is performed in consideration of the frequency band of the analog signal 14s in order to properly combine the analog signal 14s in the multiplexer 165. For example, analog signal 14
If s is an NTSC television signal, the band is up to about 6 MHz, so the frequency band for modulation in the modulator 162 is selected to be 20 MHz, for example, so as not to interfere with this.

The optical transmitter 17 is composed of a light emitting element, and blinks the light emitting element according to the input signal 16s (which is modulated in a pulse shape by the modulator 166) and outputs the optical signal 17s. In this case, the light emitting element is selected according to the transmission distance. The optical signal 17s is transmitted to the receiving device 2 via the optical fiber transmission line 3.

Next, the operation of the receiver 2 will be described. The optical signal 17s transmitted through the transmission path 3 is received by the optical receiving unit 21 of the receiving device 2, converted into a high level H or low level L electrical signal 21s as it is by the light receiving element, and demodulated by the analog demultiplexing unit 22. It is input to the circuit 221. The demodulation circuit 221 demodulates the input high-level H and low-level L electric signal 21s (rectangular wave signal) into a sine wave signal corresponding to the electric signal 21s, and the band-pass filter 22
2 and the low pass filter 225.

The bandpass filter 222 is a demodulation circuit 22.
The signal near the carrier (the signal corresponding to the signal modulated by the modulator 162 of the transmission unit 1) is extracted from the output signal of No. 1 and the detector 223 detects the signal extracted by the bandpass filter 222 to obtain the original signal. A signal component (a signal corresponding to the signal multiplexed by the transmission controller 155 of the transmitter 1) is extracted and input to the digital modulator 224. The digital modulator 224s digitizes the input signal and outputs the digital signal 22ds to the digital demultiplexing unit 23. On the other hand, by inputting the signal from the demodulation circuit 221 to the low-pass filter 225, the signal 1 from the analog signal transmission unit 14 of the transmission device 1 is input.
The same signal 22as as 4s is taken out and output to the analog signal receiving section 27.

The reception control unit 231 of the digital demultiplexing unit 23, to which the digital signal 22ds from the digital modulator 224 of the analog demultiplexing unit 22 is input, is regarded as a CMI signal for each transmission frame of the input signal and is regarded as a clock component. And the channel of each bit of the bit string forming each transmission frame content is determined at the timing of this clock component. The memory transfer switching unit 232 switches the connection with each of the reception buffers 233 to 235 according to the determination of the reception control unit, and sequentially inputs each bit signal from the reception control unit 231 to each of the reception buffers 233 to 235. The reception buffers 233 to 235 store the transmitted signals, and the stored signals are sequentially output according to the data communication means transmitted by the present transmission device. In this way, the signals output from the reception buffers 233 to 235 are the same as the signals input to the digital signal transmission units 11 to 13 of the transmitter 1.

The operation (function of each module) of this embodiment has been described above, but it is necessary that the corresponding modules between the transmitter 1 and the receiver 2 have specifications based on the same technology. That is, it is necessary that the optical transmission unit 17 and the optical reception unit 21 are matched with each other in optical transmission speed, optical transmission band, and light emission / reception level. Further, it is necessary that the analog multiplexing unit 16 and the analog demultiplexing unit 22 correspond to each other in the band of the filter. Furthermore, the digital multiplexing unit 15
And the digital demultiplexing unit 23 must match the structure of the transmission frame and the channel determination code. Furthermore, the digital signal transmitters 11 to 13 and the digital signal receivers 24 to 26 must have the same transmission procedure (protocol). Further, in each module that processes an analog signal, it is necessary that the signal conventions are matched and the transmission capacities are matched.

If the signal transmission apparatus of this embodiment is provided, the maximum digital signal can be transmitted in 3 channels and the analog signal can be transmitted in 1 channel. For example, the digital signal can be transmitted from 1 channel in a channel. If it is desired to increase the number, it is possible to freely cope with this without newly designing and manufacturing the signal transmission device. That is,
When the number of data to be transmitted is increased, only the interface module for that purpose is additionally installed, and the transmission unit can handle it without any change. This also has the effect that when installing the signal transmission device, the troublesome procedure of predicting future needs and determining the specifications of the signal transmission device is not necessary.

Further, it becomes easy for the manufacturer of the signal transmission device to standardize, which leads to cost reduction and reduction of development burden. Especially regarding the development, it is possible to develop the necessary modules step by step according to the needs, and thereby, the technology of the signal transmission device can be developed according to the development of the technology, and the signal transmission device can be expensive from the beginning. There is no need to invest in development.

