A New Architecture for Decimating FIR Filter

A new architecture for decimating finite impulse response filters is proposed. The architecture is based on using a number of accumulators; each one accumulates a partial sum corresponding to a unique set of D filter coefficients into the filter output, where D is the decimation factor. In the new decimating filter, the accumulated result of an accumulator is passed to another accumulator once for each period of D input samples, except for that of the last accumulator whereby the filter output is obtained. The size of each accumulator can be minimized, depending on the filter coefficients. A demonstrative FPGA implementation shows that this architecture is more favorable than the widely used polyphase architecture, as it requires much less area at similar power consumption.