Delta Modulation

Delta modulation (DM or Δ-modulation)is an analog-to-digital and digital-to-analog signal conversion technique used for transmission of voice information where quality is not of primary importance. DM is the simplest form of differential pulse-code modulation (DPCM) where the difference between successive samples are encoded into n-bit data streams. In delta modulation, the transmitted data is reduced to a 1-bit data stream. Its main features are:

  • the analog signal is approximated with a series of segments
  • each segment of the approximated signal is compared to the original analog wave to determine the increase or decrease in relative amplitude
  • the decision process for establishing the state of successive bits is determined by this comparison
  • only the change of information is sent, that is, only an increase or decrease of the signal amplitude from the previous sample is sent whereas a no-change condition causes the modulated signal to remain at the same 0 or 1 state of the previous sample.

To achieve high signal-to-noise ratio, delta modulation must use oversampling techniques, that is, the analog signal is sampled at a rate several times higher than the Nyquist rate.

Derived forms of delta modulation are continuously variable slope delta modulation, delta-sigma modulation, and differential modulation. Differential pulse-code modulation is the super set of DM.

Read more about Delta Modulation:  Principle, Transfer Characteristics, Output Signal Power, Bit-rate, Adaptive Delta Modulation, Applications, SBS Application 24Kbps Delta Modulation

Other articles related to "delta modulation, delta, modulation":

SBS Application 24Kbps Delta Modulation
... Delta Modulation was used by Satellite Business Systems or SBS for its voice ports to provide long distance phone service to large domestic corporations with a significant inter-corporation ... The voice ports used digitally implemented 24kbit/s Delta Modulation with Voice Activity Compression or VAC and Echo Suppressors to control the half second echo path through the satellite ... They performed formal listening tests to verify the 24kbit/s Delta Modulator achieved full voice quality with no discernable degradation as compared to a high quality phone line or the ...
Continuously Variable Slope Delta Modulation - SBS Application 24Kbps Delta Modulation
... Delta Modulation was used by Satellite Business Systems or SBS for its voice ports to provide long distance phone service to large domestic corporations with a significant inter-corporation ... The voice ports used digitally implemented 24kbit/s Delta Modulation with Voice Activity Compression or VAC and Echo Suppressors to control the half second echo path ... They performed formal listening tests to verify the 24kbit/s Delta Modulator achieved full voice quality with no discernable degradation as compared to a high quality phone ...
Pulse Modulation Methods
... Pulse modulation schemes aim at transferring a narrowband analog signal over an analog baseband channel as a two-level signal by modulating a pulse wave ... Some pulse modulation schemes also allow the narrowband analog signal to be transferred as a digital signal (i.e ... These are not modulation schemes in the conventional sense since they are not channel coding schemes, but should be considered as source coding schemes ...

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