Method and apparatus for joint source-channel map decoding

• US 7,882,421 B2
• Filed: 05/02/2005
• Issued: 02/01/2011
• Est. Priority Date: 05/06/2004
• Status: Expired due to Fees

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Raveendran, Vijayalakshumi R., Oguz, Seyfullah Halit
• Primary Examiner(s): Alphonse; Fritz
• Application Number:
  US11/120,391
• Publication Number:
  US 20050275573A1
• Time in Patent Office: 2,101 Days
• Field of Search: 714/776, 714/779, 714/799, 714/801, 714/746, 714/764, 714/788, 375/144, 375/240.27
• US Class Current: 714/776
• CPC Class Codes: H03M 13/2927 Decoding strategies
• CPC Class Codes: H03M 13/293 with erasure setting
• CPC Class Codes: H03M 13/2936 comprising an outer Reed-Solomon code and an inner convolutional code
• CPC Class Codes: H03M 13/2957 Turbo codes and decoding
• CPC Class Codes: H03M 13/3916 for block codes using a trellis or lattice
• CPC Class Codes: H03M 13/45 Soft decoding, i.e. using symbol reliability information H03M13/41 takes precedence
• CPC Class Codes: H03M 13/63 Joint error correction and other techniques H03M13/31 and H03M13/33 take precedence
• CPC Class Codes: H03M 13/6312 Error control coding in combination with data compression
• CPC Class Codes: H03M 13/6318 using variable length codes
• CPC Class Codes: H04L 1/0045 Arrangements at the receiver end
• CPC Class Codes: H04L 1/0055 MAP-decoding
• CPC Class Codes: H04L 1/0057 Block codes H04L1/0061, H04L1/0064 take precedence
• CPC Class Codes: H04L 1/0065 Serial concatenated codes
• CPC Class Codes: H04L 1/0066 Parallel concatenated codes

Abstract

A method for error correction that includes receiving a bitstream, the bitstream comprising one or more bits, determining if the bitstream has one or more corrupt bits, determining one or more hypotheses representing an error pattern, and assigning a probability to each of the hypotheses, wherein the probability is determined based on one or more reference data.

Claims

1. A method for error correction in a mobile device, comprising:

receiving coded data in a physical layer;

obtaining error characteristics for the coded data;

obtaining a bitstream in an application layer, the bitstream comprising one or more bits from the coded data;

determining if the bitstream has one or more corrupt bits;

determining one or more hypotheses representing an error pattern for the bitstream; and

assigning a probability to each of the hypotheses in order to correct the corrupt bits,

wherein the step of determining one or more hypotheses comprises determining the hypotheses for a group of bits making up a coded symbol, wherein the coded symbol is chosen from the group consisting of a macroblock type, a quantization parameter, an intra prediction direction, a motion vector, a DC coefficient and an AC coefficient,

and wherein the steps of receiving, obtaining, determining and assigning are performed in the mobile device.

2. The method of claim 1, further comprising:

decoding uncorrupt bits;

determining that one of the hypotheses leads to a syntax or semantic failure within the uncorrupt bits; and

assigning a probability of zero to the hypothesis leading to the failure.

3. The method of claim 1, wherein determining the hypotheses further comprises:

determining the hypotheses for a group of bits making up a coded symbol.

4. The method of claim 1, further comprising:

receiving the coded data over a wireless network.

5. The method of claim 1, wherein the coded data is received by a demodulator.

6. The method of claim 1, wherein the error characteristics comprise coded symbols and bits.

7. The method of claim 1, wherein the one or more hypotheses representing an error pattern for the bitstream are used to determine a later syntax or semantic failure in the bitstream.

8. The method of claim 1, wherein the probability assigned to each of the hypotheses is a refined probability distribution.

9. The method of claim 1, wherein the error pattern comprises variable length coding.

10. A method for error correction in a mobile device, comprising:

receiving coded data in a physical layer;

obtaining error characteristics for the coded data;

obtaining a bitstream in an application layer, the bitstream comprising one or more bits from the coded data;

determining if the bitstream has one or more corrupt bits;

determining one or more hypotheses representing an error Pattern for the bitstream;

assigning a probability to each of the hypotheses in order to correct the corrupt bits; and

determining a probability distribution for an incorrectly received symbol using information chosen from the group consisting of a bit-error-streak distance, an error burst length, an average number of bit errors for erased packets, neighboring bytes with no bit errors, user data fields and error characteristics of received packets,

wherein the steps of receiving, obtaining, determining and assigning are performed in the mobile device.

