Digital Modulation: The Basic Principles

The fundamental modulation methods used in 5G are Pi/2 BPSK, QPSK, 16-QAM, 64-QAM, 256-QAM, and 1024-QAM. These are the methods, therefore, that we are going to study in this chapter, along with some issues involved in their realization. In these methods, baseband signals linearly modulate an RF carrier. Ideally, we would like to cut to the chase and study these methods immediately. This is not what we will do, however. First the fundamentals of baseband transmission techniques will be reviewed, as these form the foundation upon which the techniques involving the linear modulation of an RF carrier are based. This approach will allow us to tractably and with straightforward mathematical analysis determine the spectral and error performance characteristics of the modulation methods under study.