System and method for preambles in a wireless communications network

• US 10,285,091 B2
• Filed: 07/06/2017
• Issued: 05/07/2019
• Est. Priority Date: 12/07/2011
• Status: Active Grant

• Current Assignee: Huawei Technologies Co., Ltd. (Huawei Investment & Holding Co., Ltd.)
• Original Assignee: Huawei Technologies Co., Ltd. (Huawei Investment & Holding Co., Ltd.)
• Inventors: Suh, Jung Hoon, Li, Yunbo, Au, Kwok Shum, Aboul-Magd, Osama, Sun, Sheng
• Primary Examiner(s): Mui, Gary
• Application Number:
  US15/643,253
• Publication Number:
  US 20170311203A1
• Time in Patent Office: 670 Days
• CPC Class Codes: H04B 7/0617 for beam forming
• CPC Class Codes: H04B 7/0689 using different transmission schemes, at least one of them being a diversity transmission scheme
• CPC Class Codes: H04L 27/2613 Structure of the reference signals
• 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: H04L 69/22 Parsing or analysis of headers
• CPC Class Codes: H04W 28/06 Optimizing the usage of the radio link, e.g. header compression, information sizing , discarding information system modifying transmission characteristic according to link quality by modifying frame length H04L1/0007; dynamic adaptation of the packet size for flow control or congestion control H04L47/365
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]

Abstract

A method for transmitting a frame includes generating an omni portion of the frame, the omni portion including a non-beamformed long training field and a signal field, the non-beamformed long training field including channel estimation information used to decode the signal field, the non-beamformed long training field configured to be transmitted through one of multiple antennas and multiple streams. The method also includes generating a multi-stream portion of the frame, the multi-stream portion including a data field and a multi-stream long training field, the multi-stream long training field including station-specific decoding information for station-specific data in the data field. The method further includes applying a beamforming indicator to the signal field of the omni portion, and transmitting the frame.

Claims

1. A method for transmitting a frame, the method comprising:

generating, by an access point, an omni portion of the frame, the omni portion including a signal field, and the signal field including a beam forming field indicating whether a Q matrix is changed from the omni portion of the frame to a multi-stream portion of the frame;

generating, by the access point, the multi-stream portion of the frame in accordance with a value of the beam forming field, the multi-stream portion of the frame having N spatial streams, the multi-stream portion of the frame containing N−

1 long training fields and including a data field, and the multi-stream portion of the frame being located after the omni portion of the frame; and

wirelessly transmitting, by the access point, the frame.

2. The method of claim 1, wherein the omni portion further includes a short training field and a first long training field, and wherein the first long training field includes channel estimation information for decoding the signal field.

3. The method of claim 1, wherein the multi-stream portion further includes a second long training field comprising reference signal information for channel estimation of station-specific data in the data field.

4. The method of claim 1, further comprising setting the beam forming field to a first value indicating the Q matrix is changed from the omni portion of the frame to the multi-stream portion of the frame.

5. The method of claim 1, further comprising setting the beam forming field to a second value indicating the Q matrix is not changed from the omni portion of the frame to the multi-stream portion of the frame.

6. The method of claim 1, wherein transmitting the frame comprises:

transmitting the omni portion of the frame through one stream; and

transmitting the multi-stream portion of the frame through multiple antennas and multiple streams.

7. A method for receiving a frame, the method comprising:

wirelessly receiving, by a station, an omni portion of the frame, the omni portion including a signal field, and the signal field including a beam forming field indicating whether a Q matrix is changed from the omni portion of the frame to a multi-stream portion of the frame;

decoding, by the station, the beam forming field;

wirelessly receiving, by the station, the multi-stream portion of the frame, the multi-stream portion of the frame having N spatial streams, the multi-stream portion containing N−

1 long training fields and including a data field, and the multi-stream portion of the frame being located after the omni portion of the frame; and

decoding, by the station, the multi-stream portion of the frame in accordance with the decoded beam forming field.

8. The method of claim 7, wherein the omni portion further includes a short training field and a first long training field, and wherein the first long training field includes channel estimation information for decoding the signal field.

9. The method of claim 7, wherein the multi-stream portion further includes a second long training field comprising reference signal information for channel estimation of station-specific data in the data field.

10. The method of claim 7, wherein decoding the beam forming field comprises determining the beam forming field has a first value indicating the Q matrix is changed from the omni portion of the frame to the multi-stream portion of the frame.

11. The method of claim 7, wherein decoding the beam forming field comprises determining the beam forming field has a second value indicating the Q matrix is not changed from the omni portion of the frame to the multi-stream portion of the frame.

12. An access point comprising:

a processor configured to;

generate an omni portion of a frame, wherein the omni portion includes a signal field, and wherein the signal field includes a beam forming field indicating whether a Q matrix is changed from the omni portion of the frame to a multi-stream portion of the frame;

generate the multi-stream portion of the frame in accordance with a value of the beam forming field, wherein the multi-stream portion of the frame has N spatial streams, wherein the multi-stream portion of the frame contains N−

1 long training fields and includes a data field, and wherein the multi-stream portion of the frame is located after the omni portion of the frame; and

a transmitter coupled to the processor and configured to wirelessly transmit the frame.

13. The access point of claim 12, wherein the omni portion further includes a short training field and a first long training field, and wherein the first long training field includes channel estimation information for decoding the signal field.

14. The access point of claim 12, wherein the multi-stream portion further includes a second long training field comprising reference signal information for channel estimation of station-specific data in the data field.

15. The access point of claim 12, wherein the processor is further configured to set the beam forming field to a first value indicating the Q matrix is changed from the omni portion of the frame to the multi-stream portion of the frame.

16. The access point of claim 12, wherein the processor is further configured to set the beam forming field to a second value indicating the Q matrix is not changed from the omni portion of the frame to the multi-stream portion of the frame.

17. The access point of claim 12, wherein the transmitter configured to transmit the frame comprises:

transmit the omni portion of the frame through one stream; and

transmit the multi-stream portion of the frame through multiple antennas and multiple streams.

18. A station comprising:

a receiver configured to wirelessly receive an omni portion of a frame, wherein the omni portion includes a signal field, and wherein the signal field includes a beam forming field indicating whether a Q matrix is changed from the omni portion of the frame to a multi-stream portion of the frame;

a processor coupled to the receiver and configured to decode the beam forming field;

the receiver further configured to wirelessly receive the multi-stream portion of the frame, wherein the multi-stream portion of the frame has N spatial streams, wherein the multi-stream portion contains N−

1 long training fields and includes a data field, and wherein the multi-stream portion of the frame is located after the omni portion of the frame; and

the processor further configured to decode the multi-stream portion of the frame in accordance with the decoded beam forming field.

19. The receiver of claim 18, wherein the omni portion further includes a short training field and a first long training field, and wherein the first long training field includes channel estimation information for decoding the signal field.

20. The receiver of claim 18, wherein the multi-stream portion further includes a second long training field comprising reference signal information for channel estimation of station-specific data in the data field.

21. The station of claim 18, wherein the processor configured to decode the beam forming field comprises the processor configured to determine the beam forming field has a first value indicating the Q matrix is changed from the omni portion of the frame to the multi-stream portion of the frame.

22. The station of claim 18, wherein the processor configured to determine the beam forming field has a second value indicating the Q matrix is not changed from the omni portion of the frame to the multi-stream portion of the frame.