After doing the class in you science school, college or university may be you have gone through 10 sets of books, searched in the web for a long time, tried with some picture and after failing again gone to you course teacher to clear your doubt but the concept is still not clear. Some pixels are missing in the image when you dream of a modulation scheme of a signal! What a tragic situation!?!But it is simple. Let’s see below:
“Suppose you want to send a white piece of paper (having low weight) from your house to your friends house which is 20 meter away from your house. Will you be able to send it by throwing it by hand? The answer is NO.
Now wrap a stone(Having much more weight with respect to paper) with that paper and throw it hopefully it will reach the distance.
This process of wrapping the stone with a paper is modulation in a simple sense. “
Now lets consider,
White piece of paper (having low weight) = Your Signal which you want to send.(Low Frequency)
Stone (Having much more weight with respect to paper) = The Carrier or simply transporter of your signal which is helping you to send your signal to your destination.(High Frequency)
Now if I tell you “Modulation is a process through which a base band signal of low frequency is been mixed with a carrier signal of high frequency and is sent over in the space to reach destination.”Is it understandable? Please let me know.