Design of low-complexity and high-speed digital Finite Impulse Response filters

In this paper, we introduce a design methodology to implement low-complexity and high-speed digital Finite Impulse Response (FIR) filters. Since FIR filters suffer from a large number of constant multiplications, in the proposed method the constant multiplications are replaced by addition/subtraction and shift operations. Also, based on the design objective, i.e., low-complexity or high-speed, the addition/subtraction operations are implemented using Ripple Carry Adder (RCA) or Carry-Save Adder (CSA) architectures respectively. Furthermore, high-level algorithms designed for the optimization of the number of RCA and CSA blocks are used to reduce the complexity of the FIR filter. Thus, a Computer-Aided Design (CAD) tool that synthesizes low-complexity and high-speed FIR filters in a shift-adds architecture is developed. It is observed from the experimental results on FIR filter instances that the developed CAD tool can find better FIR filter designs in terms of area and delay than those obtained using efficient general multipliers.