> PAM-4 > Pulse Amplitude Modulation 4-level (PAM4) is a multilevel signal modulation format used to transmit signal. Each signal level can represent 2 bits of

> PAM-4 > Pulse Amplitude Modulation 4-level (PAM4) is a multilevel signal modulation format used to transmit signal. Each signal level can represent 2 bits of logic information. > NRZ > Non-Return-to-Zero (NRZ), also called Pulse Amplitude Modulation 2-level, is a binary code using low and high signal levels to represent the 1/0 information of a digital logic signal. NRZ can only transmit 1 bit, i.e. a 0 or 1, of information per signal symbol period. How is PAM4 not just 2 "NRZ"?