| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a digital filter with less dependency of a frequency characteristic on the size of a quantization step with only a circuit of feed-forward. SOLUTION: In a common-mode wave detecting H3(z) filter 71, input data xn is delayed by two samples by a two sample delay element (z<-2> ) 711 and, after that, it is multiplied by a coefficient 2.5 in a multiplier 712 to be supplied to an adder 713, then added to input data xn and adopted as a common-mode wave detecting output (in). In the meantime, in an orthogonal wave detecting H4(z) filter 72, input data xn is delayed by one sample by a one sample delay element (z<-1> ) to be delayed by two samples by the two-sample delay element (z<-2> ) 722 and, after that, it is multiplied by the coefficient 2.5 by the multiplier 723 to be supplied to the adder 724, then added to the delay output of the one sample delay element 721 and adopted as an orthogonal wave detecting output qn.</p> |
