A method and apparatus provide digital frequency channelization of a digitally sampled input stream having a first bandwidth. The method and apparatus are implementable in software, firmware or hardware and convert a first set of real samples from the input stream into a first plurality of complex samples with a first functional block performing filtering, decimation and tuning functions, convert the first plurality of complex samples into a first pair of consecutive USB and a first pair of consecutive LSB complex samples with a second functional block performing filtering, decimation and tuning functions, and convert the first pair of consecutive USB and the first pair of consecutive LSB complex samples into a two pairs of complex USB and LSB complex samples with a pair of third functional blocks performing filtering, decimation and tuning functions, and apply the two pairs of complex USB and LSB complex samples to a string of n pairs (for n greater than or equal to one) third functional blocks each performing filtering, decimation and tuning functions.