Based on the proposed work as shown in Figure 1, initially the audio files in .wav format are passed through G.722 audio codec that uses Subband Adaptive Differential
Pulse Code Modulation technique.
Pulse code modulation provides only an approximation of the original analog signal, as shown in Figure 4.
Later experiments used a hybrid system involving Beta and Video Home System (VHS) format video tapes on which
Pulse Code Modulation (PCM) files were recorded.
V.92 also includes a capability called
pulse code modulation (PCM) upstream, which boosts the upstream data rates from the user to the ISP to reduce transfer times for large files and email attachments sent by the user.
ISDN is based on the development of
pulse code modulation (PCM), which samples existing analog signals at a rate of 64 kbps.
The tactical multichannel radio and cable systems that the Signal Corps developed featured
pulse code modulation; the only tactical telephone switchboards used were manual.
Other technical topics presented are quantization, aliasing, dither, and
pulse code modulation. Finally, Pohlmann discusses a complete audio digitization system that illustrates all of the theory presented.
It is a hybrid of DCT (Discrete Cosine Transform) and DPCM (Differential
Pulse Code Modulation) schemes with motion estimation [6, 8].
[1] Recommendation G.711,
Pulse code modulation of voice frequencies, ITU-T, 1972.
It is a simplified version of differential
pulse code modulation (DPCM) and the class of predictive coding [26].
