JPH0724398B2 - Signal transmission error verification method - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a signal transmission error verification method, and more particularly to a signal transmission error verification method capable of high-level error verification and correction.

[Conventional technology]

In the information transmission processing device, it is necessary to efficiently detect a code error occurring in the signal transmission path, prevent a malfunction of the system, and speed up the processing response of the system. Therefore, various error detection methods are provided. For example, the method proposed in Japanese Patent Application No. 53-49995 was found to be sufficiently effective for error checking, but on the other hand, it was confirmed that the redundancy is high.

Now, information transmission will be described.

When transmitting information, for example, if the decimal system of 0 to 9 is transmitted, the bit is given a weight as shown in FIG. 9 or FIG. 10, and the transmission numerical value (each of 0 to 9) is given a transmission error. it is common to wipe the horizontal Pariteibitsuto H _P for detecting. For Figure 9 to wipe an even Pariteibitsuto H _P of 1 bit in the binary code, in the case of FIG. 10 in combination enable Pariteibitsuto H _P the weight bits (1,2,4,7), ₅ C ₂ It is a fixed mark code. This combination of weight and parity bits H _P below, word (W)
Called.

In such a code structure, the order of transmitting and receiving information is transmitted and received as shown in FIG. That is, in FIG. 11, W ₁ , W ₂ , ... W _N is one word in decimal number in FIG. 9 or FIG. 10, each consisting of 5 bits. W ₁ , W ₂ , ... W _{N in} Fig. 11 indicates, for example, when transmitting and receiving numerical values of "3", "2", ... "6", and when transmitting such numerical values. As a transmission error detection method in a transmission device, there is a double-transmission matching method. This method, as FIG. 11, W ₁
First sends a to _W-N, further, again first sends once more W ₁ to _W-N, the W ₁ to _W-N previously received by the receiver code and the W ₁ to _W-N received a second time This is a method of matching and performing a match check, and if there is no match, it is determined that there is an error.

Further, as the second transmission error verification method, there is a method in which all the codes of the second consecutive transmission are inverted and transmitted. This method is called a reverse continuous transmission matching method.

Both the former and the latter are called the double-transmission matching method, and these have a drawback that the transmission time becomes long because the number of bits doubles.

As a method for shortening this, there is a vertical parity method. As an example, as shown in FIG. 12, the position of bit data D ₀ , D ₂ , D ₃ , D ₄ for each word in W _{1 to} W _N is examined in the vertical direction for code bits, and the code at that time is "1" P ₀ of the vertical Paris tee word V _P by the number (or the number of "0") of, P _1, P _2, P
_At position ₃ , when the number of "1" is odd, a bit like "1" is raised and this word is used as vertical parity word V _{P. In} the case of information transmission, W _{1 to} W _N are transmitted. In addition, there is a vertical parity detection method that performs error detection by transmitting and receiving the vertical parity word V _P. In this case, since the vertical parity word V _P has only the horizontal parity in the weighting and code structure of FIG. 9, it can be said that the error verification capability for each word (W _N ) is low.

That is, when an even number of bit errors occur simultaneously in the same word, the horizontal parity method cannot detect them.

[Problems to be Solved by the Invention] In comparison to this, the horizontal parity system (constant mark code configuration) of FIG. 10 has a high error verification capability. Looking at the vertical parity word V _P , in the case of FIG. 9, it is possible to add a parity word for testing the vertical parity word V _P , but the fixed mark in FIG. In a word structure consisting of code structures, the vertical parity word cannot always be error-tested because the vertical parity word is not necessarily a constant mark code structure. Further, since the vertical parity word V _P is tested, there is a drawback that the constant mark parity bit cannot be grown.

SUMMARY OF THE INVENTION An object of the present invention is to provide a signal transmission error verification method that enables accurate transmission, corrects transmission code errors, and shortens the response time of the system.

[Means for solving problems]

The present invention, which has solved the above-mentioned problems, is a transmission method for transmitting and receiving a character word in which a transmission code is composed of an ₈ C ₄ constant mark, in which “1” is always set at a specific position of the character word, and A vertical parity test word is cultivated based on the character word, and the character word and the vertical parity test word are transmitted / received. In the vertical parity word error test, the vertical position corresponding to a specific position of the character word is one-to-one. It is characterized in that the parity test is performed based on the code of the specific position of the parity test word, and the comparison test with the vertical parity word obtained from the received character word is performed.

[Action]

On the sending side, the character word is sent with horizontal parity. Next, a vertical word composed of the transmitted words is transmitted.

