The basic building blocks involved in digital communication system can be seen in the figure. Some block shown above might seem strange for the newbies. Source Coding is the process of compressing the data efficiently. In other words, source coding is the process of optimizing the length of data. An example of this can be a surveillance system. It is useless to send the whole background of the image when a motion is detected. Source coding is thereby used to send only that portion of a frame which is being changed and not the useless information in terms of the whole background. Another example of this could be the transmission of English Text. We know that the probability of occurrence of vowels i-e a,e,i,o,u is more than the other alphabets thereby giving a clue to compress the English Text in terms of bits transmitted.
After that comes the Channel Coding. For a layman, it can be referred to as opposite of Source Coding in term of process. Channel coding involves the addition of redundant bits to a message signal that will make up for the errors. This involves the identification and as well as the correction of errors, if any. Hamming code it the best example of Channel Coding. Modulation and Demodulation needs another post for discussion which will be discussed later.
More to Follow!!