| 摘要 |
PURPOSE:To suppress unnecessary signal simply and effectively without incurring the increase in the constitution scale, by obtaining the sum of weight of sum and difference signals and controlling the weight value in this weight sum processing adaptively. CONSTITUTION:The titled filter is constituted by using an output of a butterfly circuit of the preceding stage, until the number of input signals of the butterfly circuit of the succeeding stage is four, that is, the number of the variable weight circuits forming the filter is two sequentially. The weight value set to the weight circuit of the filter of each stage is controlled adaptively according to the MSN algorithm of the Applebaum-Howell. Two kinds of the filter characteristics are provided depending on the use of the sum signal of the 1st butterfly circuit 12 or the difference signal. In the filter of the 2nd stage, four kinds of the filter characteristics are obtained depending on the sum and difference signals and their combinations (the 1st and the 2nd stages). |
