JPS60109943A - Error detecting correction method - Google Patents

Abstract

PURPOSE:To improve the error correction capability by constituting the system that the identical data word comes twice or more on the same channel. CONSTITUTION:Input data including erroneous data is inputted to a CIRC decoder 12 and error detection/correction is attained. An output data 13 of the decoder 12 and a discrimination signal 14 are inputted to a data discrimination circuit 15. The circuit 15 discriminates the presence of an error in the data 13 by using the signal 14 and when an error is detected, the correction is attained by replacing the erroneous data with the one preceding or succeeding data of the same channel. The discrimination by which data of the preceding or succeeding data of the erroneous data is to be replaced is decided by detecting the location of a section of identical data being consecutive twice or over.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a one-erroneous error detection and correction method used to deal with data errors that occur during the transmission and recording of digital data.

2. Description of the Related Art Structures of Conventional Examples and Their Problems In recent years, digital signals have been recorded on various recording media so that audio signals and video signals can be digitally processed. In the transmission and recording of such digital signals, errors occur in the data signals due to imperfections in the transmission system and recording medium.

For this purpose, the encoder adds a parity word to a series of data words to perform error detection and correction, and transmits and records the signal with redundancy.
Generally, a method is used in which the harrity word and the data word are corrected or corrected and then output.

Hereinafter, a cross-interleaved lead solo conduit code (hereinafter referred to as 0IRC code) used in optical digital audio discs will be explained with reference to the drawings. Figure 1 is a block diagram of the C1IRG encoder, and Figure 2 is a diagram of the CXRC decoder.
4 is encoder, 7.9 is decoder, 1.3, 5, 6, 8.1
0 is a time axis operation circuit.

The operation of the CIRC encoder and decoder configured as above will be explained below. In order to deal with various types of errors, this code generates two Reed-Solomon codes suitable for correcting random errors, and manipulates the time axis before and after that. To explain the operation of the decoder shown in FIG. 2, reproduced data containing errors is processed by the time axis operation circuit 1i'6, and then processed by the first stage decoder I7.
Errors are detected and corrected. The content of the processing in the time axis manipulation circuit N is to apply a delay of about one code word length in order to enable the decoder I to correct burst errors of about several words. Next, it passes through a time axis operation circuit V that solves interleaving, which is a time axis operation performed to deal with long burst errors, and then passes through the second stage decoder ■9.
Then, the second error detection and correction operation is performed. There are various combinations of how the decoders 1 and 1 can be provided with the ability to detect and correct errors, but for the data that cannot be corrected, pD compensation such as mean value interpolation is performed.

The purpose of the time axis operation circuit ■ is to perform this error compensation process.It rearranges the words so that errors do not occur in consecutive words for each channel, increasing the effectiveness of error compensation such as average value interpolation. It is done like this. On the other hand, in the encoder shown in FIG. 1, a Reed-Solomon code is calculated and added using the encoder and . ,
The time axis manipulation circuits before and after these perform operations in the reverse order of the processing in the decoder, and the circuits perform the reverse time axis manipulations of W, respectively.

However, in the above configuration.

In the case of signals other than audio signals, especially in the case of signals where there is no correlation between the preceding and succeeding word data and each data has independent meaning, error compensation has no effect, and furthermore, time axis manipulation for error compensation may result in false detection. This has the problem of being a burden when improving correction ability.

OBJECTS OF THE INVENTION It is an object of the present invention to perform error detection and correction operations for data word strings that have independent meanings and have no correlation between the front and back. This is done using an error detection and correction method, and provides a method that can configure a system with extremely high error correction capabilities.

Composition of the Invention The false detection and correction method of the present invention is used for a series of data words on one or more channels, and for encoding methods that include operations that enable interpolation operations, the same data word is used more than once on the same channel. It is constructed so that the error correction occurs repeatedly, and the error correction ability can be significantly improved.

DESCRIPTION OF EMBODIMENTS An embodiment in which the present invention is applied to CIRC codes will be described below with reference to the drawings.

FIG. 3 is a block diagram of a false detection and correction method that combines an embodiment of the present invention with a CIRO decoder. In FIG. 3, 11 is the input data of the CIRC decoder, 12 is the CIR
13 is the output data of the CIRC decoder, 14 is a signal indicating the presence or absence of an error in the output data, 15 is a data discrimination circuit, and 16 is the output data of the data discrimination circuit.

The operation of the error detection and correction method of this embodiment configured as described above will be explained below. First, the input data 11 of the CIRC decoder containing erroneous data is OIR
, 0 is input to the decoder 12, where an erroneous detection and correction operation is performed. Information as to whether uncorrectable data is included in the output data 13 of the CIRC decoder 12 is determined by the signal 1.
4, and this signal 14 and CIR
C decoder output data 1311″l: data discrimination circuit 1
6 is input. The data discrimination circuit uses the signal 14 to discriminate whether or not there is an error in the input data 13. If there is no error, the data is output as is, and if an error is detected, it is output from the previous or one channel of the same data. By replacing the erroneous data with later data, a correction operation is performed and correct data is output. At this time, it is possible to determine whether to replace the erroneous data with previous or subsequent data by detecting the position of a break in the same data that occurs two or more times in succession.

As described above, according to this embodiment, for a coding method that includes an operation that enables interpolation, errors can be avoided by arranging the same data word so that it is repeated multiple times on the same channel. Detection and correction operations can be significantly improved.

FIG. 4 is a diagram comparing the burst error correction ability of an embodiment of the present invention in which the same data is arranged so as to be repeated twice for each channel with that of a conventional example. In FIG. 4, the horizontal axis indicates the length of the burst error. In the conventional example, burst errors can be corrected up to length m, interpolated up to length n (n>m), and burst errors exceeding length n cannot be corrected. The correction capability for burst errors when the data word is repeated twice) can be increased to the interpolable burst error length n in the conventional example. Note that interpolation here refers to correcting one erroneous data word using the correct data word when the data words before and after the erroneous data word are correct. Further, in this example, the number of repetitions of the same data word is set to two, but by increasing the number of repetitions to three or four times, the correctable burst error length can be made larger than n.

In addition, in the above embodiment, the output J1s from the CIRC decoder
, 14 are directly input to the data discrimination circuit 15,
Even if an interpolation circuit is inserted between the CIRC decoder 12 and the data discrimination circuit 160, it is sufficient that the signal 14 or a signal informing the interpolation operation and the output data of the interpolation circuit are input to the data discrimination circuit.

Effects of the Invention As is clear from the above description, the present invention provides an encoding method that is used for a series of data words on one or more channels and includes an operation that enables an interpolation operation. By repeatedly arranging the data words as described above, an excellent effect can be obtained in that at least all the data words on which interpolation was performed can be corrected. Moreover, this effect also ensures the high reliability required for data that has no correlation between the front and back.

[Brief explanation of drawings]

Figure 1 is a block diagram of a CIRC encoder, Figure 2 is a block diagram of a CIRC encoder, and Figure 2 is a block diagram of a CIRC encoder.
FIG. 3 is a block diagram of a main part of an embodiment of a CIRCj decoder that employs the error detection and correction method of the present invention, and FIG. 4 shows the correction ability of an embodiment of the present invention compared to a conventional example. This is a comparison diagram. 1.3, 5, 6, 8.10... Time axis operation circuit, 2.4... Encoder, 7, 9... Decoder, 11 CIRC decoder, 15...Data discrimination circuit.

Claims (1)

[Claims] A coding method that is used for a series of data words on one or more channels and includes an operation that enables an interpolation operation, is characterized in that the same data words are arranged so that they are repeated two or more times on the same channel. Error detection and correction method.