| 摘要 |
PROBLEM TO BE SOLVED: To eliminate the need of a high-speed changeover synthesizer by performing hand-over control by signals for which received input signals are digitally converted and then Fourier transformed further. SOLUTION: Different frequency control channel signals are received from plural base stations by an antenna 1, passed through a device 2 shared for transmission and reception and a high frequency low noise amplifier 3, mixed with the output of a synthesizer 16 in a first mixer 4 and turned to an intermediate frequency. The control channel signals are distributed by a coupler 5, unrequired components outside of a band are removed by a wide band intermediate frequency band pass filter 17 and then, they are passed through an A/D converter 18 and processed in an FFT processing part 19. Then, the levels of the entire control channels are simultaneously compared in a control part 13, the appropriate control channel under an environment used at present is selected and the base station for performing communication is specified. In such a manner, since the need of switching the output frequency of the synthesizer for the number of the control channels for the entire channel scanning when a power is ON is eliminated and the entire channel signal levels are simultaneously observed, the need of the high-speed synthesizer is eliminated. |
