METHOD FOR PERFORMING TRANSMISSION DIVERSITY, RADIO DEVICE, AND COMMUNICATION SYSTEM USING THE SAME

摘要

PROBLEM TO BE SOLVED: To improve transmission quality by obtaining a diversity gain not only in reception but also in transmission. SOLUTION: In a system, SDM communication is performed between a first radio device having M (M≥2:integer) antennas shared in transmission and reception and a second radio device having N (M>N≥2:integer) antennas shared in transmission and reception, and selection diversity is performed. In the selection diversity, the N antennas used for transmitting N independent signals each in transmission are selected from the M antennas shared in the transmission and reception by using a weighting factor based on SNR. Or the weighting factor is used to perform weighting transmission diversity (transmitting diversity circuit 113) for weighting the transmission power of a signal to be transmitted from M antennas, when N signals that are independent one another are simultaneously transmitted in the same frequency band from M antennas that the radio device has. COPYRIGHT: (C)2006,JPO&NCIPI