JPS58134561A - Multilevel transmission system - Google Patents

Abstract

PURPOSE:To superpose low-speed information on a data signal without causing disturbance to an online transmission line error monitoring furnction, by slightly altering a class IV partial response encoder and a code rule infringement detector. CONSTITUTION:The class IV partial response encoder 1 receives an input an and generates an output cn. The output sequence cn is divided into two; one is inputted to an interrupter 2 and the other is inputted to a 0-level detector 3. Every time the detector 3 detects the 0 level of the output sequence cn of the encoder 1, one pulse is sent out to a frequency divider 4. Every time the frequency divider 4 counts (k) pulses, control information is sent out to the interrupter 2. On receiving the control information, the interrupter 2 changes a 0 level outputted form the encoder 1 to an (m) level at the point of time to output an output sequence c'n. Therefore, a reception-side decoder receives the output sequence c'n and decodes the C'n in a conventional decoding method.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a multilevel transmission system in which low-speed information such as housekeeping information and transfer alarm information is further superimposed on a data signal of a class t+-character response code and transmitted.

Conventionally, as an example of this type of multilevel transmission system, there is a system in which low-speed information is transmitted simultaneously with the data signal by increasing the bit rate, but this method has the drawback of widening the transmission band. In addition, as another example, there is a method of transmitting by violating the class ■i4-char response law, but the class ■
- There was a drawback that it became impossible to monitor online transmission errors due to detection of violations of the physical response law.

Accordingly, it is an object of the present invention to provide a multilevel transmission system that allows low-speed information to be added to a data signal and transmitted without interfering with the online transmission path error monitoring function.゛According to the present invention, a signal of 0゜...1m-level, which is an m (≧2)-adic signal, is inputted and -m +
In a multi-level transmission system having an m-adic (2m-1) value class ■ or -sha response encoder that sends out a first output signal of 1 +..., 0°..., m-levels,
a frequency divider that counts the number of times the first output signal is at the θ level and issues a control signal every time the first output signal is input; and an interrupter that outputs a second output signal obtained by converting a level signal into a predetermined m-level or -m-level signal, and transmits the second output signal to a receiving side. A multi-value transmission system is obtained which is characterized by the following.

Before going into a detailed explanation of the present invention, let us first explain the class ■A? - The encoding and decoding method of the social response method will be briefly explained. What is the encoding method of m-adic (2m-1) value Nori2-Gual response method?

Let the input sequence of the encoder be an (0≦an×m).

As a preprocessing called Nori-coding.

bn== (an-bn-2) mOd m
- Do (1) and then.

. n=bn-bn-2"""...The correlation in (2) is taken and c (rri≦Cn×m) is sent to the transmission path.Then, the decoding method performed on the receiving side is as follows.

(1= (c) mad m ・−
It is known that this can be achieved by (3) nn.

Next, two aspects of the present invention will be explained in detail with reference to the drawings.

The figure is a block diagram showing the configuration of an embodiment of a coding device applied to the present invention. In the figure, 1 is class 1%/
i4-Sial response encoder, 2 is an interrupter, 3 is a θ level detector, and 4 is a frequency divider. As mentioned above, the class II/Sial response encoder 1 is a
is input, and C shown by equation (2) is output. Output series C is divided into two hands.

n
n One is input to the interrupter 2, and the other is input to the 0 level detector 3. The 0 level detector 3 sends a pulse to the frequency divider 4 by one every time the 0 level of the output series C of the encoder 1 is detected. The frequency divider 4 sends control information to the 2-interrupter 2 every time the frequency divider 4 counts.

Upon receiving the control information, the interrupter 2 changes the θ level input from the encoder 1 at that time to the m (or □ -m) level, and outputs it as an output sequence crl.

On the other hand, in the decoder on the receiving side that receives the output sequence c/.

cll is decoded instead of C in equation (3). here.

(m) mod m = O (or (, -m) m
od m = O), it can be seen that the decoding method can be exactly the same as the decoding method of the normal class ■partial response method. Therefore, it is possible to transmit low-speed information at a speed 17 times the modulation speed on the transmission path by superimposing it on the data signal. Also, the receiving side
When a signal of m (or -m) level is received as an input of the sial t-sponse law violation detector, it may be changed so that 0 level is input. Furthermore, a detector for detecting the m (or -m) level, which is low-speed information, is also provided on the receiving side.

In the multilevel transmission system according to the present invention, the number of levels increases from 2m-1 to 2m, but in practice 2m is 2m.
There are many cases in which the signal is multiplied by 0 curtains, and the output of the receiving discriminator is almost always multiplied by 2 curtains, so there is no problem.

As is clear from the above description, according to the present invention, by extremely slightly changing the class ■-sial response encoder on the transmitting side and the class ■-sial response coding rule violation detector on the receiving side, It becomes possible to transmit low-speed information by superimposing it on a data signal, and the effect obtained is significant.

[Brief explanation of the drawing]

The figure is a block diagram showing the configuration of an embodiment of a coding device applied to the present invention. Explanation of symbols: l is a class pJ no e-sial response encoder, 2 is an interrupter, and 3 is a 0 level detector. 4 denotes a frequency divider, and an denotes a class ①/Grusial response output series, respectively.

Claims (1)

[Claims] 1, a signal of 0, . . . 9 m-levels, which is an m (≧2) base signal, is input, and -m+1. ..., O2...9m-Lebel's first output signal is sent from the m-adic (2m-1) value class ■z? - a multi-value transmission system having a social response encoder; and an interrupter that inputs an output signal and sends out a second output signal obtained by converting an O level signal into a predetermined m level or -m level signal each time the control signal is received. , a multilevel transmission method characterized in that the second output signal is sent to the receiving side.