| 摘要 |
<P>PROBLEM TO BE SOLVED: To improve reception characteristics when switching and diversity-receiving modulation signals by a DPQSK system. <P>SOLUTION: A first signal group is formed by DPQSK reception signals z<SB>A</SB>[k] by a reception system 10 and the delay signals z<SB>A</SB>[k-1], and a second signal group is formed by DPQSK reception signals z<SB>B</SB>[k] by a reception system 20 and the delay signals z<SB>B</SB>[k-1]. A signal selection part 30 detects the magnitude of the reception signals of the reception system 10 from z<SB>A</SB>[k] and/or z<SB>A</SB>[k-1] and also detects the magnitude of the reception signals of the reception system 20 from z<SB>B</SB>[k] and/or z<SB>B</SB>[k-1]. DQPSK demodulation is made by selectively using the first signal group (z<SB>A</SB>[k] and z<SB>A</SB>[k-1]) when the former detection value is larger than the latter detection value, and the DQPSK demodulation is made by selectively using the second signal group (z<SB>B</SB>[k] and z<SB>B</SB>[k-1]) in the opposite case. <P>COPYRIGHT: (C)2011,JPO&INPIT |
