JPH08298501A - Data transmission system - Google Patents

Abstract

(57) [Summary] [Objective] To provide a data transmission system having a high communication success rate even when random noise, burst noise, or the like occurs. [Configuration] Transmitter 3 during time adjustment communication once every 10 minutes
Sends the message 11a to the receiver 7 in the format shown in FIG. The message 11a includes the header 12 and “11111
3 times expanded user arbitrary data 21a including the mark 23a with "11" set, 15 times expanded user arbitrary data 21b including the mark 23b with "0000000" set, and "1111000" set It is composed of a plurality of user arbitrary data 21 including the mark 23 such as the user arbitrary data 21c including the mark 23c.
The receiver 7 corrects the user arbitrary data 21a, the user arbitrary data 21b, the user arbitrary data 21c, ... According to the respective expansion degrees.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data transmission system for transmitting digital data.

[0002]

2. Description of the Related Art Recently, a transmitter has been connected to a gas alarm,
A system has been developed in which a receiver is connected to a microcomputer meter, and when a gas alarm detects a gas leak, a transmitter sends an alarm signal to the microcomputer meter through the receiver to shut off gas.

This alarm signal (telegram) is a signal in which a CRC code is added to the ID number and time information of the receiver, and the receiver side performs error detection by the CRC code. Therefore, if even one bit is incorrect, the message itself becomes invalid. Therefore, the same message is retransmitted 66 times at one transmission timing in order to suppress the deterioration of the communication success rate.

[0004]

However, if an error is detected in even one bit in the telegram, the telegram will be discarded. Therefore, if random noise such as carrier noise occurs, all telegrams will be invalid and the communication will be lost. There is a problem that there is a high possibility that it will be unsuccessful. In addition, if the code decompression method is simply adopted to correct the message without invalidating the message in which the error is detected, the error correction capability is improved, but the number of times the message is retransmitted is reduced. There was a problem of being weak.

The present invention has been made in view of the above problems, and its object is to provide random noise,
It is to provide a data transmission system having a high communication success rate even if burst noise or the like occurs.

[0006]

In order to achieve the above-mentioned object, according to the present invention, a transmitting side includes a first converting means for converting "1" into a first N (N is an odd number) bit string, and " 0 "is the second N having the longest Hamming distance with the first N-bit string.
Second conversion means for converting into a bit string and digital information to be transmitted are converted into a plurality while converting the value of N using the first conversion means and the second conversion means, and converted with the value of N And means for transmitting a plurality of combinations with the digital information sent to the receiving side, wherein the receiving side divides the digital information sent from the transmitting side into N bits in accordance with the value of N. , Information divided into N bits is the first N
A data transmission system characterized by comprising a means for performing correction while referring to a bit string and the second N-bit string and converting the bit string and the second N-bit string to "0" or "1", at a predetermined timing. A data transmission system, characterized in that the communication success rate is measured according to the value of N, and data is transmitted using N relating to the best communication success rate.

[0007]

In the present invention, the transmitting side sets "1" to the first N (N
Is an odd number) bit string, “0” is converted to a second N bit string having the longest Hamming distance from the first N bit string, and digital information to be transmitted is transmitted to the first conversion unit and the second The converting means is used to convert the value of N into plural while changing the value of N, and plural combinations of the value of N and the converted digital information are transmitted to the receiving side, and the receiving side is sent from the transmitting side. A unit that divides the digital information into N bits according to the value of N, and the information that is divided into N bits is the first N bits.
Data is transmitted at a predetermined timing by using a data transmission system that performs correction while referring to the bit sequence and the second N-bit sequence and converts the sequence into "0" or "1".
The communication success rate is measured according to the value of N, and data transmission is performed using N relating to the best communication success rate.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An alarm radio interlocking system will be described below as a first embodiment of the present invention with reference to the drawings.
FIG. 1 is a schematic configuration diagram of an alarm wireless interlocking system,
This alarm wireless system is composed of an alarm 1, a transmitter 3, a microcomputer meter 5, and a receiver 7. The transmitter 3 is connected to the alarm device 1, and the receiver 7 is connected to the microcomputer meter 5. When the alarm device 1 detects a gas leak or the like, it issues an alarm with a buzzer or the like and sends a signal to the transmitter 3. The transmitter 3 sends an alarm signal to the receiver 7 in a message format as shown in FIG. The microcomputer meter 5 cuts off the gas when receiving the alarm signal.

