25-08-2017, 09:32 PM
A SEMINAR ON A-D Hybrid Modulation
A-D Hybrid.pptx (Size: 389.82 KB / Downloads: 17)
what is analog
Information can be defined in two forms, digital or analog. Analog signal is considered continuous.
Its signal amplitude can take on any number of values
between the signal maximum and minimum. Voice is analog and can take any
number of volume levels between its “dynamic-range” which is the range of
volumes your vocal cords can produce
what is digital
Digital devices convert analog voice to a
digital signal by process of
sampling and quantization. The analog signal is first
sampled and then quantized in levels and then each level is converted to a binary
number.
Basic Concepts of modulation
Modulation is the process of facilitating the transfer of information over a
medium. Voice can not be sent be very far by screaming. To extend the range of
sound, we need to transmit it through a medium other than air, such as a phone
line or radio. The process of converting information (voice in this case) so that it
can be successfully sent through a medium (wire or radio waves) is called
modulat ion.
What is hybrid modulation
This is a combination of ASK & PSK
Amplitude-shift keying (ASK) is a form of modulation that represents digital data as variations in the amplitude of a carrier wave
Phase-shift keying (PSK) is a digital modulation that conveys data by changing, or modulating, the phase of a reference signal (the carrier wave ).