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Distance 4 Error Correcting Code that Detects Package Oriented Failures

IP.com Disclosure Number: IPCOM000089766D
Original Publication Date: 1977-Dec-01
Included in the Prior Art Database: 2005-Mar-05
Document File: 2 page(s) / 40K

Publishing Venue

IBM

Related People

Chen, CL: AUTHOR

Abstract

A distance 4 (72,64) code capable of detecting package failures for package size of 4 bits and 3 bits is presented.

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Distance 4 Error Correcting Code that Detects Package Oriented Failures

A distance 4 (72,64) code capable of detecting package failures for package size of 4 bits and 3 bits is presented.

The parity check matrix H of the code is shown in the figure. Bit positions 1 - 64 represent data, and bit positions 65 - 72 represent parity checks. The encoding is done by the usual way of taking data bits into an exclusive OR tree to generate 8 check bits according to the rules given by H. The decoding is also done by the conventional method. First, the syndrome vector of 8 syndrome bits is generated from the received code word. Then the syndrome vector is matched with the column vectors of H. If the syndrome bits are all 0, there is no error. If the syndrome matches the i-th column of H, the i-th bit position is in error and is corrected. Otherwise, errors are detected. The code detects 100% of the following two types of package failures: (a) 4-bit package: In this case a code word is divided into 18 4-bit packages in a consecutive order. That is, bits 4i + 1, 4i + 2, 4i + 3, 4i + 4 are in one package for o </= i </= 17. (b) 3-bit package: In this case bits 3i + 1, 3i + 2, 3i + 3 for o </= i </= 23 are in one package.

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