At the receiving side, the horizontal parity of the received word is examined. Also, a vertical parity word is constructed from the received words. Perform error checking from the horizontal parity, vertical parity word, and created vertical parity word.

〔Example〕

 Hereinafter, the present invention will be described with reference to the drawings.

FIG. 1 is a diagram showing an embodiment of the present invention, FIG. 1 (I) is a configuration diagram showing a system, Figure 1 (II) is an explanatory view showing a signal transmission example, FIG. 1 is ₈ C FIG. 6 is a diagram showing an example of a code having a constant mark code configuration of ₄ .

In FIG. 1 (I), reference numeral 1 is a transmitter, 2 is a transmission line, and 3 is a receiver. The transmitting device 1 and the receiving device 3 are devices that can control communication and may be configured by computers.

The code configuration used in FIG. 1 uses a constant mark code of ₈ C ₄ , and an example of this is shown in FIG. 1 (III). That is, in FIG. 1 (III), each word of 0 to 9 is ₈ C ₄
Is a constant mark code of 4 bits of D1, D2, D4, D7 among them, and the first 4 bits (D1, D2) of the ₅ C ₂ word structure shown in FIG.
2, D4, D7) are used as they are, and 5 of the remaining 4 bits are used.
Bit is HP, 6-th bit Y _0, 7 th bit forms a constant mark sign of Y _1, 8-th bit Y ₂ Metropolitan 4 adds a horizontal parity bits of the bit ₈ C ₄ made of. At this time, of the horizontal parity bits, the HP bit is a fixed code bit and the number of “1” or “0” in the vertical parity word is always an even number, or the VP4 bit is “1” regardless of the number of transmission words. At this time, the HP bit is always set to "1" so that the number of "1" of other bits except VP4 is odd.

With this code structure, the information word (Wn) tests the constant mark of ₈ C ₄ , but the vertical parity word (VP) is shown in FIG.
Since it is not a constant mark code as shown in (B) and (C) of I), the transmission error test of this word (VP) is
Use the bit of VP4. That is, if the bit of VP4 is "1", the number of "1" of other bits except the bit of VP4 is odd, and if the bit of VP4 is "0", the number of "1" of other bits except the bit of VP4 is even. The transmission error of the vertical parity word is tested on the assumption that

Then, in the system configuration of FIG. 1 (I), the first
As shown in FIG. (II), the case where the information signals W _{1 to} W ₄ are transmitted to the receiving device 3 via the transmitting device 1 and the transmission path 2 will be described with reference to FIGS. 2 and 3 as well. To do.

In the transmitter 1, signal processing is performed and W ₁ (“1”), W
Create ₂ (“2”), W ₃ (“6”), W ₄ (“9”) (step 1
00), and then create a vertical parity word V _P from W _{1 to} W ₄ (step 101). Then, as shown in FIG. 1 (II), W _{1 to} W ₄ are transmitted (step 102) and the vertical parity word V _P is transmitted (step 103).

When this transmission is completed, the transmitter 1 stops (step 104). In the receiving apparatus 3 receives the word W ₁ of the data W ₁ 'When (step 200), the horizontal Paris tee Chie arrive (step 20), W _1' if there is an error in the horizontal Paritei of, W ₁ 'Set the erroneous flag (step 202). In this example, since there is no error in the horizontal parity of W ₁ ′, step 203 is entered. In step 203, if word W ₂ is received and its data is W ₂ ′, step 203
At 204, make a horizontal parity check. If there is an error in the parity, an error flag is set at step 205, but since the horizontal parity is correct here, the process moves to step 206.

Step 206 receives the word W ₃ and sends its data to W ₃ ′.
Then, at step 207, a horizontal parity check is performed. In word W ₃ ′, there is an error in horizontal parity, so we move to step 208 and set an error flag. Then at step 209 the word W ₄ is received and its data
If W ₄ ′, the parity check is performed at step 210, and since it is positive in this example, the process does not proceed to step 211 but to step 212. At step 212, the vertical parity word V _P is received as data V _P ′, and then at step 21.
In 3, horizontal parity check of vertical parity word is performed. In this example, the horizontal partition is correct, so we move to step 214. In step 214, the received data
Create a vertical parity word RV _P from W ₁ ′ to W ₄ ′.
Then, in step 215, V _P ′ and RV _P are compared and V _P ′ = RV _P
If _P , move to step 218, but if V _P ′ ≠ RV _P , determine in steps 202, 205, 208, 211 whether the horizontal parities are different (step 216). If there is a flag, correct the error from RV _P and go to step 218. Move. If the flag is not set at step 216, the process proceeds to step 219, and the process ends because of a transmission error.

