Method and apparatus for hybrid digital filtering

A digital filter comprising:

• a plurality of first time domain elements, each acting on one of a plurality of main input streams, generating a plurality of first streams, wherein each of said plurality of first streams has a sample rate which is less than that of said corresponding main input stream;
• a plurality of hybrid filter sections, wherein a said hybrid filter section is comprised of a) a hybrid filter section pre-processor for processing said plurality of first streams to produce a plurality of second streams, said hybrid filter section pre-processor performing at least one linear operation, and b) a hybrid filter section processor performing processing on said plurality of second streams to produce a plurality of third streams, wherein at least one of said hybrid filter section processor of said plurality of hybrid filter sections is a transform domain processor;
• a combiner for processing based on said plurality of third streams to produce a plurality of fourth streams;
• a post-processor for processing based on said plurality of fourth streams to produce a plurality of fifth streams, said post-processor performing at least one linear operation and said processing of post-processor corresponds to said processing of said hybrid filter section pre-processor;
• a single element delay in at least one of said hybrid filter section pre-processor or said post-processor;
• and
• a second time domain element producing a main output stream by acting on said plurality of fifth streams.