ABSTRACT
The digital signal, when constructed, is in the form of well-defined pulses per the chosen line coding or digital modulation scheme. However, before this signal reaches the intended receiver, it undergoes a substantial amount of abuses, which reduce its size and distort its shape. The received pulses hardly look like pulses anymore. In fact, they look like two-dimensional profiles of “natural hillocks” when viewed on the oscilloscope. They have highly distorted shapes and much smaller amplitudes as compared with the original transmitted pulses. The transmitted and received pulses may look more or less like the ones shown in Figure 6.1.
