TECHNIQUES FOR ESTIMATING CHANNEL AND INTERFERENCE IN OFDM WIRELESS COMMUNICATION SYSTEM WITH MULTIPLE ANTENNAS

• US 20100329374A1
• Filed: 06/24/2010
• Published: 12/30/2010
• Est. Priority Date: 06/29/2009
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: PI, Zhouyue
• Granted Patent: US 8,432,982 B2
• Time in Patent Office: Days
• US Class Current: 375/260
• CPC Class Codes: H04L 27/2627 Modulators
• CPC Class Codes: H04L 27/2649 Demodulators
• CPC Class Codes: H04L 5/0007 the frequencies being orthogonal, e.g. OFDM(A), DMT
• CPC Class Codes: H04L 5/0048 Allocation of pilot signals, i.e. of signals known to the receiver

Abstract

A method and multiple antenna transmitting apparatus for transmitting a midamble in a wireless communication system, and a method and receiving device for receiving a midamble in a wireless communication system are provided. A method for transmitting a midamble by a multiple antenna transmitting device includes determining a pattern for a midamble including null subcarriers and pilot subcarriers, wherein each of the pilot subcarriers corresponds to one of a plurality of pilot signals, and each of the plurality of pilot signals corresponds to a different one of a plurality of transmit antennas, and transmitting the pilot signals in corresponding pilot subcarriers based on the determined pattern, wherein the pilot signals are transmitted in an Orthogonal Frequency Division Multiplexing (OFDM) symbol of a resource block comprising a plurality of subcarriers and a plurality of OFDM symbols.

Claims

1. A method for transmitting a midamble by a multiple antenna transmitting device in a wireless communication system, the method comprising:

determining a pattern for a midamble including null subcarriers and pilot subcarriers, wherein each of the pilot subcarriers corresponds to one of a plurality of pilot signals, and each of the plurality of pilot signals corresponds to a different one of a plurality of transmit antennas; and

transmitting the pilot signals in corresponding pilot subcarriers based on the determined pattern, wherein the pilot signals are transmitted in an Orthogonal Frequency Division Multiplexing (OFDM) symbol of a resource block comprising a plurality of subcarriers and a plurality of OFDM symbols.

2. The method of claim 1, wherein the pilot signals are transmitted in a first OFDM symbol of the resource block.

3. The method of claim 1, wherein the pattern for the midamble is determined such that the determined pattern, while offset by a subcarrier, is otherwise the same as a pattern determined for a midamble of another resource block.

4. The method of claim 1, wherein the determining of the pattern for the midamble comprises determining locations for the pilot subcarriers in the midamble.

5. The method of claim 4, wherein the determining of the locations for the pilot subcarriers in the midamble comprises determining the locations for the pilot subcarriers in the midamble based on the number of the transmit antennas.

6. The method of claim 4, wherein the determining of the locations for the pilot subcarriers in the midamble comprises determining the locations for the pilot subcarriers in the midamble based on at least one of an antenna index, a cell identity, and a frequency offset.

7. The method of claim 4, wherein the determining of the locations for the pilot subcarriers in the midamble comprises determining the locations for the pilot subcarriers in the midamble such that any two of the pilot subcarriers in the midamble signal have two null subcarriers located between them.

8. The method of claim 4, wherein the determining of the locations for the pilot subcarriers in the midamble comprises determining the locations for the pilot subcarriers in the midamble such that a set of the pilot subcarriers is repeated in the midamble, wherein the set of pilot subcarriers includes a pilot subcarrier corresponding to each of the plurality of transmit antennas.

9. The method of claim 4, wherein, when the plurality of transmit antennas comprises 2 transmit antennas, the determining of the locations for the pilot subcarriers in the midamble comprises determining the locations for the pilot subcarriers in the midamble using the equation:

mod(j,3×

2)=mod(3×

(i−

1)+mod(k,3)+3×

mod(n,2),3×

2), for i=1 and 2

where j denotes a subcarrier index, i denotes an antenna index, k denotes a cell identity, and n denotes a frame index.

