On the Ordering Problem of Cascade Realization of Nonrecursive Digital Filters.

摘要

To realize a high order nonrecursive filter, a configuration consists of cascade connection of second order sections offer many practical advantages. The noise at the output of such filters due to round-off error is highly dependent on the ordering in the cascade structure. Because the error may vary over several orders of magnitude with different orderings, it is highly desirable to be able to determine the optimum ordering. However, the determination of the exact optimum ordering requires prohibitively large amount of computation for most filters of practical interest. We propose here an effective heuristic procedure to find a near optimum ordering for fixed point filters with dynamic range constraint. The computation time is proportional to N sq for an N section filter. Examples illustrating the procedure are presented. (Author)