Multi-bit per symbol rate quadrature amplitude encoding

• US 6,683,915 B1
• Filed: 12/21/2000
• Issued: 01/27/2004
• Est. Priority Date: 12/21/2000
• Status: Active Grant

• Current Assignee: Intel Corporation
• Original Assignee: ArrayComm LLC (Ygomi LLC)
• Inventors: Trott, Mitchell D., Boros, Tibor
• Primary Examiner(s): Chin, Stephen
• Assistant Examiner(s): Ha, Dac V.
• Application Number:
  US09/748,086
• Publication Number:
  US 20040005011A1
• Time in Patent Office: 1,132 Days
• Field of Search: 375/240, 375/244, 375/246, 375/254, 375/261, 375/262, 375/265, 375/278, 375/285, 375/296, 375/298, 375/300, 375/303, 714/752, 714/755, 714/758, 714/759, 714/777-779, 714/786, 714/790, 714/792, 714/794, 714/795, 332/100, 332/103
• US Class Current: 375/262
• CPC Class Codes: H04L 1/0041 Arrangements at the transmitter end
• CPC Class Codes: H04L 1/0057 Block codes H04L1/0061, H04L1/0064 take precedence
• CPC Class Codes: H04L 1/006 Trellis-coded modulation
• CPC Class Codes: H04L 1/0068 by puncturing
• CPC Class Codes: H04L 27/3405 Modifications of the signal space to increase the efficiency of transmission, e.g. reduction of the bit error rate, bandwidth, or average power

Abstract

In one embodiment, the present invention comprises demultiplexing a bit stream into a first block and a second block, convolutionally coding the first block and block coding the second block. The invention further comprises applying the block coded second block to a function module to apply one of a plurality of different functions to form a third block at an output of the module and mapping the convolutionally coded first block and the third block to a modulation constellation for transmission, the mapping resulting in different constellation points depending on the applied function.

Claims

1. A method comprising:

demultiplexing a bit stream into a first block and a second block;

convolutionally coding the first block;

block coding the second block;

applying the block coded second block to a function module to apply one of a plurality of different functions to form a third block at an output of the module by applying one of a plurality of different look-up tables, the look-up tables containing alternative portions of the third block;

mapping the convolutionally coded first block and the third block to a modulation constellation for transmission, the mapping resulting in different constellation points depending on the applied function.

2. The method of claim 1 wherein the plurality of look-up tables each receive a different number of bits and wherein the third block comprises a shaped block that has a number of digits that is the same for all look-up tables.

3. The method of claim 1 wherein the third block is shaped to optimize transmission over a communications channel.

4. The method of claim 1 wherein the block-coded second block is the same as the third block.

5. The method of claim 1 wherein applying comprises receiving a differing number of bits depending upon the applied function and wherein forming a third block comprises forming a shaped block that has a number of digits that is the same for all functions.

6. The method of claim 1 wherein forming a third block comprises forming a third block that is represented as a base 3 digit.

7. The method of claim 6 wherein the number of base 3 digits in the third block equals the number of digits in the convolutionally encoded second block.

8. The method of claim 1 wherein the modulation constellation comprises a phase shift keyed constellation.

9. The method of claim 1 wherein mapping comprises mapping into different sets of constellation points depending on the applied function, the different sets of constellation points having different numbers of constellation points.

10. The method of claim 9 wherein the different sets of constellation points correspond to different bit-per-symbol rates, based on the demultiplexed bitstream.

11. The method of claim 1 wherein mapping comprises mapping the position of a coordinate within a sector in the constellation based on one of either the convolutionally coded first block and the third block.

12. The method of claim 11 wherein mapping comprises mapping the sign of a coordinate in the constellation based on the other of either the convolutionally coded first block and the shaped block in combination with the mapped coordinate within a sector.

13. The method of claim 1 wherein the block code comprises a parity code.

14. The method of claim 13 wherein the function module preserves the parity of the block coded second block in forming the third block.

15. The method of claim 1 further comprising appending a set of tail bits to the first block before convolutionally coding.

16. The method of claim 1 wherein demultiplexing comprises demultiplexing a differing proportion of bits to the first and second blocks based on the one of the plurality of functions applied.

