| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a demodulator and a demodulation method attaining high speed communication with excellent communication quality by carrying out delay detection without the need for using signals with a carrier frequency and an intermediate frequency. <P>SOLUTION: A clock recovery section 14 carries out composition and square sum of absolute values of differentiation signals of baseband signals SIa, SQa obtained by a quadrature detection section 11 to generate a clock signal CLK in a way synchronously with the obtained signal. Sample-holding sections 15, 16 use the clock signal CLK to carry out sampling and holding and to delay the baseband signals SIa, SQa for one symbol clock. Minus π/4 phase shift sections 17, 18 shift the phase of the delayed baseband signals by -π/4 to obtain baseband signals SIb, SQb and to supply them to a delay detection section 19. The delay detection section 19 calculates the baseband signals SIa, SQa, SIb, SQb to produce delay detection output signals UI, UQ. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
