Digital to analog
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This document discusses different digital modulation techniques used to convert digital data to analog signals for transmission, including amplitude shift keying (ASK), frequency shift keying (FSK), and phase shift keying (PSK). ASK encodes data by changing the amplitude of a carrier signal, FSK changes the frequency, and PSK varies the phase shift. PSK has advantages over ASK as it is more robust and less vulnerable to noise that affects signal amplitude.
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Digital to analog
- 1. Prof.Neeraj Bhargava Abhishek Kumar Department of Computer Science School of Engineering & System Sciences, MDS, University Ajmer, Rajasthan, India
- 2. Digital data needs to be carried on an analog signal. A carrier signal (frequency performs the function of transporting the digital data in an analog waveform. The analog carrier signal is manipulated to uniquely identify the digital data being carried.
- 5. ASK is implemented by changing the amplitude of a carrier signal to reflect amplitude levels in the digital signal. For example: a digital “1” could not affect the signal, whereas a digital “0” would, by making it zero. The line encoding will determine the values of the analog waveform to reflect the digital data being carried.
- 7. The digital data stream changes the frequency of the carrier signal, For example, a “1” could be represented by +Af, and a “0”.
- 9. We vary the phase shift of the carrier signal to represent digital data. The bandwidth requirement, B B = (1+d)xS is: PSK is much more robust than ASK as it is not that vulnerable to noise, which changes amplitude of the signal.