17. The method of claim 1 wherein the block code comprises a parity code and wherein the function module preserves the parity of the block coded second block in forming the third block.

18. A machine-readable medium having stored thereon data representing sequences of instructions which, when executed by a machine, cause the machine to perform operations comprising:

demultiplexing a bit stream into a first block and a second block;

convolutionally coding the first block;

block coding the second block;

applying the block coded second block to a function module to apply one of a plurality of different functions to form a third block at an output of the module, by applying one of a plurality of different look-up tables, the look-up tables containing alternative portions of the third block;

mapping the convolutionally coded first block and the third block to a modulation constellation for transmission, the mapping resulting in different constellation points depending on the applied function.

19. The medium of claim 18 wherein the plurality of look-up tables each receive a different number of bits and wherein the third block comprises a shaped block that has a number of digits that is the same for all look-up tables.

20. The medium of claim 18 wherein the instructions causing the machine to perform operations comprising applying further comprise instructions causing the machine to perform operations comprising receiving a differing number of bits depending upon the applied function and wherein the instructions causing the machine to perform operations comprising forming a third block further comprise instructions causing the machine to perform operations comprising forming a shaped block that has a number of digits that is the same for all functions.

21. The medium of claim 18 wherein the instructions causing the machine to perform operations comprising mapping further comprise instructions causing the machine to perform operations comprising mapping into different sets of constellation points depending on the applied function, the different sets of constellation points having different numbers of constellation points.

22. The medium of claim 18 wherein the instructions causing the machine to perform operations comprising mapping further comprise instructions causing the machine to perform operations comprising mapping the position of a coordinate within a sector in the constellation based on one of either the convolutionally coded first block and the third block.

23. The medium of claim 22 wherein the instructions causing the machine to perform operations comprising mapping further comprise instructions causing the machine to perform operations comprising mapping the sign of a coordinate in the constellation based on the other of either the convolutionally coded first block and the shaped block in combination with the mapped coordinate within a sector.

24. An apparatus:

a demultiplexer to divide a bit stream into a first block and a second block;

a convolutional coder coupled to the demultiplexer to receive and encode the first block;

a block coder coupled to the demultiplexer to receive and encode the second block;

a function module coupled to the block coder to receive the block coded second block and apply one of a plurality of different functions to form a third block at an output of the module, the function module comprising a plurality of different look-up tables containing alternative portions of the third block;

a mapper to map the convolutionally coded first block and the third block to a modulation constellation for transmission, the mapping resulting in different constellation points depending on the applied function; and

a controller coupled to the demultiplexer to control the size of the first and second blocks and to the function module to control which of the plurality of functions to apply.

25. The apparatus of claim 24 wherein the plurality of look-up tables each receive a different number of bits and wherein the third block comprises a shaped block that has a number of digits that is the same for all look-up tables.

26. The apparatus of claim 24 wherein the mapper maps into different sets of constellation points depending on the applied function, the different sets of constellation points having different numbers of constellation points.

27. A method comprising:

demultiplexing a bit stream into a first block and a second block;

convolutionally coding the first block;

block coding the second block;

applying the block coded second block to a function module to apply one of a plurality of different functions, the applied function depending on the number of bits of the block coded second block, to form a third shaped block at an output of the module that has a number of digits that is the same for all functions;

mapping the convolutionally coded first block and the third block to a modulation constellation for transmission, the mapping resulting in different constellation points depending on the applied function.

28. The method of claim 27 wherein applying one of a plurality of different functions comprises applying one of a plurality of different look-up tables, the look-up tables containing alternative portions of the third block.

29. The method of claim 27 wherein the plurality of look-up tables each receive a different number of bits and wherein the third block comprises a shaped block that has a number of digits that is the same for all look-up tables.

30. The method of claim 27 wherein the third block is shaped to optimize transmission over a communications channel.

31. The method of claim 27 wherein the block-coded second block is the same as the third block.

32. The method of claim 27 wherein forming a third block comprises forming a third block that is represented as a base 3 digit.

33. The method of claim 32 wherein the number of base 3 digits in the third block equals the number of digits in the convolutionally encoded second block.

