JP3270572B2 - Frame signal transmission system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a clock and frame signal transmission system in a digital communication system or the like.

[0002]

2. Description of the Related Art Conventionally, in a synchronous system such as a digital communication system, a slave synchronization system shown in FIG. 1 has been adopted for reasons such as prevention of slip in the system and centralized arrangement of a high-precision phase locked oscillator. General. In the figure, a clock and a frame signal 2 whose phases are managed by a clock frame supply device 1 are supplied to peripheral devices 3 to 5. Each of the peripheral devices 3 to 5 to which the clock and the frame signal 2 are input operate synchronously according to the clock and the frame signal.

However, when transmitting a frame signal of two channels whose frequency ratio does not become an integer from the clock and frame supply device 1, two transmission lines are required.

On the other hand, according to the invention disclosed in Japanese Patent Application Laid-Open No. 58-178652, it is possible to transmit a two-channel frame signal using a single transmission medium. In the present invention, first, a logical sum signal of the first and second frame signals of two channels is obtained in the transmitting device. Next, the logical sum signal and the reference clock signal are superimposed, converted to a frame transmission code accompanied by transmission code violation, and transmitted using a single transmission path. The frame transmission code transmitted to the receiving device is input to a predetermined frame signal detection circuit. The frame signal detection circuit reproduces the first and second frame signals from the input frame transmission code.

[0005]

However, in the above invention, it is necessary to newly provide a circuit for executing digital processing of the frame signal. Therefore, if transmission devices have already been designed and manufactured separately for each frame signal, these devices cannot be used, and it is necessary to newly design and manufacture a transmission / reception device. Therefore, the cost is increased. Further, the frame signal receiving apparatus also requires a frame counter for each frame signal to be transmitted, that is, two channels, and has a complicated circuit configuration.

Accordingly, the present invention provides a transmitting device capable of transmitting a two-channel frame signal using an existing frame transmitting device, and a frame signal receiving device having a simple configuration.

[0007]

A transmitting device for generating a transmission code based on a reference clock signal and first and second frame signals having different periods from each other, and a receiving device for receiving the transmission code, 2. The frame signal transmission system according to claim 1, wherein the frame signal transmission system is connected to each other by one transmission line, wherein the transmission side device transmits a first frame transmission code accompanied by a violation of the reference clock signal and the first frame signal. First means for generating, second means for generating a second frame transmission code with a violation of the reference clock signal and the second frame signal, a first frame transmission code, and an inverted signal of the second frame transmission code Are superimposed using a transformer, and an AMI (Alternate Marke)
Inverted signal) comprising superimposing means for generating a ternary signal, and transmitting means for transmitting the AMI ternary signal generated by the superimposing means as a transmission code, wherein the receiving-side device transmits the AMI ternary signal transmitted via a transmission path. Determining whether or not the superimposed first and second frame transmission codes coincide with each other from the waveform and outputting a discrimination signal based on the discrimination result; and Reproducing means for reproducing the first and second frame signals.

[0008] A transmitting device for generating a transmission code based on a reference clock signal and first and second frame signals having different periods from each other is provided, and a receiving device for receiving the transmission code is provided. 3. The frame signal transmission system according to claim 2, wherein the transmission-side device generates a first frame transmission code accompanied by a reference clock signal and a violation of the first frame signal, A second frame transmission code accompanied by a violation with the second frame signal is generated, and the generated first frame transmission code and an inverted signal of the second frame transmission code are superimposed to generate an AMI tri-level signal. A done
The transmission device transmits the MI ternary signal as a transmission code, and the receiving-side device obtains a superimposed first and second frame transmission code from a waveform of the AMI ternary signal transmitted from the transmitting-side device via a transmission path. Judge the match / mismatch of
The method is characterized in that the first and second frame signals are reproduced from the transmission code based on the result of the determination.

[0009]

In the frame signal transmission system according to the first aspect, the transmitting side device is provided with the first and second means for causing the first and second frame signals to violate the reference clock signal and the first and second frame signals. A two-frame transmission code is generated, and the inverted signal of the second frame transmission signal is superimposed on the first frame transmission code by the superimposing means, and the AMI is transmitted.
A ternary signal is generated and transmitted as a transmission code to the receiving side device via one transmission line. In the receiving device that has received the AMI ternary signal as the transmission code via the transmission path,
Based on the transmission code received by the determination means, the coincidence / mismatch between the superimposed first and second frame transmission signals is determined. The discrimination means outputs, for example, a discrimination signal of "1" when the first and second frame transmission codes match, and discriminates "0" when the first and second frame transmission codes do not match. Output a signal. The reproduction means reproduces the first frame signal and the second frame signal based on the value of the discrimination signal output from the discrimination means.

