Design of orthogonal biquad digital filters

Complex digital filter techniques are briefly discussed. Three designs of a special class of complex filters called orthogonal filters are presented: the orthogonal direct form, minimum norm, and optimal state-space filters. The direct-form structure has previously been used in the design of transmultiplexers, whereas the minimum-norm and optimal state-space structures are new. The noise and stability performance of each structure are discussed and compared.<
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