JPS6029069A - Error detection/correction encoding system - Google Patents

Abstract

PURPOSE:To shorten decoding time by using a multiple-stage encoder and time base control circuit so as to conduct reverse operation of time base operation, which is to be conducted after the first-stage encoder, before it. CONSTITUTION:Input signal data series to be encoded enters a time base operation circuit 9. The circuit 9 conducts reverse operation of the operation which is conducted by a time base operation circuit 11. An encoder 10 adds error detection/correction code which is to be processed in the circuit 11. However, this reverse operation is conducted beforehand, and therefore this output is input signal data series as it is. An encoder 12 adds the second-stage error detection/ correction codes, and finally a time base control circuit 13 processes, transmits and records them. On the other hand, signals which are transmitted in such form are processed by a time base control circuit 14 which conducts reverse operation of the circuit 13, and corrected by a decoder 15. At a point of this time, unless errors exist, data series can be outputted as it is. Consequently, there is no necessity of conducting final stage time base operation and data are outputted in a short time.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an error detection and correction encoding method used to deal with data errors that occur in the transmission and recording of digital data.

Conventional configurations and their problems In recent years, when transmitting or recording digital data, error detection and correction techniques have been developed to deal with data errors that occur due to imperfections in the transmission system or recording medium, and to improve system reliability. Symbols are widely used. In this method, an encoder adds an error detection and correction code to a series of data strings for transmission/recording, and a decoder corrects or corrects the data using the code and outputs the result. Among these encoding methods, there is one called a multiple encoding method. This is a method of configuring encoders in multiple stages and performing encoding by performing time axis operations between them.Each encoder can have a simple configuration and can efficiently obtain high correction ability. .

Hereinafter, a conventional multiplex error detection and correction encoding method will be described with reference to the drawings. FIG. 1 is a block diagram of an encoding device using a conventional dual encoding method, and FIG. 2 is a block diagram of a decoding device, in which 1 and 3 are encoders, 6
, 8 is a decoder, 2°4, 5. 7 is a time axis operation circuit.

The operation of the encoding device and decoding device for the dual encoding method configured as described above will be described below. First, a first error detection and correction code is added to the data string by an encoder 1. After that, the time axis manipulation circuit 2 rearranges the data to create a different data string, the encoder 3 adds a second error detection and correction code, and the time axis manipulation circuit 4 rearranges the data sequence once again to transmit the signal. ·Record.

The above is the operation of the encoding device, and the decoding device performs the inverse processing described above. That is, the reproduced signal from the recording medium or the transmitted signal is rearranged in the data string by the time axis operation circuit 6, which is the reverse operation of the time axis operation circuit 4, and then the data sequence is rearranged by the decoder 6 at the first stage. A second decoding operation is performed. This is done using the error detection and correction code added by the encoder 3. Next, the time axis operation circuit 7 performs the reverse operation of the time axis operation circuit 2 in the encoding device, and the decoder 8 performs a decoding operation using the error detection and correction code added by the encoder 1.

The above description has been about a double encoding method, but the same configuration can be applied to triple or more encoding methods. The decoding device is configured by cascading the .

However, since the above encoding method involves time axis manipulation, it takes time on the decoding side to obtain a decoded signal, which poses a problem particularly when extracting specific data from a recording medium. In addition, if the recording medium and transmission system are in good condition and most data errors are corrected before decoding in the final stage, there is a problem that even if the data is correct, it cannot be output unless time axis manipulation is performed in the final stage. It also had points.

Purpose of the Invention The purpose of the present invention is to shorten the time required for decoding, and if necessary, perform the reverse operation of the time axis operation performed on the final stage time axis manipulation circuit and decoder processing before the first stage encoder. and then
This uses a multi-stage encoder and a time-base manipulation circuit, which allows the arrangement of output data to be adjusted before the final-stage time-base manipulation is performed.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 3 is a block diagram of an encoding apparatus using an error detection and correction method in an embodiment in which the present invention is applied to double encoding, and FIG. 4 is a block diagram of a decoding apparatus. In both figures, 10.12 is an encoder, 15.17 is an encoder, 9, 11, 13°, 14.16 is a time axis operation circuit,
18 is an error correction controller. FIG. 6 is a diagram showing the structure of code words in each part of the block diagrams of FIGS. 3 and 4. 4. Below, the operation of the error detection and correction code method of this embodiment will be explained. First, the encoding device will be explained. The data string of the input signal to be encoded enters the time axis manipulation circuit 9. Here, 6 of W1 to W6 as shown in Figure 5 (8)
A word is considered to be one unit, and below we will consider the case where a code for error detection and correction is added. The time axis manipulation circuit 9 performs the reverse operation of the time manipulation performed after the first-stage encoder, that is, the reverse operation of the operation performed by the time base manipulation circuit 11 in this example. The codeword containing Wl at this point is shown in Figure 5 (B
).

Next, an error detection and correction code is added in the encoder 1o, in which one word of Pl is added, resulting in the form shown in FIG. 6q. Next, it is processed by the time axis operation circuit 11, but since this reverse operation has been performed in advance, the data string of the input signal is unchanged for W1 to W6 in this output, as shown in Figure 5 p). ing. After that, the encoder 12 performs the second stage of encoding, resulting in the configuration shown in FIG. 5(E) in this example.Finally, the time axis operation circuit 13 processes the code, resulting in the configuration shown in FIG. 5(F). , transmitted and recorded.

On the other hand, the operation of the decoding device shown in FIG. 4 will be explained. The signal sent in the form shown in FIG. 6 (F') becomes the form shown in FIG. The device performs error detection and correction operations, resulting in the configuration shown in FIG. At this point, the data W1 to W6 are the same as the data string of the input signal, so if there are no errors, they can be output as they are. Note that if there is an error, the time axis operation circuit 11
After the operation in the time axis operation circuit 16 that performs the inverse operation, the decoder 17 performs the second stage error correction operation, and the error correction controller 18 performs correction on the final data string. can.

As described above, according to this embodiment, by performing the inverse operation on the input signal in advance to the time axis operation performed after the first stage, on the decoding side, before performing the second stage time axis manipulation,
This makes it possible to obtain an output with the same data string as the input signal. In the above embodiment, double encoding has been described, but it goes without saying that triple or more multiple encoding can be handled in the same way.

Effects of the Invention As is clear from the above explanation, the present invention performs the inverse operation of the time axis operation performed after the first stage encoder before the first stage encoder, thereby combining multistage encoders and time axis operations. Since the circuit is used, on the decoding side, the data string becomes the same as the input signal at the point before the time axis operation in the final stage, and if there is no error, the output signal can be obtained at that point. It is something that can be effective. Particularly, when data is recorded on a recording medium and specific data is to be output, there is no need to provide a final-stage time axis manipulation circuit, and the advantage is that the data can be output in a short time.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an encoding device of a conventional double-encoding error detection and correction encoding method, FIG. 2 is a block diagram of a decoding device, and FIGS. 3 and 4 are one embodiment of the present invention. A block diagram of an encoding device and a decoding device employing the error detection and correction encoding method according to the example, FIG. 6 is similar to FIGS. 3 and 4.
It is a figure which shows the structure of the code word in each part of the block diagram of a figure. 9. 11, 13, 14. 16... mark/time axis operation circuit,
10.12... Encoder, 15.17...
- Decoder, 18...Error correction controller.

Claims (1)

[Claims] A multi-stage code is created by applying the inverse of the time axis operation performed after the first-stage encoder before the first-stage encoder.