Network for transmitting information data without error correction when a ...

United States Patent [w]

Kushita

[54] NETWORK FOR TRANSMITTING

INFORMATION DATA WITHOUT ERROR
CORRECTION WHEN A TRANSMISSION
CHANNEL QUALITY IS GOOD, OR WITH
REDUNDANCY BITS OF A
PREDETERMINED LENGTH ADDED TO
EACH DATUM WHEN THE CHANNEL
QUALITY IS POOR

[75] Inventor: Masayuki Kushita, Tokyo, Japan

[73] Assignee: NEC Corporation, Tokyo, Japan

[21] Appl. No.: 601,866

[22] Filed: Feb. 15, 1996

[30] Foreign Application Priority Data

Feb. 15, 1995 [JP] Japan 7-049295

[51] Int. CI.6 G08C 25/02; H03M 13/00

[52] U.S. CI 371/32; 371/35

[58] Field of Search 371/32, 33, 34,

371/41, 35

[56] References Cited

U.S. PATENT DOCUMENTS

4,110,558 8/1978 Kageyama et al 375/357

4,138,678 2/1979 Kirner 343/173

4,584,685 4/1986 Gajjar 371/35

4,716,573 12/1987 Bergstrom et al 375/202

4,967,413 10/1990 Otani 371/37.4

5,001,776 3/1991 Clark 455/226.2

5,371,737 12/1994 Nelson et al 370/314

5,430,743 7/1995 Marturano et al 371/5.5

5,477,550 12/1995 Crisler et al 371/32

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US005835508A [ii] Patent Number: 5,835,508 [45] Date of Patent: Nov. 10, 1998

FOREIGN PATENT DOCUMENTS

58-178650 10/1983 Japan .

63-172535 7/1988 Japan .

4100360 4/1992 Japan .

4507334 12/1992 Japan .

661921 3/1994 Japan .

OTHER PUBLICATIONS

Lin et al; Error Control Coding, Fundamentals and Applications; Prentice-Hall, Inc.; pp. 271, 272, 441, 442, Jan. 1983.

Primary Examiner—Reba I. Elmore

Assistant Examiner—Robert J. Dolan

Attorney, Agent, or Firm—Sughrue, Mion, Zinn, Macpeak

& Seas, PLLC

[57] ABSTRACT

In order to transmit information data from a station to another station through a transmission channel, only the information data (a31 to a00, b31 to b00, etc) are transmitted when the channel has a good channel quality. When the channel quality is bad, error correction code words are composed for transmission by adding redundancy bits (A15 to Aq0, B15 to B00, etc) to the information data. When the channel quality is bad even with transmission ol the code words, error correction code blocks are composed by interleaving information bits (a's, b's, etc) and the redundancy bits in a selected number of code words with the selected number increased from two depending on the channel quality. Alternatively, such data, words, or blocks are transmitted with a transmission rate adjusted.

37 Claims, 7 Drawing Sheets