Linear-phase FIR digital differentiator order estimation

Commonly used design procedures for design of digital differentiators are based on various optimization techniques and are also iterative in nature. The order estimation, for differentiators is important from design point of view as it can help in reducing the design time by providing a good initial guess of the order to the iterative design procedures. Moreover, order estimation helps in giving a fairly good estimation of the computational complexity in the overall design. This paper presents the linear-phase, finite-length impulse response (FIR) filter order estimation for integral degree differentiators of up to fourth degree. The minimax optimization based technique for the filter design and the curve fitting is used.