PAM-4 Data Transmission Quality Evaluation Using Two- and Three-Dimensional Mapping of Received Symbols

Based on four-level pulse-amplitude modulation (PAM-4) symbol transition, this study investigated a two-dimensional (2D) symbol mapping technique that evaluates the quality of transmission data to set equalizer parameters adaptively. The 2D symbol transition mapping enables visualization of the degree of intersymbol interference (ISI). The simulation results demonstrate that the 2D symbol mapping can evaluate the PAM-4 data transmission quality degraded by ISI and can visualize the effect of equalization. The applications of 2D mapping and the extension of 2D mapping to 3D mapping are also discussed.