Direct form revisited: recursive filter implementation using higher-order direct form sections
T.I. Laakso, I.O. Hartimo · 2003
The cascade implementation of recursive digital filters using fourth-order direct form sections is investigated. The implementation with TMS320 processors is studied in detail. The finite-wordlength performance and the implementation costs of six different test filters are compared. It is concluded that the cascade of fourth-order direct form sections with second-order error feedback provides a very effective and low-noise structure for signal processor implementation, except with very narrowband filters.>