10. The method of claim 4, wherein, when the plurality of transmit antennas comprises 4 transmit antennas, the determining of the locations for the pilot subcarriers in the midamble comprises determining the locations for the pilot subcarriers in the midamble using the equation:

mod(j,3×

4)=mod(3×

(i−

1)+mod(k,3)+6×

mod(n,2),3×

4), for i=1,2,3, and 4

where j denotes a subcarrier index, i denotes an antenna index, k denotes a cell identity, and n denotes a frame index.

11. The method of claim 4, wherein, when the plurality of transmit antennas comprises 8 transmit antennas, the determining of the locations for the pilot subcarriers in the midamble comprises determining the locations for the pilot subcarriers in the midamble using the equation:

mod(j,3×

8)=mod(3×

(i−

1)+mod(k,3)+12×

mod(n,2),3×

8), for i=1,2,3,4,5,6,7, and 8

where j denotes a subcarrier index, i denotes an antenna index, k denotes a cell identity, and n denotes a frame index.

12. A method for receiving a midamble by a receiver device in a wireless communication system, the method comprising:

determining a pattern for a midamble including null subcarriers and pilot subcarriers, wherein each of the pilot subcarriers corresponds to one of a plurality of pilot signals, and each of the plurality of pilot signals corresponds to a different one of a plurality of transmit antennas; and

receiving the pilot signals in corresponding pilot subcarriers based on the determined pattern, wherein the pilot signals are received in an Orthogonal Frequency Division Multiplexing (OFDM) symbol of a resource block comprising a plurality of subcarriers and a plurality of OFDM symbols.

13. The method of claim 12, wherein the pilot signals are received in a first OFDM symbol of the resource block.

14. The method of claim 12, wherein the pattern for the midamble is determined such that the determined pattern, while offset by a subcarrier, is otherwise the same as a pattern determined for a midamble of another resource block.

15. The method of claim 12, wherein the determining of the pattern for the midamble comprises determining locations for the pilot subcarriers in the midamble.

16. The method of claim 15, wherein the determining of the locations for the pilot subcarriers in the midamble comprises determining the locations for the pilot subcarriers in the midamble based on the number of the transmit antennas.

17. The method of claim 15, wherein the determining of the locations for the pilot subcarriers in the midamble comprises determining the locations for the pilot subcarriers in the midamble based on at least one of an antenna index, a cell identity, and a frequency offset.

18. The method of claim 15, wherein the determining of the locations for the pilot subcarriers in the midamble comprises determining the locations for the pilot subcarriers in the midamble such that any two of the pilot subcarriers in the midamble signal have two null subcarriers located between them.

19. The method of claim 15, wherein the determining of the locations for the pilot subcarriers in the midamble comprises determining the locations for the pilot subcarriers in the midamble such that a set of the pilot subcarriers is repeated in the midamble, wherein the set of pilot subcarriers includes a pilot subcarrier corresponding to each of the plurality of transmit antennas.

20. The method of claim 15, wherein, when the plurality of transmit antennas comprises 2 transmit antennas, the determining of the locations for the pilot subcarriers in the midamble comprises determining the locations for the pilot subcarriers in the midamble using the equation:

mod(j,3×

2)=mod(3×

(i−

1)+mod(k,3)+3×

mod(n,2),3×

2), for i=1 and 2

where j denotes a subcarrier index, i denotes an antenna index, k denotes a cell identity, and n denotes a frame index.

21. The method of claim 15, wherein, when the plurality of transmit antennas comprises 4 transmit antennas, the determining of the locations for the pilot subcarriers in the midamble comprises determining the locations for the pilot subcarriers in the midamble using the equation:

mod(j,3×

4)=mod(3×

(i−

1)+mod(k,3)+6×

mod(n,2),3×

4), for i=1,2,3, and 4

where j denotes a subcarrier index, i denotes an antenna index, k denotes a cell identity, and n denotes a frame index.

