In pulse position modulation, the amplitude and width of the pulses are kept constant ... is changed according to the instantaneous sampled value of the modulating signal. Below shown circuit diagram ...

1: NRZ signal (top) and eye diagram (bottom). Pulse amplitude modulation builds upon this concept by encoding ... C = 2*B*log2(M) The PHY circuit of a chip encodes serial data into specific voltages ...

Figure 1 PAM4 doubles the number of bits in serial data transmissions by increasing the number of levels of pulse-amplitude modulation, but does so at the cost of noise susceptibility. If we look at ...