Multidimensional signaling and coding enabling multi-Tb/s optical transport and networking: Multidimensional aspects of coded modulation

The design of next-generation optical transmission systems and networks should address the concerns with respect to a limited bandwidth of information infrastructure, high energy consumption, as well as the need to support the network heterogeneity and demand for an elastic and dynamic bandwidth allocation. To address these concerns simultaneously, we propose an adaptive, software-defined, low-density parity check (LDPC)-coded multiband approach that involves spatial-multiple-input, multiple-output (MIMO) and an all-optical orthogonal frequency-division multiplexing (OFDM) scheme since it can enable energy efficient high-bandwidth delivery with fine granularity and elastic model of bandwidth utilization. The modulation is based on multidimensional signaling to improve the tolerance to fiber nonlinearities and imperfect compensation of channel impairments and has a hybrid nature with both electrical and optical degrees of freedom employed. Optical degrees of freedom include spatial and polarization modes in optical fibers supporting spatial-division multiplexing (SDM), while electrical degrees of freedom are based on 2M orthogonal basis functions. The adaptive coding has been performed by partial reconfiguration of the corresponding parity-check matrix. The proposed scheme is suitable for the conveyance of the information over optical fibers with bit rates exceeding 10 Tb/s. At the same time, the multitude of degrees of freedom will enable finer granularity and elasticity of the bandwidth, the features essential for next generation networking.