Rate Adaptability Using LUT-Based Distribution Matching for Probabilistic Constellation Shaping

We investigate the flexibility of a LUT-based hierarchical DM for Probabilistic Constellation Shaping providing flexible net bit rates. Using a fixed parallelized input and output LUT-based architecture, including a flexible strategy to organize the input bits in each LUT, the proposed scheme shows an efficient performance in terms of rate loss vs. complexity, resulting in a DM solution to enable flexible bit rates with improved channel transmission. We use an 800G example design with soft-decision FEC to discuss the optimization strategy and to demonstrate the flexibility of the proposed method, enabling a high granularity bit rate operation in the range of 160 to 800Gb/s with a rate loss always below 0.14bits/symbol.