To enable satisfactory diversity communication flexibly adaptive to the change of a communication environment even when a communicating party is a moving object by providing plural antennas, plural diversity reception circuits and selector circuit for selecting any one of outputs from these reception circuits.
While using four antennas 104-107, a base station 103 receives radio waves sent from antennas 101 and 102 of a mobile station (such as an automobile, for example) 100. Received analog signals are converted into intermediate frequency(IF) signals, demodulated, converted into digital signals and inputted to a base band signal processing part 112. Three diversity reception circuits 113-115 having the different ability of follow-up to the environment synthesize the input signals from the respective antennas 104-107 while having directivity. A signal selector circuit 116 compares the reception quality of synthesized signals outputted from the respective diversity reception circuits 113-115 and selects the signal of the optimum reception quality.
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FUTAKI SADAKI
HIRAMATSU KATSUHIKO
YUKITOMO HIDEKI
