Variable Taylor realization and improved approximation of FIR fractional delay systems

摘要

A modular realization, based on the Taylor structure, is proposed for maximally hat fractional delay FIR systems. The realization enjoys independence of the multiplier coefficients to changes of the system order, availability of closed-form formulas and recurrence for the multiplier coefficients, requirement of one less multiplier coefficient compared to the direct-form realizations, and existence of schemes for efficient variable delay and order implementations. It is shown that for a variable delay structure, the coefficient updating operation can be performed efficiently using a simple recurrence, and the transient effects can be mitigated to at most two samples. A modified form of the structure with enhanced modularity is also proposed for odd-order systems. Two variable delay schemes are proposed for this modified structure: A transient-free scheme and a scheme to gradually improve the approximations during the transient phase. A method is also proposed for improved approximation under a fixed total number of variable multiplier coefficients. (C) 1998 John Wiley Sons, Ltd. References: 12