Interleaving different bandwidth narrowband channels in perfect reconstruction cascade polyphase filter banks for efficient flexible variable bandwidth filters in wideband digital transceivers

摘要

Cascade perfect reconstruction (PR) non-maximally decimated analysis and synthesis filter banks (NMDFBs have been applied to the task of performing filtering of extremely wide bandwidth digital signals collected at multiple GHz sample rates; rates comparable to the clock speeds of the DSP processing engines. An M-path analysis channelizer efficiently partitions a wide bandwidth input signal with sample rate f into M baseband time signals with bandwidths f/M operating at reduced sample rate of 2·f/M. A binary mask delivers a selected subset of the channelized time series to the synthesis channelizer which up-samples and up-converts the selected multiple streams to synthesize a reduced bandwidth output time series. The binary mask connecting the analysis and synthesis filter banks can synthesize filters with bandwidths k·f/M. Additional processing of the low-bandwidth signal components between the filter banks is required to synthesize filter bandwidths that differ from integer multiples of channel width. In this paper we interleave two or more variable bandwidth channel banks to permit the synthesis of a more flexible range of output filter bandwidths.