Multiple 1:N interpolation FIR filter design based on a single architecture

A VLSI architecture for the multiple 1:N interpolation FIR filter is proposed for QPSK modulation in WLL (Wireless Local Loop). Multiple filters are operated synchronously and N outputs are generated in case of 1:N interpolation. But the architecture and the operating frequency are the same as those of single FIR filter architecture except having pipeline registers. Because of using a single architecture, the proposed architecture can be implemented with less chip area. The power consumption is not increased because its operating frequency is the same as that of single architecture. When N is 4, the four-output 1:4 interpolation filter is designed using VHDL logic synthesis. The number of gates and operating frequency are compared with those of transversal FIR filter design method and look-up table design method.