Method and apparatus for receiving and decoding coded information, including transfer of error information from transmission layer to coding layer

• US 6,530,055 B1
• Filed: 11/12/1999
• Issued: 03/04/2003
• Est. Priority Date: 04/26/1999
• Status: Expired due to Term

• Current Assignee: Inphi Corporation
• Original Assignee: OKI Electric Industry Company Limited
• Inventors: Fukunaga, Shigeru
• Primary Examiner(s): TU, CHRISTINE TRINH LE
• Application Number:
  US09/439,497
• Time in Patent Office: 1,208 Days
• Field of Search: 714/746, 714/748, 714/751, 714/752, 714/758, 714/701, 714/703, 714/712, 714/48, 714/49, 714/50, 714/56, 714/14, 714/18, 370/244, 370/389, 370/474, 370/902, 370/912
• US Class Current: 714/746
• CPC Class Codes: G06F 11/0709 in a distributed system consisting of a plurality of standalone computer nodes, e.g. clusters, client-server systems
• CPC Class Codes: G06F 11/0772 Means for error signaling, e.g. using interrupts, exception flags, dedicated error registers
• CPC Class Codes: H04L 1/0061 Error detection codes
• CPC Class Codes: H04L 1/0082 fields explicitly indicating existence of error in data being transmitted, e.g. so that downstream stations can avoid decoding erroneous packet; relays
• CPC Class Codes: H04L 1/1867 Arrangements specially adapted for the transmitter end
• CPC Class Codes: H04N 19/89 involving methods or arrangements for detection of transmission errors at the decoder

Abstract

Transmission units such as packets of coded data are received in a transmission layer, converted to coding units, supplied to a coding layer, and decoded in the coding layer. Errors in arriving transmission units are detected in the transmission layer. The results of error detection in the transmission layer are used when the coding units are decoded in the coding layer, preferably by having the transmission layer provide the coding layer with error information explicitly indicating which of the coding units are free of errors and which are not.

Claims

1. A method of receiving and decoding coded data in a system having a transmission layer and a coding layer, the coded data being divided into transmission units, each transmission unit being received separately in the transmission layer, errors being detected in each transmission unit in the transmission layer, the received data being converted to coding units in the transmission layer, the coding units having a definite relation to the transmission units, the coding units being provided to the coding layer, each coding unit being decoded separately in the coding layer, comprising the steps of:

providing error information from the transmission layer to the coding layer, said error information reporting results of error detection performed in the transmission layer by indicating which of the coding units provided from the transmission layer to the coding layer are free of errors; and

using said error information, when information repeated in different coding units has different values in the different coding units, to select a correct value from among said different values.

2. A method of receiving and decoding coded data in a system having a transmission layer and a coding layer, the coded data being divided into transmission units, each transmission unit being received separately in the transmission layer, errors being detected in each transmission unit in the transmission layer, the received data being converted to coding units in the transmission layer, the coding units having a definite relation to the transmission units, the coding units being provided to the coding layer, each coding unit being decoded separately in the coding layer, comprising the steps of:

providing error information from the transmission layer to the coding layer, said error information reporting results of error detection performed in the transmission layer by indicating which of the coding units provided from the transmission layer to the coding layer are free of errors; and

using said error information to position said coding units in relation to one another.

3. A method of receiving and decoding coded data in a system having a transmission layer and a coding layer, the coded data being divided into transmission units, each transmission unit being received separately in the transmission layer, errors being detected in each transmission unit in the transmission layer, the received data being converted to coding units in the transmission layer, the coding units having a definite relation to the transmission units, the coding units being provided to the coding layer, the coding units being coded predictively, with reference to previous coding units, each coding unit being decoded separately in the coding layer, comprising the steps of:

providing error information from the transmission layer to the coding layer, said error information reporting results of error detection performed in the transmission layer by indicating which of the coding units provided from the transmission layer to the coding layer are free of errors; and

using said error information to select reliable reference data for use in decoding said coding units.

4. A method of receiving and decoding coded data in a system having a transmission layer and a coding layer, the coded data being divided into transmission units, each transmission unit being received separately in the transmission layer, errors being detected in each transmission unit in the transmission layer, the received data being converted to coding units in the transmission layer, the coding units having a definite relation to the transmission units, the coding units being provided to the coding layer, the coded data being moving-picture data comprising successive frames, each coding unit being decoded separately in the coding layer, comprising the steps of:

providing error information from the transmission layer to the coding layer, said error information reporting results of error detection performed in the transmission layer by indicating which of the coding units provided from the transmission layer to the coding layer are free of errors; and

using said error information to place each coding unit in a correct one of said frames.

