| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a demodulator capable of rapidly acquiring information from an input signal such as a digital modulation signal. <P>SOLUTION: An I/Q signal corresponding to a unit frame is inputted to an A/D converter 20. The A/D converter 20 discretizes the I/Q signal and inputs it to a division frame storage 44 and a phase difference estimator 23 as a discrete I/Q signal. The phase difference estimator 23 calculates a phase difference Δθ being a difference between the phase of the signal to express a symbol frequency, which is extracted from the discrete I/Q signal, and the phase of a reference signal on the basis of the division frame in which the unit frame is divided. The division frame storage 44 stores the discrete I/Q signal corresponding to the division frame and holds it. An I/Q signal reproducer 34 outputs a reproduction I/Q signal which is synchronized with a symbol period, based on the discrete I/Q signal which is outputted from the division frame storage 44 and the phase difference Δθ. <P>COPYRIGHT: (C)2007,JPO&INPIT |
