System and method for preambles in a wireless communications network

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

generating, by an access point, 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 one of multiple streams;

generating, by the access point, 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;

applying, by the access point, a beamforming indicator to the signal field of the omni portion, wherein applying the beamforming indicator comprises setting a status indicator in the signal field, wherein the status indicator is set to a first value when the multi-stream portion is beamformed, and wherein the status indicator is set to a second value when the multi-stream portion is not beamformed; and

transmitting, by the access point, the frame.

2. The method of claim 1 , wherein the multi-stream portion is located after the omni portion.

3. The method of claim 1 , wherein the status indicator is a one or more bit long indicator.

4. The method of claim 1 , wherein applying the beamforming indicator comprises using signal intensity at different axes of a representation of a modulation symbol of a subset of the signal field to apply the beamforming indicator.

5. The method of claim 1 , wherein applying the beamforming indicator comprises modulating a subset of the signal field.

6. The method of claim 5 , wherein the subset of the signal field is modulated using a first modulation technique if the multi-stream portion is beamformed, and wherein the subset of the signal field is modulated using a second modulation technique if the multi-stream portion is not beamformed.

7. The method of claim 6 , wherein the first modulation technique is binary phase shift keying, and wherein the second modulation technique is quadrature binary phase shift keying.

8. The method of claim 1 , wherein the multi-stream portion is transmitted through multiple antennas and multiple streams.

9. The method of claim 1 , wherein the frame is an IEEE 802.11ah frame.

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

receiving, by a station, an omni portion of the frame, the omni portion includes 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;

determining, by the station, a beamform status of a multi-stream portion of the frame;

receiving, by the station, the multi-stream portion of the frame, the multi-stream portion including a multi-stream long training field and a data field, the multi-stream long training field including station-specific decoding information for station-specific data in the data field; and

decoding, by the station, the multi-stream portion of the frame using a technique commensurate with the beamform status of the multi-stream portion of the frame.

11. The method of claim 10 , wherein determining the beamform status comprises examining a status indicator located in the signal field of the omni portion.

12. The method of claim 11 , wherein the status indicator is set to a first value if the multi-stream portion is beamformed, and wherein the status indicator is set to a second value if the multi-stream portion is not beamformed.

13. The method of claim 10 , wherein determining the beamform status comprises examining signal intensity of a subset of the signal field of the omni portion.

14. The method of claim 13 , wherein examining the signal intensity comprises determining a modulation technique used for the subset of the signal field.

15. The method of claim 14 , wherein the multi-stream portion is beamformed if the subset of the signal field is modulated using a first modulation technique, and wherein the multi-stream portion is non-beamformed if the subset of the signal field is modulated using a second modulation technique.

16. The method of claim 15 , wherein the first modulation technique is binary phase shift keying, and wherein the second modulation technique is quadrature binary phase shift keying.

17. A transmitting device comprising:

a processor configured to:

generate an omni portion of a 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 to be transmitted through one of multiple antennas and one of multiple streams,

generate 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, and

apply a beamforming indicator to the signal field of the omni portion, wherein the processor configured to apply the beamforming indicator comprises the processor configured to set a status indicator in the signal field, wherein the status indicator is set to a first value when the multi-stream portion is beamformed, and wherein the status indicator is set to a second value when the multi-stream portion is not beamformed; and

a transmitter operatively coupled to the processor, the transmitter configured to transmit the frame.

18. The transmitting device of claim 17 , wherein the processor is configured to use signal intensity at different axes of a representation of a modulation symbol of a subset of the signal field to apply the beamforming indicator.

19. The transmitting device of claim 17 , wherein the processor is configured to modulate a subset of the signal field.

20. The transmitting device of claim 19 , wherein the subset of the signal field is modulated using a first modulation technique if the multi-stream portion is beamformed, and wherein the subset of the signal field is modulated using a second modulation technique if the multi-stream portion is not beamformed.

21. The transmitting device of claim 20 , wherein the first modulation technique is binary phase shift keying, and wherein the second modulation technique is quadrature binary phase shift keying.

22. The transmitting device of claim 17 , wherein the transmitting device is an IEEE 802.11ah access point.

23. The transmitting device of claim 17 , wherein the multi-stream portion is located after the omni portion.

24. The transmitting device of claim 17 , wherein the status indicator is a one or more bit long indicator.

25. The transmitting device of claim 17 , wherein transmitter is configured to transmit the multi-stream portion through multiple antennas and multiple streams.

26. A receiving device comprising:

a receiver configured to receive an omni portion of a frame, the omni portion includes 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, and to receive a multi-stream portion of the frame, the multi-stream portion including a multi-stream long training field and a data field, the multi-stream long training field including station-specific decoding information for station-specific data in the data field; and

a processor operatively coupled to the receiver, the processor configured to determine a beamform status of the multi-stream portion of the frame, and to decode the multi-stream portion of the frame using a technique commensurate with the beamform status of the multi-stream portion of the frame.

27. The receiving device of claim 26 , wherein the processor is configured to examine a status indicator located in the signal field of the omni portion.

28. The receiving device of claim 26 , wherein the processor is configured to examine signal intensity of a subset of the signal field of the omni portion.

29. The receiving device of claim 28 , wherein the processor is configured to determine a modulation technique used for the subset of the signal field.

30. The receiving device of claim 26 , wherein the receiving device is an IEEE 802.11ah station.