5. The method of claim 4, wherein said step of using said error information to place each coding unit in a correct one of said frames further comprises the steps of:

determining a number of said coding units per frame; and

using said error information to detect missing coding units, thereby detecting frame changes not indicated in the received coding units.

6. A method of receiving and decoding coded data in a system having a transmission layer and a coding layer, the coded data being divided into transmission units, each transmission unit being received separately in the transmission layer, errors being detected in each transmission unit in the transmission layer, the received data being converted to coding units in the transmission layer, the coding units having a definite relation to the transmission units, the coding units being provided to the coding layer, each coding unit being decoded separately in the coding layer, comprising the steps of:

providing error information from the transmission layer to the coding layer, said error information reporting results of error detection performed in the transmission layer by indicating which of the coding units provided from the transmission layer to the coding layer are free of errors;

using said results of error detection when said coding units are decoded in the coding layer;

requesting retransmission of transmission units in which errors are detected in said transmission layer, thereby obtaining multiple copies of a single coding unit derived by conversion of at least one of said transmission units in which errors are detected;

providing said multiple copies from said transmission layer to said coding layer; and

selecting least erroneous data from among said multiple copies, when said error information indicates that none of said multiple copies is free of errors.

7. The method of claim 6, further comprising the steps of:

comparing said multiple copies of said single coding unit in said coding layer; and

in each copy of said single coding unit, decoding only data differing from previous copies of said single coding unit.

8. The method of claim 6, comprising the further steps of:

comparing said multiple copies of said single coding unit in said coding layer; and

decoding identical data received in said multiple copies as if said identical data had been indicated to be free of errors.

9. A method of receiving and decoding coded data in a system having a transmission layer and a coding layer, the coded data being divided into transmission units having sequence numbers, each transmission unit being received separately in the transmission layer, errors being detected in each transmission unit in the transmission layer, the received data being converted to coding units in the transmission layer, the coding units having a definite relation to the transmission units, the coding units being provided to the coding layer, each coding unit being decoded separately in the coding layer, comprising the steps of:

using results of error detection performed in the transmission layer when said coding units are decoded in the coding layer;

providing said sequence numbers from said transmission layer to said coding layer; and

using said sequence numbers when said coding units are decoded in said coding layer.

10. The method of claim 9, wherein said step of using said sequence numbers comprises the further step of:

using said sequence numbers to detect missing coding units.

11. An apparatus for receiving and decoding coded data divided into transmission units, comprising:

a receiving apparatus receiving each transmission unit, detecting errors in each said transmission unit, and converting the received transmission units to coding units having a definite relation to the transmission units; and

a decoding apparatus coupled to said receiving apparatus, receiving said coding units, and decoding each one of said coding units separately, said decoding apparatus being provided with error information resulting from error detection performed in said receiving apparatus, said error information indicating whether each of said coding units is free of errors, and said decoding apparatus comprising;

an error-information input circuit receiving said error information; and

a repeated-information comparison and correction circuit that compares information occurring repeatedly in different coding units, uses said error information, when said information is received with different values in said different coding units, to select a correct value from among said different values, and corrects each erroneous value of said information.

12. The apparatus of claim 11, said decoding apparatus further comprising a redecoding circuit decoding a previous one of said coding units again, using a corrected value provided by said repeated-information comparison and correction circuit, when said repeated-information comparison and correction circuit corrects an erroneous value in said previous one of said coding units.

13. The apparatus of claim 11, said decoding apparatus further comprising a decoding circuit decoding a current one of said coding units, using a corrected value provided by said repeated-information comparison and correction circuit, when said repeated-information comparison and correction circuit corrects an erroneous value in said current one of said coding units.

14. An apparatus for receiving and decoding coded data divided into transmission units, comprising:

a receiving apparatus receiving each transmission unit, detecting errors in each said transmission unit, and converting the received transmission units to coding units having a definite relation to the transmission units; and

a decoding apparatus coupled to said receiving apparatus, receiving said coding units, and decoding each one of said coding units separately, said decoding apparatus being provided with error information resulting from error detection performed in said receiving apparatus, said error information indicating whether each of said coding units is free of errors, and said decoding apparatus comprising;

an error-information input circuit receiving said error information; and

a positional-information comparison and correction circuit using said error information to reposition said coding units in relation to one another.

15. The apparatus of claim 14, said decoding apparatus further comprising:

a decoding circuit decoding said coding units and performing error concealment; and

an error reconcealment circuit performing error concealment again, when said positional-information comparison and correction circuit repositions one of said coding units.

