KR0152771B1 - Error detecting device for digital magnetic recording/reproducing player - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for recording and reproducing digital data on a magnetic recording medium. In the related art, a correction code is added to data to be recorded so that the error correction code is added to the error correction code. There is a problem that has a limit.

Accordingly, the present invention is to improve the error correction capability in error correction decoding by generating a symbol unit error flag in the previous step of error correction decoding during reproduction in order to solve such a conventional problem.

That is, the error occurrence is detected by using the characteristic that the repetition of the same polarity which is the magnetic recording and reproducing characteristic does not occur, so that it is applied to the magnetic recording / reproducing apparatus which performs error correction encoding, especially in the case of using double encoding. The effect is great.

Description

Error detection device of digital magnetic recorder / player

1 is a block diagram of a general digital magnetic recorder / player.

2 is a block diagram of a conventional error detection apparatus.

3 is a block diagram of an error detection apparatus according to the present invention.

(A)-(e) of FIG. 4 is explanatory drawing concerning this invention.

* Explanation of symbols for main parts of the drawings

1: magnetic tape 6: regeneration amplifier

7: equalizer 8: demodulator

9: Phase synchronous loop circuit 10: Error correction decoder

11: Bit level discriminating unit 12: Error position detecting unit

13: Sync signal detection and counter unit 14: Error flag generation unit

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an error detection apparatus of a digital magnetic recorder / player, and more particularly, to an error detection apparatus of a digital magnetic recorder / player capable of increasing error correction capability by using a level polarity of a reproduction signal.

In general, in a magnetic recorder / player which records and reproduces a digital signal, an error may occur in the digital signal when the digital signal is recorded and reproduced.

Accordingly, as a countermeasure against the occurrence of such an error, an error correcting code for adding an error correcting code is recorded in the step of recording a digital signal, and the error correction coded digital signal is reproduced by reproducing the recorded signal. The data is decoded again, and the error within the range where the error can be corrected is corrected, and the error within the range where the error cannot be corrected is sent to the next processing step as a reproduction data without correction.

That is, as shown in FIG. 1, the error detecting apparatus of the digital magnetic recorder / player reproduces the digital data to be recorded so that the error that occurs when the error correction information coding unit 2 attempts to record and reproduce the error can be corrected. The corrected and error corrected data is recorded on the magnetic tape 1 by the recording head a through the recording modulator 3 which modulates the signal into a signal suitable for the recording / reproducing channel characteristics.

Then, the signal recorded on the magnetic tape 1 is converted into a digital signal by the recording demodulation section 4 which is reproduced through the playback head b and then demodulated into a digital signal, and by the error correcting encoding section 5 After correcting the error within the range of error correction capability, it is output as playback data.

Here, looking at the digital magnetic player described above in more detail, as shown in FIG. 2, the signal recorded on the magnetic tape 1 is converted into an electrical signal through the playhead b and then reproduced to amplify the signal. This equalized signal is generated as a clock signal in the phase-locked loop circuit 9 and demodulated as a digital signal in the demodulator 8 through the amplifier 6 to equalize the waveform. Then, the error correction coder 10 is applied to the error correction coder 10, and the error correction coder 10 corrects an error in the error correction capability and outputs the reproduced data.

However, in the conventional error detection apparatus of the digital magnetic recorder / player, error correction and encoding is performed to correct an error generated in the process of recording and reproducing the digital signal.

That is, error correction coding adds an error correction code to the data to be recorded, and thus has an error correction capability. Therefore, the error correction capability increases by adding many error correction codes, which is usually limited to the error correction code added. There was a problem in that the error correction capability was limited.

In order to solve such a conventional problem, the present invention detects an error in a symbol unit in the previous step of error correction decoding, and then applies a symbol unit error flag to the error correction decoding unit to increase an error correction capability. An error detection apparatus of a recorder / player is created, which will be described in detail with reference to the accompanying drawings.

3 is a block diagram of the error detection apparatus of the present invention digital magnetic recorder / player. As shown in the figure, first, a symbol unit is selected to error-correct the recording data, so that error correction is made by symbol unit. The error flag can be known in units, and the error correction capability can be further improved.

