COMMUNICATION SYSTEMS
The main communication systems we are using now 1)voice(300-3.5khz) 2)audio(20hz-20khz) 3)video(0-4.5Mhz) 4)Data communications(Eg:broadband) Block diagram of communication system Transmitter is the first block in the block diagram of communication system. Here the message which is to be sent is generated.In Encoders process in which the actual message is converted in to symbols for transmission. In this a sequence of characters are put in a specialized format for efficient transmission.Noisy channel is nothing but the medium through which the message is transmitted.Decoder is used to decode the encoded message and retrieve the actual message.Receiver can be said as the target to which the information need to be delivered. Need for modulation in communication systems 1)To reduce the antenna height 2)Multiplexing of signals In analog communications we use (Frequency Division Multiplexing) In digital communications we use (Time Division Multiplexing) 3)To reduce the effec...