Signal processor implementation of digital all-pass filters

The implementation of digital filter structures of all-pass subfilters using modern high-speed signal processors is investigated. The focus is on digital all-pass filters realized as a cascade of first- and second-order all-pass sections. Wave digital all-pass sections are considered, with special emphasis on developing two-port adaptor structures that are suitable for signal processor implementation. Explicit formulas are developed for scaling and round-off noise analysis of these all-pass sections. Other well-known first- and second-order all-pass filter sections are considered. The performance of the various all-pass filter structures are compared with respect to roundoff noise, parasitic oscillations, and speed of signal processor implementation