[0010] In the frame signal transmission method according to the second aspect, the transmitting apparatus includes a reference clock signal and a first clock signal.
Generating a first frame transmission code with a violation with the frame signal, generating a reference clock signal and a second frame transmission code with a violation with the second frame signal, and generating the first frame transmission code; Generating an AMI tri-level signal by superimposing an inverted signal of the second frame transmission code, and transmitting the generated AMI tri-level signal as a transmission code. From the waveform of the AMI tri-level signal sent via the path, it is determined whether the superimposed first and second frame transmission codes match or not, and based on the result of the above determination, the first and second frame signals are converted from the transmission code. Reproduce.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A frame transmission system according to the present invention first uses a violation signal of a first frame signal and a reference clock signal as a first frame transmission code, as in the prior art, and generates a second frame signal and a reference clock signal. The violation signal is used as the second frame transmission code. Transmission side device 10
0 indicates that the first transmission code and the inverted signal of the second transmission code are superimposed using a transformer as shown in FIG.
(Alternate Marke Inverted
(Signal) A ternary code is formed and used as a transmission code.

The superimposition of the first transmission code and the second transmission code is executed by using the transmitting apparatus 100 shown in FIG. The apparatus 100 includes a first frame transmission unit 101 and a second frame transmission unit 101.
It comprises a one-frame transmission unit 102 and a superposition unit 103. First and second frame transmission units 101 and 1
02 is a unit that generates a violation signal of the first and second frame signals and the reference clock signal,
It is the same as the conventional device. As shown, as shown in FIG.
Numeral 3 is composed of two transformers, and the connection between the first frame transmission unit 101 and the superposition unit 103 and the connection between the second frame transmission unit 102 and the superposition unit 103 are reversed. Thereby, the first frame transmission unit 1
01 to the transmission code from the second frame transmission unit 102
Can be superimposed.

FIG. 4 shows a receiving apparatus 200 according to the present invention. The receiving device 200 includes a match / mismatch determination unit 201.
A quaternary counter 202, an RS latch 203, a ternary counter 204, a NOR gate 205, a divide-by-2 counter 206, flip-flops 207 and 208,
EXOR gates 209, 210, and 211. FIG. 5 shows that a first frame signal having a period of 7 bits of the reference clock signal and a second frame signal having a period of 3 bits of the reference clock signal are AMI3 values in the transmitting apparatus 100. FIG. 9 is a time chart showing signals and codes for 21 cycles of a reference clock signal after the codes are transmitted and converted to codes and transmitted to the reception-side apparatus 200. FIG.

The receiving device 200 has a reset signal,
The reference clock signal and the transmitted transmission code are input. Once the reset signal is set and each counter in the circuit is initialized, the match / mismatch determination section 201
In, it is determined whether or not the transmitted code has a pulse regardless of the sign. Determination unit 201
Outputs a discrimination signal of "0" when there is no pulse signal, and outputs a discrimination signal of "1" when there is a pulse signal. In the quaternary counter 202, the determination unit 2
When “1” is continuously output from 01 for three cycles of the reference clock signal, the next ternary counter 204 is triggered. The ternary counter 204, once triggered, reproduces the second frame signal via the NOR gate 205. The output of the NOR gate 205 is input to the divide-by-2 counter 206. The flip-flops 207 and 208 and the EXOR gates 209 to 211 are provided with the divide-by-2 signal output from the divide-by-2 counter 206 and the discriminator 2
01 and a reference clock signal are input. Here, as shown in FIG. 5, the signal output from the EXOR gate 211 has an exclusive OR value of “1” between the value of the reproduced second frame signal and the output value of the divide-by-2 counter 206. ", The value of the signal output from the EXOR gate 211 at the next timing is the negative value of the exclusive OR of the value of the reproduced second frame signal at that timing and the output value of the divide-by-2 counter 206 Becomes Further, the value of the exclusive OR of the value of the reproduced second frame signal and the output value of the divide-by-2 counter 206 is “
If the value is "0", the EXOR gate 21
The value of the signal output from 1 is determined by the value of the reproduced second frame signal at the timing and the divide-by-2 counter 20.
6 is the value of the exclusive OR of the output values of # 6. As described above, the first frame signal having one cycle of seven cycles of the reference clock signal is reproduced.

