TABLE OF CONTENTS Thus far we have discussed the transmission of deterministic signals over a channel, and we have not emphasized the central role played by the concept of "randomness" in communication. The word random means unpredictable. If the receiver at the end of a channel knew in advance the output from the originating source, there would be no need for communication. So there is a randonuness in the message source. Moreover, transmitted signals are always accompanied by noise introduced in the system. These noise waveforms are also unpredictable. The objective of this chapter is to present the mathematical background essential for further study of communication.
