| 摘要 |
PROBLEM TO BE SOLVED: To obtain high-quality signal receiving by creating a noise-reduced tap coefficient without sacrificing the followability of AMF (Adaptive Matched Filter) even when a modulated receiving signal is input in a digital modulation method having a variation of amplitude components like QAM (Quadrature Amplitude Modulation). SOLUTION: A complex conjugate machine 251 outputs a conjugate complex signal of a receiving signal (e.g., 16QAM signal). A complex multiplier 252 performs a complex multiplication of the conjugate complex signal from the complex conjugate machine 251 by a reference signal. An amplitude normalization circuit 253 normalizes the amplitude of a complex multiplication value output from the complex multiplier 252. A time average circuit 254 time-averages the signal output from the amplitude normalization circuit 253 to output a correlation value in any period between the receiving signal and the reference signal as a tap coefficient of the AMF. The amplitude normalization circuit 253 always normalizes the absolute value of the amplitude component to a value on a unit circle so that the error of the amplitude component can be eliminated. COPYRIGHT: (C)2011,JPO&INPIT |
