Canonic signed digit FIR filter design

A new algorithm is presented for the design of fixed point FIR digital filters that can be realized using a minimal number of adders while satisfying both the desired hardware implementation constraints and the frequency domain design constraints. The proposed algorithm makes use of a two-stage search method with a new soft-switching optimization criterion, minimizing the Chebyshev error norm in a discrete canonic signed digit (CSD) space. The proposed design method is implemented as a Matlab-based software package CSDFIR that allows the design of both Chebyshev optimal floating point and fixed point CSD FIR filters.