16. An apparatus for receiving and decoding coded data divided into transmission units, comprising:

a receiving apparatus receiving each transmission unit, detecting errors in each said transmission unit, and converting the received transmission units to coding units having a definite relation to the transmission units, said coding units being coded predictively, with reference to previous coding units; and

a decoding apparatus coupled to said receiving apparatus, receiving said coding units, and decoding each one of said coding units separately, said decoding apparatus being provided with error information resulting from error detection performed in said receiving apparatus, said error information indicating whether each of said coding units is free of errors, and said decoding apparatus comprising;

an error-information input circuit receiving said error information;

a reference-data selection circuit using said error information to select reliable reference data for use in decoding said coding units; and

a reference-data storage circuit storing the reference data selected by said reference-data selection circuit.

17. An apparatus for receiving and decoding coded data divided into transmission units, comprising:

a receiving apparatus receiving each transmission unit, detecting errors in each said transmission unit, and converting the received transmission units to coding units having a definite relation to the transmission units, said receiving apparatus requesting retransmission of transmission units in which errors are detected, thereby obtaining multiple copies of a single coding unit derived by conversion of at least one of said transmission units in which errors are detected; and

a decoding apparatus coupled to said receiving apparatus, receiving said coding units, and decoding each one of said coding units separately, said decoding apparatus being provided with error information resulting from error detection performed in said receiving apparatus, said error information indicating whether each of said coding units is free of errors, said decoding apparatus being provided with said multiple copies by said receiving apparatus, and said decoding apparatus comprising;

an error-information input circuit receiving said error information;

a coded-data input circuit receiving said multiple copies of said single coding unit from said receiving apparatus; and

a data selection circuit selecting least erroneous data from among said multiple copies, when said error information indicates that none of said multiple copies is free of errors.

18. The apparatus of claim 17, wherein said data selection circuit selects said least erroneous data according to differences between said single coding unit and adjacent coding units.

19. The apparatus of claim 17, further comprising:

a data extraction circuit extracting, from each one of said multiple copies, data differing from preceding ones of said multiple copies; and

a decoding circuit decoding the data extracted by said data extraction unit.

20. The apparatus of claim 17, wherein said data selection circuit processes identical data in said multiple copies of said single coding unit as having been decoded correctly.

21. An apparatus for receiving and decoding coded data divided into transmission units, comprising:

a receiving apparatus receiving each transmission unit, detecting errors in each said transmission unit, and converting the received transmission units to coding units having a definite relation to the transmission units, said coded data being moving-picture data comprising successive frames, said receiving apparatus detecting loss of transmission units as a type of error; and

a decoding apparatus coupled to said receiving apparatus, receiving said coding units, and decoding each one of said coding units separately, said decoding apparatus being provided with error information resulting from error detection performed in said receiving apparatus, said error information indicating whether each of said coding units is free of errors, said decoding apparatus being provided with dummy data by the receiving apparatus when said loss of transmission units is detected, and said decoding apparatus comprising;

an error-information input circuit receiving said error information;

a coded-data input circuit receiving both said coding units and said dummy data; and

a frame-change detection circuit using said error information to place each coding unit in a correct one of said frames.

22. The apparatus of claim 21, wherein said decoding apparatus further comprises a coding-units-per-frame calculation circuit determining a number of said coding units per frame, and said frame-change detection circuit uses said error information to detect missing coding units, thereby detecting frame changes not indicated in the received coding units.

23. The apparatus of claim 21, wherein said transmission units have sequence numbers, said receiving apparatus provides said sequence numbers to said decoding apparatus, said decoding apparatus further comprises a coding-units per-frame calculation circuit determining a number of said coding units per frame, and said frame-change detection circuit uses said sequence numbers to detect missing coding units, thereby detecting frame changes not indicated in the received coding units.

24. An apparatus for receiving and decoding coded data divided into transmission units, comprising:

a receiving apparatus receiving each transmission unit, detecting errors in each said transmission unit, and converting the received transmission units to coding units having a definite relation to the transmission units; and

a decoding apparatus coupled to said receiving apparatus, receiving said coding units, and decoding each one of said coding units separately, using results of error detection performed in said receiving apparatus;

wherein said receiving apparatus detects loss of transmission units as a type of error, and provides said decoding apparatus with dummy data when said loss of transmission units is detected, and said decoding apparatus comprises;

a coded-data input circuit receiving both said coding units and said dummy data; and

an error-handling switching circuit causing error handling to be performed on said dummy data.

25. An apparatus for receiving and decoding coded data divided into transmission units, comprising:

a receiving apparatus receiving each transmission unit, detecting errors in each said transmission unit, and converting the received transmission units to coding units having a definite relation to the transmission units; and

a decoding apparatus coupled to said receiving apparatus, receiving said coding units, and decoding each one of said coding units separately, using results of error detection performed in said receiving apparatus;

wherein said transmission units have sequence numbers, said receiving apparatus provides said sequence numbers to said decoding apparatus, and said decoding apparatus uses said sequence numbers in decoding said coding units.