JPS58190147A - Data transmitting method - Google Patents

Abstract

PURPOSE:To reduce the anxiety of erroneous error correction, by transmitting a data together with a redundant code which is formed by supplying the data and a dummy bit to an error correcting coder. CONSTITUTION:A data is supplied, and 0 is added to a prescribed upper bit of the data in the form of a dummy bit by a 0 adding circuit 1. The data containing a dummy bit is supplied to a parity generating circuit 2 for read Solomon code. Thus a parity is obtained. An input data is supplied to a mixing ciruit 4 via a delay circuit 3, then synthesized with the parity to be extracted as an output data. This output data is transmitted via various types of transmission systems. Then a receiving data is supplied to a 0 adding circuit 5 to be added with 0 of the dummy bit. An error correcting circuit 6 multiplies a parity check matrix and the receiving data and calculates an error syndrome to perform the decision of an error.

Description

[Detailed Description of the Invention] The present invention relates to an error-correctable data transmission method,
In particular, the error correction operation is designed to reduce the possibility of an incorrect book being produced.

- As an example, an example in which the present invention is applied to a Reed-Solomon code where the code length m is 6 pits will be explained.

For example, (a-3) Reed-Solomon code C10, g)
(When the code length is 10 and the information point is g), the parity check matrix H is as shown below.

Here, α is a primitive element of GF(,2a), and (α
S ten α4+α3+α! +/=0).

FIG. 1 shows the configuration of the encoding circuit on the transmitting side. Data with 6 pits per symbol is supplied, and in the θ addition circuit 1, 0 is added to the upper a pit of each symbol as a dummy bit. , / symbol is assumed to be g bits. 0
It is not limited to the upper position, but may be added at other positions such as the lower position. Data obtained by converting this / symbol into g bits is supplied to the Reed-Solomon code parity generation circuit 2, and g-bit parity (2 symbols) is formed.

Input data of a 6-pit / symbol is supplied to a mixing circuit 4 via a delay circuit 3, combined with parity, and taken out as output data. This output data is transmitted via a transmission system such as a digital tape recorder or digital disk system.

FIG. 2 shows the configuration of the receiving side, in which received (reproduced data) is supplied to the zero addition circuit 5. As shown in FIG. This 0 adding circuit 5 adds 0 as dummy bits to the E-order two bits of data symbols excluding parity symbols. The received data VT that has undergone this processing is supplied to the error correction circuit 6. The received data vT is expressed as a vector as shown below.

VT=(Wg r Wg ・==”””' ”1 +
'1 r "@) Here, We and Wl are parities, and the other three symbols W! to W- have O added to the upper two bits. Error correction circuit 6
Well then.

By multiplying the above parity check matrix H and the received data, the error syndrome date, 1. □ is calculated. In other words, it is determined that there is no error.

In the case of a / symbol error, setting the error location to 1 holds true. Therefore, the error syndrome S, ,S.

is calculated, the next H, (upper − C1) is calculated, and α1
S.

Error location 1 can be found by using a ROM in which a data table for converting 1 to 1 is written.

/ In the case of a symbol error, the determined error location 1 is one of C0-9).

If this does not hold true, it is a worse error than a red herring.

So, when error location 1 is θ or /, that is, when parity symbol W0 or Wl, (IL■e
Error correction is performed by calculating i=W1) (where Wi indicates a received symbol).

If this is not a parity symbol, then the error pattern ei (no other than the error Syngelome 8 K)
It can be checked whether the upper Yupitt of is 0 or not.

As mentioned above, since the data is transmitted only in the 6th pit and not in the upper 2 pits, the error pattern e1 is
If one of the uppermost pits is O, it is determined that there is a / symbol error, and the error is corrected using (r1■θ1-Wi). Here, error 14! p-7ei upper yupit/bittemo.

Otherwise, this is determined to be an error greater than or equal to Cosympol. In this example, the cosympol error is correctable.

The data appearing at the output of the error correction circuit 6 is supplied to a copit removal circuit 7, which removes the upper two dummy bits and restores the 1-bit line to a 6-pit one. Further, for symbols that could not be corrected by the error correction circuit 6, an error pointer is added to indicate that this is an error, and the next stage interpolation circuit 8 interpolates the symbol by holing the previous value or by interpolating the average value. It is considered as output data.

As can be understood from the above explanation, since the / symbol has 6 pits, on aF(,2・), (αθ+α+/=0
) is normally used to perform encoding using a Reed-Solomon code, but if this invention is applied,
Encoding is performed on GF (2"). Therefore, on the receiving side, it is checked whether the upper no bit of error pattern e1 is 0, and erroneous error correction operations can be prevented. In some cases, an error greater than or equal to Kosympol satisfies the conditions for a /symbol error, and in this case, the error detection will be incorrect.However, according to the present invention, such errors can be solved by checking using error patterns. You can reduce your fears.

In addition, in the case of Reed-Solomon encoding on GF (Coro), 1 converted from (Sait/S, = α1) is (10
≦1≦62), it is determined that the error is greater than Cosympol, whereas in the case of Reed-Solomon encoding on GF (,211), this 1 becomes (10≦1≦, 25II)
When this happens, it is determined that the error is greater than or equal to Cosympol. However, with this invention, the range in which errors are determined to be greater than that of a cosympol has been expanded.

Error detection ability is improved.

FIG. 3 shows the structure of the data bits of a digital audio disc (referred to as a compact disc), which is an example of data to which the present invention can be applied. Youday's Bit Service, songs recorded on the disc, song explanations,
Singer 1 It is used to display the composer's name, etc., and to generate audio. R, 8, T, U, V, W
Each channel exists. In addition to this, there is also the presence or absence of songs.

There is also a P channel and a Q channel that indicate the playing time of a song.

Six bits included in each of the six R-W channels are defined as /symbols, and q6 symbols are separated by synchronization signals. On the disk, the frame synchronization signal P, Q
, R - ...... The user's bit of /4' bit corresponding to the g bit of W is located, and the main data is located after that, and the q6 symbol is 27 The signal is divided symbol by symbol, and error correction encoding is applied to each 2'l symbol. For example, the lead of (211.20) where 9 parity symbols are generated.
Solomon code is used. The present invention is applied to encoding in this case.

Note that in the following explanation, a Reed-Solomon code is used, but other codes such as an adjacent code that corrects errors on a symbol-by-symbol basis may also be used.

[Brief explanation of drawings]

Figure 1 is a block diagram showing the configuration of an example of an encoding circuit to which this invention is applied, Figure 2 is a block diagram showing the configuration of an example of a decoding circuit to which this invention is applied, and Figure @3 is a block diagram showing the configuration of an example of a decoding circuit to which this invention is applied. 2 is a route map showing an example of data to which the method can be applied. 2...Parity generation circuit, 6...
・・・・・・Error correction circuit. Agent Masato Sugiura

Claims (1)

[Claims] / For data whose symbol is m pits (rl-m) (
A predetermined dummy bit (n>m) is added and supplied to the error correction encoder, an error correction code is constructed using GF (2n) (GF is a Galois field), and the redundant bits formed by this error one-leg encoder are The code and data of m pits excluding the above dummy bits are transmitted, and on the receiving side, the above dummy bits are added and multiplied by a parity check matrix to obtain the syndrome, and the above dummy bits of the error pattern are detected.
A data transmission method characterized in that error detection is performed using the fact that a corresponding portion is not a predetermined one.