Radio base system, transmission directional control method, and transmission directional control program

A method of controlling transmission directivity in a radio base station system transmitting/receiving signals to/from a plurality of terminals using a plurality of antennas (#1-#4) arranged in a discrete manner, comprising the steps of:

• calculating a weight vector for separating a signal from a specific terminal among said plurality of terminals, based on signals received with said plurality of antennas;
• estimating a reception response vector of a propagation path from said specific terminal, based on signals received with said plurality of antennas;
• estimating a transmission response vector of said propagation path in transmission, based on said estimated reception response vector;
• and
• controlling transmission directivity of said antennas, based on said estimated transmission response vector;
• wherein
• said step of estimating said transmission response vector includes the steps of
• regarding a function of temporal change of an element of each antenna of said estimated reception response vector as a composite waveform of signal waveforms of a prescribed number of prescribed frequency components which are different from each other,
• predicting temporal changes at arbitrary timing positions in transmission, of the signal waveforms of respective frequency components, and
• synthesizing said transmission response vector.

A program for controlling transmission directivity in a radio base station system transmitting/receiving signals to/from a plurality of terminals using a plurality of antennas (#1-#4) arranged in a discrete manner, causing a computer to execute the steps of:

• calculating a weight vector for separating a signal from a specific terminal among said plurality of terminals, based on signals received with said plurality of antennas;
• estimating a reception response vector of a propagation path from said specific terminal, based on signals received with said plurality of antennas;
• estimating a transmission response vector of said propagation path in transmission, based on said estimated reception response vector;
• and
• controlling transmission directivity of said antennas, based on said estimated transmission response vector;
• wherein
• said step of estimating said transmission response vector includes the steps of
• regarding a function of temporal change of an element of each antenna of said estimated reception response vector as a composite waveform of signal waveforms of a prescribed number of prescribed frequency components which are different from each other,
• predicting temporal changes at arbitrary timing positions in transmission, of the signal waveforms of respective frequency components, and
• synthesizing said transmission response vector.