| 摘要 |
PROBLEM TO BE SOLVED: To reduce the number of taps of a bandpass filter using a FIR filter. SOLUTION: The bandpass filter (Lpf) for passing a first frequency band is composed of the FIR filter 1. When a difference between an output of a first bandpass filter and original input data is calculated, an output of a second bandpass filter (Hpf) for passing frequency bands other than the first band can be obtained. The original input data for calculating the difference is made to pass a delaying means 4 in order to make the phase of the original input data coincide with that of output data of the FIR filter 1. Since this reduces the use count of the FIR filter 1, the number of taps can be reduced. COPYRIGHT: (C)2004,JPO&NCIPI |
