Method and apparatus for acknowledging reverse link transmissions in a communications system

• US 7,957,263 B2
• Filed: 09/07/2004
• Issued: 06/07/2011
• Est. Priority Date: 09/08/2003
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Gaal, Peter
• Primary Examiner(s): Ngo; Ricky
• Assistant Examiner(s): Phung; Luat
• Application Number:
  US10/935,973
• Publication Number:
  US 20050117508A1
• Time in Patent Office: 2,464 Days
• Field of Search: 370/209, 370/203, 370/208, 370/335, 375/146, 375/147
• US Class Current: 370/209
• CPC Class Codes: H04J 13/0025 M-sequences
• CPC Class Codes: H04J 13/0044 OVSF [orthogonal variable spreading factor]
• CPC Class Codes: H04J 13/10 Code generation
• CPC Class Codes: H04L 1/08 by repeating transmission, e.g. Verdan system H04L1/1858 and H04L1/189 take precedence
• CPC Class Codes: H04L 1/16 in which the return channel carries supervisory signals, e.g. repetition request signals
• CPC Class Codes: H04L 1/1607 Details of the supervisory signal
• CPC Class Codes: H04L 1/1858 Transmission or retransmission of more than one copy of acknowledgement message
• CPC Class Codes: H04L 2001/125 Arrangements for preventing errors in the return channel

Abstract

A method and apparatus for acknowledging reverse link transmissions in a communications system. An information bit is set and then repeated. The repeated information bit is covered with a code having a frame length defined by S=M*N*R, where S is the frame length, M is the number of code symbols per slot, N is the number of slots per frame, and R is the code repetition factor. The gain is then set relative to a power control transmission and the frames resulting from the coding operation are then modulated. After modulation, the result is spread on a designated channel using quadrature spreading and after spreading the acknowledgement is transmitted over the reverse link.

Claims

1. A method comprising:

generating a set of codewords corresponding to a first channel for acknowledging correctly decoded transmissions according to an acknowledgment frame, the codewords based on a first matrix and each acknowledgment frame including one of the codewords and a repetition of the one of the codewords, the repetition of the one of the codewords being a different permutation of symbols of the one of the codewords.

2. The method of claim 1, wherein:

the first matrix is an m-sequence matrix, formed by assembling all possible cyclic shifts of a specific length as the rows of a submatrix, and extending the sub-matrix to a predetermined dimension by adding an all ‘

+’

row and an all ‘

+’

column.

3. The method of claim 1, wherein:

the first matrix is a Hadamard matrix.

4. The method of claim 1, wherein:

the first matrix is a permuted H₁₂ matrix interleaved with the basis vectors of a fast Fourier transform of a specific length.

5. The method of claim 2, wherein:

the first matrix is an H₁₆ resulting from m-sequence construction, interleaved with the basis vectors of a fast Fourier transform of a specific length.

6. A method for reducing cross-talk between channels used in acknowledging transmissions, the method comprising:

generating a set of codewords corresponding to a first channel for acknowledging correctly decoded transmissions according to an acknowledgment frame, the codewords based on a first matrix and each acknowledgment frame including one of the codewords and a repetition of the one of the codewords, the repetition of the one of the codewords being a different permutation of symbols of the one of the codewords;

forming the first matrix, and

spreading using a spreading function using a second matrix that is smaller than the first matrix.

7. The method of claim 6, wherein forming the first matrix comprises:

forming the first matrix using m-sequence construction by assembling all possible cyclic shifts of a specific length as the rows of a submatrix, and extending the sub-matrix to a predetermined dimension by adding an all ‘

+’

row and an all ‘

+’

column.

8. The method of claim 6, wherein:

the first matrix is a Hadamard matrix.

9. The method of claim 6, wherein:

the first matrix is a permuted H₁₂ matrix interleaved with the basis vectors of a fast Fourier transform of a specific length.

10. The method of claim 7, wherein:

the first matrix is a permuted H₁₆ matrix interleaved with the basis vectors of a fast Fourier transform of a specific length.

