Digital filter, digital signal processing method, and communication apparatus

摘要

A digital filter according to the invention is an x-time interpolation (x is an interpolation ratio) type FIR filter. The digital filter is provided with a plurality of stages of delay elements(5101-5108) into which serial data are inputted, and a plurality of data distributor(5211-5214) which distribute the respective output data of the plurality of stages of delay elements into x different signal channels by a time-sharing system. The respective data distributors(5211-5214) operate a rate higher by x times than the input rate of serial data and distribute data into x different channels by time-sharing. Preferably, by utilizing the symmetry of a digital filter coefficients, only the digital filter coefficients (h1-h16) corresponding to the half taps at one side of the digital filter are prepared, wherein the respective output data of a pair of delay elements located at the symmetrical positions are inputted into one data distributor, and the respective data are distributed by a time-sharing system. <IMAGE>