Estimation of signal transition activity in FIR filters implemented by a MAC architecture

A novel method for the accurate calculation of the transition activity at the nodes of a multiplier-accumulator (MAC) architecture implementing finite impulse response filters is proposed in this paper. The method is developed for input signals, which can be described by a stationary Gaussian process. The transition activity per bit of a signal word is modeled according to the dual-bit-type (DBT) model and it is described as a function of the signal statistics. An efficient analytical method has been developed for the determination of the signal statistics at each node of the MAC architecture. It is based on the mathematical formulation of the multiplexing in time of signal sequences with known statistics. The effect of the multiplexing mechanism on the breakpoints of the DBT model, which influences significantly the accuracy of the method, is also determined. Several experiments both with synthetic and real data have been conducted. The numerical results produced by the proposed models are in very good agreement with the measured values of the transition activity