That is, for example, in the transmission procedure of FIG. ₁ , when W _{1 to} W ₄ are transmitted / received and it is determined by the horizontal parity test of each of them that only one word has a transmission error, the last word of transmission ( V _P ) received and a series of transmissions (W ₁ ~
If only 1 bit in 1 word out of W ₄ and V _P ) is erroneous, it can be corrected as shown in FIG. 1 (note that if more than 2 words are erroneous, it cannot be corrected). That, RV and _P (series of received words W _1, Ikuo the vertical Paris ~Wn tee words), (transmitted by Ikuo at the transmitting end, the vertical Paris tee word received at the receiving end) V _P 'and data By using the bit positions with different signs, the bit position of the error occurrence in the word can be known (the error occurs at the position D _{3 in} the figure). Accordance connexion, if correct bits of D ₄ correction word (Wn) (if inverting the bit data) becomes correct data (step 21
7).

Thus, in the system of FIG. 1 which is an embodiment of the present invention,
RV when only one word in the transmission word has an error
_You can use _P to correct the data in that word correctly, but if an error occurs in two or more words, you may not be able to correct it.

In particular, one of the possible causes of transmission error is lightning. Since lightning discharges in a short time, it is considered that an error in the transmission line 2 occurs continuously for several bits. Therefore, depending on the timing of occurrence, an error will occur over two words. That is,
In the word and word sakai, it is impossible to make use of the above-mentioned bit correction function even in the case of a two-word co-parity or fixed mark test in which lightning damage occurs.

Therefore, in the second embodiment, the bursts are continuously generated as described above. It is intended to provide a correction function even for a transmission bit error (that is, over two words or more).

Below, errors that occur over two words (burst)
The correction function that can deal with the case will be described. It is obvious that the correction of the continuous error occurrence of 3 words or more may be performed by dividing into 3 or more according to the following description.

FIG. 4 shows a transmission procedure in which the transmission error can be corrected even when the transmission error occurs in two words (for example, W ₃ and W ₄ ).

VP _{1 in} FIG. 4 is a vertical parity word grown from odd words like W ₁ and W ₃ of the transmission word, and VP ₂ is a vertical parity word grown from even words like W ₂ and W _4. Is. The transmission procedure is to transmit W _P1 and V _P2 after W _{1 to} W ₄ and perform horizontal parity inspection as described above, and then perform V _P1 and V _P2.
It suffices to make a correction to each of the above. That is, even N
By correcting the word group of o. and the word group of odd No. as described above, it is possible to correct the error of two consecutive words.

In the above explanation, the vertical parity word itself is verified by a parity bit test of the vertical word itself at a parity bit position of a fixed bit, which is different from other word tests. An example of this is shown in FIGS.

In Figure 5, vertically Paris tee word 2 minutes to be transmitted (until _{D 1 ~D 7, H P,} y 0, y 1, y 2) , respectively to V _PH,
In the transmission procedure, the transmission word is followed by VP ₁ as shown in Fig. 6.
And VP ₂ are transmitted. In this transmission, at V _1P ,
An inverted sign of 4 bits of V _PH H _P, arranged in y _0, y _1, the position of the bits of y _2. Furthermore, assigning the V _PL of Figure 5 to the bit position of the D ₁ to D ₇ in V _P2, the inverted sign of the V _PL H _P, y _0,
Place at the bit positions of y ₁ and y ₂ . By performing the transmission in this way, the error test of the vertical parity word can be performed with the same ability as that of the inverted continuous transmission check. As a result, even if the number of transmission bits is small, it is possible to perform more sophisticated error verification and correction.

Further, if the method of FIG. 6 and the method of FIG. 4 are combined to perform error correction, more reliable correction data with high transmission reliability can be obtained.

Further, in the present embodiment, one word is described as 8 [Bit],
The number of bits may be arbitrary without being fixed to this.

Furthermore, in the embodiment of the present invention, for example, when the zero-phase carrier transmission system is applied, the transmitting side can receive the signal content transmitted by itself and perform data verification, so that lightning or the like is transmitted to the transmission line. When is superimposed, a data error on the receiving side can be realized by utilizing the receiving circuit on the transmitting side at the same time. Therefore, if it is verified whether or not the transmission data error occurs more than once in the same word group, the transmission can be stopped by itself after the data error occurs more than twice, and the retransmission By doing so, it is possible to effectively and quickly send a signal to the other party.

