00:01
Hello students in this question.
00:02
The first part is the key difference between coherent and non -coherent demodulation.
00:19
So the carrier phase in coherent demodulation coherent demodulation is called this c and this is non -c right in coherent demodulation.
00:30
The receiver has access to carrier phase information.
00:34
This is the wave.
00:36
So this is the sender.
00:40
This is the information from the sender and the receiver will have information about the phase at different phases 515253.
00:51
So 5 4 similarly, he has the this is the receiver receiver has the information.
00:57
So they only have to map the data just as it is without going further right? you they only have to map the data to the corresponding phase that is coherent demodulation.
01:09
So the carrier phase is synchronized at the receiver to accurately demodulate the received signal synchronization allows for precise detection of symbols like in the presence of phase shifts fading effects.
01:23
All these things we can ignore and we can correct them.
01:28
So coherent demodulation is used in modulation schemes like qpsk, which is quadrature phase shift keying on higher order psk higher order psk, which is again phase shift scheme keying methods.
01:46
Now, this is now this is coherent.
01:50
Now non -coherent does not rely on the information of phase in for those phase information is not available for sender and receiver.
02:00
So it like the detection is based upon the amplitude or the envelope right this amplitude based on the amplitude or the envelope of the signal.
02:11
We demodulate that is non -coherent.
02:15
There is no phase information.
02:17
If the data is like this, we will take the data and then finalize on the amplitude and the envelope right envelope wave and then decode those things to find the actual data.
02:32
Okay.
02:32
This is what is being done.
02:34
This is commonly like it is very useful in cases where we cannot estimate the phase.
02:43
Okay, the ribbon recovery is there.
02:46
We cannot estimate the phase then we can use this prince this mode model...