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The word pulse in the term pulse-code modulation refers to the pulses to be found in the transmission line. This perhaps is a natural consequence of this technique having evolved alongside two analog methods, pulse-width modulation and pulse-position modulation , in which the information to be encoded is represented by discrete signal pulses of ...
Sub-band coding is used in the G.722 codec which uses sub-band adaptive differential pulse code modulation (SB-ADPCM) within a bit rate of 64 kbit/s. In the SB-ADPCM technique, the frequency band is split into two sub-bands (higher and lower) and the signals in each sub-band are encoded using ADPCM.
Differential pulse-code modulation (DPCM) is a signal encoder that uses the baseline of pulse-code modulation (PCM) but adds some functionalities based on the prediction of the samples of the signal. The input can be an analog signal or a digital signal .
Adaptive differential pulse-code modulation (ADPCM) is a variant of differential pulse-code modulation (DPCM) that varies the size of the quantization step, to allow further reduction of the required data bandwidth for a given signal-to-noise ratio.
G.726 is a waveform speech coder which uses Adaptive Differential Pulse Code Modulation PSQM testing under ideal conditions yields mean opinion scores of 4.30 for G.726 (32 kbit/s), compared to 4.45 for G.711 ( μ-law ) [ citation needed ]
Trellis-coded pulse-amplitude modulation (TC-PAM) is the modulation format that is used in HDSL2 and G.SHDSL.It is a variant of trellis coded modulation (TCM) which uses a one-dimensional pulse-amplitude modulation (PAM) symbol space, as opposed to a two-dimensional quadrature amplitude modulation (QAM) symbol space. [1]
PCM30 describes an application of pulse-code modulation (PCM) in which 30 telephony analog signals are binary coded into a digital signal stream.. The term is used today mostly as a synonym for the encoding of 30 channels each with a signalling rate of 64-kbit/s.
DM is the simplest form of differential pulse-code modulation (DPCM) where the difference between successive samples is encoded into n-bit data streams. In delta modulation, the transmitted data are reduced to a 1-bit data stream representing either up (↗) or down (↘). Its main features are: