20-07-2013, 02:42 PM
PHASE SHIFT KEYING (MODULATION AND DEMODULATION)
AIM:
To design and study the working of PSK circuit and to demodulate the above signal with a suitable
circuit.
THEORY:
Phase shift keying is one of the most efficient digital modulation techniques. It is used for very high bit
rates. In PSK, the phase of the carrier is modulated to represent Binary values. In BPSK, the carrier phase
is used to switch The phase between 00 and1800 by digital polar Format. Hence it is also known as phase
reversal keying.
PROCEDURE:
The connections are made as per the circuit diagram.
A sine wave of amplitude 5v and 2kHz is fed to the Collector of the transistor as carrier.
the message signal, a square wave of amplitude 5V and 150Hz is fed to the base of the transistor.
The BPSK wave is observed at pin 6 of the op-amp IC 741.
The demodulation circuit is also connected.
BPSK wave obtained is fed as input to the demodulation circuit.
The demodulated waveform is observed
All the required waveform to be plotted.