JPS5983441A - Pulse transmission system - Google Patents

Abstract

PURPOSE:To reproduce correctly two code strings instantly, by using a disturbance (CRV) of the code regularity of a high speed code string to reproduce correctly the 2nd code string in transmitting a pulse while superimposing a low speed code. CONSTITUTION:One word consists of two blocks, and when the low speed code string is changed in the polarity of code in the direction of ''1'', the regularity of the selection of the preceding block in the word is disturbed and when the polarity of code is changed in the direction of ''0'', the regularity of the selection of the succeeding block in the word is disturbed. When the 2nd code string 103 is superimposed on the original CMI (code mark inversion) code string 102 according to the direction, the code string 201 is obtained. Further, the 202 in Figure shows the location of block where the regularity of selection of block is disturbed. The code string 201 is received at the receiving side to use the word synchronism and it is detected that the disturbance of the regularity of the selection of block in the word takes place in the preceding block or the succeeding clock to discriminate the change in the ''1 '' or ''0'' direction of the 2nd code string superimposed on the code string 201.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention deals with disturbances in the code conversion rules of high-speed code strings (normally CRV
This relates to a pulse transmission method in which low-speed codes are superimposed and transmitted using the Coding Rule Violation (Coding Rule Violation).

The first code string is coded into 71 codes every m (m is the number of positive poles), and each is given redundancy based on a certain code rule.
CMI (Coded MarkTnve
rsion) has a sign. The CMI code is n-1, n
Binary stroke II in case of -2] II and II Oll
II 10II or II 01 I for one of
Fixed to I, +11111 for the other of the above two-valued symbols
Alternatively, it is a code in which 111111 and 1100II are inverted each time the corresponding code appears.

Here, a CMT code will be explained with reference to FIG. 1 as an example.

Figure 1 shows a code string based on the conventional pulse transmission method, with 1
Month is the first code string, 102 is the code string obtained by CMT encoding 101, 103 is the second code string to be superimposed, 104 is 10
CMT code string 1 in which the flock selection regularity is disturbed when the code polarity of code string 103 changes in code string 1
05 represents a block in the code string 104 in which the regularity of flock selection is disturbed. However, in this case, when CM encoding is performed, II is set to 111111 or II 001
1, II Q II to II O] II is fruitful. Therefore, in code string 102, II in code string 101]
, every time II appears Ill] II and II 00
II and OII are "01"I'c conversion tails. Further, in the code string 104, the first irregular disturbance occurs at II OII of the code string 101. Therefore, II OII is converted to 1110II. The second irregular disturbance occurs at 11111 of the code string 101. Therefore, the original value is 11ooll, but it is 1
Convert to 11111.

On the receiving side, upon receiving the CMI code string 104, II 1
1 II and II 00 II to Kan 1111, II
O] II OJ: and 1110II II () II
The original code string 101 is obtained by inversely transforming the code string 101, and by detecting irregularities in the regularity, it is known that the sign of the superimposed second code string has been inverted.

However, with this method, it can be seen from the disturbance of regularity that the code polarity of the second code string has been reversed, but the JL of the low-speed code string
lka II Q II! It cannot be determined by l.

In order to eliminate such drawbacks, the present invention aims at an improvement so that the second code string can be correctly reproduced on the receiving side as well.

FIG. 2 shows a code string according to an embodiment of the present invention.
1.102.103 are code string 1 in Fig. 1, respectively.
Shows the same thing as 01.102.103. Still, one word consists of two words, and the low-speed code string is II I I
When the code polarity changes in the direction of I, it disturbs the regularity of the selection of the previous clock in the word, and when the code polarity changes in the direction of II OII, it disturbs the regularity of the selection of the later clock in the word. I will disturb it. If the second code string 103 is superimposed on the original CMI code string 102 according to this direction, a code string 201 is obtained. Note that 202 indicates a block position where the regularity of flock selection is disturbed.

The reception l1111 receives the code string 201, performs word synchronization, detects whether the disturbance in the regularity of the selection of blocks within a word occurs in the previous block or in the next 70 blocks, and then synchronizes the code string 201. 20] is the second code string superimposed on I
I ] Is the sign polarity changed in the direction of II?
It is determined whether the sign polarity has changed in the direction of ll.

In FIG. 2, word separation and block selection rule 5 - 202 indicating the block position with disordered gender is shown as ):su,r+
p.

