Data transmission system and error correcting method applicable to the same

A data transmission system comprising:

• a receiving device for receiving data to which a pair of error correction codes is added, one error correction code having a data arrangement identical with the order in which the receiving device receives the data;
• a temporary storage device for storing said data temporarily;
• an error sensing device for sensing errors in one error correction code, before storing said data in the temporary storage device, said error sensing device including a syndrome computing device which calculates a syndrome for the one of said pair of error correction codes consisting of product codes;
• an error correcting device for correcting errors in said data stored in said temporary storage device, said error correcting device executing erasure correction of the other error correction code by using information on errors in the one error correction code sensed at said error sensing device;
• and
• a transmitting device for transmitting the data whose errors have been corrected by the error correcting device,
• wherein said data transmission system is used for a DVD reproducing device and further comprises:
• a 8-16 decoding device for subjecting the data received by said receiving device to 8-bit-to-16-bit demodulation;
• and
• a scramble cancel device to which the data whose errors have been corrected at said error correcting device is inputted and which outputs the scramble-canceled data to said transmitting device.

An error correcting method comprising:

• a first step of sensing errors in one error correction code received in the order, in which data has been received of a pair of error correction codes consisting of product codes added to said data, including calculating syndromes for said one error correction code and then storing said data in a temporary storage device;
• a second step of calling back the other error correction code of the product codes added to said data from said temporary storage device and performing not only an error correcting process using only the other error correction code but also erasure correction on the basis of information on the errors in said one error correction code sensed in said first step;
• and
• a third step of correcting said data stored in said temporary storage device,
• wherein said second step performs error detection using a specific number of syndromes instead of using the result of calculating all of the syndromes for said one error correction code.

An error correcting method comprising;

• a first step of sensing errors in one error correction code, received in the order in which data has been received, of a pair of error correction codes consisting of product codes added to said data, and then storing said data in a temporary storage device;
• a second step of calling back the other error correction code of the product codes added to said data from said temporary storage device and performing not only an error correction process using only the other error correction code but also erasure correction on the basis of information on the errors in one error correction code sensed in said first step;
• a third step of correcting said data stored in said temporary storage device;
• a fourth step of calling back said one error correction code for said data from said temporary storage device;
• a fifth step of performing not only an error correcting process using only said one error correction code but also erasure correction using information on errors in said other error correction code;
• a sixth step of correcting said data stored in said temporary storage device;
• a seventh step of calling back said other error correction code from said temporary storage device;
• an eighth step of performing not only an error correcting process using only said other error correction code but also missing-error correction on the basis of information on errors in said one error correction code;
• and
• a ninth step of correcting said data in said temporary storage device.