Sub-banding DSP for flexible optical transceivers

Flexibly optical transceivers (with reconfigurable rate and modulation format) may be efficiently realized using filter-bank based digital sub-banding. The new ASIC architecture achieves record low complexity and high performance. The processing is partitioned into two tiers. The filter-bank top tier is hard-coded in high-speed hardware, whereas the bottom processing tier at ~1 GHz speed per sub-band may be flexibly implemented in an array of programmable DSP structures, realizing flexible software-radio like transceivers, readily reconfigurable and amenable to software upgrades as DSP algorithms evolve. In particular this DSP architecture supports the most hardware efficient FPGA realizations of real-time 2×25 GBd full-functionality coherent OFDM transceivers to date, equipped with flexible reconfigurability.