34. The method of claim 27 wherein the modulation constellation comprises a phase shift keyed constellation.

35. The method of claim 27 wherein mapping comprises mapping into different sets of constellation points depending on the applied function, the different sets of constellation points having different numbers of constellation points.

36. The method of claim 35 wherein the different sets of constellation points correspond to different bit-per-symbol rates, based on the demultiplexed bitstream.

37. The method of claim 27 wherein mapping comprises mapping the position of a coordinate within a sector in the constellation based on one of either the convolutionally coded first block and the third block.

38. The method of claim 37 wherein mapping comprises mapping the sign of a coordinate in the constellation based on the other of either the convolutionally coded first block and the shaped block in combination with the mapped coordinate within a sector.

39. The method of claim 27 wherein the block code comprises a parity code.

40. The method of claim 39 wherein the function module preserves the parity of the block coded second block in forming the third block.

41. The method of claim 27 further comprising appending a set of tail bits to the first block before convolutionally coding.

42. The method of claim 27 wherein demultiplexing comprises demultiplexing a differing proportion of bits to the first and second blocks based on the one of the plurality of functions applied.

43. A machine-readable medium having stored thereon data representing sequences of instructions which, when executed by a machine, cause the machine to perform operations comprising:

demultiplexing a bit stream into a first block and a second block;

convolutionally coding the first block;

block coding the second block;

applying the block coded second block to a function module to apply one of a plurality of different functions, the applied function depending on the number of bits of the block coded second block, to form a third shaped block at an output of the module that has a number of digits that is the same for all functions;

mapping the convolutionally coded first block and the third block to a modulation constellation for transmission, the mapping resulting in different constellation points depending on the applied function.

44. The medium of claim 43 wherein the instructions causing the machine to perform operations comprising applying one of a plurality of different functions further comprise instructions causing the machine to perform operations comprising applying one of a plurality of different look-up tables, the look-up tables containing alternative portions of the third block.

45. The medium of claim 44 wherein the plurality of look-up tables each receive a different number of bits and wherein the third block comprises a shaped block that has a number of digits that is the same for all look-up tables.

46. The medium of claim 43 wherein the instructions causing the machine to perform operations comprising mapping further comprise instructions causing the machine to perform operations comprising mapping into different sets of constellation points depending on the applied function, the different sets of constellation points having different numbers of constellation points.

47. The medium of claim 43 wherein the instructions causing the machine to perform operations comprising mapping further comprise instructions causing the machine to perform operations comprising mapping the position of a coordinate within a sector in the constellation based on one of either the convolutionally coded first block and the third block.

48. The medium of claim 47 wherein the instructions causing the machine to perform operations comprising mapping further comprise instructions causing the machine to perform operations comprising mapping the sign of a coordinate in the constellation based on the other of either the convolutionally coded first block and the shaped block in combination with the mapped coordinate within a sector.

49. An apparatus:

a demultiplexer to divide a bit stream into a first block and a second block;

a convolutional coder coupled to the demultiplexer to receive and encode the first block;

a block coder coupled to the demultiplexer to receive and encode the second block;

a function module coupled to the block coder to receive the block coded second block and apply one of a plurality of different functions, the applied function depending on the number of bits of the block coded second block, to form a third shaped block at an output of the module that has a number of digits that is the same for all functions;

mapper to map the convolutionally coded first block and the third block to a modulation constellation for transmission, the mapping resulting in different constellation points depending on the applied function; and

a controller coupled to the demultiplexer to control the size of the first and second blocks and to the function module to control which of the plurality of functions to apply.

50. The apparatus of claim 49 wherein the function module comprises a plurality of different look-up tables, the look-up tables containing alternative portions of the third block.

51. The apparatus of claim 50 wherein the plurality of look-up tables each receive a different number of bits and wherein the third block comprises a shaped block that has a number of digits that is the same for all look-up tables.

52. The apparatus of claim 49 wherein the mapper maps into different sets of constellation points depending on the applied function, the different sets of constellation points having different numbers of constellation points.

53. The method of claim 49 wherein the block code comprises a parity code and wherein the function module preserves the parity of the block coded second block in forming the third block.