11. An apparatus for error correction, comprising:

means for receiving coded data in a physical layer;

means for obtaining error characteristics for the coded data;

means for obtaining a bitstream in an application layer, the bitstream comprising one or more bits from the coded data;

means for determining if the bitstream has one or more corrupt bits;

means for determining one or more hypotheses representing an error pattern for the bitstream; and

means for assigning a probability to each of the hypotheses in order to correct the corrupt bits,

wherein the means for determining one or more hypotheses comprises means for determining the hypotheses for a group of bits making up a coded symbol, wherein the coded symbol is chosen from the group consisting of a macroblock type, a quantization parameter, an intra prediction direction, a motion vector, a DC coefficient and an AC coefficient.

12. The apparatus of claim 11, further comprising:

means for decoding uncorrupt bits;

means for determining that one of the hypotheses leads to a syntax or semantic failure within the uncorrupt bits; and

means for assigning a probability of zero to the hypothesis leading to the failure.

13. The apparatus of claim 11, wherein determining the hypotheses further comprises:

means for determining the hypotheses for a group of bits making up a coded symbol.

14. The apparatus of claim 11, further comprising:

means for receiving the coded data over a wireless network.

15. The apparatus of claim 11, wherein the coded data is received by a demodulator.

16. The apparatus of claim 11, wherein the error characteristics are received comprising coded symbols and bits.

17. The apparatus of claim 11, wherein the one or more hypotheses representing an error pattern for the bit stream are used to determine later syntax or semantic failure in the bistream.

18. The apparatus of claim 11, wherein the probability assigned to each of the hypotheses is a refined probability distribution.

19. The apparatus of claim 11, wherein the error pattern comprises variable length coding or Huffmann coding.

20. An apparatus for error correction, comprising:

means for receiving coded data in a physical layer;

means for obtaining error characteristics for the coded data;

means for obtaining a bitstream in an application layer, the bitstream comprising one or more bits from the coded data;

means for determining if the bitstream has one or more corrupt bits;

means for determining one or more hypotheses representing an error pattern for the bitstream;

means for assigning a probability to each of the hypotheses in order to correct the corrupt bits; and

means for determining a probability distribution for an incorrectly received symbol using information chosen from the group consisting of a bit-error-streak distance, an error burst length, an average number of bit errors for erased packets, neighboring bytes with no bit errors, user data fields and error characteristics of received packets.

21. An electronic device for error correction, the electronic device configured to receive coded data in a physical layer, obtain error characteristics for the coded data, obtain a bitstream, the bitstream comprising one or more bits, for the coded data in an application layer to determine if the bitstream has one or more corrupt bits, to determine one or more hypotheses representing an error pattern for the bit stream, and to assign a probability to each of the hypotheses in order to correct the corrupt bits,

wherein the electronic device is further configured to determine the hypotheses for a group of bits making up a coded symbol, wherein the coded symbol is chosen from the group consisting of a macroblock type, a quantization parameter, an intra prediction direction, a motion vector, a DC coefficient and an AC coefficient.

22. The electronic device of claim 21, further configured to decode uncorrupt bits, to determine that one of the hypotheses leads to a syntax or semantic failure within the uncorrupt bits, and to assign a probability of zero to the hypothesis leading to the failure.

23. The electronic device of claim 21, further configured to determine the hypotheses for a group of bits making up a coded symbol.

24. The electronic device of claim 21, further configured to receive the bitstream over a wireless network.

25. The electronic device of claim 21, wherein the coded data is received by a demodulator.

26. The electronic device of claim 21, wherein the error characteristics comprise coded symbols and bits.

27. The electronic device of claim 21, wherein the one or more hypotheses representing an error pattern for the bit stream are used to determine later syntax or semantic failure in the bitstream.

28. The electronic device of claim 21, wherein the probability assigned to each of the hypotheses is a refined probability distribution.

29. The electronic device of claim 21, wherein the error pattern comprises variable length coding.

30. An electronic device for error correction, the electronic device configured to receive coded data in a physical layer, obtain error characteristics for the coded data, obtain a bitstream, the bitstream comprising one or more bits, for the coded data in an application layer to determine if the bitstream has one or more corrupt bits, to determine one or more hypotheses representing an error pattern for the bit stream, and to assign a probability to each of the hypotheses in order to correct the corrupt bits,

Wherein the electronic device is further configured to determine a probability distribution for an incorrectly received symbol using information chosen from the group consisting of a bit-error-streak distance, an error burst length, an average number of bit errors for erased packets, neighboring bytes with no errors, user data fields and error characteristics of received packets.

31. A computer readable medium embodying means for causing a computer to execute a method comprising:

receiving coded data in a physical layer;

obtaining error characteristics for the coded data;

obtaining a bitstream in an application layer, the bitstream comprising one or more bits from the coded data;

determining if the bitstream has one or more corrupt bits;

determining one or more hypotheses representing an error pattern for the bitstream, including determining the hypotheses for a group of bits making up a coded symbol, wherein the coded symbol is chosen from the group consisting of a macroblock type, a quantization parameter, an intra prediction direction, a motion vector, a DC coefficient and an AC coefficient; and

assigning a probability to each of the hypotheses in order to correct the corrupt bits.