Fig. 3: Comparisons for constellation diagrams with scenarios involving no RSOA (RSOA, reflective semiconductor optical amplifier), one RSOA, and two RSOAs.

The related constellation diagrams of 9.1-Gbit/s/24-GHz 16-QAM-OFDM (16-QAM-OFDM, 16-quadrature amplitude modulation-orthogonal frequency-division multiplexing) signal at wavelength of λ1 in the scenarios with a no RSOA, b one RSOA, and c two RSOAs, over 100-m optical wireless link and at −27.2-dBm received MMW (MMW, millimeter-wave) power.