‫Now in the amplitude, more Galicians scheme that we started, we have seen that deep modulated message
‫signal occupies weisse bandwidth as compared to the original baseband signal.
‫And this disadvantage of price bandwidth can easily be overcome using these quadrature amplitude modulation.
‫And in the quadrature amplitude modulation, we actually send two signals within the same bandwidth.
‫And within the same bandwidth.
‫And how do we do it?
‫We multiply the first signal, which is m one of the cosine of megacity.
‫And we multiply the second signal, which is M-2 of DVD sign of megacity.
‫And then we add these two signals to get the quadrature amplitude modulated signal, which is sent within
‫this same bandwidth.
‫And the M one of these and the M-2 of B would not interfere with one another because cosine of megacity
‫and design of the megacity are orthogonal to each other.
‫And what does that mean?
‫That means that, for example, if we multiply sine of megacity with cosine of megacity and we integrate
‫the result, over one time period we would get zero.
‫And here I am.
‫One of these is called as the infuse component are I and M two of the is called as the auditory component.
‫Are you.
‫Now, this diagram shows the more relation and the demobilization procedure in the case of quadrature,
‫amplitude modulation scheme.
‫On the mobility side, we multiply and one of the which is the eye component with also megacity.
‫And we multiply and two of DB, which is the quadrature component with Sinovel Megacity.
‫And then we add Deepu deserting signals to generate these quadrature amplitude modulated signal.
‫And this signal is then received at the receiver and at the receiver in order to recover.
‫And one ofthe we multiply the received signal with two cause of megacity and we pass it to the low pass
‫filter to get m one of these.
‫And we multiply the received signal with to sign off Megacity and Bossert through the low pass filter
‫to recover the M2 ofthe.
‫Now, here we are, Schwing Hall, and one of B is recovered mathematically to recover.
‫And one of these will multiply the received quadrature amplitude modulated signal with two cores of
‫megacity.
‫And this is or quadrature amplitude, more related signal.
‫And when we multiply it with the cause of all megacity, here we get.
‫Cause square of megacity.
‫And here we get a sign of a mega city in two.
‫Calls for megacity.
‫So we know that the square of a megacity is equal to.
‫One plus was two of megacity divided by two.
‫So we put it here and sign of a megacity into all of megacity.
‫It is equal to.
‫Sign of megacity divided by two.
‫So we bought sign two of megacity to head back to here.
‫And as a result, we get this expression and we can see that if we pass this signal to a low pass filter.
‫These two terms will be eliminated and we would get the end one of these, which is the original message.
‫And similarly, in a similar way, we can recover M-2 of B by multiplying the quadrature amplitude modulated
‫signal with you sign of megacity and then passing it through the low pass filter.
‫Now, this is a simulation of the quadrature amplitude, more relation.
‫And here this knob is being used to generate the eye component.
‫And this eye component is then multiplied by the cosine of megacity.
‫And we can see that the eye component is being carried on the peaks of the sine wave.
‫And here dequeue component is being multiplied by the Sinochem megacity.
‫And the cube component is being carried on the big of the sine wave.
‫And then we are adding the AI and the Q.
‫And since these sine wave and the cosine wave are in 90 degree features shift with one another.
‫And the signal is ion you are being carried by the peaks of the cosine and design waves respectively.
‫So the ion you component do not interfere with one another.