22. The method of claim 15, wherein, when the plurality of transmit antennas comprises 8 transmit antennas, the determining of the locations for the pilot subcarriers in the midamble comprises determining the locations for the pilot subcarriers in the midamble using the equation:

mod(j,3×

8)=mod(3×

(i−

1)+mod(k,3)+12×

mod(n,2),3×

8), for i=1,2,3,4,5,6,7, and 8

where j denotes a subcarrier index, i denotes an antenna index, k denotes a cell identity, and n denotes a frame index.

23. A multiple antenna transmitting apparatus for transmitting a midamble in a wireless communication system the apparatus comprising:

a midamble pattern determiner for determining a pattern for a midamble including null subcarriers and pilot subcarriers, wherein each of the pilot subcarriers corresponds to one of a plurality of pilot signals, and each of the plurality of pilot signals corresponds to a different one of a plurality of transmit antennas;

a subcarrier mapper and an Orthogonal Frequency Division Multiplexing (OFDM) modulator for, based on the determined pattern, including the pilot signals in corresponding pilot subcarriers of an OFDM symbol of a resource block; and

a transmitter for transmitting the resource block,

wherein the resource block comprises a plurality of subcarriers and a plurality of OFDM symbols.

24. The apparatus of claim 23, wherein the pilot signals are transmitted in a first OFDM symbol of the resource block.

25. The apparatus of claim 23, wherein the pattern for the midamble is determined such that the determined pattern, while offset by a subcarrier, is otherwise the same as a pattern determined for a midamble of another resource block.

26. The apparatus of claim 23, wherein the midamble pattern determiner, when determining the pattern for the midamble, determines locations for the pilot subcarriers in the midamble.

27. The apparatus of claim 26, wherein the midamble pattern determiner, when determining the locations for the pilot subcarriers in the midamble, determines the locations for the pilot subcarriers in the midamble based on the number of the transmit antennas.

28. The apparatus of claim 26, wherein the midamble pattern determiner, when determining the locations for the pilot subcarriers in the midamble, determines the locations for the pilot subcarriers in the midamble based on at least one of an antenna index, a cell identity, and a frequency offset.

29. The apparatus of claim 26, wherein the midamble pattern determiner, when determining the locations for the pilot subcarriers in the midamble, determines the locations for the pilot subcarriers in the midamble such that any two of the pilot subcarriers in the midamble signal have two null subcarriers located between them.

30. The apparatus of claim 26, wherein the midamble pattern determiner, when determining the locations for the pilot subcarriers in the midamble, determines the locations for the pilot subcarriers in the midamble such that a set of the pilot subcarriers is repeated in the midamble, wherein the set of pilot subcarriers includes a pilot subcarrier corresponding to each of the plurality of transmit antennas.

31. The apparatus of claim 26, wherein, when the plurality of transmit antennas comprises 2 transmit antennas, the midamble pattern determiner, when determining the locations for the pilot subcarriers in the midamble, determines the locations for the pilot subcarriers in the midamble using the equation:

mod(j,3×

2)=mod(3×

(i−

1)+mod(k,3)+3×

mod(n,2),3×

2), for i=1 and 2

where j denotes a subcarrier index, i denotes an antenna index, k denotes a cell identity, and n denotes a frame index.

32. The apparatus of claim 26, wherein, when the plurality of transmit antennas comprises 4 transmit antennas, the midamble pattern determiner, when determining the locations for the pilot subcarriers in the midamble, determines the locations for the pilot subcarriers in the midamble using the equation:

mod(j,3×

4)=mod(3×

(i−

1)+mod(k,3)+6×

mod(n,2),3×

4), for i=1,2,3, and 4

where j denotes a subcarrier index, i denotes an antenna index, k denotes a cell identity, and n denotes a frame index.

33. The apparatus of claim 26, wherein, when the plurality of transmit antennas comprises 8 transmit antennas, the midamble pattern determiner, when determining the locations for the pilot subcarriers in the midamble, determines the locations for the pilot subcarriers in the midamble using the equation:

mod(j,3×

8)=mod(3×

(i−

1)+mod(k,3)+12×

mod(n,2),3×

8), for i=1,2,3,4,5,6,7, and 8

where j denotes a subcarrier index, i denotes an antenna index, k denotes a cell identity, and n denotes a frame index.

