JPS62199138A - Detecting method and apparatus for error in parallel transmission - Google Patents

Abstract

PURPOSE:To transfer additional information with code rule violation and to facilitate error detection due to the violation of code rule by applying simultaneously the code rule violation to the transmission codes of m-line of transmission lines. CONSTITUTION:Four-bit parallel information series (a)-(d) from terminal 41-44 are converted into a CMI code at CMI coding circuits 1-4, the code rule violation is applied when a frame location pulse (e) is inputted from a terminal 51, and the result is sent to transmission lines 31-34. On the other hand, in decoding circuits 11-14, received CMI codes (f)-(i) are converted into reception information series, which are outputted to terminals 45-48. Further, detection circuits 21-24 generate a pulse when the code rule violation is detected in each CMI code and a detection circuit 61 generates a frame pulse when all pulses are detected. Moreover, a detection circuit 62 generates an error detection pulse when the number of the code rule violation is 1-3.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an error detection method and apparatus in digital transmission.

[Prior Art] Generally, when transmitting digital information, a method is used in which the information is converted into a transmission code suitable for the transmission medium and then transmitted.

Among these transmission codes, CMI code (CodedMa
In codes such as rk Inversion Code), code rule violation (C'ode Ru1e Viol
(hereinafter abbreviated as CRV), it is possible to easily monitor errors in the transmission path (for example, as described in "Easy Digital Transmission" edited by Shiroshita, published by Telecommunications Association, p. 142).

FIG. 3 shows an example of a configuration for detecting transmission errors using the above-mentioned Toto<CMI code.

In FIG. 3, the digital information input from the input terminal 41 is input to the CMI encoding circuit 1 as follows:
It is converted into a CMI code according to the I code rules.

In other words, in the CMI code rule, input information “0”
is converted into “01”, and input information “1” is converted into “00” and “11” alternately.

In the above case, the signal converted to the CMI code is transmitted through the transmission line 3.
1 to the receiving side.

On the receiving side, the CMI decoding circuit 11 decodes the received signal.
01”, the information is “0”, and the received signal is “00”.
“or 11”, information “1” is output from the output terminal 45.

In addition, in the CRV detection circuit 21, the above C
If a signal that violates the MI code rules is received, that is, if a signal of ``10'' is received or if ``00'' and ``11'' are not alternated, an error is detected and the error detection pulse output terminal A pulse is output from 53.

On the other hand, "Study of intra-office pulse transmission in digital networks"
(Tade, Fukinuki, co-author, Institute of Electronics and Communication Engineers Technical Research Report CS
77-171), there is a method of actively utilizing CRV to transfer frame information in the above case.

In this method, the transmitting side intentionally applies CRV to the starting position of a frame and transmits the frame, and the receiving side detects the CRV to identify the starting position of the frame.

[Problem that the invention seeks to solve]

However, when error detection is performed using the CRV shown in FIG. It becomes impossible to distinguish whether there is an error in the transmission path or not.

Therefore, when performing error detection using CRV, CRV
There is a problem in that the method of transferring frame information using RV cannot be used, and other transfer methods such as separate line transfer or pattern transfer must be used.

The present invention is capable of transmitting additional information such as frame information using a CRV when performing parallel transmission using a transmission code such as CMI, and is capable of easily detecting errors using the CRV. The object of the present invention is to provide a detection method and apparatus.

[Means for solving problems]

In order to achieve the above object, one aspect of the present invention is as follows.

Specific m transmission lines among standing trees (2≦m S Q )
Additional information is transmitted by simultaneously applying CRV to the transmission codes of
The configuration is such that if the number of transmission lines where V is detected is m, it is determined to be additional information, and if the above number is 1 or more and less than m, it is determined to be error detection.

[Effect]

In the present invention, the transmission codes of 1 m transmission lines are simultaneously
Since RV is applied, if the number of transmission paths that violate transmission code rules detected on the receiving side is m, which is the same number as above, it can be determined that the information is additional information.

In addition, if the above number is less than m, it can be determined that the CRV is not an intentional CRV but an error in the transmission path. Therefore, if the above number is greater than or equal to 1 and less than m, it becomes an error.

[Embodiments of the invention] FIG. 1 is a block diagram of one embodiment of the present invention.

In FIG. 1, 41 to 44 are parallel information series (a) to (
d) input terminal, 51 is an input terminal for frame position pulse (e), 1 to 4 are CMI encoding circuits, 31 to 34 are transmission lines, 11 to 14 are CMI decoding circuits, 21 to 24 are CR
V detection circuit, 45 to 48 are output terminals for parallel information series, 5
2 is a frame position pulse output terminal, 53 is an error detection pulse output terminal, 61 is a frame detection circuit, 62 is an error detection circuit, 71.73 is an AND circuit, and 72 is an OR circuit.

