Method and apparatus for transmitting control information in WLAN system

• US 9,065,502 B2
• Filed: 01/28/2014
• Issued: 06/23/2015
• Est. Priority Date: 09/09/2009
• Status: Active Grant

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Lee, Dae Won, Roh, Dong Wook, Kang, Byeong Woo, Seok, Yong Ho, Noh, Yu Jin, Kim, Bong Hoe
• Primary Examiner(s): Nguyen, Brian D
• Application Number:
  US14/166,602
• Publication Number:
  US 20140140311A1
• Time in Patent Office: 511 Days
• Field of Search: 370/329, 370/330, 370/336, 370/337, 370/338, 370/343
• US Class Current: 1/1
• CPC Class Codes: H04B 7/0452 Multi-user MIMO systems
• CPC Class Codes: H04B 7/0671 using different delays between antennas
• CPC Class Codes: H04L 25/0226 sounding signals per se
• CPC Class Codes: H04L 25/03343 Arrangements at the transmitter end
• CPC Class Codes: H04L 5/001 the frequencies being arranged in component carriers
• CPC Class Codes: H04L 5/0023 Time-frequency-space
• CPC Class Codes: H04L 5/0048 Allocation of pilot signals, i.e. of signals known to the receiver
• CPC Class Codes: H04L 5/0053 Allocation of signaling, i.e. of overhead other than pilot signals
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]

Abstract

There is provided a method of transmitting control information in a Wireless Local Area Network (WLAN) system, comprising transmitting first control information by means of cyclic shift delay diversity beam-forming and transmitting second control information. The first control information comprises information necessary for each of a plurality of target stations of the second control information to receive the second control information. The second control information beamformed and transmitted to the plurality of target stations.

Claims

1. A method of signal transmission in a Wireless Local Area Network (WLAN) system, the method comprising:

generating, by a station, a first very high throughput (VHT) signal containing control information;

generating, by the station, a second VHT signal containing control information; and

transmitting, by the station, the first VHT signal and the second VHT signal, wherein when the second VHT signal is generated for a single target station the second VHT signal is transmitted to the single target station, wherein when the second VHT signal is generated for a plurality of target stations the second VHT signal is transmitted to the plurality of target stations, and wherein the first VHT signal includes an indicator indicating that the second VHT signal is to be transmitted by using a single-user multiple input multiple output (SU-MIMO) scheme or a multi-user multiple input multiple output (MU-MIMO) scheme.

2. The method of claim 1, further comprising:

applying a multi-user multiple input multiple output (MU-MIMO) steering matrix to the second VHT signal to form a pre-coded second control signal.

3. The method of claim 1, wherein the second VHT signal includes a modulation and coding scheme (MCS) index indicating a MCS used in the transmitting step.

4. The method of claim 1, wherein when the second VHT signal is generated for the plurality of target stations the first VHT signal includes a spatial stream identifier indicating a number of spatial streams for each of the plurality of target stations used in the transmitting step.

5. The method of claim 1, wherein the first VHT signal is transmitted over first data subcarriers in each of two orthogonal frequency division multiplexing (OFDM) symbols and the second VHT signal is transmitted over second data subcarriers in one OFDM symbol.

6. The method of claim 5, wherein the number of the first data subcarriers is 48 and the number of the second data subcarriers is 52.

7. The method of claim 1, wherein when the second VHT signal is generated for the plurality of target stations, different scrambling codes are applied to signals transmitted to the plurality of target stations.

8. The method of claim 1, wherein when the second VHT signal is generated for the plurality of target stations an identification value indicating one of the plurality of target stations is included in the first VHT signal or the second VHT signal.

9. The method of claim 1, further comprising:

applying a column matrix to the second VHT signal to form a pre-coded signal, wherein when the second VHT signal is generated for the plurality of target stations a number of row of the column matrix is determined based on a number of spatial streams for each of the plurality of target stations.

10. The method of claim 1, wherein a first cyclic shift is applied to the first WIT signal and a second cyclic shift is applied to the second VHT signal.

11. The method of claim 1, wherein when the second VHT signal is generated for the single target station the first VHT signal indicates a number of spatial streams for the single target station.

12. The method of claim 1, wherein when the second VHT signal is generated for the plurality of target stations, the first VHT signal indicates a total number of spatial streams for the plurality of target stations.

13. The method of claim 1, wherein the first control signal includes indication information indicating at least one spatial stream of another target station.

14. The method of claim 13, wherein the indication information is used to reduce interference caused by the at least one spatial stream of another target station.

15. A radio apparatus for signal transmission in a Wireless Local Area Network (WLAN) system, the radio apparatus comprising:

a processor configured to;

generate a first very high throughput (VHT) signal containing control information; and

generate a second VHT signal containing control information; and

a transceiver configured to;

transmit the first VHT signal and the second VHT signal, wherein when the second VHT signal is generated for a single target station the second VHT signal is transmitted to the single target station, wherein when the second VHT signal is generated for a plurality of target stations the second VHT signal is transmitted to the plurality of target stations, and wherein the first VHT signal includes an indicator indicating that the second VHT signal is to be transmitted by using a single-user multiple input multiple output (SU-MIMO) scheme or a multi-user multiple input multiple output (MU-MIMO) scheme.