The disturbance (A,) before the column 201 is caused by the fact that the second code column is II 1
It can be seen that the sign polarity of the later disturbance (B) changed to II OII.

Word delimiters can be easily synchronized by counting new blocks from the time a specific code appears in the code string 201.

In this example, 2 nolocks are taken as one word, but it is obvious that 3 nolocks or more can be taken as one word.

For example, if you turn 3 blocks into 1 word! I II and 1
Not just 101 but 1” IIQ II II 111
It is also possible to superimpose ternary signals as shown in FIG.

Further, although the explanation has been given here using an example in which the original code string 101 is CMI encoded, a similar method can be applied when converting to a DMI code or the like.

In addition, in the above embodiment, when the code string 201 is received, when detecting an error in the transmission path from the irregularity of the block selection of the code string 201, the code string 201 is detected from the clock synchronization of the second code string 103. It is necessary to estimate the position where the regularity of the block selection is disrupted during the process, and exclude the block at that 6-position from the target of error detection. In reality, the number of blocks to be removed from error detection due to clock jitter in the low-speed code string 201 may be several depending on the system.

Therefore, a circuit for estimating blocks to be removed from error detection targets becomes complicated.

As a countermeasure to this problem, if a word is provided with not only a block that indicates the direction of change in code polarity of the low-speed code string, but also a block that detects errors from disturbances in the regularity of block selection, it is possible to prevent not only the superposition of the second code string , even error detection is possible, and addition of this block can be easily configured by simply adding a counter to the word synchronization circuit.

In order to be able to extract the clock of the superimposed low-speed code string on the receiving side, it is necessary that the frequency spectrum of the second code string itself has a line spectrum. Therefore, first, one of 111 and II □ II of the third code string is converted to II 10II or "old", and the other is converted to 1) 1111 or II 0011, and the second code string is converted to shall be. Methods for this conversion include the above-mentioned CMI encoding and DMI encoding. Next, the converted second code string is superimposed, and the receiving side reproduces the converted second code string due to irregularities in block selection, and performs inverse transformation to obtain the original third code string. It will be done.

As another method, 1111 and 11O of the third code string
One of H is converted into a Joll block and the other is converted into an n0111 block to form a second code string, and then these are superimposed, and the receiving side converts the second code string due to irregularities in the block selection. When the code string is reproduced and inversely transformed, the original third code string is obtained.

As described above, in the present invention, even if another code string is superimposed on an encoded code string, it is possible to instantly and correctly reproduce two code strings. Also, for error detection! 7 also has the advantage of preventing an increase in circuit scale and eliminating ambiguity in the detection rate.

[Brief explanation of the drawing]

Figure 1 is a diagram showing a code string according to the conventional pulse transmission method.
FIG. 2 is a diagram showing a code string according to an embodiment of the present invention. 101...First code string, 102...
... Code string obtained by code conversion of code string 101, 10
3...Second code string, 201...
. . . A code string obtained by superimposing the second code string 103 on code string [02] by the method of the present invention. =9=-o-o-o-.

Claims (4)

[Claims] (1) Transmitting a second code string superimposed on the first code string,
In a pulse transmission method in which a first code string and a second code string are regenerated from a code string received on the receiving side, the first code string is divided into m blocks at the transmission f11, and each is divided into m blocks based on a certain code rule. converting the blocks into a block consisting of n codes with redundancy, further forming two or more blocks into words, and making the direction of change in code polarity of the second code string correspond to the block position within the word; When the code polarity of the second code string changes, the block corresponding to the direction of change is transmitted by disturbing the above fixed law, and on the receiving side, the block consisting of n codes is inversely converted into m codes. The second code string is reproduced by reproducing the first code string and detecting the block position in the word where the above-mentioned constant law is disturbed and knowing the change in the code polarity of the second code string. A pulse transmission method characterized by: (2) The pulse transmission system according to claim (1), characterized in that a block position is also provided in the word to detect a code error on the receiving side from a certain disturbance in the code rule. (3) 1Jll of the third code string different from the second code string
and +110″ or II 01 for one of 60″
II flock, "11'1 or 001 to the other
The pulse transmission system according to claims (1) and (2), characterized in that the second code string is obtained by converting the code into a bootbook. (4) 111″ of the third code string different from the second code string
and 1lOL+ to one block of 1lIQl+, and the other to a block of 1lo1n, and the second
Claim No. (1) characterized in that the code string is
) and (2).