JPS6061961A - Information recording and reproducing device - Google Patents

Abstract

PURPOSE:To attain correction to a single erasion error in a reproduction mode by using the error detection as a pointer and to improve the error factor of a sector, by adding previously a check sum to the data to be recorded then performing the coding. CONSTITUTION:The reproduction data 20 obtained from the signals reproduced from a recording medium are distributed into a prescribed matrix by a deinterleaver 14. This matrix, i.e., the reproduction train data 21 are transmitted successively. Each of these data 21 is decoded by an internal decoder 15, and the decoded train data 22 is obtained. Here if an error within the correcting capacity of an inner code is produced, it is perfectly corrected. While an error outside said correcting capacity is also detected with high probability. Then an error detecting signal 23 is sent to an error detection number counter 18 from the decoder 15. The data 22 is sent to a buffer 17 and distributed into another matrix and also sent to a check sum generating circuit 19. Then a check sum is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an information recording/reproducing apparatus for recording or reproducing information on a recording medium having an information recording area divided into a plurality of sectors.

Conventional configuration and its problems Information recording and reproducing apparatuses that record and reproduce information on a sector-by-sector basis employ an error control method that is completed within a sector in order to prevent error propagation between sectors. If the reliability and error characteristics of the recording medium itself are not very good,
It becomes necessary to correct so-called complex errors in which random errors and burst errors coexist. Therefore, in conventional information recording and reproducing devices, the data to be recorded on the memory card is divided into multiple pieces, each of which is encoded into a code word, and then interleaved within the sector and recorded, so that burst errors are randomly generated during playback. , and each code error is corrected as a random error. However, to increase the effectiveness of the reliability improvement, it is necessary to correct more multiple errors in each code word, which results in a significant increase in redundancy and increases the size and complexity of the code decoder. invite

OBJECTS OF THE INVENTION The present invention solves the problems of the conventional method described above, and provides a method that does not significantly increase redundancy and has the advantage of suppressing the complexity of the decoder in order to improve reliability. As a result, it is an object of the present invention to provide an information recording and reproducing device that is highly reliable and has a large information capacity.

Structure of the Invention In order to achieve the above object, the present invention is provided with means for recording and reproducing signals on a recording medium having a sector structure in which an information recording area is divided into a plurality of sections, and the original data to be recorded in each sector is means for adding a checksum to the data to which the checksum has been added by the means, means for adding redundancy for error control to data for each checksum length, and a plurality of data to which redundancy has been added. A means is provided for interleaving sequences within a sector.

In general, information becomes meaningful only when it has a certain scale, such as one sector's worth of information, and even if one sector of information is incorrect, that sector is incorrect. Therefore, the reliability of an information recording and reproducing device that records and reproduces information in sector units should be evaluated based on the error rate of the sector, rather than the bit or symbol error rate 'T: which is the unit of error control. It is a kimono. Therefore, when looking at the average error rate, in a conventional method in which error control is completed in each code word that makes up a sector, the error rate in code word units, symbol units, or bit units is It's good, but the error rate per sector is bad. This is because when errors exceeding the error control of individual codes 8M occur in the entire sector, there is a relatively high probability that the errors will be concentrated in one code word after dinterleaving is performed. In other words, the number of error-controllable errors in the entire sector does not exceed the number of error-controllable errors in the code words constituting the sector. Therefore, in the present invention, after adding a checksum to the data to be recorded as described above, encoding and interleaving are performed and recorded in the same manner as in the conventional method, and during playback, error control is performed for each code word. By setting a pointer for errors that exceed the number of errors and performing single erasure error correction using a checksum, it is possible to improve the sector error rate.

Description of examples Embodiments of the present invention will be described below based on the drawings.

FIG. 1 shows a principle diagram of a code structure for error control error coding used in an information recording/reproducing apparatus according to an embodiment of the present invention. 11) is recorded data, (2) is a checksum, and (3) is a check symbol. - Data to be recorded in a sector is recorded data i in a (kXz) matrix as shown in Figure 1.
Arrange in l+. Here, the elements of this matrix are represented by i bits. Next, checksum (2) is obtained as a result of taking the exclusive OR of the corresponding bits of one i-bit set in each row in the (kXz) matrix, and is Can be expressed.

Then, the l bit sets in each column of the (kX[l+1]) matrix obtained by the above processing are encoded into a code having error correction and error detection capabilities,
Inspection symbols (3) of r i-pit sets are added to each column. It is configured as above ([k+r]x(l+tl
) By interleaving the code of the matrix within the sector, the order in which horizontally written sentences are read, that is, the matrix elements (1, 1), (
1, 2), (1, 3)..., (2, 1), (
2, Ri.

--, ([k+r], /), ([k+rl, [l+1]
) to the recording modulator and recorded on the recording medium.

Here, the code with error correction and error detection ability is
Usually, when i=1, it is BCH code, and when i≧2, it is GF
Use the Reed Solomon code above in (g). In the following, a data sequence expressed in the form of a (k A code that has error correction and error detection capabilities is called an inner code.

