Speech signals have a significant role in facilitating communication among humans. They travel in the form of a sound wave, which is converted into electric signals for transmission over communication networks. Initially, communication systems conveyed and received electric analog speech signals. As a result, challenges such as the inability to separate complex analog structures from random transmission noise occurred. However, advancement in technology led to the development of pulse code modulation as the problem’s solution.
Pulse Code Modulation (PCM) in modern digital communication systems improves the quality of transmitted and received signals. According to Arisandi (2020), PCM is a digital method of sampling analog signals at regular intervals and coding amplitudes into binary values’ sequences, modulating a pulsed transmit. The standard digital acoustic is used in such applications as digital telephony, computers, and compact discs is PCM. Notably, a series of coded pulses represents a message signal in PCM, which is achieved by converting it into a discrete form in amplitude and time. The fundamental elements that comprise the PC modulator circuit include sampling, quantizing, and encoding.
An analog signal goes through the low pass filter, where high-frequency components are eliminated before reaching the sampler, where the collection of data at instant values to reconstruct the original signal occurs (Arisandi, 2020). Quantizing reduces the excessive bits and confines the data of the message signal. The encoding aspect of the PC modulator digitizes the analog signal and minimizes the bandwidth used. The primary function of PCM in VoIP is to convert the analog signals to digital before their transmission to other devices (Alajmi et al., 2017). PCM ensures delivery of quality voices or sound by combating packet loss and obtaining higher coding efficiency VoIP. Therefore, PCM is an essential component of digital telecommunication networks.
References
Alajmi, N. K. A., Haj Aliwi, H. S., & Alieyan, K. (2017). VoIP protocols’ bandwidth based-mini/RTP header using different codecs: A comparison. Asian Journal of Scientific Research, 10(3), 110−115. Web.
Arisandi, E. D. (2020). Preliminary design of pulse code modulation encoder for telemetry data rocket. AIP Conference Proceedings, 2226(1). Web.