Moreover, FIG. 2 is a signal waveform diagram of the circuit of FIG. 1, and (a
) to (0) indicate the signal waveforms at the locations designated by the same reference numerals in FIG. 1, respectively.

The operation of the circuit shown in FIG. 1 will be explained below based on FIG. 2.

In the CMI encoding circuits 1 to 4, input terminals 41 to 4
The 4-bit parallel information series (a) to (d) input from 4 is converted into a CMI code, and when a frame position pulse (e) is input from input terminal 51, it is subjected to CRV and sent to transmission lines 31 to 34.

On the other hand, the CMI decoding circuits 11-14 convert the received CMI codes (f)-(i) into received information sequences and output them to output terminals 45-48.

Further, the CRV detection circuits 21 to 24 generate pulses when detecting the CRV of each CMI code.

Then, in the frame detection circuit 61, all CRV
Generates a frame pulse when receiving a pulse from the detection circuit.

Further, the error detection circuit 62 generates a pulse indicating error detection when the number of CRVs is 1 or more and 3 or less.

As mentioned above, when transmitting frame information, when the frame position pulse (e) is input, the pulse subjected to CRV is transmitted on all transmission paths, so
As shown in (j) to (m) of FIG. 2, CRV is detected in all the CRV detection circuits on the receiving side, and therefore a pulse is output from the AND circuit 71 to the frame position pulse output terminal 52, and the pulse is output at the frame position. Something is identified.

In this case, an AND circuit 73 is used to connect the error detection pulse output terminal 5 so that the error detection pulse is not output.
Mask 3.

On the other hand, if CRV occurs due to an error in a certain transmission line, rather than when CRV is intentionally applied to all transmission lines as described above, as shown in the shaded area in (f) of Figure 2, , CRV is detected only by the CRV detection circuit connected to the transmission line.

Therefore, the output of the AND circuit 71 remains at a low level, no frame pulse is output, and on the contrary, an error detection pulse is output to the error detection pulse output terminal 53 as shown in FIG. 2(o).

Note that if no CRV is detected in any of the CRV detection circuits, neither the frame pulse nor the error detection pulse is output.

In addition, in the embodiment shown in Fig. 1, when transmitting frame information, CRV is intentionally applied to all four transmission lines, but it is also possible to apply CRV to only a specific transmission line. In other words, the number m of transmission lines to which CRV is applied may be 2 or more and Q (4 in this embodiment) or less.

〔Effect of the invention〕

As explained above, according to the present invention, when performing parallel transmission using transmission codes such as CMI, additional information can be transferred using CRV, and error detection using CRV can be easily performed. Effects can be obtained.

[Brief explanation of drawings]

FIG. 1 is a block diagram of one embodiment of the present invention, and FIG. 2 is a block diagram of an embodiment of the present invention.
A signal waveform diagram of the circuit shown in the figure, and FIG. 3 is an example diagram of a conventional error detection device. ~24... CRV detection circuit 31-34... Transmission line 61... Frame detection circuit 62... Error detection circuit Attorney Junnosuke Nakamura Figure 2 (d) (e) (i) ( m) (n) Figure 3

Claims (1)

[Claims] 1. l pieces of digital data transmitted in parallel (l≧2)
The additional information is transmitted by simultaneously performing transmission code rule violation processing on the transmission codes of specific m (2≦m≦l) transmission lines among the transmission lines, and on the receiving side, The number of transmission lines for which a violation of the transmission code rule was detected in the same time slot is m.
An error detection method in parallel transmission characterized in that if the above number is 1 or more and less than m, it is determined to be additional information, and if the above number is 1 or more and less than m, it is determined to be a transmission error. 2. l lines that transmit digital data in parallel (l≧2)
The information to be transmitted on each of the transmission paths is encoded based on a predetermined transmission code rule, and when transmitting additional information, a specific m transmission path (2≦m≦l) among the above l transmission paths is encoded. a first means for transmitting a transmission code rule violation process on the transmission codes at the same time; and a second means for receiving the transmission codes and detecting whether or not there is a violation of the transmission code rules for the specific m transmission codes. and additional information if the second means detects a violation of the transmission code rule in all of the specified m lines in the same time slot, and additional information if the number of detected transmission code rule violations is 1 or more and less than m. and third means for determining a transmission error.