Puntsri, K., and P. Suttisopapan. “High Spectrum Efficiency of MIMO-SC-FDMA for Optical Wireless Communication Systems”. Research on Modern Science and Utilizing Technological Innovation Journal (RMUTI Journal), vol. 12, no. 3, July 2019, pp. 1-12, https://ph01.tci-thaijo.org/index.php/rmutijo/article/view/185240.