Wireless communication system, weight control apparatus, and weight vector generation method

Abstract

Signals received by a plurality of antenna elements are supplied to a beam forming circuit via a distributor. The beam forming circuit weights and combines the signals to output a reception signal corresponding to a beam having a predetermined directionality pattern. A weight used to control weighting and combining is set by a weight controller. Upon receiving a registration request from an unregistered terminal, the weight controller calculates a weight vector used to form a beam having null directionality toward that terminal, and maximum directionality toward the range of an area other than an area where the terminal is located of a plurality of areas obtained by dividing the area covered by the antenna elements in accordance with direction.

1 - 9 . (canceled)  
   
   
       10 . A wireless communication system for making packet transmission control based on carrier sense, comprising: 
 a plurality of cells each of which includes a plurality of wireless base stations which use radio channels that do not interfere with each other, and    at least one wireless terminal for communicating with the wireless base station, each wireless base station includes:    a transmission adaptive array for making transmission beam control; and    a reception adaptive array for making reception beam control,    said reception adaptive array reducing an interference wave from the wireless base station in a neighboring cell that uses a radio channel which becomes an interference source to not more than a carrier sense level, and    an arbitrary location in the cell being covered by a transmission beam formed by said transmission adaptive array and a reception beam formed by said reception adaptive array of at least one wireless base station.    
   
   
       11 . A system according to  claim 10 , wherein the neighboring cells use different radio channels.  
   
   
       12 . A system according to  claim 10 , wherein an arbitrary location in the cell is covered by transmission beams formed by the transmission adaptive arrays and reception beams formed by the reception adaptive arrays of at least two wireless base stations.  
   
   
       13 . A method of controlling an adaptive array for a wireless base station, 
 wherein after a wireless terminal which communicates with the wireless base station roams to another wireless base station, and the wireless terminal which communicates with a wireless base station in a neighboring cell that uses a radio channel which becomes an interference source roams to another wireless base station,    a reception adaptive array of the wireless base station makes beam control to suppress reception power after combining of the reception adaptive array to less than a carrier sense level while the wireless base station in the neighboring cell that uses the radio channel which becomes the interference source sends a packet.    
   
   
       14 . A method according to  claim 13 , wherein suspension of packet transmission by the wireless base station for a predetermined period of time makes the radio terminal, which communicates with the wireless base station, roam to another wireless base station.  
   
   
       15 . A method of controlling an adaptive array for a wireless base station, 
 wherein a reception adaptive array of a wireless base station makes beam control to suppress reception power after combining of the reception adaptive array to not more than a carrier sense level while a wireless base station in a neighboring cell that uses a radio channel which becomes an interference source sends a multi-cast packet.    
   
   
       16 . A method according to  claim 15 , wherein the wireless base station in the neighboring cell that uses the radio channel which becomes the interference source sends the multi-cast packet while setting the reception adaptive array not to receive any packet.  
   
   
       17 . An adaptive array connected to a wireless base station for making packet transmission control based on carrier sense, comprising: 
 a plurality of antenna elements that receive signals;    a reception beam forming circuit to form a beam by weighting reception signals received by said plurality of antennas;    a reception level suppression unit configured to suppress an output level of said reception beam forming circuit to not more than a predetermined value, and to provide the output thereof to the wireless base station;    a transmission level suppression unit configured to suppress an output level from the wireless base station to not more than a predetermined value;    a transmission beam forming circuit to form a beam by weighting the output from said transmission level suppression unit; and    an interference generation unit configured to generate an interference for sending a packet irrespective of the reception signals received by said plurality of antenna elements.    
   
   
       18 . An adaptive array according to  claim 17 , wherein said interference generation unit comprises: 
 a reception disconnector configured to control said reception level suppression unit to suppress the output level of said reception beam forming circuit to not more than the predetermined value; and    a multi-cast packet transmission controller configured to issue a command to the wireless base station to send a multi-cast packet.    
   
   
       19 . An adaptive array connected to a wireless base station for making packet transmission control based on carrier sense, comprising: 
 a plurality of antenna elements that receive signals; a reception beam forming circuit to form a beam by weighting reception signals received by said plurality of antennas;    a reception level suppression unit configured to suppress an output level of said reception beam forming circuit to not more than a predetermined value, and to provide the output thereof to the wireless base station;    a transmission level suppression unit configured to suppress an output level from the wireless base station to not more than a predetermined value;    a transmission beam forming circuit to form a beam by weighting the output from said transmission level suppression unit; and    an interference suppression unit configured to calculate and set a weight to be set in said reception beam forming circuit on the basis of the output from said reception beam forming circuit while no packet is sent from said plurality of antenna elements.    
   
   
       20 . An adaptive array according to  claim 19 , wherein said interference suppression unit comprises: 
 a transmission disconnector configured to control said transmission level suppression unit to suppress the output level from the wireless base station to not more than the predetermined value; and    a weight controller configured to calculate and set the weight to be set in said reception beam forming circuit on the basis of the output form said reception beam forming circuit.