FIG. 2 is a format diagram of a transmission message. The transmission message 11 has a header 12 and a plurality of user arbitrary data 21 following the header 12. The header 12 has a bit synchronization signal 13, a frame synchronization signal 15, and a calling signal 17 defined by the Radio Law. Bit sync signal 13
Is a signal for synchronizing in bit units. The frame sync signal 15 indicates the beginning of a frame. The call signal 17 is a number that is uniquely attached to the radio to identify its own radio.

FIG. 3 is a format diagram of normal user arbitrary data 21. User arbitrary data 21 includes mark 23, STX 25, meter ID signal 27, CRC2
It has 9, time information 31, and CRC33. Mark 23
Is a signal for synchronizing in wireless communication. STX
25 indicates the beginning of the text. Meter ID signal 27
Indicates the ID number of the microcomputer meter 5. CRC code 2
9. The CRC code 33 is a code used for error control. The time information 31 is set to a value in which the time (seconds) before interruption is 0.5 seconds. At the first time when the warning radio wave is emitted, a value of 120 is set by being expressed by a binary number of 8 bits, and the receiver 7 is set to, for example, 40 seconds later.
When it receives a telegram with a value of seconds, it counts the timer in itself, and after 40 seconds, it starts receiving again. At that time, if the time information 31 in which the value of 0 is set can be received, the microcomputer meter 5 is shut off.

FIG. 4 is a diagram showing the relationship between the mark 23 and the user arbitrary data 21. As the mark, for example, M
If the mark value is “1111111” using a series,
The user arbitrary data 21 is transmitted by the triple expansion method (referred to as user arbitrary data 21a), and the value of the mark is "11.
In the case of "11000", the user arbitrary data 21 is transmitted without decompression (referred to as user arbitrary data 21c), and when the value of the mark is "0000000", the user arbitrary data 21 is expanded by 15 times (user arbitrary data 21b).
Sent).

FIG. 5 is a format diagram of a transmission message 11a transmitted at the time adjustment communication once every 10 minutes.
The transmission message 11a includes a header 12 and user arbitrary data 2
1a, user arbitrary data 21b, user arbitrary data 21c, ...

In the present embodiment, the transmitter 3 converts the transmission message 11 shown in FIG. 2 as shown in FIG. 5 and sends it to the receiver 7. The receiver 7 performs error correction according to the degree of data expansion. Done. Here, the triple expansion method will be described. Figure 6
[Fig. 3] is a diagram showing conversion of data by the transmitter 3 and is a diagram showing a converted first 3-bit string of "1" and a converted second 3-bit string of "0". That is, in the transmitter 3, “1” is converted into the first 3-bit string “101”, and “0” is “101”, which is the longest Hamming distance “0”.
It is converted into a second 3-bit string "10".

FIG. 7 is an explanatory diagram of error correction by the receiver 7. The receiver 7 divides the transmitted data into 3 bits, and the 3-bit bit string is set to "101" or "0".
It is converted to "1" or "0" with reference to "10".

For example, when "0" is transmitted from the transmitter 3, it is converted into "010" as shown in FIG.
However, an error occurred during transmission and the receiver 7
When "00" is received, the receiver 7 receives the error bit string "0".
After correcting "00" by 1 bit to correct the regular bit string "010", it is converted into the final bit value "0".

