Frequency domain design for digital Laguerre networks

The design of digital Laguerre networks with a complex desired frequency re sponse and the Chebyshev error criterion is investigated. This nonlinear op timization problem in the complex domain can be converted to an equivalent semi-infinite linear programming problem. Additional constraints are introd uced to control the group delay error (i.e., allowing approximate rather th an exact linear phase). The Laguerre network with approximately linear phas e in the passband can achieve the same desired specification as the convent ional FIR filters with a smaller number of coefficients, especially for nar row-band specifications.