Digital Laguerre Filter Design With Maximum Passband-to-Stopband Energy Ratio Subject to Peak and Group Delay Constraints

In this paper, we formulate a general design oftransversal filter structures with maximum relative passband-to-stopband energy ratio subject to complex frequencyresponse constraints in the passband and the stopband as wellas additional constraints such as null constraints. These nullconstraints are important for applications where the suppressionof noise at certain frequencies are important. Additional constraintsare introduced allowing approximately linear phase andconstant group delay in the passband. For a given set of basisfunctions, the design problem can be formulated as a semi-infinitequadratic optimization problem in the filter coefficients, whichare the decision variables to be optimized. In this paper, we focuson the design of digital Laguerre filter and digital finite impulseresponse (FIR) filter structures. A modified bridging algorithmis developed for searching for the optimum pole of the Laguerrefilters. Design examples are given to demonstrate the effectivenessof the proposed algorithm.