Similarly, the receiver 7 causes the error bit string "001".
Is received, it is corrected to the regular bit string “101” and then converted to the final bit value “1”. The same correction is made thereafter. In FIG. 6, when “010” or “101” is sent to the receiver 7, no error has occurred,
As it is, “010” is converted into “0” and “101” is converted into “1”.

Further, in the case of 15-fold expansion, "1" is set to the first 15-bit string (for example, "10101010101010").
101 ") and convert" 0 "to the first 15-bit string and the second 15-bit string having the longest Hamming distance (for example," 1 ").
01010101010101 ") and transmits. In this case, error correction of up to 7 bits can be performed.

Next, the operation of the first embodiment will be described. During the time adjustment communication once every 10 minutes, the transmitter 3 transmits the message 11a to the receiver 7 in the format shown in FIG. The message 11a includes the header 12 and "1111111".
Mark 23a in which is set, the user arbitrary data 21a which is expanded 3 times, the mark 23b in which "0000000" is set, the user arbitrary data 21b which is expanded 15 times, and the mark 23 in which "1111000" is set
c and a plurality of marks 2 such as user arbitrary data 21c
3 and user arbitrary data 21.

Here, the processing of the user arbitrary data 21a which is expanded three times will be described. As shown in FIG. 8, when transmitting 4-bit data 71 “1001”, the content “1” of the first bit 73 is set to “101” as the 3-bit string 81 as shown in FIG. The content "0" of 75 is "010" as the 3-bit string 83 as shown in FIG. 6, the content "0" of the third bit 77 is "010" as the 3-bit string 85 as shown in FIG.
The content "1" of the fourth bit 79 is 3 as shown in FIG.
The bit string 87 is converted into “101”.

FIG. 9 shows the triple-expanded data received by the receiver 7. The receiver 7 has 3-bit strings 81a, 83.
a, 85a, 87a are received. In this case, the second 3-bit string 8 is transmitted during transmission between the transmitter 3 and the receiver 7.
An error of 1 bit occurs in 3a and the fourth 3-bit string 87a. The received 3-bit string 81a and 3-bit string 85a are regular bit strings, and as shown in FIG. 6, they are directly received as the content "1" of the first bit 73a and the content "0" of the third bit 77a. Received 3
Bit string 83a (“000”) and 3-bit string 87a
Since "(100") is an incorrect bit string, the receiver 7
6 corrects the correct bit sequence 83b as "010" and 87b as "101", respectively, and referring to FIG. 6, the contents of the second bit 75a "0" and the fourth bit Converted to the content "1" of 79a.

Although the user arbitrary data 21a has been described above, even if the user arbitrary data 21b is converted into a 15-bit string, error correction up to 7 bits can be performed in the receiver 7.

As described above, according to the first embodiment, the identification information is set in the mark 23 so that the mark 23 is expanded by 3 times.
It is possible to transmit a plurality of conversion data such as double expansion and no expansion.

In this embodiment, 3 times extension and 15
Although the case of double expansion has been described, the identification value set in the mark 23 may be changed to an odd double expansion such as 5 × expansion or 7 × expansion. That is, “1” is converted into a first N-bit string (N is an odd number), “0” is converted into a second N-bit string having the longest Hamming distance from the first N-bit string, and each mark 23 is converted. Set an identification value and set N
The double-decompressed user arbitrary data 21 may be transmitted. In this case, error correction up to (N-1) / 2 bits can be performed.

Next, the operation of the second embodiment will be described. FIG. 10 is a flowchart when data transmission is performed at a predetermined timing. By the method as described in the first embodiment, transmission is performed to the receiver 7 during time adjustment communication once every 10 minutes from the transmitter 3 (step 10).
1). When the meter ID 27 in the user arbitrary data 21 matches the ID of the microcomputer meter 5, the communication is considered to be successful, and a table showing the communication success rate as shown in FIG. 11 is created and stored in the transmitter 3. (Step 103).

FIG. 11 is a diagram of a table required for measuring the communication success rate stored in the transmitter 3. FIG.
In the example of 1, the communication with a high communication success rate immediately before the actual communication is the 15-fold expansion method.