That is, the reproduction amplifier section 6 reproduces the digital data recorded through the reproduction head b on the magnetic tape 1 and amplifies the reproduction signal, and the equalizer 7 equalizes the waveform of the amplified signal. And a demodulator 8 for restoring the output signal of the equalizer 7 to the digital signal and a phase-locked loop circuit 9 for restoring the clock, and correcting an error occurring in the demodulated digital data and outputting it as reproduction data. In the error detecting device of the digital magnetic recorder / player configured by the error correcting coder 10, a bit level board for detecting a value determined in units of bits in order to digitalize the output signal of the equalizer 7 Error position that detects whether there are bits of different polarities between the same polarity in the data of the other column 11 and the bit level discriminating unit 11, and if there are no bits of different polarities, an error flag is attached to all the bits between the same polarities. A synchronizing signal detection and counter unit 13 which detects a synchronizing signal among the digital signals demodulated by the output unit 12 and the demodulation unit 8 and the phase synchronizing circuit 9 and counts the data following the synchronizing signal in symbol units. ) And a bit unit error flag generated by the error position detection unit 12 is compared with the output of the synchronization signal detection and counter unit 13 to generate an error flag in units of symbols, and to the error correction encoder 10. It consists of the error flag generation part 14 which apply.

Referring to Figure 4 the operation and effects of the present invention configured as described above are as follows.

First, as shown in (a) of FIG. 4, the electrical signal reproduced from the magnetic tape 1 through the reproducing head b is amplified by the reproducing amplifier 6 and then equalized by the equalizer 7 to obtain a digital signal. The demodulation section 8 to recover and the phase synchronization loop circuit 9 to recover and the bit level discriminating section 11 for determining the level in bits are applied respectively.

Accordingly, in the bit level discriminating section 11, output data as shown in FIG. 4B is obtained, and the output data is applied to the error position detecting section 12. FIG.

That is, since there is no other polarity (-1) between the 6th bit and the 10th bit polarity (1) as shown in (b) of FIG. Float as shown in (c) of 4 degrees.

On the other hand, the digital signal output from the demodulator 8 is applied to the synchronous signal detection and counter unit 13 and the error correcting coder 1 which detects the synchronous signal and then cuts and counts it from symbol to bit unit.

Therefore, in the error flag generating unit 14 which generates the bit unit error flag as a symbol unit error flag by comparing the outputs of the synchronization signal detection and counter unit 13 and the error position detection unit 12, the symbol for increasing error correction capability. An error flag is output and applied to the error correction decoding unit 10. At this time, as shown in (d) and (e) of FIG. 4, the symbol error flag is generated differently according to the position of the bit error flag.

As described in detail above, the present invention generates a symbol unit error flag in the previous step of error correction decoding when error correcting and decoding, thereby adding the same amount of error correction code to exhibit a greater correction capability.

Therefore, it is effective in error correction / decryption that requires an additional component or means to perform a prescribed function, and the parent item does not fail even if a part thereof fails, that is, redundancy is required. Becomes large.

Claims (1)

Regeneration amplifier 6 and equalizer 7 in which the electric signals reproduced from the magnetic tape 1 through the reproduction head b are amplified and equalized, and the output signals of the equalizer 7 are restored to digital signals. And a phase correction loop circuit 9 for restoring a clock, and an error correction decoder 10 for correcting an error occurring in the demodulated digital data and outputting the reproduced data. The error position is determined by the bit level discrimination unit 11 which detects the level of the bit unit in the output signal of the equalizer 7, and the repetitive characteristic of the polarity in which the opposite polarity must exist between the same polarity at the bit unit level. An error position detection unit 12 for detecting a signal, a synchronization signal detection and counter unit 13 for detecting a synchronization signal from the demodulated digital data signal, and counting a symbol unit from the next data of the synchronization signal; 12) and awards An error detection device for a digital magnetic recorder / player characterized in that it comprises an error flag generation unit (14) for error correction by generating an error flag for each symbol by comparing the synchronization signal detection and the output of the counter unit (13). .

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