Patent ID: 7792495

Claim:
A radio apparatus receiving and transmitting a signal using a plurality of antennas, comprising: an adaptive array reception processing unit performing a reception process on a reception signal received by said plurality of antennas by adaptive array processing; a reception response vector generation unit generating a reception response vector based on the reception signal received by said plurality of antennas; a modulation scheme selection unit selecting a modulation scheme; a modulation unit modulating transmission data; a transmission scheme selection unit selecting one of a first transmission weight for forming transmission directivity to direct a beam of a transmission radio wave in a direction of desired another radio apparatus and direct a null of a transmission radio wave in a direction of an interference wave and a second transmission weight for forming transmission directivity to maximize reception power at said desired another radio apparatus; a transmission weight generation unit generating said first transmission weight based on a reception process resulted from said adaptive array reception processing unit or said reception response vector if said first transmission weight is selected, and generating said second transmission weight based on said reception response vector if said second transmission weight is selected; a transmission weight processing unit generating array transmission data having said transmission directivity, based on said modulated transmission data and said generated transmission weight; and a transmission unit converting said array transmission data into a transmission signal, wherein said transmission scheme selection unit selects said first transmission weight if a number of levels of said selected modulation scheme is less than a prescribed value, and selects said second transmission weight if a number of levels of said selected modulation scheme is equal to or more than said prescribed value.