That is, in general, even at the transmitting end, if the outgoing signal is received from the transmission line and is received by the above-mentioned method, it is possible to judge whether or not the received signal can be corrected by the other party. Therefore, on the transmitting side, if the transmission is interrupted at the time when a word error in any one of the same word groups occurs twice or more, the receiving side does not continue the unnecessary signal reception, and further, the signal error test is transmitted. Since the transmission is performed at two locations, one on the receiving side and the other on the receiving side, more reliable transmission is possible.

7 and 8 (a) and 8 (b) show a transmission procedure flow of the second embodiment of the present invention. FIG. 7 shows the transmission procedure. For example, when transmitting the data of word 1 (W ₁ ) to word 4 (W ₄ ) in FIG. 4, V _P1 is the derivation of the vertical parity of V _P1 in FIG. (Step 301), and V _P2 derives the vertical parity of the same even number word as V _{P2 in} FIG. 4 (Step 302).

Then it starts sending, sending W _{1 first} , then W ₂ , W ₃ ,
Transmission is performed in the order of W ₄ (step 303), V _P1 derived earlier is transmitted next to the transmission of W _{1 to} W ₄ , but SV _P1 is used as a symbol indicating that it is transmission V _P1 in the flow diagram. (Step 304). Then send SV _P2 for final transmission (step 3
05), and ends the transmission process (step 306).

On the other hand, on the receiving side, in FIGS. 8A and 8B, the word W ₁ is received (step 401), and the horizontal parity of the word is checked (step 402). Remembered that there was an error (Step 40
3) The next word is received (step 404). Sequential W ₂
For ~ W ₄ , check the horizontal parity for each word in the same manner as above, and when there is an error, set a flag indicating that the word has an error (steps 404 to 412). next,
SV _P1 which is the vertical parity transmitted is received (step
413), perform a horizontal parity check (step 41).
Four). Furthermore, SV _P2 receives the same as SV _P1 (step 415),
Perform horizontal parity check (step 416). At this time, if there is a horizontal parity error in SV _P1 and SV _P2 (steps 414, 416), transmission error processing is performed (for example, no operation or control is performed) (step 417). SV _P1
Or if there is no horizontal error in SV _P2 (steps 414, 41
6) The vertical parity is derived from the received data W ₁ and W ₃ as in FIG. 4 (step 418). Here are the RV _P1 a material obtained by derivation. This RV _P1 is compared with the received SV _P1 (step 419) and if they do not match, W
_It is judged that there is a received word error of ₁ or W ₃ (step 4
20), the correction process is executed (step 421). At this time, look at the flag set by the horizontal parity check earlier, and correct the word that has been set in error (however, if there is a two-word error in both W ₁ and W ₃ (not shown), do not correct it). ).

In the same way, check correction is also applied to SV _P2 .

From the above, it is possible to correct a transmission error of two words that spans odd and even numbers.

〔The invention's effect〕

As described above, according to the present invention, even if the number of transmission bits is small, a higher degree of error verification and correction can be performed, so that there is an effect that the response speed of the device to which the transmission is applied becomes faster.

[Brief description of drawings]

FIG. 1 is a diagram showing a first embodiment of a signal transmission error checking method according to the present invention, FIG. 2 is a flow chart showing a transmitting procedure of the same embodiment, and FIG. 3 is a flow showing a receiving procedure of the same embodiment. FIG. 4 is a chart showing a second embodiment of the present invention, FIG.
FIG. 6 and FIG. 6 are diagrams showing a bit configuration used in the second embodiment, FIG. 7 is a flow chart showing a transmitting procedure of the second embodiment, and FIG. 8 is a receiving procedure of the second embodiment. The flow chart shown in FIGS. 9 to 12 is an explanatory view for explaining a conventional example. 1 ... Transmitting device, 2 ... Transmission path, 3 ... Receiving device.

Claims (3)

[Claims] 1. In a transmission method for transmitting and receiving a character word having a transmission code composed of ₈ C ₄ constant marks, "1" is always set at a specific position of the character word, and the character word is used as a basis. The word for vertical parity test is cultivated, and the character word and the word for vertical parity test are transmitted and received. In the error test of the vertical parity word, the word for vertical parity test corresponding to the specific position of the character word is described. A signal transmission error test method characterized by performing a parity test based on a code at a specific position and performing a comparison test with a vertical parity word obtained from a received character word. 2. The signal transmission according to claim 1, wherein the first half bit vertical parity of the character word is inverted and set to the second half bit of the vertical parity word so that the vertical parity word can be subjected to a fixed mark test. Error checking method. 3. A signal transmission error test method according to claim 1, wherein an error test of a vertical parity word is performed, and a one-word error of an error-occurring word is corrected on condition that there is no error in this word.