'$B is a block diagram showing an example of an apparatus for recording the code shown in FIG. 1 on a recording medium. (4) is an outer code encoder, (5) is a buffer, (6) is a checksum generation circuit, (7) is an inner code encoder, (8) is an interleaver, +91 Fi recording data, (10) is the checksum, (11) is the column data, Q is the inner code word data, and 01 column data. - Data (9) to be recorded in a sector is input to an outer code encoder (4) composed of a buffer (5) and a checksum generation circuit (6), and a code word of the outer code is generated. Then, in the buffer (6), the sequence of code words of the outer code arranged like the (kx(Z+l) matrix in FIG. 1, ie, the column data (11)) is sequentially sent to the inner code encoder (7). .Inner code encoder())
adds the check symbol (3) to the column data (l) and outputs the inner code word data Q21.The interleaver (8) accumulates the inner code word data (12i) for − sectors and outputs the inner code word data (12i) as shown in FIG.
The data is arranged like a (f+rlX[j+1]) matrix and its rows, that is, row data (l instants) are sequentially sent to the recording modulator.

FIG. 3 is a block diagram showing an example of a device for reproducing recordings recorded by the recording device shown in FIG. 2. 04)
is the dinter leaver, (I5) is the inner code decoder, the ring is the outer code decoder, and O? ) is the buffer, on is the error detection number counter, (I is the checksum generation circuit, 4 is the playback data, Aki is the playback column data, (4 is the decoded column data, (shio is the error detection signal, 嬅) is the disappearance The error correction trigger, □□□ is the erased error pattern, and the wire is the decoded data.The reproduced data obtained by the recording demodulator from the reproduced signal reproduced from the recording medium is processed by the dinter leaver (I4) to the ([[ k+r ] Then, decoded string data is obtained.Here, if an error within the inner code's powder correction ability occurs in each code word of the inner code, that is, the reproduced string data e1), the error is If the error is completely corrected, but more errors occur, the error within the error detection capability will be completely detected, and further errors will be detected with a high probability, and the error detection signal (c) will be detected within the error detection capability. The error detection number is sent from the code decoder (I) to the counter end. The decoded ytJP-tar is sent to the buffer (l?) and is (kxtz+t)
) are arranged like a matrix and sent to a checksum generation circuit to derive a checksum. This checksum will be all 0 if there is no error in - sector's worth of decoded string data (4).However, if there is an error in - sector's worth of decoded string data (2), for example, certain reproduced string data (211) will be 0. If an uncorrectable error is detected, the reproduced sequence data (1) is not processed at all and is sent out as decoded sequence data (221), so the checksum is all 0.
It is not. If only one uncorrectable error is detected in the decoded string data for - sectors, that is, when the decoded string data for - sectors has been accumulated in the buffer (lno), the number of errors detected will be counted. (If the content of 181 is ``1'', checksum generation time FIII-
The checksum generated in , indicates the error pattern of the decoded string data (goods) for which error detection has been performed. Therefore,
When the error detection count counter (1m) is 1", the erasure error correction trigger is sent and the checksum generation circuit -
The checksum derived in is sent to the buffer (I7) as an erasure error pattern transport, and the decoded string data is corrected. Then, the contents of the buffer (I?) are output as decoded data.

As is clear from the above explanation, the error that occurs in one sector and is 100% corrected is an error that is within the error correction capability of the code corresponding to the inner code in the conventional method, whereas the method according to the present invention In this case, the error is within the error detection capability of the inner code. As is generally known, in the decoding of error correction codes, increasing the error correction capability increases the complexity of the decoder exponentially, whereas error detection is very simple. Therefore, compared to the conventional method, the method according to the present invention can be expected to have a much higher sector error rate improvement effect if the same level of redundancy is allowed, and if the same level of sector error rate is expected. , reduced redundancy, and code decoder complexity.

Effects of the Invention The information recording/reproducing apparatus of the present invention adds a checksum to the data to be recorded in advance and encodes the data.
Single erasure error correction can be performed using error detection as a pointer during playback. Therefore, the amount of fat that is corrected within the - sector increases, and the error rate of the sector can be improved. Conversely, if you do not want to improve the sector error rate, you can greatly simplify the error control encoding and decoding after checksum addition, which has a great practical effect.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the principle of a code structure for encoding for error control used in an information recording/reproducing apparatus according to an embodiment of the present invention;
FIG. 2 is a block diagram of the recording circuit in the information recording and reproducing apparatus, and FIG. 3 is a block diagram of the reproducing circuit. ill...recorded data, (2)...checksum,
(3)...Check symbol, (4)...Outer code encoder s
1tt)...buffer, (6)...checksum generation circuit, (7)...inner code encoder, (8)...
Interleaver, (3)...recorded data, (to)...
・Checksum, (■)...Column data, (I@...
Inner sign 8-word data, (l 紫... line data, 04)...
・Dinter leaver, (I-shu...inner code decoder, ring ・
... Outer code decoder, +1 needle ... Buffer, Ol ... Error detection number counter, (11 ... Checksum generation circuit, Iya ... Reproduction data s C20) ... Reproduction string data, Kan - ...Decoded string data, (To)...Error detection signal, (To)...Erasure error correction trigger, (To)...Erasure error Shiba turn, -...Decoded data agent Yoshihiro Morimoto No. 1 figure

Claims (1)

[Claims] 1. A means for recording and reproducing a signal on a recording medium having a sector structure in which an information recording area is divided into a plurality of parts, and means for adding a checksum to the original data recorded in each sector; An information recording and reproducing apparatus comprising means for adding redundancy for error control to data of each checksum length and means for interleaving a plurality of data sequences to which redundancy has been added within a sector.