Design of CIC compensators with SPT coefficients based on interval analysis

Abstract

The simplest multiplierless decimation filter is the cascaded-integrator-comb (CIC) filter. However, the magnitude response of this filter has a high passband droop, which is not tolerable in many applications. The droop can be reduced by the filter called CIC compensator. In this paper, we present a method for the design of finite-impulse-response CIC compensators whose coefficients are expressed as the sums of powers of two (SPT). The method is based on the minimax error criterion. To obtain the SPT coefficients, we use a global optimization technique which is based on the interval analysis. The proposed compensators are multiplierless and result in wide compensation bands. Therefore, they are suitable for application in software radio receivers operating with low decimation factors.