Transmitting digital signal

• US 20040081254A1
• Filed: 11/13/2003
• Published: 04/29/2004
• Est. Priority Date: 12/22/2000
• Status: Active Grant

• Current Assignee: CommWorks Solutions, LLC (IP Investments Group LLC)
• Original Assignee: Amosmet Investments LLC (Intellectual Ventures LLC)
• Inventors: Tirkkonen, Olav
• Granted Patent: US 8,031,800 B2
• Time in Patent Office: Days
• US Class Current: 375/299
• CPC Class Codes: H04L 1/0618 Space-time coding

Abstract

An arrangement for coding digital symbols and transmitting them through at least two antennas. A coder reads at least two symbols belonging to the same transmission block and forms channel symbols of the symbols of the transmission block by means of a block code. The coder multiplies at least one symbol belonging to the transmission block by a first nonzero weighting coefficient and at least one symbol belonging to the transmission block by a second nonzero weighting coefficient, and the division ratio of the first and second weighting coefficients differs from values ±1, ±j and ±1/sqrt(2). The thus formed channel symbols are transmitted to the radio path through the antennas.

Claims

1. A method for transmitting digital symbols, in which method at least two symbols belonging to the same transmission block are read in the transmitter, characterized by

forming a block code comprising channel symbols from the symbols belonging to the transmission block by performing at least one of the following operations to each symbol:

repetition, conjugation, multiplying by a weighting coefficient, summing two or more symbols, and multiplying at least one symbol belonging to the transmission block by a first nonzero weighting coefficient and at least one symbol belonging to the transmission block by a second nonzero weighting coefficient, and having the division ratio of the first and second weighting coefficients differ from values ±

1 and ±

j, and transmitting the formed channel symbols via two or more transmission antenna routes.

2. A method as claimed in claim 1, characterized by transmitting the formed channel symbols by utilizing two or more data transmission resources.

3. A method as claimed in claim 2, characterized in that the data transmission resources are established by time, frequency or code division.

4. A method as claimed in claim 1, characterized in that the transmission antenna routes are two or more antenna lobes achieved using two or more antennas.

5. A method as claimed in claim 1, characterized by using two or more data transmission resources for each antenna route and forming the channel symbols to be transmitted through each antenna route by multiplying at least one symbol belonging to the transmission block by a first nonzero weighting coefficient and at least one other symbol belonging to the transmission block by a second nonzero weighting coefficient, and having the division ratio of the first and second weighting coefficients differ from values ±

1 and ±

j.

6. A method as claimed in claim 1, characterized by forming the channel symbols to be transmitted to different antenna routes by using each data transmission resource in such a manner that at least one symbol belonging to the transmission block and utilizing the data transmission resource by a first nonzero weighting coefficient and at least one other symbol belonging to the transmission block by a second nonzero weighting coefficient, and having the division ratio of the first and second weighting coefficients differ from values ±

1 and ±

j.

7. A method as claimed in claim 1, characterized in that the coding rate of the block code is higher than the coding rate allowed by orthogonality.

8. A method as claimed in claim 1, characterized by selecting the block code defining the channel symbols in such a manner that the block code has full diversity.

9. A method as claimed in claim 1, characterized by multiplying at least one read symbol by a weighting coefficient differing from coefficients ±

1 and ±

j.

10. A method as claimed in claim 1, characterized by forming the channel symbols of the transmission block by using for at least one symbol belonging to the transmission block a phase-rotated modulation constellation in relation to a second symbol of the transmission block.

11. A method as claimed in claim 1, characterized in that the block code is unitary for the part of each symbol belonging to the transmission block.

12. A method as claimed in claim 1, characterized in that a non-orthogonality matrix formed by means of the Hermitian square of the block code is traceless.

13. A method as claimed in claim 1, characterized in that the block code is made non-power-balanced.

14. A method as claimed in claim 1, characterized in that the block code is non-power-balanced.

15. A method as claimed in claim 1, characterized in that in the block code, at least two symbols are coded orthogonal with respect to each other.

16. A method as claimed in claim 1, characterized in that the transmission block comprises four symbols and that the first two symbols are coded orthogonal with respect to each other and the last two symbols are coded orthogonal with respect to each other.

17. A method as claimed in claim 1, characterized by forming complex channel symbols of the read symbols by means of block code C that is of form

18. A method as claimed in claim 1, characterized by forming complex channel symbols of the read symbols by means of block code C that is of form

19. A method as claimed in claim 18, characterized in that at least one of the matrices U, V is of form

20. A method as claimed in claim 19, characterized in that the matrix W is

21. A method as claimed in claim 20, characterized in that the angle φ

is selected from the range;

approximately 34°

, approximately 45°

.

