Patent ID: 7853293
Filing Date: 2010-12-14
Classification: H04B,H04W

Abstract:
1. A radio apparatus, including: a computing unit which computes a received response vector of a terminal apparatus which is a targeted communication party, based on signals received from the targeted terminal apparatus, the received response vector indicating a received response characteristic of a received signal from the terminal apparatus against a transmission signal; an acquiring unit which acquires one of virtual response vectors with respect to corresponding one of a plurality of virtual terminal apparatuses assumed such that directions in which the plurality of virtual terminal apparatuses exist are mutually different from each other, the virtual response vectors being stored in advance; a generator which generates a transmission weight vector based on the received response vector computed by said computing unit and the one of the virtual response vectors acquired by said acquiring unit, the received response vector and the virtual response vectors being used to form the transmission weight vector indicting an antenna's directional pattern such that a signal strength in a direction to the terminal apparatus becomes greater whereas a signal strength in a direction to one of the virtual terminal apparatuses becomes smaller; and a transmitter which transmits a predetermined signal to the targeted terminal apparatus based on the transmission weight vector generated by said generator, wherein said acquiring unit acquires again another virtual response vector such that one of the direction in which the one of the virtual terminal apparatus exists is changed to another direction, and the thus reacquired virtual response vector is again subject to processes by said generator and said transmitter, and said acquiring unit reacquires another virtual response vector whose value of correlation with the received response vector computed by said computing unit is less than or equal to a predetermined threshold value, and the thus reacquired virtual response vector is again subject to the processes by said generator and said transmitter, the radio apparatus further including: a measuring unit which measures the intensity of a signal received from the targeted terminal apparatus; and an intensity determining unit which instructs said acquiring unit to switch to the virtual response vector whose value of correlation with the received response vector computed by said computing unit becomes less than or equal to a predetermined threshold value if a signal strength value of the targeted terminal apparatus, which is calculated from the transmission weight vector, the received response vector and information on the intensity of the received signal measured by said measuring unit, is less than or equal to a threshold value.