As described above, in the frame signal transmission system of the present invention, by using the transmission side apparatus 100, a frame signal of a simple configuration including a conventional apparatus for converting each single frame signal into a transmission code and transmitting the code is transmitted. Transmission device 100
Can be provided. Further, by using the receiving device 200, the first frame signal and the second frame signal can be reproduced from the transmitted code. Further, in this embodiment, the signals to be transmitted are limited to the reference clock signal and the frame signal. However, in a system for transmitting three types of signals of the reference clock signal frame signal and the data through one transmission line, a plurality of types of signals are transmitted. The present invention can also be applied to the case of transmitting the frame signal of

[0016]

According to the frame signal transmission system of the present invention, by using the transmitting side device according to the first aspect, the superimposing means including a predetermined transformer can be used without executing special digital processing. By using this, a two-channel frame signal is converted into an AMI ternary signal, and this is transmitted as a transmission code to a receiving-side apparatus using a single transmission path. The receiving device reproduces the first frame signal and the second frame signal from the transmitted transmission code.

Further, in the frame signal transmission method according to the present invention, the transmitting apparatus converts the two-channel frame signal into a predetermined AMI tri-level signal without performing digital processing such as logical addition. Can be transmitted as a transmission code to a receiving-side device via a transmission path. The receiving device can determine whether the first and second frame transmission codes match or not based on the waveform of the transmitted AMI tri-level signal, and reproduce the first and second frame signals based on the determination result.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a conventional dependent frame signal transmission system.

FIG. 2 shows first and second transmission codes obtained by violating a first frame signal and a second frame signal with a reference clock signal, and an AMI tri-level signal generated from the first and second transmission codes. FIG.

FIG. 3 is a diagram showing a configuration of a transmission side device 100 in the frame signal transmission system of the present invention.

FIG. 4 is a diagram showing a configuration of a receiving device 200 in the frame signal transmission system of the present invention.

FIG. 5 is a diagram showing a case where a transmission code transmitted via one transmission path from the transmission side device 100 shown in FIG. 3 is received;
5 is a time chart illustrating states of signals and codes in the reception-side device 200 illustrated in FIG. 4.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 101 ... 1st frame signal transmission unit 102 ... 2nd frame signal transmission unit 103 ... Superimposition part 201 ... Match / mismatch determination part 202 ... Quaternary counter 203 ... RS latch 204 ... Tertiary counter 205 ... NOR gate 206 ... Divide by 2 Counters 207, 208 ... flip-flops 209, 210, 211 ... EXOR

Claims (2)

(57) [Claims] 1. A transmitting apparatus for generating a transmission code based on a reference clock signal and first and second frame signals having different periods from each other, and a receiving apparatus for receiving the transmission code. In a frame signal transmission system connected by a transmission path, the transmission-side device includes: a first unit that generates a first frame transmission code accompanied by a reference clock signal and a violation of the first frame signal; , A second means for generating a second frame transmission code accompanied by a violation with the second frame signal, and superimposing the first frame transmission code and the inverted signal of the second frame transmission code by using a transformer, and AMI3 A receiving unit that includes a superimposing unit that generates a value signal, and a transmitting unit that transmits, as a transmission code, the AMI ternary signal generated by the superimposing unit. Discriminating means for discriminating the coincidence / mismatch of the superimposed first and second frame transmission codes from the waveform of the AMI ternary signal transmitted via the transmission path, and outputting a discrimination signal based on the discrimination result; And a reproducing means for reproducing the first and second frame signals from the transmission code based on the discrimination signal to be transmitted. 2. A transmitting device for generating a transmission code based on a reference clock signal and first and second frame signals having different periods from each other, and a receiving device for receiving the transmission code, wherein one device is provided. In a frame signal transmission system connected by a transmission line, the transmission side device generates a first frame transmission code accompanied by a violation of a reference clock signal and a first frame signal, and generates a reference clock signal and a second frame. Generating a second frame transmission code with a violation with the signal; superimposing the generated first frame transmission code on the inverted signal of the second frame transmission code to generate an AMI tri-level signal; The value signal is transmitted as a transmission code, wherein the receiving device transmits the AMI three-value signal transmitted from the transmitting device via a transmission path. Frame signal transmission characterized by judging the coincidence / mismatch of the superimposed first and second frame transmission codes from the form, and reproducing the first and second frame signals from the transmission codes based on the result of the judgment. Method.