Control manner of the over sampling FIR filter and the over sampling FIR filter, and the semiconductor integrated circuit which possesses the over sampling FIR filter, with the over sampling FIR filter being the over sampling FIR filter which filtering is done with

摘要

PROBLEM TO BE SOLVED: To maintain continuity in the output response of a filter even when the number of oversampling is changed during the operation of the filter concerning an oversampling FIR filter to be used for portable equipment or the like in a mobile communication system.;SOLUTION: Plural selectors corresponding to the respective holding parts of a shift register for successively shifting input data successively select a prescribed tap coefficient out of plural tap coefficients synchronously with a clock. The input data held in the holding part and the tap coefficient selected by the selector corresponding to the holding part are multiplied. The multiplied results are added and outputted as the output data. By changing the tap coefficient to be selected by the selector corresponding to a change in the number of oversampling, continuity in the output data can be maintained. Since it is not necessary to provide holding parts as many as the number of oversampling, the circuit scale of the oversampling FIR filter can be reduced.;COPYRIGHT: (C)2002,JPO