Patent ID: 6888904

Claim:
A 108-tap 1:4 interpolation FIR filter device for digital mobile communication, comprising: four shift registers for shifting and storing 1-bit filter inputs each inputted from four channels to produce 27-bit parallel data, respectively; a selector for sequentially selecting said 27 -bit parallel data of the four channels one by one; an address generator for receiving said 27-bit parallel data outputted from the selector to produce addresses depending on look-up tables of each of coefficient groups; four look-up table groups for generating filter outputs of the coefficient groups using the addresses generated in said address generator; a pipeline register I for delaying filter outputs per coefficient groups outputted in parallel from said four look-up table groups; a group selector for serially transforming said delayed filter outputs from said pipeline register I, channel by channel; and a pipeline register II for delaying the output from said group selector to match the time of the filter output per channel.