Antenna array apparatus and beamforming method using GPS signal for base station in mobile telecommunication system
There is provided an antenna array apparatus using a GPS signal in a base station and a beamforming method thereof. In the antenna array apparatus, a GPS signal processor receives GPS position information from a mobile station and calculates the position information of the mobile station. A signal processor calculates a weight vector using the position information to form a transmission/reception beam. A transmission/reception beamformer forms the transmission/reception beam according to the weight vector.
1. A transmission antenna array apparatus of a base station in a mobile communication system having a mobile station that receives GPS (Global Positioning System) position information of the mobile station from satellites and outputs the GPS information representative of the absolute position of the mobile station, the apparatus comprising:
a position information generator for receiving the GPS position information from the mobile station and generating position information of the mobile station;
an array signal processor for calculating a weight vector using the position information to form a transmission beam; and
a forward processor having a transmission beamformer, for forming the transmission beam according to the weight vector in the direction of the mobile station through the transmission beamformer and outputting a transmission message to the antenna array by the transmission beam,
wherein the weight vector is an optimum transmission array weight vector calculated by
W T =k T a (θ,φ,λ T )
where w T is the weight vector for the transmission array, k T is an arbitrary positive real number, and λ T is the wavelength of the transmission signal and θ is an elevation angle of the z axis by a position data the mobile station receives from the satellite and Φ is an azimuth angle by a position data that the mobile station receives from the satellites.
2. The transmission antenna array apparatus of claim 1 , wherein the transmission beamformer forms transmission beams by generating as many transmission signals as M antenna devices by duplicating the transmission signal and multiplying each duplicate signal by a corresponding forward weight generated from the array signal processor, wherein M is a number of antenna devices.
3. A reception antenna array apparatus of a base station in a mobile communication system having a mobile station that receives GPS position information of the mobile station from satellites and outputs the GPS information representative of the absolute position of the mobile station, the apparatus comprising:
a position information generator for receiving the GPS position information from the mobile station and generating position information of the mobile station;
an array signal processor for calculating a weight vector using the position information to form a reception beam; and
a reverse processor having a reception beamformer, for forming the reception beam according to the weight vector in the direction of the mobile station through the reception beamformer and processing a message received through the antenna array by the reception beam,
wherein the weight vector is an optimum reception array weight vector calculated by
W R =k R a (θ,φ,λ R )
where W R is the weight vector for the reception array, k R is an arbitrary positive real number, and λ R is the wavelength of the received signal and θis an elevation angle of the z axis by a position data the mobile station receives from the satellite and Φ is an azimuth angle by a position data that the mobile station receives from the satellites.
4. The reception antenna array apparatus of claim 3 , wherein the reception beamformer obtains a final array output signal by receiving signals through M antenna devices, multiplying each antenna device output signal by a corresponding reverse weight generated from the array signal processor, and summing the multiplied signals, wherein M is a number of antenna devices.