34. A receiver apparatus for receiving a midamble in a wireless communication system, the apparatus comprising:

a receiver for receiving a resource block;

a midamble pattern determiner for determining a pattern for the midamble including null subcarriers and pilot subcarriers, wherein each of the pilot subcarriers corresponds to one of a plurality of pilot signals, and each of the plurality of pilot signals corresponds to a different one of a plurality of transmit antennas; and

an Orthogonal Frequency Division Multiplexing (OFDM) demodulator and a subcarrier demapper for, based on the determined pattern, extracting the pilot signals from corresponding pilot subcarriers of an OFDM symbol in the resource block,

wherein the resource block comprises a plurality of subcarriers and a plurality of OFDM symbols.

35. The apparatus of claim 34, wherein the pilot signals are received in a first OFDM symbol of the resource block.

36. The apparatus of claim 34, wherein the pattern for the midamble is determined such that the determined pattern, while offset by a subcarrier, is otherwise the same as a pattern determined for a midamble of another resource block.

37. The apparatus of claim 34, wherein the midamble pattern determiner, when determining the pattern for the midamble, determines locations for the pilot subcarriers in the midamble.

38. The apparatus of claim 37, wherein the midamble pattern determiner, when determining the locations for the pilot subcarriers in the midamble, determines the locations for the pilot subcarriers in the midamble based on the number of the transmit antennas.

39. The apparatus of claim 37, wherein the midamble pattern determiner, when determining the locations for the pilot subcarriers in the midamble, determines the locations for the pilot subcarriers in the midamble based on at least one of an antenna index, a cell identity, and a frequency offset.

40. The apparatus of claim 37, wherein the midamble pattern determiner, when determining the locations for the pilot subcarriers in the midamble, determines the locations for the pilot subcarriers in the midamble such that any two of the pilot subcarriers in the midamble signal have two null subcarriers located between them.

41. The apparatus of claim 37, wherein the midamble pattern determiner, when determining the locations for the pilot subcarriers in the midamble, determines the locations for the pilot subcarriers in the midamble such that a set of the pilot subcarriers is repeated in the midamble, wherein the set of pilot subcarriers includes a pilot subcarrier corresponding to each of the plurality of transmit antennas.

42. The apparatus of claim 37, wherein, when the plurality of transmit antennas comprises 2 transmit antennas, the midamble pattern determiner, when determining the locations for the pilot subcarriers in the midamble, determines the locations for the pilot subcarriers in the midamble using the equation:

mod(j,3×

2)=mod(3×

(i−

1)+mod(k,3)+3×

mod(n,2),3×

2), for i=1 and 2

where j denotes a subcarrier index, i denotes an antenna index, k denotes a cell identity, and n denotes a frame index.

43. The apparatus of claim 37, wherein, when the plurality of transmit antennas comprises 4 transmit antennas, the midamble pattern determiner, when determining the locations for the pilot subcarriers in the midamble, determines the locations for the pilot subcarriers in the midamble using the equation:

mod(j,3×

4)=mod(3×

(i−

1)+mod(k,3)+6×

mod(n,2),3×

4), for i=1,2,3, and 4

where j denotes a subcarrier index, i denotes an antenna index, k denotes a cell identity, and n denotes a frame index.

44. The apparatus of claim 37, wherein, when the plurality of transmit antennas comprises 8 transmit antennas, the midamble pattern determiner, when determining the locations for the pilot subcarriers in the midamble, determines the locations for the pilot subcarriers in the midamble using the equation:

mod(j,3×

8)=mod(3×

(i−

1)+mod(k,3)+12×

mod(n,2),3×

8), for i=1,2,3,4,5,6,7, and 8

where j denotes a subcarrier index, i denotes an antenna index, k denotes a cell identity, and n denotes a frame index.