A local minimum stagnation avoidance in design of CSD coefficient FIR filters by adding Gaussian function

In this paper, a method for designing FIR (Finite Impulse Response) filters with CSD (Canonic Signed Digit) coefficient using PSO (Particle Swarm Optimization) is proposed. In such a design problem, there are a large number of local minimums. The updating procedure of normal PSO tends to stagnate around such a local minimum and thus indicates a premature convergence property. Therefore, a new method for avoiding such a situation is proposed, in which the Gaussian function is added as a penalty to the evaluation function. Several design examples are shown to present the effectiveness of the proposed method.