Filling the space-time channels in SDMA

Abstract

Embodiments of the present invention provide an apparatus capable of filling space-time channels in Spatial-Division Multiple-Access (SDMA) in a Medium Access Control (MAC) protocol, comprising, a base station operable in a wireless network and adapted for uplink and downlink multi-user and multi antenna operation, the base station including a MAC scheduler to schedule transmissions using packet scheduling in the wireless network, and wherein the MAC scheduler schedules variable length packets for transmission using packet scheduling in the wireless network based on transmission times to transmit on each of M spatial channels to mobile stations operable in the wireless network by filling the M spatial channels using data packets buffered for the mobile stations operable to communicate with the base station.

1 . A apparatus capable of filling space-time channels in Spatial-Division Multiple-Access (SDMA) in a Medium Access Control (MAC) protocol, comprising:
 a base station operable in a wireless network and adapted for uplink and downlink muliti-user and multi antenna operation, said base station including a MAC scheduler to schedule transmissions using packet scheduling in said wireless network; and   wherein said MAC scheduler schedules variable length packets for transmission using packet scheduling in said wireless network based on transmission times to transmit on each of M spatial channels to mobile stations operable in said wireless network by filling the M spatial channels using data packets buffered for said mobile stations operable to communicate with said base station.   
     
     
         2 . The apparatus of  claim 1 , where M is a constant less than or equal to a number of antennas at the access point. 
     
     
         3 . The apparatus of  claim 1 , further including adaptive antenna arrays used in conjunction with a beam forming algorithm to achieve spatial diversity and implementing Spatial-Division Multiple-Access (SDMA), wherein the adaptive antenna array changes beam weights based on the schedule. 
     
     
         4 . The apparatus of  claim 1 , wherein the scheduler in a downlink provides a schedule of transmission intervals for different mobile stations. 
     
     
         5 . The apparatus of  claim 1 , wherein the schedule accounts for traffic information to the mobile stations based on packet size. 
     
     
         6 . The device of  claim 1 , wherein the schedule accounts for traffic information to the mobile stations based on queue size. 
     
     
         7 . The apparatus of  claim 1 , wherein the schedule accounts for traffic information to the mobile stations based on priority. 
     
     
         8 . The apparatus of  claim 1 , wherein the access point sends multiple schedules in a protected time interval to the mobile stations. 
     
     
         9 . The apparatus of  claim 8 , wherein a first schedule of the multiple schedules is sent to a first mobile station and a second schedule is sent to a second mobile station. 
     
     
         10 . A method to fill space-time channels in Spatial-Division Multiple-Access (SDMA) in a Medium Access Control (MAC) protocol, comprising:
 using a base station operable in a wireless network and adapted for uplink and downlink muliti-user and multi antenna operation, said base station including a MAC scheduler to schedule transmissions using packet scheduling in said wireless network; and   wherein said MAC scheduler schedules variable length packets for transmission using packet scheduling in said wireless network based on transmission times to transmit on each of M spatial channels to mobile stations operable in said wireless network by filling the M spatial channels using data packets buffered for said mobile stations operable to communicate with said base station.   
     
     
         11 . The method of  claim 10 , where M is a constant less than or equal to a number of antennas at the access point. 
     
     
         12 . The method of  claim 10 , further including retrieving antenna resources in the access point to form spatial channels developed on the fly for a waiting mobile station. 
     
     
         13 . The method of  claim 10 , wherein a channel is accessed by the access point sending a Clear-To-Send (CTS) frame that broadcasts a protected time interval, and wherein the protected time interval is announced by the access point such that no mobile station contends for the medium during that time interval. 
     
     
         14 . The Method of  claim 13 , wherein the time interval length may be equal to the length of a buffered packet.