Null data packet sounding for preamble puncture techniques

1. A wireless communication method comprising:

encoding a preamble punctured Null Data Packet Announcement (NDPA) for a new connection at a first station;

encoding a preamble punctured Null Data Packet (NDP) for the new connection at the first station;

wherein the preamble punctured NDPA includes a preamble puncture mode indicator;

transmitting by the first station the preamble punctured Procedure Protocol Data Unit (PPDU) including the preamble punctured NDPA and the preamble punctured NDP on a primary channel and a secondary channel for the new connection to a second station, wherein the secondary channel for the new connection overlaps with a secondary channel of an existing connection; and

receiving at the first station a PPDU from the second station carrying a compressed beamforming feedback frame, wherein the compressed beamforming feedback frame contains a plurality of beamforming feedbacks of which each is obtained from a contiguous Resource Unit (RUs).

2. The wireless communication method of claim 1 , wherein the new connection and the existing connection are in a same basic service set (BSS).

3. The wireless communication method of claim 1 , wherein the preamble punctured NDPA is duplicated and transmitted on each sub-channel of the primary channel and each sub-channel of the secondary channel.

4. The wireless communication method of claim 3 , wherein the duplicated preamble punctured NDPA is not transmitted on a punctured sub-channel.

5. The wireless communication method of claim 1 , wherein the preamble puncture mode indicator of the preamble punctured PPDU carrying the NDPA also represent a mode indicator of the NDP transmitted after a Short Interframe Space (SIFS).

6. The wireless communication method of claim 5 , wherein the plurality of beamforming feedback includes an average Signal to Noise Ratio (SNR) of space-time streams calculated over all data subcarriers not within the punctured 20 MHz channels of the preamble puncture NDP.

7. The wireless communication method of claim 1 , wherein a partial bandwidth information field of the preamble punctured NDPA indicates a frequency range within one contiguous Resource Units (RUs) amount a set of contiguous RUs in a channel bandwidth of the preamble punctured NDPA excluding a punctured sub-channel for which a beamformer is requesting a feedback.

8. The wireless communication method of claim 7 , wherein the partial bandwidth information field is included in a Station (STA) information subfield of the preamble punctured NDPA.

9. The wireless communication method of claim 1 , wherein a bandwidth field of a Next-Generation (NG) Signal (SIG) in the preamble punctured NDP includes a preamble puncture mode indicator of a punctured sub-channel.

10. The wireless communication method of claim 1 , wherein a user-specific and variable length signal field carries indication information of a punctured secondary channel.

11. The wireless communication method of claim 10 , wherein a Station Identifier (STA-ID) field in the user-specific and variable length signal field indicates whether a Resource Unit (RU) assignment in a frequency domain mapped by the user-specific and variable length signal field is punctured or not.

12. The wireless communication method of claim 10 , wherein a Station Identifier (STA-ID) in the user-specific and variable length signal field indicates an Association Identifier (AID) of a beamformee for which a beamformer is requesting feedback on a Resource Unit (RU) mapped by the user-specific and variable length signal field.

13. The wireless communication method of claim 12 , wherein, when a beamformer requests beamforming feedback from multiple contiguous Resource Units (RUs), a Multi-Input Multi-Output (MIMO) control field in a beamforming feedback frame specifies a frequency start index and a frequency end index within each contiguous RU.

14. The wireless communication method of claim 13 , wherein a plurality of beamforming feedback frames are aggregated in an Aggregated Media Access Control Protocol Data Unit (A-MPDU).

15. The wireless communication method of claim 13 , wherein a frequency start index and a frequency end index in the Multi-Input Multi-Output (MIMO) control field in the beamforming feedback frame covers the punctured secondary channel.

16. A wireless communication method comprising:

receiving at a second station a preamble punctured Procedure Protocol Data Unit (PPDU) on a primary channel and one or more secondary channels for a new connection, wherein at least one secondary channel of the new connection overlaps with a secondary channel of an existing connection;

decoding at the second station a preamble punctured Null Data Packet Announcement (NDPA) in the preamble punctured PPDU;

decoding at the second station a preamble punctured Null Data Packet (NDP) in the preamble punctured PPDU;

decoding at the second station a preamble puncture mode indicator in a signal field of the preamble punctured PPDU;

encoding at the second station a compressed beamforming feedback in a preamble punctured Multi-User Multi-Input Multi-Output (MU-MIMO) PPDU in response to the preamble punctured NDPA and preamble punctured NDP; and

transmitting by the second station the preamble punctured MU-MIMO PPDU on the primary channel and the one or more secondary channels to a first station.

17. The wireless communication method of claim 16 , wherein the new connection and the existing connection are in the same basic service set (BSS).

18. The wireless communication method of claim 16 , further comprising:

receiving a Trigger Based (TB) PPDU on each sub-channel of the primary channel and each sub-channel of the secondary channel.

19. The wireless communication method of claim 16 , wherein the preamble punctured NDPA is received on each sub-channel of the primary channel and each sub-channel of the secondary channel.

20. The wireless communication method of claim 19 , wherein the preamble punctured NDPA is not received on a punctured sub-channel of the primary channel.