El-Nahal, Fady. “Coherent 16 Quadrature Amplitude Modulation (16QAM) Optical Communication Systems”. Photonics Letters of Poland 10, no. 2 (June 30, 2018): 57–59. Accessed June 16, 2024. https://www.photonics.pl/PLP/index.php/letters/article/view/10-21.