2.2.6 Digital pulse modulation

Digital pulse modulation includes two types:


$$\mathcal{Y}(t) = \Delta(t) \sum\_{n = -\infty}^{+\infty} \delta(t - nT\_s) \tag{13}$$

Figure 12. PAM modulation.

Figure 13. PWM modulation.

In Figure 15, the reference signal msð Þt is the signal with rectangular edges superimposed on the smooth sine wave message signal. The reference signal is obtained by integrating y tð Þ as follows [8]:

$$m\_s(t) = \sum\_{n = -\infty}^{+\infty} \Delta(nT\_s) \int\_0^t \delta(t - nT\_s) d\tau \tag{14}$$

3. Session initiation protocol (SIP)

Figure 14. PPM modulation.

Telecommunications Protocols Fundamentals DOI: http://dx.doi.org/10.5772/intechopen.86338

Figure 15. Delta modulation.

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Modern telephony systems are based upon the Voice over IP (VoIP) protocols, such as SIP, which is a call control and signalling protocol adopted by the 3GPP in

The difference value Δð Þ nTs is calculated at the nth sampling instant. The reference signal msð Þt is a stair-step approximation of m tð Þ as shown in Figure 15.

Telecommunications Protocols Fundamentals DOI: http://dx.doi.org/10.5772/intechopen.86338

Figure 14. PPM modulation.

Figure 15. Delta modulation.
