Implementation of high-order direct- form digital filter structures

High-order direct form structures are generally avoided in the design of digital filters because of a number of finite wordlength problems associated with these structures. However, in adaptive or timevarying filter designs the high-order direct-form structure is a natural and convenient choice. A block floating-point implementation of a high-order direct-form structure is proposed, which gives lower roundoff noise and has improved scaling properties compared to the conventional high-order implementations.