In the description of the above embodiments, the signal transmission device capable of transmitting three digital signals and one analog signal has been described as an example, but the number is not limited to these numbers, and the maximum allowable value. It can be freely selected within the range of transmission capacity. And, for example, if there is only one channel for digital signals and one channel for analog signals,
The digital signal transmission units 12 and 13 and the digital multiplexing unit 15 are unnecessary, and the digital signal transmission unit 11 may be directly connected to the analog multiplexing unit 16, or if there is no analog signal channel, analog multiplexing is performed. Part 1
6 is unnecessary, the digital multiplexing unit 15 may be directly connected to the optical transmission unit 17, and the analog demultiplexing unit 22 of the receiving device 2 is also unnecessary. Further, if the channel is a single digital signal channel or a single analog signal channel, the digital signal transmission section 11 or the analog signal transmission section 14 can be directly connected to the optical transmission section 17 (in this case, If you need a clock component in high-speed digital, it is necessary to attach a clock).

Further, in the description of the above embodiments, the optical fiber is illustrated as the transmission line 3 between the transmitter 1 and the receiver 2, but this may be a metal cable, in which case, The analog multiplexing unit 16 and the analog demultiplexing unit 22 are directly connected to the metal cable. The digital multiplexing unit 15 may have a multi-tiered hierarchical structure.

[0031]

As described above, according to the present invention, each part of the transmission device on the transmission side and each part of the transmission device on the reception side are composed of modules, and the modules of the corresponding modules of the transmission device on the transmission side and the transmission device on the reception side correspond. Since the signal transmission device was configured with the specifications matching each other, if you want to increase the number of transmission and reception channels,
It is possible to freely cope with this without newly designing and manufacturing the signal transmission device. This also has the effect that when the signal transmission device is installed, the troublesome procedure of predicting future needs and determining the specifications of the signal transmission device is not necessary. Further, it becomes easy for the manufacturer of the signal transmission device to standardize, which leads to cost reduction and reduction of development burden.

[Brief description of drawings]

FIG. 1 is a block diagram of a signal transmission device according to an embodiment of the present invention.

FIG. 2 is a block diagram of a digital multiplexing unit shown in FIG.

FIG. 3 is a block diagram of an analog multiplexing unit shown in FIG.

FIG. 4 is a block diagram of an analog demultiplexing unit shown in FIG.

5 is a block diagram of a digital demultiplexing unit shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 transmitter 2 receiver 3 transmission line 10 signal transmitter 11-13 digital signal transmitter 14 analog signal transmitter 15 digital multiplexer 16 analog multiplexer 17 optical transmitter 20 signal receiver 21 optical receiver 22 analog multiplexer Separating unit 23 Digital demultiplexing unit 24-26 Digital signal receiving unit 27 Analog signal receiving unit 101 Signal multiplexing unit 201 Signal demultiplexing unit

Claims (7)

[Claims] 1. A signal transmitting apparatus for transmitting an arbitrary signal from a transmitting side to a receiving side, wherein a transmitting side transmitting apparatus installed on the transmitting side is a signal transmitting section for transmitting the arbitrary signal, and from these signal transmitting sections. A signal multiplexing unit that multiplexes the signals of
And each module of the optical transmission unit that converts the signal from this signal multiplexing unit into an optical signal and transmits it,
A receiving-side transmission device installed on the receiving side, an optical receiving unit that receives an optical signal and converts the optical signal into an electric signal, a signal demultiplexing unit that separates the signal from the optical receiving unit into individual signals, and Each module separated by the signal demultiplexing unit is composed of each module of the signal receiving unit, and the specifications of the corresponding modules of the transmission side transmission device and the reception side transmission device are matched with each other. A signal transmission device characterized by the above. 2. The signal transmitting unit according to claim 1,
The signal multiplexing section is composed of a digital signal transmitting section and an analog signal transmitting section, and the signal multiplexing section includes a digital multiplexing section for multiplexing a plurality of digital signals, a signal from the digital multiplexing section and the analog signal transmitting section. And an analog multiplexer / demultiplexer that multiplexes an analog signal among the signals from the optical receiver, and the optical receiver. And a digital demultiplexing unit that separates the digital signals among the signals from the digital signals into individual signals. 3. The digital multiplexing section according to claim 2, wherein the digital multiplexing section multiplexes a plurality of digital signals by time division, and the analog multiplexing section converts the signal from the digital multiplexing section into an analog signal. In addition, the signal transmission device is characterized in that the converted signal is frequency-multiplexed with the analog signal from the analog signal transmitting section. 4. The digital multiplexing unit according to claim 2, wherein the digital multiplexing unit receives a plurality of digital signals by a transmission buffer, time division multiplexes the signals with a predetermined clock, and the digital demultiplexing unit receives the signals with the clocks. Then, the signal transmission device is characterized by sequentially storing in a reception buffer corresponding to the transmission buffer. 5. The signal multiplexed by the digital multiplexer according to any one of claims 2 to 4,
A signal transmission device characterized by being an RZ type pulse signal. 6. The signal multiplexed by the digital multiplexing unit according to claim 2, wherein the signal is C
A signal transmission device, which is an MI coded signal. 7. The signal transmission device according to claim 2, wherein the digital multiplexing unit is hierarchically configured in a plurality of stages.