A multiplexing scheme for multirate digital filtering with half-band filters

The multiplexing scheme presented here applies to multirate filtering with half-band FIR filters which must be implemented with the help of a single multiplier. It consists of interleaving the data samples of the filter stages, according to the binary rate multiplier principle. For the realization of the stages, the transposed direct form is retained with serial processing of the data. No extra buffer memories are requised between stages and control signals are easily generated.