How Close are we to the Shannon Limit? The Role of Modulation Schemes to Close the Gap

High-speed serial and optical I/Os are pushed continuously to higher density and bandwidth to enable the scaling of data centers, driven by a digitally connected world. As the per-lane data-rates in wireline begin to exceed 224Gb/s, a fundamental question remains as to how much room is left to close the remaining gap to Shannon’s capacity limit. To close this gap, alternative signal modulation techniques are being considered, including multi-carrier schemes. In this presentation, the fundamental limits of signaling for wireline communication will be discussed and alternative signaling will be presented to possibly close the gap to these limits.