System and method for coordinated beamforming for overlapping basic service set in wlan

Abstract

Embodiments are provided for enabling a coordinated beamforming (CB) mechanism in WLAN scenarios. In an embodiment, an AP sends a Feedback Request (FBR) frame to each one of the STAs in the OBSSs. The OBSSs comprise the STAs and a plurality of APs including the AP. The AP then receives a feedback frame from each STA of the STAs that participate in the CB transmission. The feedback frame includes channel state information (CSI) of the STA. The CSI enables the sending AP of performing CB on downlink. In an embodiment, the AP receives an initiate CB frame from a second AP initiating a CB transmission, and then sends an ACK frame to the second AP before sending the FBR frame to each one of the STAs. The AP starts the CB transmission with each one of the other APs that participate in the CB transmission.

What is claimed is: 
     
         1 . A method by a station (STA) in overlapping basic service sets (OBSSs) in wireless local area network (WLAN), the method comprising:
 receiving from an access point (AP) a Feedback Request (FBR) frame, wherein the OBSSs comprise a plurality of APs including the AP and other APs, and further comprise a plurality of stations (STAs) including the STA; and   sending a feedback frame to the AP, wherein the STA participates in a coordinated beamforming (CB) transmission with the AP, and wherein the feedback frame includes channel state information (CSI) of the STA enabling the AP to perform CB on downlink.   
     
     
         2 . The method of  claim 1 , further comprising:
 receiving data from the AP using CB to coordinate with the other APs participating in the CB transmission;   receiving a Block Acknowledgment (ACK) Request (BAR) frame from the AP; and   sending a Block ACK (BA) frame to the AP.   
     
     
         3 . The method of  claim 2 , further comprising sending the BA frame to the AP using CB on uplink concurrently with other STAs associated with the AP. 
     
     
         4 . The method of  claim 2 , further comprising receiving the BAR frame from the AP in consecutive sequence with other STAs associated with the AP. 
     
     
         5 . The method of  claim 1 , wherein the STA is associated with one of the other APs, and not with the AP. 
     
     
         6 . The method of  claim 1 , wherein the FBR frame received from the AP indicates Media Access Control (MAC) addresses of the AP and a target STA. 
     
     
         7 . The method of  claim 1 , further comprising starting the CB transmission with the AP and each one of the other APs participating in the CB transmission, after the AP sends an initiate CB frame to each one of the other APs in the OBSSs. 
     
     
         8 . The method of  claim 7 , further comprising starting the CB transmission after each one of the other APs intending to participate in the CB transmission sends an acknowledgement (ACK) frame. 
     
     
         9 . The method of  claim 1 , further comprising ending the CB transmission after the AP sends an end of service period (EOSP) frame. 
     
     
         10 . The method of  claim 1 , further comprising receiving the FBR frame from the AP in consecutive sequence with other STAs associated with the AP. 
     
     
         11 . The method of  claim 1 , further comprising estimating a channel between the STA and AP to generate the CSI. 
     
     
         12 . A station (STA) in overlapping basic service sets (OBSSs) in wireless local area network (WLAN), the STA comprising:
 a non-transitory memory storage comprising instructions; and   one or more processors in communication with the memory storage, wherein the one or more processors execute the instructions for:
 receiving from an access point (AP) a Feedback Request (FBR) frame, wherein the OBSSs comprise a plurality of APs including the AP and other APs, and further comprise a plurality of stations (STAs) including the STA; and 
 sending a feedback frame to the AP, wherein the STA participates in a coordinated beamforming (CB) transmission with the AP, and wherein the feedback frame includes channel state information (CSI) of the STA enabling the AP to perform CB on downlink. 
   
     
     
         13 . The STA of  claim 12 , wherein the one or more processors further execute the instructions for:
 receiving data from the AP using CB to coordinate with the other APs participating in the CB transmission;   receiving a Block Acknowledgement (ACK) Request (BAR) frame from the AP; and   sending a Block ACK (BA) frame to the AP.   
     
     
         14 . The STA of  claim 13 , wherein the one or more processors further execute the instructions for sending the BA frame to the AP using CB on uplink concurrently with other STAs associated with the AP. 
     
     
         15 . The STA of  claim 13 , wherein the one or more processors further execute the instructions for receiving the BAR frame from the AP in consecutive sequence with other STAs associated with the AP. 
     
     
         16 . The STA of  claim 12 , wherein the STA is associated with one of the other APs, and not with the AP. 
     
     
         17 . The STA of  claim 12 , wherein the FBR frame received from the AP indicates Media Access Control (MAC) addresses of the AP and a target STA. 
     
     
         18 . The STA of  claim 12 , wherein the one or more processors further execute the instructions for starting the CB transmission with the AP and each one of the other APs participating in the CB transmission, after the AP sends an initiate CB frame to each one of the other APs in the OBSSs. 
     
     
         19 . The STA of  claim 18 , wherein the one or more processors further execute the instructions for starting the CB transmission after each one of the other APs intending to participate in the CB transmission sends an acknowledgement (ACK) frame. 
     
     
         20 . The STA of  claim 12 , wherein the one or more processors further execute the instructions for ending the CB transmission after the AP sends an end of service period (EOSP) frame. 
     
     
         21 . The STA of  claim 12 , wherein the one or more processors further execute the instructions for receiving the FBR frame from the AP in consecutive sequence with other STAs associated with the AP. 
     
     
         22 . The STA of  claim 12 , wherein the one or more processors further execute the instructions for estimating a channel between the STA and AP to generate the CSI.