Radio communication system using adaptive array antenna
View Patent ↗A radio communication system and method having an array antenna and a weighting arrangement that provides a downlink array weight for a downlink on the basis of information about bearings of a plurality of incoming signals received through a plurality of uplinks, and transmission power control information about transmission data to be transmitted through a downlink.
1. A transmission control method for a base station which communicates with a plurality of mobile stations via an array antenna, comprising the steps of:
receiving, using said array antenna, a plurality of uplink signals transmitted from said plurality of mobile stations;
providing a downlink array weight for transmitting downlink signals to one of said plurality of mobile stations such that said downlink array weight represents an antenna pattern having a maximum beam in a direction of said one of the plurality of mobile stations which transmitted a first uplink signal received using said array antenna, and having a null in a direction of a mobile station other than said one of the plurality of mobile stations which transmitted a second uplink signal received using said array antenna,
wherein said downlink array weight is provided according to transmission power control information for a plurality of downlinks to said plurality of mobile stations.
2. The transmission control method according to claim 1 , wherein said transmission power control information is used to select said mobile station other than said one of the plurality of mobile stations for which said antenna pattern has a null.
3. The transmission control method according to claim 1 , wherein said transmission power control information is determined according to a transmission rate for a corresponding downlink.
4. The transmission control method according to claim 1 , wherein the direction for the maximum beam is determined according to spatial information extracted from a plurality of symbols of the first uplink signal, and the direction for the null is determined according to spatial information extracted from a plurality of symbols of the second uplink signal.