FIG. 12 is a flowchart showing a procedure for performing communication with the best communication success rate. The transmitter 3 searches the table as shown in FIG. 11 stored in step 103 to obtain the method with the best communication success rate (step 201). When the method with the best communication success rate is code decompression (step 203), the mark 23 of the user arbitrary data 21 in FIG.
111000 "is set, and data transmission is performed without expansion (step 205). When the method having the best communication success rate is the triple expansion (step 207), the mark 23 of the user arbitrary data 21 of FIG.
11111 "is set and data is transmitted by triple code expansion (step 209). If the method with the best communication success rate is 15 times expansion, user arbitrary data 2 in FIG.
"0000000" is set to the mark 23 of No. 1 with reference to FIG. 4, and data transmission is performed by 15-fold code expansion (step 211).

As described above, according to the second embodiment, the data transmission can be performed by the method having the best communication success rate among the 3-fold expansion, the 15-fold expansion, and the non-expansion. Even if random noise, burst noise, etc. occur, the communication success rate can be improved.

In this embodiment, 3 times extension and 15
Although the case of double expansion has been described, a method having the best communication success rate may be selected from a plurality of N times expansion (N is an odd number). In addition, although the above-described embodiments have been described by taking the alarm wireless interlocking system, the present invention is not limited to the alarm wireless interlocking system and can be applied to other digital data transmission systems.

[0029]

As described above in detail, the present invention is
It is possible to provide a data transmission system having a high communication success rate even when random noise, burst noise, or the like occurs.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of an alarm radio interlocking system according to an embodiment of the present invention.

[Fig. 2] Format diagram of transmission message 11

[Fig. 3] Format diagram of normal user arbitrary data 21

FIG. 4 is a diagram showing a relationship between a mark 23 and user arbitrary data 21.

FIG. 5 is a format diagram of a transmission message 11a during time adjustment communication.

FIG. 6 is a diagram showing a converted first 3-bit string and a second 3-bit string of “1” and “0”.

FIG. 7 is an explanatory diagram of an error bit string and a corrected bit string.

FIG. 8 is a diagram showing conversion of transmission data.

FIG. 9 is a diagram showing correction of received data.

FIG. 10 is a flow chart when data is transmitted at a predetermined timing.

FIG. 11 is a diagram of a table necessary for measuring a communication success rate.

FIG. 12 is a flowchart showing a procedure for performing communication with the best communication success rate.

[Explanation of symbols]

 1 ... Alarm device 3 ... Transmitter 5 ... Microcomputer meter 7 ... Receiver 11 ... Transmission message 12 ... Header 13 ... Bit synchronization signal 15 ... Frame synchronization signal 17・ ・ ・ Call signal 21 ・ ・ ・ User arbitrary data 23 ・ ・ ・ Mark 25 ・ ・ ・ STX 27 ・ ・ ・ Meter ID 29 ・ ・ ・ CRC code 31 ・ ・ ・ Time information 33 ・ ・ ・ CRC code

Claims (2)

[Claims] 1. A first side for converting a "1" into a first N (N is an odd number) bit string on the transmission side.
Conversion means, second conversion means for converting “0” into a second N-bit string having the longest Hamming distance to the first N-bit string, digital information to be transmitted, A second conversion means for converting the value of N into a plurality while varying the value of N, and transmitting a plurality of combinations of the value of N and the converted digital information to the reception side. Refers to means for dividing the digital information sent from the transmission side into N bits according to the value of N, and the information divided into N bits with reference to the first N-bit string and the second N-bit string. While making corrections,
A data transmission system comprising: a means for converting into "0" or "1". 2. The data transmission system according to claim 1, data transmission is performed at a predetermined timing, a communication success rate is measured according to a value of N, and data is transmitted using N relating to the best communication success rate. The data transmission system according to claim 1, wherein the data transmission is performed.