ANALOG-TO-DIGITAL CONVERSION The Pulse Code Modulation (PCM) Technique By Dr. Ernest Simo 1.0 Nyquist Sampling The Sampling Process Consider a typical speech signal s(t). In the Time-domain, it looks very non-deterministic and almost random. In the Frequency-domain, it is a band-limited signal with most of its energy concentrated between 0 and 4 KHz. CODE: AN INTRODUCTION By Dr. Ernest Simo © 1999 DR. ERNEST SIMO - SPACE2000