11. A method for reducing code length in an acknowledgment channel, the method comprising:

generating a set of codewords corresponding to a first channel for acknowledging correctly decoded transmissions according to an acknowledgment frame, the codewords based on a first matrix and each acknowledgment frame including one of the codewords and a repetition of the one of the codewords, the repetition of the one of the codewords being a different permutation of symbols of the one of the codewords;

forming the first matrix, and

spreading using a spreading function using a second matrix that is smaller than the first matrix.

12. The method of claim 11, wherein forming the first matrix comprises:

forming the first matrix using m-sequence construction by assembling all possible cyclic shifts of a specific length as the rows of a submatrix, and extending the sub-matrix to a predetermined dimension by adding an all ‘

+’

row and an all ‘

+’

column.

13. The method of claim 11, wherein:

the first matrix is a Hadamard matrix.

14. The method of claim 11, wherein:

the first matrix is a permuted H₁₂ matrix interleaved with the basis vectors of a fast Fourier transform of a specific length.

15. The method of claim 12, wherein:

the first matrix is a permuted H₁₆ matrix interleaved with the basis vectors of a fast Fourier transform of a specific length.

16. An apparatus for generating an acknowledgment channel, the apparatus comprising:

means for generating a set of codewords corresponding to a first channel for acknowledging correctly decoded transmissions according to an acknowledgment frame, the codewords based on a first matrix and each acknowledgment frame including one of the codewords and a repetition of the one of the codewords, the repetition of the one of the codewords being a different permutation of symbols of the one of the codewords;

means for forming the first matrix, and

means for spreading using a spreading function using a second matrix that is smaller than the first matrix.

19. The apparatus according to claim 16, further comprising:

means for forming the first matrix, and

means for spreading using a spreading function using a second matrix that is smaller than the first matrix.

20. The apparatus according to claim 16, wherein:

the first matrix is an m-sequence matrix, formed by assembling all possible cyclic shifts of a specific length as the rows of a submatrix, and extending the sub-matrix to a predetermined dimension by adding an all ‘

+’

row and an all ‘

+’

column.

21. The apparatus according to claim 16, wherein:

the first matrix is a Hadamard matrix.

22. The apparatus according to claim 16, wherein:

the first matrix is a permuted H₁₂ matrix interleaved with the basis vectors of a fast Fourier transform of a specific length.

27. The apparatus according to claim 20, wherein:

the first matrix is an H₁₆ resulting from m-sequence construction, interleaved with the basis vectors of a fast Fourier transform of a specific length.

17. An apparatus for generating an acknowledgment channel, the apparatus comprising:

a processor configured to generate a set of codewords corresponding to a first channel for acknowledging correctly decoded transmissions according to an acknowledgment frame, the codewords based on a first matrix and each acknowledgment frame including one of the codewords and a repetition of the one of the codewords, the repetition of the one of the codewords being a different permutation of symbols of the one of the codewords.

23. The apparatus according to claim 17, wherein said processor is further configured to:

form the first matrix, and

spread using a spreading function using a second matrix that is smaller than the first matrix.

24. The apparatus according to claim 17, wherein:

the first matrix is an m-sequence matrix, formed by assembling all possible cyclic shifts of a specific length as the rows of a submatrix, and extending the sub-matrix to a predetermined dimension by adding an all ‘

+’

row and an all ‘

+’

column.

25. The apparatus according to claim 17, wherein:

the first matrix is a Hadamard matrix.

26. The apparatus according to claim 17, wherein:

the first matrix is a permuted H₁₂ matrix interleaved with the basis vectors of a fast Fourier transform of a specific length.

28. The apparatus according to claim 24, wherein:

the first matrix is an H₁₆ resulting from m-sequence construction, interleaved with the basis vectors of a fast Fourier transform of a specific length.

18. A storage medium including processor-executable instructions thereon for performing a method comprising:

generating a set of codewords corresponding to a first channel for acknowledging correctly decoded transmissions according to an acknowledgment frame, the codewords based on a first matrix and each acknowledgment frame including one of the codewords and a repetition of the one of the codewords, the repetition of the one of the codewords being a different permutation of symbols of the one of the codewords.