Subbanded DSP Architectures Based on Underdecimated Filter Banks for Coherent OFDM Receivers: Overview and recent advances

Subbanded digital signal processing (DSP) with underdecimated (Udeci) filter banks (FBs), is a recent DSP technique whereby the optical channel bandwidth is digitally sliced into multiple spectrally disjoint subbands (SBs) to be processed in parallel. In terms of DSP hardware (HW) architecture, digital subbanding amounts to an alternative mode of parallelizing the receiver signal processing task to multiple slower processors, whereby the parallelization performed in the frequency domain (FD) rather than in the time domain (TD). We show that FD parallelization is especially suited to the long-haul optical fiber channel and present novel receiver DSP structures based on Udeci FBs, providing substantial complexity savings for ultra-high-speed optically coherent transmission.