Design of variable fractional delay FIR filters using genetic algorithm

This paper presents a new method for design of variable fractional delay (VFD) FIR digital filters using a genetic algorithm. In this method, each sub-filter of Farrow structure is designed separately with defined accuracy and bandwidth. Also, a variable mutation probability is employed, which improves the accuracy of the solution. Compared with existing methods, it reduces the computational complexity and enhances the design flexibility. Sum-of-power-of-two (SOPOT) representation is applied to the filter coefficients. Therefore, SOPOT coefficients of Farrow structure are determined using a simple genetic algorithm without recourse to computational techniques. Using the SOPOT representation, the filter multipliers can be built with simple shift registers and adders. This results in a high-speed and low-power filter implementation.