Muhammad, A.B., et al. “Design and Realization of Digital Modulator BPSK, QPSK and 16-QAM on FPGA”. JMECS (Journal of Measurements, Electronics, Communications, and Systems), vol. 2, no. 1, Dec. 2016, pp. 1-8, doi:10.25124/jmecs.v2i1.1482.