Chin Chen

US Patent:

41421744, Feb 27, 1979

Filed:

Aug 15, 1977

Appl. No.:

5/824763

Inventors:

Chin L. Chen - Wappingers Falls NY
Mu Y. Hsiao - Poughkeepsie NY

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

G06F 1112

US Classification:

3401461AL

Abstract:

This specification covers a simplified and high speed decoding scheme for Reed-Solomon codes capable of correcting up to three symbol errors in code words made up of k data and n-k check symbols where each symbol consists of m binary bits of information. In such a code the error location polynomial. sigma. (x) = x. sup. e +. sigma. sub. 1 x. sup. e-1. . . . . sigma. sub. e where e equals the number of symbol errors and the coefficient of. sigma. (x) are related to the error syndromes S. sub. i by the equation S. sub. i+e +. sigma. sub. 1 S. sub. i+e-1 +. . . . +. sigma. sub. e-1 S. sub. i+1 +. sigma. sub. e S. sub. i = 0. The decoder first tests if S. sub. 0 = 0. If S. sub. 0. noteq. 0, the assumption is made that a single symbol error has occurred. The decoder quickly verifies this by determining if S. sub. 2 +. sigma. S. sub.

US Patent:

44647530, Aug 7, 1984

Filed:

Dec 30, 1981

Appl. No.:

6/349482

Inventors:

Chin L. Chen - Wappingers Falls NY

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

G06F 1110

US Classification:

371 38

Abstract:

A modularized error correction apparatus for correcting package errors is provided by expanding an N bit single error correction, double error detection code to cover N packages of M bits each, so that the Exclusive-OR of all M bit single bit error syndromes in any given package results in a composite syndrome which is unique for each package. See FIG. 2 for the parity matrix H and the matching matrix M for the error correction code.

US Patent:

40357678, Jul 12, 1977

Filed:

Mar 1, 1976

Appl. No.:

5/662493

Inventors:

Chin Long Chen - Wappingers Falls NY
Robert A. Rutledge - Poughkeepsie NY

Assignee:

IBM Corporation - Armonk NY

International Classification:

G06F 1112

US Classification:

3401461AQ

Abstract:

This specification describes a convolutional code and apparatus for the correction of errors in differentially encoded quadrature phase shift keyed data (DQPSK). In each sequence of forty bits 24 are information bits and the remainder are parity bits. Two parity bits are generated for each three information bit set in the sequence in accordance with the following equations: P. sub. 8. sup. a = i. sub. 8. sup. a. sym. i. sub. 8. sup. b. sym. i. sub. 6. sup. b. sym. i. sub. 1. sup. b. sym. i. sub. 3. sup. c. sym. i. sub. 2. sup. c P. sub. 8. sup. b = i. sub. 8. sup. a. sym. i. sub. 6. sup. a. sym. i. sub. 3. sup. a. sym. i. sub. 5. sup. b. sym. i. sub. 8. sup. c. sym. i. sub. 4. sup. c where i. sub. 8. sup. a, i. sub. 8. sup. b and i. sub. 8. sup. c are the three information bits in the set associated with the parity bits P. sub. 8. sup. a and P. sub. 8. sup.