(the fundamental, f) to pass through. Similarly, Fig. 2-1(c)–(e) show the spectra
and reconstructed functions for higher-bandwidth channels. For digital transmission,
the goal is to receive a signal with just enough fidelity to reconstruct the sequence
of bits that was sent. We can already do this easily in Fig. 2-1(e), so it is
wasteful to use more harmonics to receive a more accurate replica