16. The radio apparatus of claim 15, wherein the processor is configured to apply a multi-user multiple input multiple output (MU-MIMO) steering matrix to the second VHT signal to form a pre-coded second control signal.

17. The radio apparatus of claim 15, wherein the second VHT signal includes a modulation and coding scheme (MCS) index indicating a MCS used in the transmission of the first VHT signal and the second VHT signal.

18. The radio apparatus of claim 15, wherein when the second VHT signal is generated for the plurality of target stations the first VHT signal includes a spatial stream identifier indicating a number of spatial streams for each of the plurality of target stations used in the transmission of the first VHT signal and the second VHT signal.

19. The radio apparatus of claim 15, wherein the first VHT signal is transmitted over first data subcarriers in each of two orthogonal frequency division multiplexing (OFDM) symbols and the second VHT signal is transmitted over second data subcarriers in one OFDM symbol.

20. The radio apparatus of claim 19, wherein the number of the first data subcarriers is 48 and the number of the second data subcarriers is 52.

21. The radio apparatus of claim 15, wherein when the second VHT signal is generated for the plurality of target stations, different scrambling codes are applied to signals transmitted to the plurality of target stations.

22. The radio apparatus of claim 15, wherein when the second VHT signal is generated for the plurality of target stations an identification value indicating one of the plurality of target stations is included in the first VHT signal or the second VHT signal.

23. The radio apparatus of claim 15, wherein the processor is further configured to apply a column matrix to the second VHT signal to form a pre-coded signal, wherein when the second VHT signal is generated for the plurality of target stations a number of row of the column matrix is determined based on a number of spatial streams for each of the plurality of target stations.

24. The radio apparatus of claim 15, wherein a first cyclic shift is applied to the first VHT signal and a second cyclic shift is applied to the second VHT signal.

25. The radio apparatus of claim 15, wherein when the second VHT signal is generated for the single target station the first VHT signal indicates a number of spatial streams for the single target station.

26. The radio apparatus of claim 15, wherein when the second VHT signal is generated for the plurality of target stations, the VHT signal indicates a total number of spatial streams for the plurality of target stations.

27. The radio apparatus of claim 15, wherein the first control signal includes indication information indicating at least one spatial stream of another target station.

28. The radio apparatus of claim 27, wherein the indication information is used to reduce interference caused by the at least one spatial stream of another target station.

29. A radio apparatus for signal transmission in a Wireless Local Area Network (WLAN) system, the radio apparatus comprising:

a means for;

generating a first very high throughput (VHT) signal containing control information; and

generating, by he station, a second VHT signal containing control information; and

a means for transmitting the first VHT signal and the second VHT signal, wherein when the second VHT signal is generated for a single target station the second VHT signal is transmitted to the single target station, wherein when the second VHT signal is generated for a plurality of target stations the second VHT signal is transmitted to the plurality of target stations, and wherein the first VHT signal includes an indicator indicating that the second VHT signal is to be transmitted by using a single-user multiple input multiple output (SU-MIMO) scheme or a multi-user multiple input multiple output (MU-MIMO) scheme.

30. The radio apparatus of claim 29, further comprising:

applying a multi-user multiple input multiple output (MU-MIMO) steering matrix to the second VHT signal to form a pre-coded second control signal.

31. The radio apparatus of claim 29, wherein the first VHT signal is transmitted over first data subcarriers in each of two orthogonal frequency division multiplexing (OFDM) symbols and the second VHT signal is transmitted over second data subcarriers in one OFDM symbol.

32. The radio apparatus of claim 29, wherein when the second VHT signal is generated for the plurality of target stations, different scrambling codes are applied to signals transmitted to the plurality of target stations.

33. The radio apparatus of claim 29, wherein when the second VHT signal is generated for the plurality of target stations an identification value indicating one of the plurality of target stations is included in the first VHT signal or the second VHT signal.

34. The radio apparatus of claim 29, wherein a first cyclic shift is applied to the first VHT signal and a second cyclic shift is applied to the second VHT signal.

35. The radio apparatus of claim 29, wherein when the second VHT signal is generated for the single target station the first VHT signal indicates a number of spatial streams for the single target station.

36. The radio apparatus of claim 29, wherein when the second VHT signal is generated for the plurality of target stations, the first VHT signal indicates a total number of spatial streams for the plurality of target stations.

37. The radio apparatus of claim 29, wherein the first control signal includes indication information indicating at least one spatial stream of another target station.

38. The radio apparatus of claim 37, wherein the indication information is used to reduce interference caused by the at least one spatial stream of another target station.