22. A method as claimed in claim 19, characterized in that the matrix W is

23. A method as claimed in claim 22, characterized in that

24. An arrangement for transmitting digital symbols, comprising a coder (308) for coding digital symbols into channel symbols, and one or more transmission antennas (314 to 318) connected to the coder (308) for transmitting the channel symbols, characterized in that

the coder (308) is arranged to read at least two symbols belonging to the same transmission block and, by means of a block code defining the coding, to form channel symbols of the symbols belonging to the transmission block by performing at least one of the following operations to each symbol:

repetition, conjugation, multiplying by a weighting coefficient, summing two or more symbols, and that the coder (308) is arranged to multiply at least one symbol belonging to the transmission block by a first nonzero weighting coefficient and at least one symbol belonging to the transmission block by a second nonzero weighting coefficient, the division ratio of the first and second weighting coefficients differing from values ±

1 and ±

j, and

the arrangement is arranged to transmit the formed channel symbols via two or more transmission antenna routes (314 to 318) generated by means of said one or more antennas.

25. An arrangement as claimed in claim 24, characterized by transmitting the formed channel symbols by utilizing two or more data transmission resources.

26. An arrangement as claimed in claim 25, characterized in that the data transmission resources are established by time, frequency or code division.

27. An arrangement as claimed in claim 24, characterized in that the transmission antenna routes are two or more antenna lobes achieved using two or more antennas.

28. An arrangement as claimed in claim 24, characterized in that the arrangement is arranged to use two or more data transmission resources for each antenna route and to form the channel symbols to be transmitted through each antenna route by multiplying at least one symbol belonging to the transmission block by a first nonzero weighting coefficient and at least one other symbol belonging to the transmission block by a second non-zero weighting coefficient, and that the division ratio of the first and second weighting coefficients differs from values ±

1 and ±

j.

29. An arrangement as claimed in claim 24, characterized in that the arrangement is arranged to form the channel symbols to be transmitted to different antenna routes by using each data transmission resource by multiplying at least one symbol belonging to the transmission block and utilizing the data transmission resource by a first nonzero weighting coefficient and at least one other symbol belonging to the transmission block by a second nonzero weighting coefficient, and that the division ratio of the first and second weighting coefficients differs from values ±

1 and ±

j.

30. An arrangement as claimed in claim 24, characterized in that the coding rate of the block code is higher than the coding rate allowed by orthogonality.

31. An arrangement as claimed in claim 24, characterized in that the block code has full diversity.

32. An arrangement as claimed in claim 24, characterized in that the coder is arranged to multiply at least one read symbol by a weighting coefficient differing from coefficients ±

1 and ±

j.

33. An arrangement as claimed in claim 24, characterized in that the arrangement is arranged to transmit each symbol belonging to the transmission block to the radio path at at least two different time instants.

34. An arrangement as claimed in claim 24, characterized in that the coder is arranged to form the channel symbols of the transmission block by using for at least one symbol belonging to the transmission block a phase-rotated modulation constellation in relation to a second symbol of the transmission block.

35. An arrangement as claimed in claim 24, characterized in that the block code is unitary for the part of each symbol belonging to the transmission block.

36. An arrangement as claimed in claim 24, characterized in that a non-orthogonality matrix formed by means of the Hermitian square of the block code is traceless.

37. An arrangement as claimed in claim 24, characterized in that the block code is made non-power-balanced.

38. An arrangement as claimed in claim 24, characterized in that the block code is non-power-balanced.

39. An arrangement as claimed in claim 24, characterized in that in the block code, at least two symbols are coded orthogonal with respect to each other.

40. An arrangement as claimed in claim 24, characterized in that the block code is a block code for the purpose of transmitting four symbols, in which the first two symbols are coded orthogonal with respect to each other and the last two symbols are coded orthogonal with respect to each other.

41. An arrangement as claimed in claim 24, characterized in that the coder is arranged to form complex channel symbols of the read symbols by means of block code C that is of form

42. An arrangement as claimed in claim 41, characterized in that the coder is arranged to form complex channel symbols of the read symbols by means of block code C that is of form

43. An arrangement as claimed in claim 42, characterized in that at least one of the matrices U, V is of form

44. An arrangement as claimed in claim 43, characterized in that the matrix W is

45. An arrangement as claimed in claim 44, characterized in that the angle φ

is selected from the range;

approximately 34°

, approximately 45°

.

46. An arrangement as claimed in claim 43, characterized in that the matrix W is

47. An arrangement as claimed in claim 46, characterized in that